Second International Graduate Student Conference

SECOND INTERNATIONAL GRADUATE STUDENT CONFERENCE

EnergyEfficiencyand RenewableEnergySources SoutheastEuropeinfocus CONFERENCEPROCEEDINGS FROM14THOFJUNE2010 CONTENTS

Acknowledgements...... iii Summary of the conference...... iv Venue...... vi Committees…...... vii Organizing committee…………………………………………………………………………………………vii Scientific committee……………………………………………………………………………………………vii Agenda of the conference...... viii Biographies of the papers’ contributors……………………………………………………………………………x

PAPERS

Aleksandar D. Prodanov

Solar Keymark – Solar Thermal Products in EU –

Where is R. Macedonia?...... 1

Ana Colovic Leskoska, Fidanka McGrath, Pippa Gallop

Can the International Financial Institutions do more to support new

renewables and energy efficiency in southeast Europe?...... 7

Andreja Naumoski

Energy efficient decision support system in ecology with

novel classification algorithm...... 32

Igor Panchevski

Adaptive street lighting………………………………………………………………………………….45

Maja Lazareska

Energy and the climate change……………………………………………………………………….55

Nikola Petkovski

Storage of energy…………………………………………………………………………………………..64

Pellumb Gjinolli

Geothermal Energy as source for heating in Kosovo……………………………………………77

Slobodan Parizoski

Possibilities for Exploiting Solar Energy in Macedonia…………………………………………88

Tanja Ivanovska

Dye-sensitized Solar Cells………………………………………………………………………………………97

ACKNOWLEDGEMENTS

On behalf of the organizing committee I would like to express my gratitude to all participants who took part in the Second International Graduate Student Conference on Energy Efficiency and Renewable Energy Sources (Southeastern Europe in focus). Thank you all for your presentations and papers and for your bright ideas and dedication to the topics of Energy Efficiency and Renewable Energy Sources.

I want to express my gratitude especially to PhD Hristina Spasevska from the SOLTEC Center and the Faculty of Electrical Engineering and Information Technologies in Skopje Macedonia for her valuable help and input in the organization of the conference and especially for her moral and logistic support throughout this process.

I would also like to thank the other members of the organizing committee, my colleague Natasha Hroneska and Igor Panchevski for their unconditional dedication to the organization of the conference.

Special thanks go to the Dean of the Faculty PhD Mile Stankovski for the opening words and allowing this conference to be held at the premises of the Faculty as well as to Analytica’s Founding Council members and other staff for their support, patience and valuable advices and inputs.

Last but not least I would like to thank the European Fund for the Balkans, our donors, without whose assistance and funding this event would have not been possible.

Skopje, Macedonia 15th of July 2010 Member of the organizing committee

Sonja Risteska

iii

SUMMARY OF THE CONFERENCE

Within the EU Approximation and Integration Advocacy Programme together with the Energy and Infrastructure Programme, Analytica organized its Second International Graduate Student Workshop on the topic of “Implementing Energy Efficiency through Renewable Energy Solutions - are Southeast European Countries on track?””. The participants at the workshop were professors, PhD candidates, officials from the Energy Agency and the EU Mission in Skopje, professionals working in the field of energy, civil society organizations and post-graduate students from Macedonia, Serbia, Kosovo, Germany and other countries giving presentations on the topics of New Energy Efficiency Trends in the Western Balkans, Renewable Energy Technologies, Solar Energy Solutions and Regional Cooperation on EE and RES matters.

This conference is part of a bigger project that Analytica is conducting called Energy policy, EU and the Western Balkans: challenges of reforms and accession - Republic of Macedonia as a case study financed by the European Fund for the Balkans in Belgrade, Serbia. The aim of the project is to contribute to faster EU integration of the Western Balkans states, and Macedonia in particular, by providing policy options and recommendations to improve the quality of the policy-making process in the field of energy policy.

On the topic of energy efficiency and renewable energy sources, the Conference was opened with the presentations of PhD Hristina Spasevska from the SOLTEC Center at the FEIT. The panels that followed dealt with the EE and RES legislation and trends in the country, the on-going projects on local level on these matters and the experiences that CSOs have in dealing with energy efficiency projects. The last two panels were reserved for the post-graduate students and their presentations on solar energy solutions, RES case studies etc.

Few of the presentations by Macedonian and foreign experts have raised the question of tardiness: Why the Balkans is always lagging behind Europe? And why the abundant renewable energy sources in this part of Europe are not exploited in economic and efficient way? The panelists have agreed that the latter is a result of inconsistency of policies. The conclusions were that EU institutions should take the lead in financing projects of renewable energy and EE, as the banks in this region and wider are still reluctant to start with financing of projects on a non-commercial level, seen as investments with high risk. On the other side new credit lines with lower interest rates should be made available for the private sector – for development of the EE and RE market. Through this kind of financial support developing countries (or no-OECD countries like Macedonia) will witness different benefits: creation of new jobs, support to the local economy, increase of the share of electricity produced by renewable energy sources in the total electricity production in the country, etc.

Another conclusion of the conference discussions is related to the overall situation in the energy sector in the Western Balkans in the last two decades. It was underlined that there are certain political actors and structures that do not see any benefit from investing in energy efficiency and renewable energy and therefore they hinder their development. Resistance to these structures

iv requires good organization, persistence, and big pressure by the CSO sector and the media. With a joint action and positive propaganda, through legislative amendments, organization of public discussions, and increasing of public awareness, the civil society and all interested parties should put a great pressure on the state institutions to prioritize RE and EE. Lobbing also should be directed towards EU institutions that should take in consideration the needs of the non-EU countries in the final European energy agenda, particularly when it comes to new investments in RE and EE.

The success of the conference of Analytica and SOLTEC is in the attempt to bring together decision- makers, policy executors, academia, CSOs and students on a same table, where many provocative questions were raised. Some answers were given, but it is an area that is yet to come on the headlines of the energy policy of the governments in the region. Solutions are available; it is the political will and momentum that needs to be created.

VENUE

The Conference was held at the Faculty of Electrical Engineering and Information Technologies (FEIT), "Ss. Cyril and Methodius" University in Skopje, Republic of Macedonia. The Faculty is located in the Campus of Technical Research Area at the University, 3 km far from the Centre of Skopje. FEIT and its surroundings provided good service for organizing such type of events, and offered the visitors a warm welcome.

COMMITTEES

I. Organizing Committee

• Sonja Risteska

Research Fellow at Analytica, Think Tank. Responsible for the EU Approximation and Integration Advocacy Programme.

• Natasha Hroneska

Research Coordinator and Research Fellow at Analytica, Think Tank. Responsible for the Energy and Infrastructure Prgoramme.

• Sani Demiri

Director and also a Founding Member of Analytica, Think Tank.

• Igor Panchevski

Free-lance consultant for NGO’s and SOLTEC center for low cost solar cells technologies

• PhD Hristina Spasevska

President of Narodna Tehnika, Head of SOLTEC and Professor at the Faculty for Electrical Engineering and Information Technologies, Skopje.

II. Scientific Committee

• PhD Mile Stankovski

Dean of the Faculty for Electrical Engineering and Information Technologies, Skopje.

• PhD Atanas Iliev

Associate professor at FEIT and Head of the EC and RP Institute.

• PhD Hrisitna Spasevska

President of Narodna Tehnika. Head of SOLTEC and Professor at the Faculty for Electrical Engineering and Information Technologies, Skopje.

• Sonja Risteska

Research Fellow at Analytica, Think Tank. Responsible for the EU Approximation and Integration Advocacy Programme.

vii

AGENDA

Graduate Student Conference: Implementing Energy Efficiency through Renewable Energy Solutions - are Southeast European Countries on track?

Monday 14th of June 2010

Faculty of Electrical Engineering and Information Technologies Skopje

09:00 Registration

09:30 Opening of the workshop

o PhD Hristina Spasevska – SOLTEC Centre o PhD Mile Stankovski - Dean of the Faculty of Electrical Engineering and Information Technologies o Mr. Sani Demiri – President of Analytica

10:05 First panel discussion

Chairperson PhD Hristina Spasevska

o Atanas Iliev, PhD – Macedonian legislation on EE and RES o Lazar Gechevski – Director of the Energy Agency of Republic of Macedonia– The development of EE and RES on national level o Daniel-Alexander Schroth, EU Mission – Promotion of energy efficiency and RES in the country from an EU perspective o Ljupco Dimov Municipality of Karposh – Local Projects and EE Development in the municipality

10:50 Second panel discussion – Applicative measures and policies

Chairperson Natasha Hroneska

o Garret Tankosic-Kelly, SEE Change Network, Sarajevo, BIH – Trends; towards or away from sustainability in South East Europe o Dragan Blazev, ENSI – Strengthening Energy Efficiency in Macedonian Municipalities o Igor Petrusevski, MSc. Candidate, Macedonian Center for Energy Efficiency - Wide the SEE with Success Thermal Solar Model o Bojana Stanojevska, Center for Climate Change – Power of energy efficiency in industry sector in Macedonia Discussion

12:15 Cocktail

viii

13:45 Third panel discussion – CSOs working in the field of energy and energy polices research, regional dimension: Transfer of know-know and experiences Chairperson Igor Panchevski

o ANALYTICA - Sonja Risteska – The case of successful Macedonian municipalities – positive experiences and lessons learned o FRAKTAL - Ana Rankovic – Regional dimension of EE and cooperation in the area of Energy Efficiency and RES o PRAXIS - Pellumb Gjinolli – Geothermal Energy as source for heating in Kosovo o CEE Bankwatch Network - Ana Colovic Leskoska - Can the International Financial Institutions do more to support new RES and energy efficiency in southeast Europe?

Discussion

15:30 Coffee break

15:45 Third panel discussion – Students, Topic: Renewable Energies Chairperson Tanja Ivanovska

o Igor Panchevski - Adaptive street lighting o Aleksandar Prodanov – Solar Keymark – Solar Thermal Products in EU – Where is R. Macedonia? o Tanja Ivanovska – Dye-sensitized solar cells Discussion

16:30 Forth panel discussion – Students, Topic: RES, Climate Change, Ecology Chairperson Sonja Risteska

o Slobodan Parizoski - Possibilities for exploiting solar energy in Macedonia o Andreja Naumoski - Energy efficient decision support system in ecology with novel classification algorithm o Nikola Petkovski – Storage of Energy o Maja Lazarevska - Energy and the Climate Change Discussion

17:45 Conclusions and closure of the workshop

End of the workshop and departures of participants.

Biographies of the papers’ contributors

Aleksandar D. Prodanov is advisor for develop and quality of measurement at Hydro- meteorological Service, Skopje, Macedonia. He works at Solar Test Center (which is part of Hydro- meteorological Service). Aleksandar graduated in meteorology, Institute for Physics at the Faculty of Natural Sciences and Mathematics in Skopje. He is currently enrolled at Master studies in Metrology at the Faculty of Electrical Engineering and Information Technologies in Skopje.

Ana Colovic Leskoska Nationality: Macedonian Language: Macedonian, English, Serbian, conversational Bulgarian and Russian Ana has been working for CEE Bankwatch Network since 2001, as the national coordinator for Macedonia. She also serves as the Executive Committee member in the Network. In Macedonia she is based in Eko-svest in Skopje and works there as the organisation’s Director. Ana studied Biology at the University of Cyril and Methodius in Skopje and is currently studying International Environmental Law under UNITAR’s law programme.

Fidanka McGrath Nationality: Bulgarian Language: Bulgarian, English, Romanian, proficient also in Russian and Serbian Fidanka became CEE Bankwatch's Network's Coordinator for Southeastern Europe in June 2004 and has been working for the NGO Za Zemiata in Sofia, Bulgaria. Fidanka studied Environmental Science and Policy at the Central European University in Budapest, Hungary, and holds a Bachelors degree in Southeast European Studies from the American University in Bulgaria. She has taken an undergraduate course in the Biosphere 2 Center of Columbia University in Arizona, USA.

Pippa Gallop Nationality: British Languages: English, German, conversational Croatian Pippa began working for CEE Bankwatch Network in 2005, initially within Croatian partner group Green Action and later as Bankwatch’s Research Co-ordinator. From June 2009 she is also interim EBRD Co-ordinator. Prior to joining Bankwatch she was active in a number of environmental and social groups in the UK. She has a BA (Hons) Degree in German and International Politics and an MSc (Econ) in Postcolonial Politics at the University of Wales Aberystwyth.

Andreja Naumoski is a teaching and research assistant at the Faculty of Electrical Engineering and Information Technologies in Skopje, Macedonia. In 2008 was awarded with a Degree of MSc in Computer Science specialized in area of Eco-informatics with his MSc Title Thesis “Dynamic and habitat suitability models of Lake Prespa”. From April 2009 he start his work on his PhD Thesis titled “New classification algorithms for analysis and knowledge discovery from diatom community

x as bio-indicators in aquatic ecosystems” improving the ecological knowledge about the diatoms community used as bio-indicators with state-of the art information technologies, methods and algorithms of data mining methodology. His main research areas include developing novel classification algorithms based on fuzzy decision trees and fuzzy-neuro classification methods, decision support system for ecology, ecological modeling, GIS and etc. He has published more than 20 conference papers and 2 journal papers and he has worked on 3 projects EU projects.

Igor Panchevski is focusing his career on managing renewable energy and environmental projects. He works with NGO’s and SOLTEC center for low cost solar cells technologies where he was responsible for implementing and projects delivery. Earlier in his career he was working on computer network solutions and hardware maintenance. Igor has a BA in electrical engineering from the state University Ss. Cyril and Methodius in Skopje.

Maja Lazareska holds a Bachelor degree in Biology and is currently completing a Master’s degree in Environmental Management at South East European University in the Republic of Macedonia. Her research is focused on sustainable rural development and environmental management. Her previous work experience includes rural development and European Union Instrument for Pre Accession Assistance for Rural Development (IPARD). She is currently Head of the Unit for programming, implementation, monitoring and evaluation of the IPA in the Ministry of Agriculture, Forestry and Water Economy of the Republic of Macedonia.

Nikola Petkovski has a BA in Electronics and telecommunications at the Faculty of Electrical Engineering and Information Technologies in Skopje. Currently he is enrolled in a Masters Programme for Renewable Energy sources at the FEIT. Nikola has also few years of experience in the field of industrial property.

Pellumb Gjinolli is Environmental engineer and also holds a Master Degree in Renewable Energy from the Vienna University of Technology. He is the owner of GET Company (Green Energy Technologies) and co-founder of NGO Praxis. He is currently involved in three different projects in Kosovo dealing with environment and energy.

Slobodan Parizoski finished primary school in Prilep. After that he finished specialized high school of electro-mechanical branch "Gjorgi Naumov" in Bitola. On July, 2, 2009 he graduated from the Faculty of Electrical Engineering and Information Technologies in Skopje on the subject: "Implementing of fuzzy-logic control in car climate systems". Currently he is enrolled in postgraduate studies on the same faculty, studying under the programme: "Renewable energy sources".

Tanja Ivanovska has graduated in applied physics at the Faculty of Natural Sciences and Mathematics in Skopje. She is currently enrolled at Master studies in Renewable Energy Sources at the Faculty of Electrical Engineering and Information Technologies in Skopje. She is also a member of the team of the Center for Low-Cost Solar Cell Technologies – SOLTEC.

P A P E R S

xii

Solar Keymark – Solar Thermal Products in EU – Where is R. Macedonia?

Aleksandar D. Prodanov Hydrometeorological Service Skupi bb, 1000 Skopje R. Macedonia e-mail: [email protected]

Abstract

The market has been fragmented due to different national and regional requirements in (buildings) regulation and financial incentive schemes. By removing remaining barriers to trade, consumers will have improved access to solar thermal quality products resulting in a higher uptake of solar thermal energy in the EU. European standardisation and certification is starting to work. The standards are now implemented at all main European test institutions and the European certification scheme; based on these standards - the Solar Keymark - has been established. The project aims at opening up the European market for solar thermal quality products. 7 reasons why Solar Keymark is needed: reduced testing and administration costs, certified product & manufacturing system, enhanced customer confidence, improved opportunities to increase turnover, improved image for company why have Solar Keymark, improved image of solar thermal industry, passport to European solar thermal markets. The objective of the QAiST project is to improve the quality assurance framework so that the European solar thermal heating and cooling industry can sustainably contribute to the targets agreed by the EU member states (20% of RES by 2020) and become a technological world leader. In 2008 was establish Solar Test Center (STC) in Skopje, R. Macedonia. The aim of STC is to test solar collectors according EN 12975 and EN 12976 standards. From February 2010 STC is part of QAiST project.

Key words: Solar Keymark, QAiST project, Solar Test Center, solar collectors.

Introduction

As a consequence of the booming solar thermal market, a considerable number of new solar thermal products, such as solar thermal collectors or complete systems, are entering the market. For determination of the thermal performance and to certify the durability and reliability of these solar products, testing according to international standards is an important requirement. To ensure comparable and representative results, tests of solar thermal products are carried out according to well established procedures. Such test procedures are specified e.g. in the European Standard EN 12975 or the International Standard ISO 9806 for solar thermal collectors and in the ISO 9459 for solar thermal systems.

European standardisation and certification is starting to work. The standards are now implemented at all main European test institutions and the European certification scheme, based on these standards - the Solar Keymark - has been established. The project aims at opening up the European market for solar thermal quality products.

Past: A couple of years ago each European country required the solar products to be tested at their own national test institutes.

Now: Most of the (accredited) European test institutes accept test results from each other for certification in connection with national and regional regulation and subsidy schemes.

Future: Once tested and certified the product automatically fulfils all national and regional requirements in regulation and subsidy schemes.

As the European solar thermal industry grew and became more international, the “past” situation became more and more inconvenient and a barrier to further growth. That is why the industry in the mid-90’ties initiated the development of common European standards and a few years later a certification scheme was linked to these standards. The development described above is the result of this initiative and its implementation. The implementation has so far been very successful thanks to the very positive and constructive co-operation between the European test labs and industry, motivated by the argument that an open market indeed gives the best conditions for increasing the total volume.

The situation today is that the most important standards are implemented and operated at all the main European test institutes - the Solar Keymark certification scheme is established and ready for use.

The last step is to have the Solar Keymark recognised as the general accepted European quality mark, being accepted by all national and regional requirements in regulation and subsidy schemes. This is a matter of informing and convincing the European/national/regional authorities/decisions makers to make use of this common European approach to minimise the market barriers and help the solar thermal market to grow for the benefit of environment and security of energy supply.

THE CEN/CENELEC KEYMARK

The CEN/CENELEC European Mark - The Keymark - is a voluntary third-party certification mark, developed by the European Committee for Standardisation (CEN). The clear and simple message of the Keymark is that the product complies with the European Standard(s) covering the product. The basic elements in the certification scheme are:  Initial type testing of products according to the EN standards  Factory production control (at ISO 9000 level)  Inspection and surveillance tests

THE SOLAR KEYMARK

The Keymark is now available for solar thermal products. This “Solar Keymark” is stating conformity with the following European standards:  EN 12975. Thermal solar systems and components - Solar collectors  EN 12976. Thermal solar systems and components - Factory made systems

The specific rules and procedures for the Solar Keymark certification – the specific scheme rules - are given in: “Specific CEN Keymark Scheme Rules for Solar Thermal Products” - available from the Solar Keymark web site: www.solarkeymark.org.

These specific scheme rules give details especially for the solar thermal products and specify those deviations from the general scheme rules, which are needed to account for special conditions and characteristics of solar thermal products. E.g. due to the fact that testing of solar products are expensive and time consuming it is specified that:  only a few tests are needed to cover the whole range of different sizes of the same collector type  the obligatory biannual surveillance test is a physical inspection of the product

HOW TO GET A SOLAR KEYMARK LICENSE?

The whole procedure and requirements for obtaining the license for the Solar Keymark is described in the general Keymark rules and the specific Keymark Scheme Rules for solar thermal products. Some general criteria for obtaining a Keymark can be listed: • Application/Contract: Formal application for the grant of a license to use the Keymark is made through the signing of a contract between the manufacturer and an empowered certification body. • Factory Production Control: A product line related factory control taking into account the elements of ISO 9000 must be established and operated. • Initial Inspection and Initial Type Testing. • Surveillance Procedures: At least once a year the Factory Production Control is inspected and every second year a sample of the product is taken for surveillance test (physical inspection). • License Fee: A low annual fee for the right to use the Keymark label must be paid.

So to start the process - the manufacturer should contact one of the empowered certification bodies for certifying solar thermal products at CEN web site: http://www.cen.eu/ or at the Solar Keymark web site (www.solarkeymark.org).

WHY SOLAR KEYMARK IS NEEDED?

There 7 reasons why Solar Keymark is needed:

• reduced testing and administration costs, • certified product & manufacturing system, • enhanced customer confidence, • improved opportunities to increase turnover, • improved image for companies which have Solar Keymark, • improved image of solar thermal industry, • ‘passport’ to European solar thermal markets.

QAiST project (Quality Assurance in Solar Heating and Cooling Technology)

Objective:

This project, running from June 2009 until May 2012, is focused on promoting good, operational and widely accepted European quality assurance standards for solar thermal products, as this is a key element to the development of a large and open European solar thermal market. The long term objective is to prepare quality assurance framework which will help to meet the 2020 targets.

One element in this context is Solar Keymark certification. For further information please see: www.solarkeymark.org

The key actors such as certification bodies, test laboratories, inspectors and manufacturers involved in Solar Keymark certification are organised in the Solar Keymark Network.

Within this QAiST-project, it is envisaged to involve in addition test labs/institutes from Central European countries in the Solar Keymark Network. Further information can be fined at: http://www.estif.org/solarkeymark/network.php

Benefits:

• Extending the scope of EN 12975 to fully cover also medium temperature collectors (tracking, concentrating collectors, evacuated tube collectors) • Clarification of durability and reliability requirements and test methods in EN 12975 • Extrapolation procedure for performance calculation of factory made systems • Clarification of reliability tests in EN 12976 • Continuing the quality assurance of testing laboratories

• Developing a harmonised approach on Function & Yield Control for large solar thermal systems • Reducing testing costs for solar domestic hot water systems being part of a common “system family” • Promoting the Solar Keymark in CEE countries • Raising interest in further development of EN standards and Solar Keymark by the “established” Solar Thermal industry

Solar Test Center in Skopje

R. Macedonia has laboratory for testing of solar collectors - Solar Test Center (STC) - which is part of the Hydro-meteorological Service in Skopje. STC was established in 2008. The aim of STC is to test solar collectors according ISO 9459, ISO 9806, EN 12975 and EN 12976 standards. From February 2010 STC is part of QAiST project.

Contributions in QAiST project consist of:

Keymark Network meetings to gain knowledge of the Solar Keymark procedure; • participation in a minimum of 4 Solar regarding quality assurance measures for solar thermal products; • at the second meeting, presentation of an initial country report on the current situation ction plan on how the Solar Keymark certification (or other country specific quality assurance methods) will be set up; • presentation of an a installers and representatives from government bodies about the European solar thermal standards• organisation as well of as two on “Solar the Solar thermal Keymark Quality certification; Workshops” to inform manufacturers, designers,

products within the duration of the QAiST project. • submission of a report on progress regarding quality assurance measures for solar thermal

References

ISO 9459, 1995: Solar heating - Domestic water heating systems. ISO 9806, 1995: Test methods for solar collectors. EN 12975, 2006: Thermal solar systems and components - Solar collectors. EN 12976, 2006: Thermal solar systems and components - Factory made systems. http://www.estif.org/solarkeymark/network.php http://www.solarkeymark.org/ http://www.cen.eu/ http://www.qaist.org/ http://www.estif.org/

Can the International Financial Institutions do more to support new renewables and energy efficiency in southeast Europe?

ANA COLOVIC LESKOSKA, FIDANKA MCGRATH, PIPPA GALLOP CEE Bankwatch Network Na Rozcesti 6, Prague 9, 190 00, Czech Republic

Central and Eastern Europe

[email protected] [email protected], [email protected],

Abstract

As Europe is “greening” its economy and gearing up to decarbonise by 2050, most southeast European (SEE) countries still view energy efficiency and renewable energy as greens on the side of their main dish. Coal power and large hydropower are still the favorites on the menu, as they depend on indigenous resources and keep energy import dependency lower. At the same time other abundant indigenous resources – the renewable ones – are not utilized, due to a lack of incentives for investors, public institutions and households. SEE countries, driven by EU harmonization processes, have been developing primary and secondary energy legislation in the last few years. Production and distribution of renewable electricity is still very complex in the region, which continues to discourage investors. Legislation on renewable energy certification is yet to be approved and implemented in most countries; agencies and procedures are needed to implement support mechanisms, and licensing procedures tailored to RES projects are lacking. A significant number of renewable energy projects are planned in SEE but it is unclear how many will find financing. The International Financial Institutions are playing a crucial role in the energy sector in the Balkans. The European banks – EIB and EBRD, which will be the focus of this paper – have made considerable investments into improving energy efficiency of transmission and distribution of electricity, and rehabilitation of district heating and existing hydropower plants. Some EE/RES credit lines have been developed via commercial bank intermediaries, along with direct lending facilities, however in the western Balkans these have started only recently and as yet the results are unclear. The IFIs, like other investors, point to legislative and administrative barriers to new renewables and expect that investment will increase as soon as these are removed. At the same time the EBRD and EIB have supported a number of fossil fuel projects and the EBRD is framing as “sustainable energy” projects that may demonstrate some efficiency benefits, but are ultimately keeping the region locked into its carbon “addiction”. In line with EU objectives, national and regional energy strategies should set ambitious aims and mandatory targets for decreasing energy intensity and CO2 emissions and increasing the share of sustainable renewable energy sources (excluding large hydropower plants). EE/RES solutions should be promoted on both the industrial and local/household level, with the active support of the IFIs, where other sources of financing are not available.

Key words: Energy, IFIs, investment

JEL Classification: F3, Q2, Q4.

Introduction 7

The Western Balkans countries face significant energy challenges, namely the need for investment in infrastructure to provide a reliable supply of energy, and for institutional and policy reform to enable the development of a modern and efficient energy system. Since the fall of Communism the energy sector in the region has suffered from underinvestment. The projected investment needed in generation, transmission, and distribution in South Eastern Europe from 2006 until 2030 is USD 82 billion.(1) Sustainable energy solutions need to be promoted by policy makers and by international donors in the Western Balkans, in order to assist economic development, to address energy poverty and to reduce environmental impacts.

Energy intensity levels of the Western Balkan economies are high, ex. in Serbia it is up to 2.5 times higher than the average for European OECD countries, and the overall efficiency of the energy systems ranges from 58% in Serbia to 80% in Croatia. Croatia’s estimated energy saving potential is significant – in the range of 25% of TPES (Total Primary Energy Supply). Extrapolating such levels across the region would produce savings equivalent to Serbia’s annual imports of oil and gas combined. (2) According to the World Bank, every additional USD 1 invested in more-efficient electrical equipment and appliances could avoid more than USD 2 in supply-side investment. (3)

The Western Balkans is a diverse region, yet the low level of exploitation of the potential of renewable energy sources (RES) and energy efficiency (EE) is a common feature, as well as the low uptake of IFIs and EU Funds for such projects. Barriers to RES/EE development are the lack of pro-energy efficiency policies, legislation and regulatory frameworks, lack of experience with large scale energy efficiency projects, regulated energy prices and low awareness of the potential of energy efficiency and renewables among decision makers at all levels. At the same time the SEE region is becoming a major transit region for oil and gas, and potentially an EU supplier of electricity generated either through the burning of fossil fuels or the destruction of invaluable ecosystems for large hydro power plants.

While governments have focused on increasing generation capacities and stabilising the transmission and distribution systems, progress in institutional and policy reform is lagging behind and there is a need for SEE countries to co-ordinate their energy sector strategies with those for poverty reduction, human development, governance and the environment.

Little progress has been made towards ensuring greater transparency in SEE’s energy sector, and new investments are often made without clear strategic justifications, and with terms and conditions which are extremely favourable to the companies involved but not necessarily to the local people and environment or the state economy. In spite of the lack of accurate data and predictions, in recent years there have been increased investments in electricity generation capacity, and the coming years are likely to see yet more. For example:

• The Albanian state energy company has constructed a combined cycle thermal power plant in Vlora. The Porto Romano coal-fired power plant in Durres is under consideration. Enel has announced a plan to assess the feasibility of building a nuclear power plant in Albania. Several large scale RES projects have been announced, however, most of them are intended to produce electricity for export. Examples include new wind energy parks, including two wind parks in the Lezha energy park for 234 MW and the 500 MW wind farm at the pristine Karaburuni peninsula near Vlora. Large hydro

projects are under way on the Rivers Drini, Vjosa (Skavica HPP, 350MW), and Devoll (3 HPPs, up to 370MW). (4) • Bosnia and Herzegovina has ambitious plans for several hydro power plants, eg. on the Neretva and Drina and a cascade on the Bosna River, and new coal power plants in Stanari and Gacko. • The Croatian government has developed its new energy strategy, which foresees investments in coal, gas, hydropower and possibly nuclear, in spite of the country’s lack of coal resources. Renewable energy is marginalised and there is no commitment for an overall increase by 2020. • Macedonia is planning a series of hydropower plants at Cebren (3x110 MW) and at Galishte (3X64 MW). • Montenegro is moving ahead with plans for a new 240 MW installed capacity HPPs on the River Moraca (tender underway) and a 170 MW one on the River Komarnica. These investments are associated with a planned cable for export of electricity to Italy. (5) • Serbia plans new lignite power plants at Kolubara and Kostolac. • UNMIK plans to build the Kosova e Re lignite power plant alongside the existing Kosova A and B units, as well as a large HPP at Zhur (292 MW).(6)

In spite of their renewable energy potential, Western Balkan countries are highly dependent on energy imports, in 2005 ranging from 32% for Serbia and BIH to 51% and 58% for Albania and Croatia (2). In addition to the challenges of adequately providing for its own energy consumption, SEE is also becoming a transit zone for oil and gas for western consumption. Several oil and gas pipeline projects are under discussion, including:

Oil • The Bourgas-Alexandroupolis oil pipeline (Bulgaria-Greece) - 30-50 mt/year • The AMBO oil pipeline (Albania-Macedonia-Bulgaria) - 30-40 mt/year • The Pan-European Oil Pipeline (PEOP) (Romania-Serbia-Croatia-possibly Slovenia-Italy) - 60-90 mt/year • The integration of the existing Druzhba and Adria pipelines (Croatia-Hungary-Ukraine- Russia) (This project was halted several years ago as environmental concerns relating to the Adriatic Sea had not been overcome. However the new Croatian energy strategy opens up the possibility of reviewing the project).

Gas • Nabucco (Turkey-Bulgaria-Romania-Hungary-Austria) - up to 31 bcm/year • South Stream (Russia-Bulgaria then Greece-Italy and Serbia/Romania-Hungary- Austria/Slovenia-Italy) - around 30 bcm/year • Trans-Adriatic Pipeline (Greece-Albania-Italy) 10-20 bcm/year • Poseidon (Greece-Italy), at least 8 bcm/year.

SEE governments are engaging in an energy reform agenda framed by the Energy Community Treaty, a regional cooperation framework for rebuilding energy networks and the creation of a regional energy market. Until recently EE and RES have been rather marginal in the Energy Community for SEE (ECSEE), however in the last two years some steps have been taken to promote the significant potentials for energy savings and harnessing renewable power in the SEE region. The Energy Community has set up EE and RES task forces, and together with IFIs,

9 such as the EIB and the EBRD, organised a series of workshops and investment conferences about EE and RES. Additionally, the ECSEE has commissioned a number of reports, ex.:

• a study on the implementation of the new EU RES Directive in the Energy Community: currently under finalisation. Based on the study outcomes, the Renewable Energy Task Force of the ECSEE will prepare a final report that includes recommendations on the adoption of the Directive 2009/28/EC in the Energy Community. The report shall be submitted for adoption at the Ministerial Council meeting in 2010.(6) • a study on the potential for combating climate change in power generation in the ECSEE: the outcomes of the study will be delivered at a planned workshop in the 2nd half of 2010.

The European Investment Bank (EIB) and the European Bank for Reconstruction and Development (EBRD) are also influential players in the energy sector in southeast Europe, particularly during the current financial crisis when commercial financing for energy investments has become particularly hard to obtain. The European Investment Bank, being the EU’s house bank, has a duty to promote EU policy such as the targets to reduce greenhouse gas emissions by 20 percent by 2020 and to achieve 20 percent of renewable energy by the same date in the EU. The European Bank for Reconstruction and Development is also majority-owned by the EU states, although its mandate is somewhat different - to promote the transition from centrally planned to market economies and to promote sustainable development.

This paper aims to examine the investments made by the international financial institutions in the energy sector in the region so far. It will show that there have been very few IFI investments into renewable energy in the Western Balkans and make recommendations on how the banks could do more to stimulate this sector.

Western Balkans energy landscape

Import dependency

The region in total is dependent on imported energy, primarily oil and natural gas, as there are some countries which are import dependent to a very high degree (7). Energy insecurity and high import dependence highlight the importance of increasing energy efficiency and diversifying energy resources in the Western Balkan countries. Better utilisation of indigenous renewable energy resources will decrease the vulnerability of the region to geopolitical instability and global price increases.

One of the major challenges that the region faces is the lack of reliable supply of electricity, which can sometimes cause shortages and blackouts. Bosnia and Herzegovina is the only country in the Western Balkans that produces a surplus of electricity and the region as a whole is an importer. The main trading pattern in the region is a flow of electricity from the north to the south. Import is mainly provided from Hungary, Romania and Bulgaria, via Serbia, which is the main transit country with a relative balance. Some countries are heavily dependent on import of electricity, ex. Albania, which relies solely on hydro power, in years of drought. (7)

Electricity generation

The total electricity generation in the Western Balkans region is predominantly a mix between thermal generation (mostly coal) and hydro power plants (mostly large scale ones), as the generation structure is very diverse in the different countries. For example, Albania gets more than 95% of its domestic electricity from large HPPs, while BiH, Croatia and Serbia get at least a third of their generation from hydro power. UNMIK, on the other extreme, is almost entirely reliant on generation from lignite TPPs. (7)

According to UCTE and Platts data, the current generation capacity in the region is about 54 GW, however a recent World Bank study (7) argues that “the firm capacity in the region would be approximately 40 GW particularly for lignite plants the actual available capacities are substantially lower than the reported figures.”

The World Bank study points to the fact that some generation capacity is either not producing or unreliable, due to the lack of maintenance. Additionally most of the generational capacity in the region needs to be replaced, which is especially concerning when it comes to old lignite power plants. With 4 000 MW of coal and lignite fired plants exceeding 30 years of age, and with increasing electricity demand in the region, decision-makers are continuously raising the argument that the region needs to invest heavily into more generation capacity. There are three questions, however, that surround this rhetoric:

The first question is:

Should increased generational capacity become a priority number one, pushing the great need to improve energy efficiency further down the to-do-list?

The economies in the region generally have high energy intensities, which is a result of the degraded state of energy infrastructure, high energy losses in transformation, transmission and distribution and inefficiency in the end-use sector. The countries have high carbon intensities compared to OECD averages. Serbia has the highest level of carbon intensity (1.2) which corresponds to its high dependency on coal and Albania the lowest (0.3) due to its high usage of hydropower resources. (7)

Transmission network losses in the SEE region are generally quite large ranging from 14% in Croatia, up to 37% in UNMIK, with an average of 23%. Additionally, distribution losses in the region are comparatively high, and although they are showing a decrease in recent years, there is a long way to go before they will reach the average European levels. For example in UNMIK around 45% and in Albania around 30% - 40% is lost in distribution, mainly resulting from low collection rates. (8)

At the same time energy prices per unit in the region need to rise, in order to cover the production cost and to introduce incentives for energy savings. Additionally the expected growth in energy consumption will translate into further strain on household budgets - it is estimated that 16% of people are already exposed to energy poverty. (2) In this situation urgent actions are necessary to increase energy efficiency and energy savings, in order to mitigate the negative economic impact of the expected increases in electricity prices.

The second question is:

Should new generation capacity come from conventional means – i.e. large hydro and thermal power? Or should it come from new renewables?

Low quality lignite is considered a competitive source of energy in the countries that have their own lignite reserves. However, it has obvious climate and pollution drawbacks.

If we exclude large HPPs as unsustainable source of energy that causes irreversible damage to natural ecosystems, then we can state that renewable energy sources currently play an insignificant role in the region.

It is questionable to what extent it is sustainable to continue the exploitation of the abundant water resources in the region for more hydro power, as ambitious energy planners often disregard the potential to use these resources for purposes different than electricity production. Particularly in countries like Albania, the need to diversify the production mix is highlighted by estimates of high vulnerability to climate change (valid for most of southern Europe).

Albania, BiH, Croatia and Montenegro have HPPs dominating their RES generation mix and contributing for half or more of national electricity production - app. 95%, 50%, 60%, and 50% in different years, respectively. In Serbia hydro power accounts for less - a mere 25% of the generation mix, yet it still dominates the RES capacity. At the same time all countries have significant potentials for biomass, wind and solar, according to USAID's Stocktaking report for regional assessment of RES (9).

And the third question is:

What is the purpose of increasing of the generation capacity: to secure a sufficient and reliable supply on the national and regional level, or to satisfy demand coming from richer neighbouring countries and the EU?

Several SEE governments are developing new electricity generation projects for electricity export, including in Bosnia and Herzegovina, Kosovo, Montenegro and Albania - a somewhat surprising candidate for energy exports given the unreliability of its own electricity supply.

However these plans do not appear to be based on thorough analyses of the real costs and benefits of electricity exports, nor even in most cases of the needs of domestic and target markets. These plans threaten to turn SEE into a source of ‘dirty energy’ from nuclear, lignite, and large hydropower plants, with the region’s people and environment paying the real costs of the exported electricity without assurance that domestic needs will be fulfilled.

The European Commission is sending mixed messages regarding such electricity export plans. On one hand, it purports to promote the implementation of the EU acquis on issues such as environmental protection, public access to information and public procurement, yet on the other it tolerates SEE governments plans to promote electricity generation projects which in several cases conflict with the EU environmental acquis. It also does not require governments of candidate and potential candidate countries to develop energy strategies in line with the EU long-term goal of decarbonisation of the economy.

The European Investment Bank, on the other hand, in its recent Special report "Partnering with the world" presents a case study on RES projects around Mostar, Bosnia and Herzegovina, expressing hopes for strengthening the country's role as a net exporter of RES electricity - "a plus point for joining the EU." (10)

Does it matter if the region exports renewable energy, which causes much less damage to its environment than coal or nuclear-based electricity exports? Even though renewable electricity exports are clearly preferable to coal ones, it should be borne in mind that the first investors get the best sites. By allowing large-scale new renewable developments for export, SEE countries are restricting their own possibilities for developing their RES capacity for domestic use.

Energy policy in the Western Balkan countries

SEE countries, driven by EU harmonization processes, have been developing primary and secondary energy legislation in the last few years. All of the countries covered with this paper (Albania, Croatia, Macedonia and Serbia) are signatories of the Energy Charter Treaty and Energy Community Treaty and have adopted a general Energy Law and National Energy Strategies.

Albania for example has an Energy Strategy from 2003, and in 2006 it updated it, but never approved the new document. The Action plan for its implementation is from 2007. Even the 2006 strategy has gone out of date already as the government has been handing out permits for electricity generation developments which were not foreseen in the strategy. The country has also developed a dedicated Energy Efficiency Law, but it has barely been set in force and even though there is an existing National Energy Efficiency Program on paper, there is no special authority to implement it.

Croatia last year approved a new and very controversial National Energy Strategy including the construction of new coal, gas, and potentially nuclear capacity, with no overall increase in the proportion of new renewables foreseen by 2020.

In Macedonia, a Strategy for Energy Development was adopted in early 2010. The main pillars of the strategy are the construction of new thermal and hydro power plants, analysis of a potential nuclear power plant and natural gas supply and the improvement of energy efficiency by 30 per cent in 2020 compared to the base year 2006 (11). According to the strategy, the main energy efficiency measures on the production side will be the construction of cogeneration power plants. The Strategy is focused on fossil fuels and does not consider a major decrease of dependency on fossil fuels or a significant shift toward more sustainable ways of energy production. Renewable energy use is elaborated in more depth in a Strategy for renewable energy use, currently up for adoption by the Government.

Regarding legislation for energy efficiency, the countries have either a dedicated legislation in place (Energy Efficiency law in Albania) or tackle the issue within the existing energy strategies or legislation. Most of the countries have already adopted a Building Act, or procedure on energy efficient constructions of buildings, but their implementation is either very slow or not happening. Regarding renewable energy, Albania and Macedonia are currently in the process of developing/approving laws and strategies for the use of renewable energy sources. Croatia has

13 gone the furthest with the legislation development and has so far the legislation closest to the EU acquis.

As regards incentives for investments in the sector, Croatia and Serbia have an Environmental Protection and Energy Efficiency Fund established on the national level. However in the Croatian case the majority of the money has been used for waste management projects so far and in the Serbian case, this Fund is facing capacity barriers and is not able to disburse the entire amount of allocated funds. Other than a few programmes and projects which support energy efficiency and renewable energy use, incentives are limited to national credit lines and feed-in tariffs and in Albania these do not exist.

In countries where feed-in tariffs are developed (Croatia, Macedonia and Serbia), there are still few investments in renewables. In Croatia two wind farms (with total installed capacity of 5.95 MW) were already in operation before the feed-in tariffs were implemented, and another with an installed capacity of 9.6 MW started operating at the end of 2009. Currently there are several new projects under development but they have been slowed by the financial crisis.

In Albania there are still no public funds allocated to support energy efficiency or renewable energy projects. Moreover, there are no incentives for energy efficiency and renewable energy initiatives in the residential sector and there is no support scheme for other renewable sources apart from small hydro. This does not stop investors applying for (and obtaining) permits for renewable energy projects, although it is unclear how many of these projects will actually be realised. In 2006, electricity generation in Albania amounted to 5.443 GWh, 98 per cent of which is produced through hydro power plants (12). Albania has 7 large hydro power plants with a total capacity of 1.4 GW. Generation from small HPP from 1990-2001 declined from 50 GWh to 6.7 GWh, due to lack of maintenance and their old technology. (13) As for planned hydro projects, since March 2007, more than 170 new projects on small hydro power plants have been considered and 60 concessionary agreements have been approved. Additionally, there are 4 large hydro power plants, several wind farms and a biomass plant planned, for which 9 licenses are already issued. The focus of the Albanian Government appears to be mainly on the export of electricity, although this is not reflected in the 2006 national energy strategy. According the Albanian Energy Regulatory Authority, 2 percent of the electricity produced from all the renewable projects planned will remain for consumption in Albania (14). Albania has taken the path of new construction and energy production without much of a strategy to support the process, while other countries are harmonizing their legislation in line with the European acquis, and struggling with obstacles in implementing the laws.

The lack of investment in the sector can be explained by numerous barriers in the region, mainly legal, institutional and administrative ones, but also financial and economic barriers. Such barriers include the complexity and lack of transparency of the regulatory framework, difficult grid connection procedures, regulatory instability and discontinuity, caused by uncoordinated updates and revisions of the current policy framework. For example, in Macedonia, the Energy Regulatory Commission, soon after announcing excellent feed-in tariffs for photovoltaic energy production, decided to decrease the tariff from 0.46€/KWh to 0.38€/KWh and decreased the contract period from 20 to 15 years, creating an uncertain climate for investments.

Overall, in the countries in the region there is a lack of operational instructions, tools, standards and procedures necessary to implement primary legislation or strategic programmes, there is

14 inefficient bureaucracy, non-transparent administrative procedures up to widespread corruption in public administration, and the authorisation procedures for new projects are excessively complex. There is also lack of cooperation between different ministries and agencies involved in energy policy as well as between ministries and local administrations which makes the implementation of these laws and regulations even more difficult.

On the economic side, there is a lack of availability of state or private funds for financing initiatives and programmes: premium tariffs for renewable energy sources are developed but often not operational and frequently they are of limited extent (e.g. they apply only to certain technologies or have restrictive requirements, an example being Albania where a feed-in tariff is in only place for small hydro). Energy efficiency funds, if they are operational, have limited resources; no alternative incentive measures such as soft dedicated credit lines, tax exemptions or support schemes for third-party financing are in place (15). According to the United Nations Development Programme (16), the Environmental and Energy Efficiency Fund in Serbia has managed to disburse only EUR 3 million out of EUR 15 million. Moreover, the fund has not received any requests for financing energy efficiency and renewable energy sources projects so far.

Can the International Financial Institutions do more to support new renewables and energy efficiency in southeast Europe?

International Financial Institutions - mainly the European Bank for Reconstruction and Development (EBRD), and the European Investment Bank (EIB) - are playing a major role in financing energy projects in southeast Europe. The question is whether they are playing a sufficient role in the financing of renewable energy and energy efficiency in the region, and whether they could do more to promote transition to an energy-efficient, low carbon economy. This section will, after introducing the EBRD and EIB, look at what their role should be in this field, what it has been so far, why they have not done more, and what in our opinion they should now do.

Introducing the EBRD and EIB

The EBRD was founded in 1991 to promote the transition from centrally-planned to market economies in the former Eastern Bloc, and also has the mandate to promote sustainable development throughout its activities. It is owned by 61 countries - including European countries, the countries of operation, the USA, Japan and others, plus the European Commission and European Investment Bank, and operates in 29 countries. Between 1991 and 2009 the EBRD invested a total of nearly EUR 12.5 billion in southeast Europe (17) in all sectors, with nearly EUR 1.9 billion in 2009 alone.(18)

The EIB is the European Union’s house bank, created by the Treaty of Rome in 1958 in order to “contribute towards the integration, balanced development and economic and social cohesion of the EU Member States.”(19) The EIB operates on a non-profit basis and lends at close to the cost of borrowing. Transport and credit lines through financial intermediaries were by far the most heavily financed sectors between 2000 and 2009.(20) The EIB also lends outside of the European Union to future EU Member States and EU Partner countries. Between 1991 and 2009 it lent EUR 16.9 billion in southeast Europe, of which EUR 3.3 billion was in 2009 (21).

What is the role of the EBRD and EIB in energy financing in southeast Europe?

Both the EBRD and EIB exist primarily to fill gaps left by the commercial banking sector and to finance projects that would otherwise not be financed. It is therefore worth briefly outlining why we consider that they should play a role in promoting energy efficiency and renewable energy in southeast Europe at all.

Putting aside the economic crisis, which has dampened private financing across the board, renewable energy and energy efficiency were reliant on public financing in southeast Europe long before the crisis, and will no doubt be for several years to come. Why is this so? If renewable energy is a desirable thing and energy efficiency is a win-win solution, why doesn’t the market take care of them?

As examined above, renewable energy and energy efficiency face many barriers in the region which prevent them from competing effectively on the market. These include:

• legal and administrative barriers, for example difficulty in obtaining permits and arranging grid connections • policy barriers: most of the countries’ energy strategies are still heavily reliant on coal/lignite, gas and large hydropower plants and show limited support for a significant switch to renewable energy. • political barriers: promoters of fossil fuel and large hydropower generation have more political influence than those promoting renewables and energy efficiency • economic barriers: coal/lignite is still cheaper than renewable energy because it does not pay its external costs, and economic incentives for renewables and energy efficiency are not operational in all countries, or are insufficient. • general resistance to change and unwillingness among decision-makers to believe that renewable energy can make up a significant proportion of the energy mix; prestige and relative ease of building new generation capacity compared with implementing many smaller energy efficiency projects. • difficulty of implementing residential projects due to decision-making procedures in multiple occupancy dwellings. • lack of ability in many cases to control amount of energy used eg. for space heating and therefore to impact on energy bills.

These factors make renewable energy and energy efficiency less attractive for commercial banks and private investors than the region’s large potential would suggest. Yet unlike most other new areas of investment, it is absolutely crucial for the region that energy efficiency and renewable energy investments increase and succeed.

These are key to energy independence and ability to resist fossil fuel price or supply shocks, as well as reducing climate impacts and other pollution and increasing employment. As we have seen, efforts to create conditions for sustainable renewable energy and energy efficiency investments are at various stages in southeast Europe, but in none of the countries examined have governments created conditions which would encourage consistent private sector support for renewables and energy efficiency. Given the urgency of increasing such investments the international financial institutions need to be actively involved in financing projects and

16 encouraging governments to remove barriers and increase incentives for sustainable renewables and energy efficiency.

EBRD and EIB financing for the energy sector in southeast Europe

Both the EBRD and the EIB have recognised the importance of financing renewable energy and energy efficiency and adopted targets. In its 2006 energy strategy the EBRD committed to lend or invest a minimum of EUR 1 billion in energy efficiency and renewable energy projects between 2006 and 2010.(22) Also in 2006 it launched its Sustainable Energy Initiative (SEI) Phase 1 (2006-2008), which aimed at EUR 1.5 billion worth of sustainable energy investments (23) during the period but was in fact exceeded, with EUR 2.7 billion invested. However, this initiative has unfortunately muddied the waters somewhat in terms of what is regarded as sustainable energy, with energy efficiency elements of projects in any sector included, even if the project involves prolonging the life of a coal thermal power plant or expanding a heavy industry facility. Phase 2 of the Sustainable Energy Initiative (2009-2011) is now underway, with a target of EUR 3-5 billion in investments.(24) In 2009 EUR 1.3 billion was invested under the SEI, out of a total annual business volume of EUR 7.9 billion.(25)

The EIB has set itself several renewable energy targets, such as 50 percent renewable share of total new generation in the EU by 2010. However its newer targets are aimed only at the EU and its renewables investments elsewhere are much lower - between 2002 and 2008 its energy investments in non-EU, non-European Free Trade Area countries comprised only 4 percent renewable energy (26). More generally, the level of EIB investments into renewable energy – EUR 1.39 billion in 2008 for the EU member states – needs to be set against the estimate of around EUR 40 billion per year required to meet EU targets over the next decades.(27)

The EBRD’s energy investments in SEE

The graphs below show the EBRD’s energy lending in southeast Europe, which amounted to EUR 1.962 billion in 2000-2009 (28). The figures are subject to interpretation depending on categorisation of projects and which projects are included. The methodology used is as follows.

The calculations cover the period 2000-2009. This was deemed to be long enough a period to get a good overview of what the banks have been financing without going back into the 1990s when investments in some countries may have been influenced more by immediate post-war repair needs than anything else.

The project data comes from the EBRD.(29) However we use our own project categorisations as outlined below. The project data for energy efficiency from 2006-2009 covers components of projects rather than whole projects, whereas such detailed data from pre-2006 was not available and the EBRD’s list of energy efficiency projects was used.

Rather than using the EBRD’s categories, it was deemed important to see what kind of energy sources the EBRD is supporting, so projects have been according to energy source, or where two energy sources are involved and cannot be clearly separated, they have both been named. In a few cases such as district heating rehabilitation it was not possible to ascertain which energy source or sources was involved and projects were therefore categorised as ‘other’. The ‘other’ category also includes projects such as transmission projects with no clearly stated energy

17 efficiency component and no clarity about which energy source is being supported. Those pre- 2006 projects categorised as ‘other’ may include an energy efficiency component, however it was not possible to quantify these.

It was decided to include energy efficiency due to the great role this needs to play in moving the region towards sustainable energy use.

This includes energy efficiency across various sectors, not only energy production and transmission, as this is the nature of the changes needed.

However this leads to difficult questions. In the energy sector, if a coal thermal power plant unit is replaced with a more efficient unit, should this be counted as energy efficiency? While it may indeed be argued that the plant is now more efficient than before, it is not clear that it would result in fewer emissions compared to non-coal alternatives. Given that such investments are likely to increase the lifetime of the plant and to make coal generation more efficient, we believe that such investments tend more towards supporting the coal industry than moving towards truly sustainable energy. The same applies for projects to increase the efficiency of oil facilities. In the energy sector this has mainly applied to one project, the EUR 80 million Turceni thermal power plant rehabilitation in Romania, so variants are presented below with both Turceni as a coal investment and Turceni as an energy efficiency investment.

A similar problem arises with the transport sector: Should transport projects with an energy efficiency component be categorised as energy efficiency projects? The EBRD has undertaken several transport projects with an energy efficiency component. Some of these are relatively clearly reducing overall greenhouse gas emissions, for example by increasing the efficiency of trolley buses, while some are more questionable. Most notably, EUR 22.3 million of the EUR 180 million loan for the Corridor Vc motorway in Bosnia and Herzegovina is categorised as an energy efficiency project although it is hard to imagine that the motorway will not induce traffic and that it will not cause an overall increase in greenhouse gas emissions, even if relieving congestion in a few locations. It is beyond the scope of this paper to examine the greenhouse gas impacts of each project overall, and data is in many cases not available, it was decided to exclude transport-related energy efficiency from the calculations, although recognising the great scope for its contribution to reducing greenhouse gases and increasing energy efficiency.

Graph 1 - EBRD investments in the SEE energy sector 2000-2009 (without transport, Turceni as coal)

Energy source EUR million Fossil fuels 1023 RES/EE 541 Other 398

Graph 2 - EBRD investments in the SEE energy sector 2000-2009 (without transport, Turceni as energy efficiency)

Energy source EUR million Fossil fuels 943 RES/EE 600 Other 398

Graph 3 - EBRD investments in the SEE energy sector 2000-2009 (without transport, Turceni as coal) - a more detailed version of Graph 1

Energy source EUR million

Coal 286 Gas 343 Oil 248 Oil/Gas 146 RES 102 RES/EE 113 EE 326 Other 398

Graph 4 - EBRD investments in the SEE energy sector 2000-2009 (without transport, Turceni as energy efficiency) - a more detailed version of Graph 2

Energy source EUR million Coal 206 Gas 342 Oil 248 Oil/Gas 146 RES 102 RES/EE 113 EE 386 Other 398

In both cases EBRD financing for fossil fuel projects outweighs financing for renewable energy and energy efficiency. In the variant including Turceni as coal, support for fossil fuels makes up 52 percent of the total, and support for renewable energy and energy efficiency 28 percent. Including the Turceni as an energy efficiency project makes 48 percent support for fossil fuels and 31 percent for renewables and energy efficiency.

It should be noted that the situation may be even more tilted in favour of carbon-intensive development than shown here because this analysis does not include expansion of heavy industry or transport-intensive developments, whereas it does include the energy efficiency components of projects in all sectors after 2006.

While the EBRD has financed quite a large number of energy efficiency projects both directly and through financial intermediaries, (particularly in Bulgaria) it has financed very few renewable energy projects so far. It is not possible to trace exactly which smaller projects have been financed as the bank does not disclose the final beneficiaries of its financial intermediary lending.

A closer look at the Albania, Croatia, Macedonia and Serbia shows that the lending has also been uneven, with very little energy efficiency and renewables lending in the Western Balkans.

Albania

Energy Source EUR million Oil and gas 68.445 RES/EE 21.75

The majority of energy efficiency and renewables lending is accounted for by one EUR 16 million investment into upgrading electricity substations. The rest consists of an energy efficiency component of a shopping centre development, a private equity fund to invest into renewables

21 and energy efficiency and a credit line for energy efficiency. No information is publicly available about the sub-investments made through these latter two projects.

The oil and gas projects comprise supporting oil extraction at the Patos-Marinza oilfield, and the construction of the controversial 97 MW Vlora thermal power plant, which was heavily opposed by local people. It is now constructed but it is not clear whether it will even be used regularly or only for back-up.

Croatia

Energy source EUR million Gas 70 Oil 32.377 RES/EE 16.4

There have been few energy investments by the EBRD in Croatia. The gas investment is a single gas storage project, while the oil projects comprise a refinery rehabilitation and two very small oil spill protection projects.

The main energy efficiency projects are loans to a sugar producer, a private equity fund to invest into renewables and energy efficiency and a credit line for energy efficiency. No information is publicly available about the sub-investments made through these latter two projects.

Macedonia

Energy source EUR million Energy efficiency 37.5 Oil 17.338 Other 57.021

In Macedonia the EBRD has supported electricity distribution network efficiency improvements and since 2009 has supported energy efficiency credit lines. The oil investment comprised support for the Thessaloniki-Skopje pipeline. Out of the four countries covered by this study Macedonia is the only one where energy efficiency investments outweigh the bank’s support for fossil fuels. If a EUR 5.9 million energy efficiency component of a road maintenance project is included the figure increases to EUR 43.4 million for energy efficiency, however in our opinion, although road maintenance is important, it is difficult to justify the inclusion of a component of a road transport project as an energy efficiency project.

Serbia

Energy source EUR million RES/EE 23.8 Coal 60 Other 120 The picture in Serbia is rather unclear, as it is not known which energy sources, in which proportions, some of the older loans supported. They have therefore been categorised as ‘other’. According to the project summary documents on the EBRD’s website they are likely to have

22 comprised a combination of support for coal-based thermal power and large hydropower, with some efficiency improvements. The coal loan was for modernisation of lignite mine equipment and upgrade of the power system.

There has been more potential support for new renewables in Serbia compared to the other countries - out of the EUR 23.8 million for energy efficiency and renewables EUR 11.25 million may potentially be used for renewables projects. However as the credit line and private equity fund were supported by the EBRD only in 2009, and since no information is disclosed about the final beneficiaries of such financing it is unclear whether it has been used for renewable energy or energy efficiency, or indeed whether it has been used at all. The remainder of the energy efficiency projects was for relatively small industrial energy efficiency components and an energy efficiency credit line.

In addition to the figures quoted above, the EBRD includes EUR 99 million out of a 2009 EUR 100 million loan for new trains under energy efficiency. While this is a worthwhile and welcomed investment, including almost all of it as an energy efficiency investment is debatable. In addition, from a climate point of view it makes little sense to look at public transport investments that save energy without also looking at investments into unsustainable modes of transport - road and aviation.

This is particularly important in Serbia, which is a major transit country for goods travelling between Turkey, Greece, Bulgaria and most of the EU. Almost double has been invested by the EBRD in Serbia into road traffic compared to rail. No financing has been provided by the EBRD for sustainable transport modes other than rail, such as trams, trolleybuses, or buses.

It is often argued that it is logical that there should be more road investment than rail because the road network is more extensive and used by more people. However, while well-maintained roads are clearly needed, it is highly debatable how much investment should be made into constructing new ones.

Most of the EBRD-financed road projects in Serbia involve new construction or significant upgrading of existing roads rather than maintenance. Transport is the main sector in which European countries are failing to stem greenhouse gas emissions. In European Economic Area (EEA) countries, greenhouse gas emissions from transport (excluding international aviation and maritime transport) - far from being reduced - grew by 28 percent between 1990 and 2007, and now account for around 19 percent of total emissions.(30) Southeast European countries are already following these unsustainable trends, and making road transport quicker and more comfortable while it does not pay its external costs will inevitably lead to its further expansion.

The EIB

Between 2000 and 2009 the EIB invested EUR 1029.5 million in the southeast European energy sector - just over half as much as the EBRD invested. So far we have obtained data on EIB energy efficiency projects in non-energy sectors only from 2007 onwards, so any which took place before that are excluded. The ‘other’ investments comprise improvements to the electricity transmission and distribution network. Transport-related energy-efficiency investments are excluded in the graphs below, but there were 2 x EUR 20 million components in rail projects in Romania during the period

Graph 5 - EIB SEE energy investments 2000-2009

Energy source EUR million Large hydro 51.5 Oil/gas 520 Energy Efficiency 88 Other 370

Graph 6 - more detailed EIB SEE energy investments 2000-2009

Energy source EUR million Large hydro 51.5 Oil/gas 40 Gas 480 RES 11.5 Energy Efficiency 78.5 Other 370

The large hydropower investment was a rehabilitation, and the oil/gas project was the same power plant in Vlora that was financed by the EBRD, as well as the World Bank. As can be seen gas has been by far the dominant energy source supported, comprising investments in the Croatian distribution network and construction of a gas power plant in Romania. Support for new renewables has been conspicuous by its near absence. The renewables investment shown is part of an investment into a biofuel production plant in Romania, plus five EUR 0.3 million sections of energy efficiency credit lines. In 2009 the EIB did approve one EUR 130 million loan for the Mostar wind and hydro project in Bosnia and Herzegovina (31), however at the time of writing this has not been signed. It is also controversial because of the plans to site a small hydro plant on the picturesque River Kocusa.

Albania

Energy source EUR million Other 30.00 Energy efficiency/RES 3 Oil/gas 40

The EIB has made much-needed investments in the Albanian transmission and distribution network. More controversial, however, is its investment in the oil and gas-fired Vlora thermal power plant. Few conclusions can be drawn from such a small number of projects, however there is a clear lack of support for new renewables, with only EUR 0.3 million of a EUR 3 million energy efficiency credit line dedicated for this purpose.

Croatia

Energy source EUR million Gas 280 Energy efficiency 5

In Croatia the EIB has mostly invested in the gas distribution network, with very little for energy efficiency and apparently nothing for renewables.

Macedonia

Energy source EUR million Other 13 Energy efficiency and RES 3

In Macedonia the EIB has made relatively small investments in the energy sector, and has supported power transmission and distribution and energy efficiency, with only EUR 0.3 million for RES.

Serbia

Energy source EUR million Other 116.5 Energy efficiency and RES 3

In Serbia the bulk of the EIB’s investments have supported power transmission and distribution, along with a small energy efficiency credit line project. Regarding transport projects, which are not included here, but to which attention was drawn in the EBRD section, above, the EIB portfolio in Serbia is less imbalanced than the EBRD’s.

Could the IFIs do more to support new renewables in southeast Europe?

The most notable conclusion from the above analysis is that the European Investment Bank has invested very little into new renewables in southeast Europe. A EUR 10 million biofuel project component plus 5 x EUR 0.3 million credit line components cannot be considered a serious attempt to invest in the sector in the region. While the EBRD has done more, particularly in Bulgaria, its renewables investments in the Western Balkan countries have been small, very recent, and hidden, because they have been carried out through credit lines and a private equity fund whose final beneficiaries are not disclosed. The EBRD has also supported more climate- damaging fossil fuel projects in the region, as well as road construction projects in Serbia, which have not nearly been matched by financing for public transport.

Both banks have made some energy efficiency investments, particularly in the power transmission and distribution sector. Investments in this sector need to be further developed, particularly to include residential energy efficiency and energy efficiency in public buildings.

The EIB is perhaps even better placed than the EBRD to make loans for renewable energy projects in southeast Europe because its loans are made at cost price and thus have lower interest rates than the EBRD’s, and it is thus particularly of concern that it has barely done so thus far. If the EBRD has managed to finance at least some renewable energy projects, at least in Bulgaria, why has the EIB done even less?

Regarding the barriers faced by the banks in the region, the EBRD has explained its lack of renewable energy financing in Croatia as follows: “The lack of renewable energy projects was due to the combination of slow licensing of projects and lack of sufficient equity capital of developers who were not prepared to share the potential profits with an external shareholder.”(32) Similar explanations may well apply for other countries in the region. An investor in a wind energy project in Croatia, which started operating in 2006, also stated that the EBRD was approached to back the project but quoted a higher interest rate than commercial banks and declined to finance the project as the necessary paperwork was considered to negatively affect the economic viability of the project.(33) The situation might well be different if the project happened now due to the lack of private financing available, but the issue is worth reflecting on if the EBRD is to make a useful contribution. Further conversations with the EBRD have pointed to issues of complex and slow grid connection procedures. A further issue is the lukewarm commitment by southeast European countries to renewable energy and energy efficiency in their energy strategies. Almost all countries in the region have ambitions to become net energy exporters, and have energy strategies full of large-scale new-build energy generation capacity rather than small and smart energy efficiency and renewable energy investments.

The international financial institutions can only select projects initiated by others, which fit their policy goals, and a lack of clear government commitment to making renewable energy and energy efficiency into a force to be reckoned with in their countries may dampen private companies’ appetites to develop new projects that might be financed by the European public banks. However, this cannot explain the current situation of low IFI support for renewable energy in southeast Europe, as investment plans for renewable energy do exist in almost all of the countries, whether wind farms in Croatia or small hydro plants in Albania.

The question is whether the IFIs are perhaps being too perfectionist in wishing to ensure that the conditions for renewable energy investments are in place before supporting the sector. After all, is it not the role of public banks to lead investments in new markets that are still considered too risky for the private sector? In our opinion, IFI investments in renewable pilot projects could considerably assist in opening the way for further investments by making renewable energy project approval and grid connection procedures more logical and proportional. This should not include throwing caution to the wind and allowing all kinds of developments in any location, but should ensure that projects with low environmental and social risk are treated as such.

Recommendations for International Financial Institutions

• We call upon the International Financial Institutions to shift their funding from fossil fuel energy projects into renewable and energy efficiency projects in the region. This should not include new large hydro power plants, which are not considered sustainable due to biodiversity and water quality impacts and vulnerability to dry weather. Moreover, concerning renewable energy projects, IFIs should support projects where the energy is not primarily intended for export, but its production benefits the development of the country and improves the quality of life of its people. • IFIs should not wait until the conditions are perfect before financing renewable energy projects, but instead use pilot investments to push through change in the countries in the sector. • Regarding district heating energy efficiency projects, we recommend the IFIs to look into supporting biomass utilization rather than fossil fuels. Considering the constant problems with increasing gas prices and rising costs of heating and hot water in big cities, we believe the sector has potential, even though economically such initiatives may not be considered as viable in all countries at present. We propose that further research is developed in this area, to show best practices and sustainability of these systems. • Although energy efficiency in the residential sector is a massive initiative, we expect IFIs to have an active role in assisting the Governments from the region in addressing the low efficiency of buildings and providing proper finances in order to help implement energy efficiency measures. Additionally, thermostats and control switches in households should be included as mechanisms. • A large percentage of the biomass used in this region is accounted for by wood, and in some countries there is illegal logging that is additionally contributing to significant problems (such as deforestation and erosion, destruction of habitats and harming biodiversity). A programme to support the switching of inefficient with efficient burners is one way to address deforestation. • Support should be provided to private companies in the countries developing renewable energy technologies. Supporting them through credit lines would have a multi-beneficiary aspect - it would create jobs, support local economic development and increase the share of renewable energy production in the overall energy production in the country. This would also indirectly help households make a major step in introducing renewable energy technology. • Regarding industrial energy efficiency, there is an urgent need to the improve energy efficiency of existing large industry in the region and decrease high energy intensity. However, there should be a main focus on very clear and transparent accounting and public information disclosure in order to make sure that the companies are really using the support to significantly improve their energy efficiency. • As there are significant capacity constraints within national and local administrations, the IFIs could step up technical co-operation to support the staff within the ministries and agencies in increasing their knowledge and skills. Providing technical support in developing laws, regulations and toolkits as well as ways to implement them could also assist the Governments in achieving their goals. • Some regional Governments argue that they can't attract investments in certain renewable energy utilization projects because they do not have proper data to provide the investors with. The IFIs could also support more research into potentials and in combination with

their existing expertise from different countries; such initiatives would be beneficial to all parties concerned. • In terms of energy efficiency in the transport sector, the IFIs need to step up support for sustainable transport. Urban investments need to encourage better urban planning and decrease climate impacts by decreasing dependency on cars, by providing alternative public transport, use of the bicycle and walking. Elsewhere, the IFIs should drastically decrease financing for motorway and highway construction and invest more in railways. • When assessing energy and transport projects, IFIs need to look at various national strategies and EU legislation rather than just sectoral strategies for the energy and transport sectors. Energy and transport sector strategies, where they exist at all, often conflict with the need to reduce greenhouse gas emissions in order to meet EU targets once the SEE countries join the EU.

References:

(1)http://siteresources.worldbank.org/ECAEXT/Resources/258598- 1268240913359/chapter3.pdf (2) IEA, Energy in the Western Balkans, The Path to Reform and Reconstruction, 2008 (3)http://web.worldbank.org/WBSITE/EXTERNAL/COUNTRIES/ECAEXT/0,,contentMDK:2249 7075~pagePK:146736~piPK:146830~theSitePK:258599,00.html (4) Albanian Ministry of Economy, Trade and Energy, presentation “Investing in energy efficiency and renewable energy in the Energy Community” at the Investment Conference on EE and RES, Energy Community of SEE and EBRD, Vienna, March 2010 (5) Ministry of Economy of Montenegro, presentation on “Renewable sources in Montenegro” at the Investment Conference on EE and RES, Energy Community of SEE and EBRD, Vienna, March 2010 (6) Gabriela Cretu, Energy Community Secretariat, presentation “The Driving Role of the Energy Community for a Sustainable Development of the Western Balkans, The World Bank Regional Conference on Business Environment Reform in SEE “Growth and Competitiveness: Weathering the Crisis and Looking Ahead”, Tirana, 17-19 November 2009 (7) Pöyry Energy Consulting and Nord Pool Consulting, Report “SEE Wholesale Market Opening”, commissioned by the World Bank, April 2010 (8) IPA Energy and Water Economics, Report “Study on Tariff Methodologies and Impact on Prices and Energy Consumption Patterns in the Energy Community” to Energy Community, March 2009 (9) USAID, Stocktaking report for regional assessment of RES. Regional Findings and country Summaries, April 2009 (10) EIB special report "Partnering with the world", May 2010 URL: http://www.eib.org/about/publications/eib-information-1-2010-n137-special- edition.htm (11)http://www.economy.gov.mk/WBStorage/Files/precisten_tekst_Strategija_za_energetika_n a_RM.pdf (12) International Energy Agency (IEA). http://www.iea.org/Textbase/stats/electricitydata.asp?COUNTRY_CODE=AL (13) Draft National Energy Strategy for Albania, 2006, p.12 (14) Regional Analysis of Policy Reforms to promote Energy Efficiency and Renewable Energy Investments, on the basis of personal interview with the Albanian Energy Regulatory Authority. (15) Regional Analysis of Policy Reforms to promote Energy Efficiency and Renewable Energy Investments (16) Regional Analysis of Policy Reforms to promote Energy Efficiency and Renewable Energy Investments (17) Defined as Albania, Bosnia and Herzegovina, Bulgaria, Macedonia, Montenegro, Romania, Serbia and Croatia. The EBRD categorizes Croatia as Central Europe and the Baltic States however we have chosen to include it in southeast Europe. (18) European Bank for Reconstruction and Development: Annual Report 2009, p. 4 (19) European Investment Bank website: http://www.eib.org/about/index.htm, accessed 01.06.2010 (20) European Investment Bank website http://www.eib.org/projects/loans/sectors/index.htm?start=2000&end=2009, accessed 01.06.2010

(21) Calculated from data from the EIB website at: http://www.eib.org/projects/loans/regions/index.htm, accessed 01 June 2010. Southeast Europe is defined by the EIB as including Turkey and Croatia but not Romania or Bulgaria, however we have here used figures including Croatia, Romania and Bulgaria, but excluding Turkey. (22) European Bank for Reconstruction and Development: Energy Operations Policy, 11 July 2006 (23) European Bank for Reconstruction and Development: Sustainable Energy Initiative brochure, May 2009 (24) European Bank for Reconstruction and Development: Sustainable Energy Initiative Phase 2 (2009 - 2011) factsheet, May 2009 (25) European Bank for Reconstruction and Development: Annual Report 2009, p. 1 (26) CEE Bankwatch Network: Change the lending, not the climate, 02 December 2009, p.19 (27) CEE Bankwatch Network: Change the lending, not the climate, 02 December 2009 p. 21 (28) Excluding investments categorised by the EBRD as energy efficiency investments in the transport sector. (29) The basic figures come from the EBRD’s own project database at: http://www.ebrd.com/pubs/general/ar09.htm (accessed 28 May 2010). Figures for energy efficiency projects 2006-2009 come from a database provided by the EBRD on request. Figures for energy efficiency projects from 2000-2005 come from the project list at: http://www.ebrd.com/projects/signed/index.htm (accessed 28 May 2010) (30) European Environment Agency: Towards a resource-efficient transport system, TERM 2009: indicators tracking transport and environment in the European Union, EEA Report No 2/2010 (31)European Investment Bank website: http://www.eib.org/projects/pipeline/2007/20070438.htm?lang=-en, accessed 1 June 2010 (32) European Bank for Reconstruction and Development: Strategy For Croatia: 2010 – 2013, approved 27 April 2010 (33)South East Europe Development Watch/CEE Bankwatch Network: Real Energy Security Is Staring Us In The Face: Renewable Energy Case Studies From South East Europe, December 2007, p.23

Energy efficient decision support system in ecology with novel classification algorithm

Andreja Naumoski1

1 University “Ss. Cyril and Methodius”, Faculty of Electrical Engineering and Information Technology, Skopje, Macedonia- Karpos II P.O. Box 574 e-mail: [email protected]

Abstract

The ecological data contains very important information about the physical-chemical and the biological aspects of the water ecosystem health. This information could be used for improving the ecological management of any ecosystem, by implementing a decision support system. This system will use this information, which is collected in both spatially and time aspects in a specific measurement policy. These measurements could be collected using efficient energy sensor grip, which later the gather data could be transmitted to the central station for processing. After the data is processed, the decision support system based on the information algorithms automatically predicts the diatom-environment relationship. Because the diatoms are well known bio-indicators of certain environment, we can use them for automatically classification of the newly discover diatoms in certain water quality class (WQC). The WQC is defined within a certain range for important physical-chemical characteristics of the environment, such as pH, conductivity and saturated oxygen. This is very important to the biological experts, to get the right information very fast and greater prediction accuracy. Both these properties are considered, while building this system. In this paper, we present the conceptual diagram of the wireless sensor network placed in Lake Prespa, as a part of the overall decision support system. The sensors that we plan to be part of the grid network for acquiring measurements, must satisfy certain conditions, mainly they should be energy efficient because they rely on battery power. Many research papers suggest that proper chose of routing protocol could increase the energy-efficient data transmitting. The sensors operate with different modes; mode for sleep, which is the purpose to save energy and mode for transmitting data, which is the most consuming mode for any sensor node. All these operational modes are discussed later in the paper. In the last section, we present several of the rules and decisions obtain using the decision support system. This support system contains two parts: the algorithm for automatic generating rules from data and one part as a user interface, which displays the results. They discussed algorithm, which has been discovered very recently, have been shown to be a very effective way for solving ecological problems using information technologies. In the area of eco-informatics, this is a very intensive topic for research. Using these data mining methods we obtain model trees, which graphically represent the diatom-environment relationship. Generated model trees can be easily covert into rules. Together with the model trees, they are very efficient way of knowledge representation for the biological experts, which are the end users of this decision support system. At the end of the paper we give a conclusion and discuss the presented model, together with the future direction for our research.

Keywords: Decision support system, ecology, algorithm, Lake Prespa, automated, energy efficient

JEL Classification: C8

Introduction

Delivering the right information for the end-users, in our case the biological experts, has to be the highest priority for the future decision support systems. The environmental problems demand constant monitoring of the ecosystem, in order to evaluate the ecological state of the aquatic ecosystems. This ecological balance is a very unstable value because the system has own dynamic equilibrium and always changes plus the outside pollution activities. With this effect, the lake ecological status is hard to determinate, and it needs constant monitoring and analysis of the data. In best cases, the collected measurements are used to determinate the influence factors on organisms, key to their survival. This can be done by using the diatoms as bio- indicators and their classification. Building an ecological model (diatom-indicator relationship) for the given lake ecosystem in a non-trivial task, due to the complex interaction that living organisms and the environment have. In order to have more precision accurate model tree, we also need more accurate description of the given ecosystem, which is provided by the measurements gain from the sensors. The sensors must satisfy certain conditions, but most of all for long-life work, they must be energy efficient. Lake Prespa has its own geographical specification that we have embedded during the process of designing the network sensor grid. This has an impact on the choice of the routing protocol. The wireless sensors operate on different modes, which main goal is to conserve the energy needed for data transmission. That’s why most of the time they are in the sleep mode. Keeping this on mind, the presented paper introduces a conceptual diagram of wireless sensor grid on one of the three largest lakes in Macedonia, Lake Prespa, which dramatically reduces time and cost for monitoring. Most important, the quality and quantity of the measured data are increased. Several algorithms exist for increasing the energy efficiency of the sensors in wireless sensor networks. For example, TDMA-based protocols are naturally energy preserving, because they have a duty cycle built-in, and do not suffer from collisions [2]. Another way of energy saving is to use an extra radio the so-called wake-up radio, which operates on a different frequency than the radio used for communication [7]. As the wake-up radio is only for waking up other nodes, it needs no data processing and therefore, uses much less energy. Introducing a duty cycle into a contention-based (CSMA) protocol that only uses a single frequency requires some kind of in- band signalling. The well-known IEEE 802.11 protocol, for example, has power-saving features, even when working in ad-hoc mode [4]. The TinyOS project [14] includes a sensor-networks specific optimization of the basic CSMA protocol that tackles the idle-listening problem: by sending out a very long preamble, receivers only need to be weak up periodically to sense activity. Another protocol specifically designed for sensor networks is S-MAC [12]. The basic idea of this single-frequency contention-based protocol is that time is divided into-fairly large- frames. Every frame has two parts: an active part and a sleeping part. During the sleeping part, a node turns on its radio to preserve energy. Then usually this data is processed to the main station, or the decision support system (DSS), which has implementation of novel classification algorithm. A branch of artificial intelligence called machine learning, allows us to build such a model in an easy and automatic way. This is the main reason why we use data mining algorithms, which extracts knowledge directly from the measured data, without any need of previous knowledge for the complex interaction. The algorithm automatically builds a tree model, from which can be directly seeing the relationship between the diatoms and the environment. Previously used methods by the biological experts such as classical statistical approaches; canonical 33 correspondence analysis (CCA), detrended correspondence analysis (DCA) and principal component analysis (PCA), are most widely used as modelling techniques [15]. Although these techniques provide useful insights in the data, they are limited in terms of interpretability. Obvious progress in this research area in a direction of interpretability, have been made using data mining techniques, particularly decision trees. These data mining methods, improves the interpretability and increases the prediction power of the model trees. First attempt to model diatom-environment relationship for Lake Prespa, have been made very recently [16, 17]. Different settings were applied to the datasets and different models were obtained, which later they were discussed with the biological expert. Several of the models produced for the first time, knowledge about the newly discovered diatom relationship with the environment [17, 18]. The classical decision trees also have several disadvantages, which are improved very recently by the pattern tree methods. This novel machine learning method for diatom classification in correct WQC has robustness of data change, and they are resistant to over-fitting, this implies especially for the pattern tree method. This method is used in this paper for automatic prediction of the diatom-environment relationship. The measure data that we have induced in this paper was collected during one year period, without using wireless sensors nodes. The rest of the paper is organized as fallows. In section 2 several energy-efficient protocols will be discussed for wireless sensor networks (WSN), while in sub-section 2.2, we will present the conceptual model for the proposed implementation of sensor networks for collecting the needed parameters. The definition of the pattern tree's algorithm for automatic prediction of the diatom-environment relationship for Lake Prespa will be given in section 3 together with the implementation interface in section 4. Section 5 concludes the paper and gives direction of further research.

1. Energy-efficient protocols for the wireless sensors

In this section, a novel sensor network with energy-efficient protocol using MICA2 sensor network support, in the Lake Prespa, is introduced. From essential importance it is to implement sensor networks in the Lake Prespa due to the on-demand necessity of measured parameters, which must be collected in real-time and distributed to the main data centre for further processing. Here we propose seven sensor networks in the key locations of the Lake Prespa, but in the future this number will be higher (see Fig 2.)

1.1. MAC energy-efficient protocols overview

Communication in wireless sensor networks can, like most network communication, can be divided into several layers. One of those is the Medium Access Control (MAC) layer. This layer is described by a MAC protocol, which tries to ensure that no two nodes are interfering with each other's trans-missions, and deals with the situation when they do. Those MAC protocols play an important role in the energy saving process. From this perspective, it is very important to design such protocol to ensure the sensor-node to be energy-efficient. Wireless sensor networks consist from several sensor nodes. Every sensor node is battery- operated, energy consumable. The radio on a sensor node is usually the component that uses most energy. Not only transmitting cost energy; receiving, or merely scanning the ether for communication, can use up to half as much, depending on the type of radio [8]. While traditional MAC protocols are designed to maximize packet throughput, minimize latency and provide

34 fairness, protocol design for wireless sensor networks focuses on minimizing energy consumption. The application determines the requirements for the (modest) minimum throughput and maximum latency. Fairness is usually not an issue, since the nodes in a wireless sensor network are typically part of a single application and work together for a common purpose. Most frequently used type of sensors are MICA2 [3] (see Fig. 1), which operates on a 2.4 GHz Mote module used for enabling low-power.

Figure 1. MICA2 system architecture

The recent research based on MAC protocol layers, [6] introduce a novel system to handle load variations in time and location T-MAC introduces an adaptive duty cycle in a novel way: by dynamically ending the active part of it. This reduces the amount of energy wasted on idle listening, in which nodes wait for potentially incoming messages, while still maintaining a reasonable throughput. The experiments conducted by [6] based on the implementation of the T-MAC protocol have shown that, during a high load, nodes communicate without sleeping, but during a very low load, nodes will use their radios for as little as 2.5% of the time, saving as much as 96% of the energy in comparison to a traditional protocol. Table 1 summarizes the research in [6]. The message length used in these experiments was 20 bytes [6].

Table 1: Average energy consumption of sending and receiving EYES nodes (T-MAC protocol).

Msg/s Transmit [mA] Receive [mA] 0 0.138 0.138 1 0.400 0.246 10 1.516 0.890 Max 9.590 7.473

Table 1 shows the average electrical current during each experiment. We can see that transmitting nodes use significantly more energy than receiving nodes. This is logical, since transmitting the measure data takes more energy than receiving. More importantly, we see that the idle average current (0.138 mA) is less than 4% of the current of a non-energy saving protocol (which would be between 3.75 and 4 mA) [6]. More research is made, in the area of underwater sensor networks by [10], which is an important issue in ecology. Different applications have different requirements on MAC protocols.

In [10], the authors have aimed to design a MAC protocol for the long term applications such as environment monitoring. They propose an energy efficient MAC protocol, reservation-based MAC protocol, R-MAC for underwater sensor networks. In R-MAC, they schedule the transmission of control packets and data packets on both the sender and receiver to avoid data packet collision completely. Moreover, R-MAC supports fair sharing of the channel among the competing senders. In [10], they have conducted some simulations to evaluate the performance of R-MAC by comparing the performance of R-MAC with TMAC, a protocol proposed for radio sensor networks [6]. The experiments have shown that the R-MAC protocol is energy efficient than the modified T-MAC under variable data traffic. According to [10] the power consumption on transmission mode is 2 W, power consumption on receive mode is 0.75 Watts, and the power consumption on the sleep state is 8 mW. Under these assumptions, the best energy-efficient protocol to be used depends from the purpose of the measurements.

1.2. Lake Prespa energy efficient sensor network

The presented algorithms previously should be implemented in the proposed sensor grid (see Fig. 2). The most optimal sensor-node distribution should be made with the biological expert who has to determinate the importance of the measure location by physical-chemical and biological aspect.

Figure 2. Locations of proposed sensor networks in Lake Prespa

In our proposed sensor grid, we propose seven sensor networks are proposed for implementation. In every sensor network (SNx), each sensor temporally will collect measurement about several physical-chemical parameters in specific locations in the lake. Those sensors can move from time to time, and will send measured parameters to the nearest Data Centre (DC in Fig.2, which can include Base Station in it or be near Base Stations and collect information from it). As can be seen, there have only one Main Data Centre (MAIN DC in Fig.2), where the decision support system with a novel diatom classification algorithm is implemented

36 and is connected (wireless with GSM/GPRS – Global System for Mobile Communications/ Generic Packet Radio Service) with other six Data Centres. When the measured parameters are collected in the MAIN DC further calculation can be done, which is described above. After the data is collected then is processed by the decision support system.

2. Algorithm for automatic generating rules in decision support system

The measured data processed by the decision support system is then analysed using a novel diatom classification algorithm. The concept of pattern trees [1] and the proposed novel diatom classification method by similarity measures and different fuzzy aggregations is described in this section. In this paper, we will use Gaussian evenly distributed membership function, to obtain correct diatom classification and to predict the quantity of diatoms in the measured sample for each WQC. The quantities of diatoms are express through fuzzy terms. Every model tree than can be easily converted into the rule and presented to the decision makers and environmental engineers.

2.1. Algorithm metrics and water quality classification setup

The pattern tree method is composed by different similarity measures and fuzzy aggregation. One similarity metric is used in our research work, the RMSE metric. Let A and B be two fuzzy sets [11] defined on the universe of discourse U. The root mean square error (RMSE) of fuzzy sets A and B can be computed as:

n 2 ∑(µµAi()xx− Bi ()) RMSE(;) A B = i=1 (1) n

where xi A(xi) and

B(xi) are the fuzzy membership values of xi for A and B. The RMSE based fuzzy set similarity can thus be defined, i = as:1, . . . ,n, are the crisp values discretized in the variable domain, and μ μ Sim(;)1 A B= − RMSE (;) A B (2)

A(xi B(xi) ∈ sameThe larger principle the if value alternative of Sim(A,B), fuzzy set the similarity more similar definitions A and such B are. as AsJaccard μ ),are μ used. [0, 1], 0 ≤ AccordingSim(A;B) ≤ to 1 the holds fuzzy according logic theory, to (1) the and fuzzy (2). Note aggregation that the i patterns logic operators tree induction applied follows to fuzzy the membership values or fuzzy sets. They have three sub-categories, namely t-norm, t-conorms, and averaging operators such as weighted averaging (WA) and ordered weighted averaging (OWA). In our experimental setup, we use the basic operators which operate on two fuzzy membership values a and b, where a, b [0, 1]. In [1] the authors combine for the first time, all the three sub-categories of fuzzy aggregation. As can be seen, a pattern tree can be generated using different fuzzy aggregation functions.∈ The measuring procedure of diatoms from water samples has several disadvantages, which later will reflect on the data quality used for data mining procedures. In another hand, the data mining algorithm used to extract knowledge from the data has an error which reflects as accuracy of the gained knowledge. When combined with the previous error within the data, this problem can lead to serious low validity and quality of knowledge. However, if these two parts of

37 the process combine in the right direction, can lead to high accuracy and generality of the extracted knowledge. As we pointed earlier before, the water quality class is, in fact, a classification problem and also can be represented with fuzzy membership function. In this direction, we will transform the crisp values into fuzzy values and then assign a certain membership name to that particular range presented in Table 2.

TABLE 2. FUZZY MEMBERSHIP FUNCTIONS AND THEIR VALUES TOP 10 Low Medium High Diatoms APED 0-4.335 4.34-8.665 8.665-13 CJUR 0-28.665 28.665-57.33 57.333-86 COCE 0-27 27-54 54-81 CPLA 0-13.335 13.34-26.66 26.665-40 CSCU 0-13.665 13.66-27.33 27.33-41 DMAU 0-4 4-8 8-12 NPRE 0-6.335 6.34-12.66 12.665-19 NROT 0-8 8-16 16-24 NSROT 0-10.335 10.33-20.66 20.665-31 STPNN 0-7 7-14 14-21

The induction process is very simple. First we divide the data into two groups, but maintaining into a single file, the TOP10 diatoms abundance data and three water quality classes from measured SatO, pH and Conductivity parameters. Then using an automatic procedure each diatom is divided into three evenly ranges, which will be represented with fuzzy membership functions and names like (low, medium and high) shown in Table 2. While using this data mining technique we learn pattern trees, which can predict the outcome of the water quality class from the data based on the particular diatom found in the tree. Advantages of this proposed approach, is the fuzzy value (low, medium, high) in a certain range assign to each measurement, identifying the bio-indicator (diatom) for certain WQC. This algorithm automatically extracts knowledge from the diatom dataset. In fact, the both techniques can be merged in order to improve the overall prediction accuracy of diatoms-environment relationship.

2.2. Experimental data description and experimental setup

The datasets used in the experiments consist from 13 input parameters representing the TOP10 diatom's species (diatom species that exist in Lake Prespa [13]) with their abundance per sample, plus the three water quality classes for conductivity, pH and Saturated Oxygen. These measurements were made as a part of the TRABOREMA project [5]. The water quality classes are defined according to the three physical-chemical parameters: Saturated Oxygen [9], Conductivity [11] and pH [9, 11] which are given in Table 3. Among the input parameters, 10 are numerical parameters and the rest 3 are nominal with the number of possible classes from 4 up to 6. In this work, we induce a general pattern tree which consists from 2 candidate trees, 3 low level trees and depth = 3. For similarity definition, we use RMSE similarity and only AND and OR for

38 fuzzy aggregation procedure. We use three simple evenly distributed membership function from each membership function (triangular, trapezoidal and Gaussian). The configuration of the experiments is set up as fallows. 1) A simple fuzzification method based on three evenly distributed membership functions for each input variable is used to transform the crisp values into fuzzy values (Exp1); and 2). Two experiments are carried out, with the first (Exp2 – odd-even) using odd labelled data as training set and even labelled data as test set, and the second (Exp3 – even-odd) using even labelled data as training set an odd labelled data as a test set. Table 4 shows results of different membership function applied on the diatom's water quality classification dataset.

TABLE 3. WATER QUALITY CLASSES FOR THE PHYSICAL-CHEMICAL PARAMETERS

Physical-chemical parameters Name of the WQC Parameter range Oligosaprobous SatO > 85 -mesosaprobous 70-85 Saturated Oxygen -mesosaprobous 25-70 -mesoβ / polysaprobous 10-25 α acidobiontic pH < 5.5 α acidophilous pH > 5.5 circumneutral pH > 6.5 pH alkaliphilous pH > 7.5 alkalibiontic pH > 8 Indifferent pH > 9 fresh < 20 Conductivity fresh brackish < 90 brackish fresh 90 – 180 brackish 180 - 900

2.3. Model trees and rules obtain with the algorithm

The built trees from the data mining procedure are presented in this section. Due to the extensive number of build tree and paper constrains, we present several trees, one for each water quality class with the highest similarity factor.

Figure 3. Pattern tree for Conductivity WQC- brackish-fresh (left) and pH WQC – circumneutrala (right) Every tree can be transformed into a rule very easy, which is done for every tree. The pattern tree in Fig.3 clearly indicates that high abundance of the COCE and CSCU diatoms, medium abundance of STPNN and low abundance of the DMAU diatom can exist in brackish-fresh waters. This tree has the highest similarity between the classes of 52.59 %. This tree is built using three evenly distributed trapezoidal membership functions. As it was mention before the tree is transformed into a rule, as it has been shown below – Rule1. The complete names of the lake Prespa diatoms can be found in [2].

Rule1: If (COCE is High or CSCU is High) or STPNN is Medium and DMAU is Low then the class is brackish-fresh (with confidence of 0.5295) The tree shown on the Fig.3 –right, predicts the pH WQC, and then is transform into Rule2. Rule2: If (NROT is Medium or NPRE is High) or NSROT is Low then the class is circumneutrala (with confidence of 0.7278).

This tree has the high level of 72.78 % of similarity between the fuzzy terms compared with the previous one. The high abundance of NPRE and medium abundance of NROT diatoms indicates that the pH WQC is circumneutrala according to the model tree.

Figure 4. Pattern tree for SatO WQC - β-mesosaprobous Nevertheless, each WQC presented in the Table 1 have built several separate trees, but here we present only the tree with the highest confidence factor for each output class of the given WQC.

Rule3: If (CPLA is High or DMAU is Low) or APED is Low then the class is β-mesosaprobous (with confidence of 0.6713)

According to the tree for the Saturated Oxygen WQC (see Fig. 4), high abundance of CPLA diatom is the indicator of β-mesosaprobous. The derive rule is presented with Rule3. Using the proposed algorithm in this paper, we can see that the obtain models are easy interpretable, and they can be transformed into rules with certain prediction accuracy. Using a standard classification algorithm, an evolution procedure for estimating the prediction power of the algorithm is made. The results are given below (see Table 4.)

TABLE 4. 10-FOLD CROSS-VALIDATION CLASSIFICATION ACCURACY OF CLASSICAL CRISP CLASSIFIERS AND FOUR VARIANTS OF PT (IN %)

Bays Baggi Boost MultiBo SPT1 DataSet C4.5 kNN e ng ed SPT5 PT5 PT10 ost C4.5 0 Net C4.5 C4.5 Conductivi 63.30 68.1 68.6 69.0 68.1 ty 10-cross 65.60 66.51 68.81 63.76 69.72● ○ 6 4 7 4 xVal Saturate Ox. 47.26 58.71 54.5 54.5 53.0 55.0 54.73 53.23 56.22 55.72 10-cross ○ ● 0 0 0 0 xVal pH 46.33 61.47 57.6 57.1 56.7 56.2 10-cross 55.50 56.42 49.54 57.40 ○ ● 2● 6 3 8 xVal ●, ○ statistically significant improvement or degradation

3. Decision Support System for Lake Prespa

Using the previous energy efficient algorithms for data transmitting and the proposed novel classification algorithms for diatom classification it is possible to construct a decision support system. One possible implementation of such a system is given with Fig. 5.

Figure 5. Interface of the Decision Support System (DSS) for Lake Prespa On the left side of the interface, the map of Lake Prespa is shown, together with the given legend. On the right side is the operative part, which consists from Data Collection Centre where the user can read data from the sensor nodes and save to the local disk. The user can also monitor the last download time from the sensors, and if any of the sensors is not functioning, he can

41 immediately notice and send a repair team to replace the sensor. Under the Data collection centre, is the pattern tree algorithm settings. The user can set several of the options that were described earlier in the experimental setup of this paper work. Membership type, aggregation and similarity metric are one of the several options given for this DSS. And at the bottom of this interface we can see the rule generated from the algorithm. Because the rule is in AND and OR form, the user can immediately read and give an interpretation of the rules from the DSS. This system can be also upgraded with other decision making algorithms. More energy efficient algorithms can be implemented into the system for more efficient data transmission.

Conclusion

In this paper, we have presented a conceptual model for integrating energy-efficient protocols for data transmission into the decision system support with a novel diatom classification algorithm in ecology. The data received by the decision system is processed with a high-efficient algorithm for automatic knowledge discovery for diatom-environment relationship. We have presented several of the model trees obtained from the algorithm, which clearly express the knowledge gained from the measured data. This measure data was collected using old-fashion way, so we upgrade that process by providing a model diagram for wireless sensor network with energy efficient algorithms. The energy-efficient algorithms, discussed in this paper, have several advantages, over the previously used algorithms in data transmissions. The data measurements have to be in real- time in order to obtain more accurate models AND can be achieved by using the previous protocols. The best fit protocol can be R-MAC protocol, which according to [10], achieved greater performance, and it’s ideal for our ecological monitoring purpose. As we pointed earlier, the position and the density of the WSN should be determinate and discussed. Furthermore, future work is needed to achieve even greater energy-efficiency to the process of data transmissions. Even in hard conditions that the environment imposes; the discussed protocols have shown that it is possible to reduce the energy consumption. The model trees take the diatom's property as a bio-indicator and with classification algorithms: pattern trees we have extracted knowledge that predicts the water quality class. The extracted knowledge is with satisfied classificatory accuracy and similarity between the classes. Many of the produced rules can be validated with the knowledge of the biological expert, but in many cases new diatoms are discovered and their ecological preference is unknown. Presented procedure in this paper, leads to improvement of the process of faster classification of newly discover diatoms, which is an essentially greater improvement over the classical approaches. The presented pattern trees show that we can extract certain valid knowledge for the diatom- environment relationship. In fact, many of the pattern trees, such as the tree presented with Fig. 3 clearly indicate that SatO WQC can be indicated with high abundance of CPLA. Nevertheless, other pattern trees indicate that they can be used for extracting knowledge from diatom data. In future work, we plan to investigate more diatoms and improve the classification accuracy of the algorithm used for automatic extraction of knowledge together with more energy-efficient algorithms for data transmission. More research is needed in the area of designing efficient protocols, and network design of the sensors used in ecology, to achieve better DSS.

References

[1] HUANG, Z. H., GEDEON, T. D., NIKRAVESH, M.: Pattern Trees Induction: A New Machine Learning Method. In: IEEE Transaction on Fuzzy Systems. Vol. 16, No. 3. (2008), pp. 95 - 970.

[2] HAVINGA, P., SMIT, G.: Energy-efficient TDMA medium access control protocol scheduling. In: Asian International Mobile Computing Conference (AMOC 2000). (November 2000), pp. 1 - 9.

[3] Data sheet for MICA2 wireless measurement system. In: Crossbow Inc. (2003).

[4] LAN MAN Standards Committee of the IEEE Computer Society. IEEE Std. 802.11-1999, Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications. (1999)

[5] “TRABOREMA Project” WP3, (2005-2007). EC FP6-INCO project no. INCO-CT-2004-509177.

[6] VAN DAM, T., LANGENDOEN, K.: An Adaptive Energy-Efficient MAC Protocol for Wireless Sensor Networks. In: ACM SenSys’03. Los Angeles, California, USA, (November 2003).

[7] SINGH, S., RAGHAVENDRA, C.: PAMAS: Power aware multi-access protocol with signalling for ad hoc networks. ACM SIGCOMM Computer Communication Review. Vol. 28, No. 3 (July 1998), pp. 5 - 26.

[8] STEMM, M., KATZ, R. H.: Measuring and reducing energy consumption of network interfaces in hand-held devices. In: IEICE Transactions on Communications, E80-B(8). (1997), pp.1125 - 1131.

[9] KRAMMER, K., LANGE-BERTALOT, H.: Die Ssswasserflora von Mitteleuropa 2: Bacillariophyceae. 1 Teil,” pp. 876, Stuttgart: Gustav Fischer-Verlag, 1986.

[10] HIE, P., JUN-HONG, C.: An Energy-efficient MAC for underwater sensor networks. INFOCOM 2007. (2007). CD-ROM proceeding.

[11] VAN DER WERFF, A., HULS. H: Diatomeanflora van Nederland. Abcoude - De Hoef, (1957, 1974).

[12] YE, W., HEIDEMANN, J., ESTRIN, D.: An energy-efficient MAC protocol for wireless sensor networks. In: 21st Conference of the IEEE Computer and Communications Societies (INFOCOM). Vol. 3, (June 2002). pp. 1567 - 1576.

[13] (Macedonia). In: Iconographia Diatomologica, Vol. 16, (2006), pp. 603. LEVKOV, Z. KRSTIČ, S., METZELTIN, D., NAKOV, T.: Diatoms of Lakes Prespa and Ohrid [14] http://webs.cs.berkeley.edu/tos/.

[15] STROMER, E.F., SMOL. J.P.: The diatoms: Applications for the Environmental and Earth Sciences, Cambridge University Press, Cambridge, (2004), pp. 192 – 198. 43

[16] Diatoms in Lake Prespa using machine learning method of regression trees. The 6th European DŽEROSKI, S., MITRESKI, K., KRSTIČ, S., NAUMOSKI, A.: Constructing Habitat Models for conference on Ecological Modelling, ECEM '07. Trieste, Italy: Challenges for ecological modelling in a changing world: global changes, sustainability and ecosystem based management: conference proceedings. [S. l.: s. n.], (20070. pp.149 - 150.

[17] Predicting chemical parameters of water quality form diatoms abundance in lake Prespa and its NAUMOSKI, A., KOCEV, D., ATANASOVA, N., MITRESKI, K., KRSTIČ, S., DŽEROSKI, S,.: tributaries. The 4th International ICSC Symposium on Information Technologies in Environmental Engineering - ITEE 2009. Thessaloniki, Greece, Springer Berlin Heidelberg press, (2009). pp. 264- 277, doi: 10.1007/978-3-540-88351-7

[18] KOCEV, D., NAUMOSKI, A., MITRESKI, K., K S., D , S.: Learning habitat models for the diatom community in Lake Prespa. Journal of Ecological Modelling. (2009). Vol. 221, Issue 2, pp. 330-337. RSTIČ, ŽEROSKI

Adaptive street lighting

IGOR PANCHEVSKI Faculty of electrical engineering and information technologies Rugjer Boshkovik bb, PO Box 574, 1000 Skopje Republic of Macedonia [email protected]

Abstract Street lighting is of key importance to all of us. It can reduce traffic accidents by 30 to 50%, it is an effective means of fighting crime and promoting public security and it is essential for tourism, trade and business. Climate changes resulting from the CO2 emitted by burning fossil fuels pose a major challenge for the planet. The operation of street lighting consumes a significant amount of electricity, particularly when considered on a community, regional, provincial or national basis. Cities need to find solutions that reduce their streetlight network costs which are up to 40 percent of the budget, while improving light efficiency and safety. Lighting solutions as adaptive street lighting or intelligent street lighting ensure reducing the amount of energy consumed by street lighting and have a potential of providing significant savings to owners and at the same time make a valuable contribution to reducing CO2 output. Some manufacturers offer systems that can control, monitor and record the operating status of luminaires in a lighting system from a remote location using a desktop computer or mobile phone. In addition these systems can control the lumen output of the lamp thus allowing lighting levels to be varied at various times of the night. The systems typically use miniature solid state control devices that can retrofit into a luminaire. The solid state devices can be used to access data and control the luminaire via wireless technologies. These systems are typically designed with software to allow an owner to build a database of the asset and monitor performance on an area-wide basis. Additionally, luminaire locations can be identified by global positioning satellite (GPS) coordinates for easy identification, tracking and locating. With these system components in place, there is the potential to identify luminaire outages and schedule maintenance through the use of mapping software to identify and optimize maintenance routes. Benefit is reducing energy costs by 60 percent or more and short payback periods as 5 years or less. The paper will introduce the technology and benefits of intelligent street lighting which satisfies European Union's new EuP Directive and its requirements to ensure environmental sustainability by minimizing CO2 emissions.

Keywords: adaptive lighting, energy saving, street lighting, intelligent street lights, Trademark ownership

Acknowledgments

I am heartily thankful to my colleague B.Sc.Electrical Engineer Natasa Dimovska from the company VINT Dooel Skopje which is authorized distributor for PHILIPS Lighting for her support and assistance.

Introduction Europeans face many challenges in the coming decades. Our children, and their children, will increasing amounts of energy as fossil fuel reserves diminish faster and prices grow higher than ever.have to live with the effects of climate change. At the same time, Europe will need to import ever Reducing the amount of energy we use by choosing energy- for Europe to cut its energy use by 20 % in real terms efficientby 2020 appliances without compromising and services that on reduce energy use and ensuring we do not waste energy can make a big difference. It is possible technologies – electively doing more with less. performance,Presently, 14% through of the electricitychanges in consumption consumer behavior is accounted and by fo investingr by lighting in morein the efficient EU and energyalmost two-thirds of the lamps used are inefficient. Below there is a table where the energy saving potential in Europe is shown:

Expected Energy Savings Potential in EU-27 Annual Energy Savings Potential Area of Application Million KWh Billion Euro Euro/KWh CO2 (Million Tons) Home Lighting 62,2 12,4 0,20 23 Office Lighting 21,6 2,2 0,10 8 Industrial Lighting 21,6 2,2 0,10 8 Street Lighting 9,5 0,9 0,10 3,5 Total 114,9 17,7 - 42,5

Streetlights are among a city’s most important and expensive assets, typically accounting for 40% of its electricity bill. With energy prices increasing, this is driving the demand for energy- conserving technologies for municipal lighting. Despite being such a major electrical energy application, street lighting technologies remain somewhat out of focus for efficiency opportunities. Today’s target is to have the most energy-efficient street lighting that utilizes the latest technologies for optimizing the light intensity according to the situation by dimming the lamp and balance between economical goals and citizens’ safety needs. On today’s market there are few systems that represent a state-of-the-art telemanagement system, which is the most energy-efficient system. The most popular and recognizable are Philips (Starsense), Vossloh-Schwabe (Lixos), Jennic Technologies (Jennic), Streetlight Intelligence Ltd (Lumen IQ) and Echelon (LonWorks). This paper will consider only Starsense Telemanagement system by Philips, with all features and costs for its design and implementation.

1. Technology of the Philips Starsense adaptive street lighting system Philip’s Starsense telemanagement system enables individual light points to be switched ON or OFF at any given time, or to be set to any dimming level. The light points at a specific location can be grouped to react at the same time. The age and condition of each lamp can be monitored and any failures are reported by exact location. These capabilities make it possible to reduce

47 maintenance costs significantly through extended lamp life and accurate planning of service calls. The following illustration presents it more visually:

Starsense Configurator

The Segment Controller (SC)

Outdoor Luminaire Controller (OLC).

The Starsense system architecture consists of: Firstly the Starsense system is based upon the LonWorks® power-line communication protocol. Starsense devices use the existing 230VAC outdoor lighting power grid to communicate with each other. Each Starsense device has a LonWorks® power-line transceiver to enable it to use the LonWorks® communication protocol. This technology provides in a universal and open data communication protocol, which is mature and has proved itself in many different application areas. The LonWorks® technology is developed by the Echelon® Corporation. It is widely used in thousands of control networks and in all kinds of applications, such as building management systems, metering, transportation, industrial automation processes and more.

Outdoor Luminaire Controller (OLC) The Outdoor Luminaire Controller switches and dims the lamp and detects lamp failures. Communicates to the Segment Controller via a power line and uses a 1-10 V dimming signal to interface with the electronic ballast and a relay to switch it on and off. The OLC has a digital input designed to connect to a photocell, enabling local on/off switching.

Segment Controller (SC) The Segment Controller controls a number of OLCs connected to the same power grid and gathers information from them to be sent, when required, to the remote PC via Internet, typically through GPRS. The SC can be used to interface with other devices in the cabinet, such as traffic counters or weather sensors. The SC is normally located in a nearby feeder pillar.

Starsense Supervisor Software The software is used for monitoring and managing the data from the SCs. It collects aggregates and filters data before storing it in a central database. Provides “one-click” data analysis in order to help them reduce maintenance costs and energy consumption and improve the lighting service to citizens. Energy analysis, problem detection, problem location, lamp lifetime forecast and many other features are just one click away.

a. Methodology of implementation of adaptive street lighting To verify that the power grid is in good shape, the following measurement scenario is advised: • Measurements (power-line, noise, crossover, phase coupling)

After the power-line measurements outcome is positive, then the next phase of implementation comes: • Supplier mounts OLCs in a dedicated box usually combined with a driver and fuses; • An electrical installer will install the luminaire on-site; • The SC is installed in the electrical cabinet filled with traffic control systems, fuse boxes, measuring devices, and connectivity solutions; • When all the parts are physically installed afterwards software needs to be setup and connectivity network needs to be established; • An IT department needs to set up a computer with access to the connectivity network; • Integrator might commission and configure the Starsense Configurator and Starsense Supervisor to achieve the end-user objective;

• After completion the end-user will utilize the Starsense Supervisor tool; • An administrative end-user will ensure that the Starsense Supervisor tool will comply with the end-user information and modify the Starsense Supervisor accordingly.

b. Case study for municipality of Gazi Baba Although telemanagement for street lighting system usually is implemented into wider city areas or whole cities were the possibilities are higher and return on investment is much faster, there are exculpatory facts to be installed on small-scale areas. Next case that will be presented is small-scale municipality in Macedonia, Gazi Baba which is located in the city of Skopje. The municipality has 72 000 inhabitants and it is spread on 92 square km and it has 994 luminaries. On the table bellow is shown the current condition in municipality Gazi Baba, regarding the street lighting.

Current condition in Municipality Gazi Baba Type of bulb Power Qty. Total Pwr. (kW) Mercury-vapor 125W 139 117 16,3 Mercury-vapor 250W 272 58 15,8 Mercury-vapor 400W 429 388 166,5 High Pressure Sodium 70W 84 10 0,8 High Pressure Sodium 150W 169 14 2,4 High Pressure Sodium 250W 278 388 107,9 High Pressure Sodium w/ignitor 110W 124 3 0,4 High Pressure Sodium w/ignitor 220W 242 16 3,9 TOTAL: 313,8

As we can see, more than a half of the lamps are inefficient, so we designed a new proposal with two levels of illumination during the working hours.

New proposal with energy efficiant bulbs, electronic ballast and controllers Level of illuminance 100% Level of illuminance 50% Total Total Type of bulb Power Qty. Pwr Power Qty. Pwr (kW) (kW) Mercury-vapor 125W / / / / / / Mercury-vapor 250W / / / / / / Mercury-vapor 400W / / / / / / High Pressure Sodium 70W 78 130 10,1 39 130 5,1 High Pressure Sodium 150W 161 88 14,2 80,5 88 7,1 High Pressure Sodium 250W 269 776 208,7 134,5 776 104,4 High Pressure Sodium w/ignitor / / / / / / 110W High Pressure Sodium w/ignitor / / / / / / 220W TOTAL 233,1 116,5 197,3 Savings in total installed power [100%] 80,8 kW [50%] kW 50

From the table above we can see that when we have 100% of illuminance, savings in total power are 80,8kW or 25%, and when we have 50% of illuminance, savings are 116,5kW or 63% which is significant value.

Next table is showing the scenario of the new system, when it will work six hours with 100% of illuminance and five hours with 50% of illuminance despite of the old inefficient system.

Energy consuption in Municipality Gazi Baba from street light system Level of illuminance: (Price: 0,072 € / kWh) 6h 100% + 5h 50% New proposal with energy Current condition in Municipality Gazi Baba efficiant bulbs, electronic ballast and controllers Total Total Consuptio Consuptio Powe Powe Type of bulb Qty. n per Qty. n per r [W] r [W] anum. anum. (kWh) (kWh) Mercury-vapor 125W 139 117 65.296 / Mercury-vapor 250W 272 58 63.341 / Mercury-vapor 400W 429 388 668.305 / 78 22.207 High Pressure Sodium 70W 84 10 3.373 130 39 9.253 161 31.028 High Pressure Sodium 150W 169 14 9.499 88 80,5 12.928 269 457.149 High Pressure Sodium 250W 278 388 433.074 776 134,5 190.479 High Pressure Sodium w/ignitor 110W 124 3 1.494 / High Pressure Sodium w/ignitor 220W 242 16 15.546 / TOTA [kWh] 1.259.927 723.044 TOTAL [€] 108.300,00 € 62.151,00 € kWh Savings in total consuption of energy : 536.883 Euros: 46.150,00 €

In the next few tables are shown all the cost and expenditures for the maintenance of the new system despite the old one as well as all the needed parts for implementation of the new telemanagement system, period of ROI and reduction in CO2 emission.

Summary of the expenditures per year for maintenance of street light system New proposal with energy Current condition in Municipality Gazi Baba efficiant bulbs, electronic ballast and controllers Bulb Bulb Powe life Annual Powe life Annual Type of bulb r [W] time cost [€] r [W] time cost [€] (h) (h)

Mercury-vapor 125W 139 8000 612,00 / / / Mercury-vapor 250W 272 8000 451,00 / / / Mercury-vapor 400W 429 8000 4.135,00 / / / High Pressure Sodium 70W 84 18000 41,00 70 19800 410,00 High Pressure Sodium 150W 169 20000 62,00 150 22000 302,00 High Pressure Sodium 250W 278 20000 2.117,00 200 22000 3.212,00 High Pressure Sodium w/ignitor / / / 110W 124 18000 17,00 High Pressure Sodium w/ignitor / / / 220W 242 12000 134,00 Factor of uneconomic maintenance 2 TOTAL 17.863,00 € 3.925,00 € Savings in annual maintenance 13.938,00 €

Costs of the design and implementation of Starsense telemanagement system Type of expenditure Qty. Price [€] Total [€] Deassembly and assembly of the old street luminaires with new ones, electronic ballast and assembly of parts for the new Starsense sytem Selenium SGP340 SON-T 70W K EB + OLC 130 406,5 € 52.845,00 € Selenium SGP340 SON-T 150W K EB + 88 423,00 € 37.224,00 € OLC Selenium SGP340 SON-T 250W K EB + 340.664,00 776 439,00 € OLC € Assemby of the telemanagement system for monitoring, controlling, metering and diagnosing outdoor lighting 2.764,00 Segment Controller PHILIPS LFC7065 20 55.284,00 € € GSM/GPRS Modem 20 285,00 € 5.700,00 € 4.878,00 Unpredictable costs 4.878,00 € € TOTAL 585.970,00 €

Return On Investment (ROI) Cost of the design and implmentation of the projdect 585.970,00 € Total annual savings 60.088,00 € Uncovered investment after 1 year 525.882,00 € ROI in years 8,75

Type of savings Unit Before After Savings % Energy kWh 1.259.927 723.044 536.883 42,61 CO2 kg 1.222.129 701.353 520.777

Conclusion

The need of electrical energy is increasing with each coming year without tendency of decreasing. Production does not have the capacity to meet all market demands. Only reasonable solution to the problem is saving the energy. It is very clear that the benefit of using energy-efficient light bulbs as well as telemanagement system is huge. Although in this project there is a replacement of all inefficient luminaries the payback period is acceptable. This is on what municipalities and their old street light systems need to focus their work. Energy saving is not only relevant parameter in this system, accurate measurement of the energy and correct billing are significant part as well.

However the possibilities of expanding with new services for the future, like electricity plugs for the electrical vehicle; emergency calls; supervising of the streets and many more; make this system to be flexible and capable for future upgrades. Although, systems like this require big investments, governments and authorities must realize that this is necessary and imperative to energy savings, reduction of greenhouse gas emissions and for proper implementation of the European environmental legislation.

References

[1] EIRIK BJELLAND, VIKEN NETT, Intelligent Road Lighting – “Light – on the road”, CIE Session (2003)

[2] BERLINER ENERGIEAGENTUR GMBH, Status quo on Street Lighting Contracting in Europe, (July 2006)

[3] HENK WALRAVEN, ECHELON AS, E-street Initiative - Market Assessment and Review of Energy Savings, (July, 2006)

[4] PHILIPS, Starsense User Manual, pp. 23-25, 29-31, 63,

[5] VOSSLOH-SCHWABE, Energy-Efficient Street Lighting with VS Components

[6] http://www.echelon.com

Energy and the Climate Change

MAJA LAZARESKA Ministry of Agriculture, Forestry and Water Economy Republic of Macedonia [email protected] [email protected]

Abstract

Energy is the key issue present in the all sectors of economics. The availability of a cheap and safe energy sources is the main factor for sustainable development of the economy. The environmental aspects of energy consumption are very important but vulnerability of the energy system is increasing with the price shock in the energy sector. Risks of global climate change started to rise on the international political agendas, in particular climate change issues have come into force with the UN Framework Convention on Climate Change agreed on the “Earth Summit” in Rio de Janeiro (1992) and the ratification of the United Nations Framework Convention on Climate Change (UNFCCC) was in 1994. The commitments were adopted at the Third Conference of the Parties to the FCCC (COP-3) in Japan of the Kyoto Protocol in 1997. This protocol sets out legally binding quantified emission limitation and reduction commitments for the industrialized countries. The overall target amounts to a 5,2% reduction in emissions from 1990 levels, for a basket of greenhouses gases, by the commitment period 2008-2012. The European Union has agreed to ratify the Kyoto Protocol before the start of the World Summit on sustainable Development in Johannesburg, South Africa 2002, but the process will move without participation of the United States. The energy sector holds the key to meeting the targets of the Kyoto Protocol. It both emits a substantial share of greenhouse gases and has significant opportunities for substantial reductions of greenhouse gases. Energy sector plays key role in the emissions’ markets, investments in renewable energies and achieves substantial reductions on greenhouse gases. This paper will focus on the international process to combat climate change which is considered to be the greatest environmental challenge facing the world and the role of renewable sources of energy in allowing a more efficient use of the energy.

Key words: climate change, energy sector, Kyoto Protocol, greenhouse gases, renewable energy

Introduction

The world demand for energy is growing rapidly. It is expected to increase by 30% till 2010, and by nearly 60% by 2020. Demand for electricity is growing particularly strongly; it surpasses demands for any other energy end-use. The growth is though uneven: in developed countries (OECD) it is projected to grow by 1.6% annually, while in developing countries by 4.6%. Today, nearly 1.6 billion people in the world do not have access to modern, commercial energy services. Most of these people live in developing countries, many in rural areas or isolated communities. Energy poverty is a primary factor for their poor living conditions and low prospects, and renewable energy can help alleviate this situation. In developing countries with inadequate supplies of electricity, renewable energy can offer an alternative to expensive extensions of the grid to sparsely populated or rural areas, or a contribution to the grid-based energy mix to meet rapidly expanding electricity demand in urban areas. Other benefits include economic and social development, health benefits, and income generation for local communities, capacity building, local employment and expertise. In industrialised countries and economies in transition, with practically universal access to electricity, renewable energy is seen primarily as a means of reducing or avoiding GHG emissions and diversifying fuel mix. The investments required to address future energy demand as well as climate change are substantial. Significant scaling up of investment flows into the development and deployment of low-carbon energy technologies is urgently required in both developed and developing countries. Growing global concern about climate change since the 1980s led to the establishment of the Intergovernmental Panel on Climate Change (IPCC) in 1988, and made it a focal point of the Earth Summit in Rio de Janeiro in 1992, at which the United Nations Framework Convention on Climate Change (UN FCCC) was negotiated. The Convention committed all its 189 signatory governments to take actions to achieve “the stabilisation of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system”. The Kyoto Protocol of the UNFCCC, which has now been ratified by 149 governments and which came into force in February 2005, is a subsidiary treaty of that Convention, committing 23 countries (the co-called Annex 1 countries, which have ratified the Protocol) to specific emissions reductions by 2012 (a very short timeframe in terms of the investments needed). In addition, at the regional, national and even sub-national level, numerous climate change response initiatives are being launched. As emissions from the use of fossil fuels are seen as one of the contributory factors most amenable to corrective action, many of the policies and measures being implemented or considered are directed at the energy sector. Atmospheric and environmental pollution as a result of extensive fossil fuel exploitation in almost all human activities has led to some undesirable phenomena that have not been experienced before in known human history. They are varied and include global warming, the greenhouse effect, climate change, ozone layer depletion, and acid rain. Since 1970 it has been understood scientifically by experiments and research that these phenomena are closely related to fossil fuel uses because they emit greenhouse gases such as carbon dioxide (CO2) and methane (CH4) which hinder the long-wave terrestrial radiation from escaping into space and, consequently, the earth troposphere becomes warmer. The need to address climate change while facilitating continued economic growth and social progress is one of the key challenges facing world today. Energy is critical to continued 56 economic growth and according to the International Energy Agency (IEA) population growth and increasing industrialization will drive demand for energy upwards by more than 50% between now and 2030.1 The demand for energy will rise most rapidly in developing countries as they develop energy services to drive economic growth and social progress. The solutions lie in creating framework conditions with the right incentives to cause a large scale technological shift toward a lower carbon and more energy efficient economy that also delivers affordable energy solutions for the 2.4 billion people who are currently without basic energy services. This relies on scaling up investments into the development and deployment of lower carbon technologies, such as carbon capture and storage (CCS), renewables, as well as adapting behaviours and lifestyles to favour these technologies across the developed and developing world. Governments and business can work together to solve these challenges by aligning policies, promote investment in new technologies and energy services in developing countries, and contribute to overall sustainable development.

Renewable Energy Alternatives and Climate Change

Renewable energy is closely associated with the concept of sustainable development introduced to the broad public in the report “Our Common Future” published in 1987 by the World Commission on Environment and Development chaired by Gro-Harlem Brundtland. The concept is defined in the report as: “Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Renewable is a term used for forms of energy which are not exhausted by use over time. It means that the renewable resources can be regenerated or renewed in a relatively short time. The sources of renewable energy can be divided, according to their origin, into natural renewable resources (wind, geothermal, solar, hydro, etc.) and renewable resources resulting from human activity (biomass, including landfill gas, industrial heat recovery power). By definition, renewables should provide a continuous and unlimited supply of energy. Renewable energy sources are expected to become economically competitive as their costs already have fallen significantly compared with conventional energy sources. New renewable energy sources offer huge benefits to developing countries, especially in the provision of energy services to the people who currently lack them. The advantages of renewable energy are that they are sustainable, ubiquitous (found everywhere across the world in contrast to fossil fuels and minerals), and essentially clean and environmentally friendly. The disadvantages of renewable energy are its variability, low density, and generally higher initial cost. For different forms of renewable energy, other disadvantages or perceived problems are pollution, odor from biomass, avian with wind plants, and brine from geothermal. The world energy demand depends, mainly, on fossil fuels with respective shares of petroleum, coal, and natural gas at 38%, 30%, and 20%, respectively. The remaining 12% is filled by the

1 IEA. World Energy Outlook. 2006. 57 non-conventional energy alternatives of hydropower (7%) and nuclear energy (5%) (Zekai Sen, 2008). It is expected that the world oil and natural gas reserves will last for several decades, but the coal reserves will sustain the energy requirements for a few centuries. This means that the fossil fuel amount is currently limited and even though new reserves might be found in the future, they will still remain limited and the rate of energy demand increase in the world will require exploitation of other renewable alternatives at ever increasing rates. Fossil fuels are not available in every country because they are unevenly distributed over the world, but renewable energies, and especially solar radiation, are more evenly distributed and, consequently, each country will do its best to research and develop their own national energy harvest. Fossil fuel combustion leads to some undesirable effects such as atmospheric pollution because of the CO2 emissions and environmental problems including air pollution, acid rain, greenhouse effect, climate changes, oil spills, etc. Renewable energy and especially solar irradiation are effective energy technologies that are ready for global deployment today on a scale that can help tackle climate change problems. Solar energy is the most ancient source and the root for almost all fossil and renewable types. Solar energy comes at the top of the list due to its abundance and more even distribution in nature than other types of renewable energy such as wind, geothermal, hydropower, biomass, wave, and tidal energy sources. Renewable energy sources could be significant in many sectors – not just electricity, but also heating and potentially in transport.

Solar Energy

The interest in solar energy utilization has taken place since 1970, principally due to the then rising cost of energy from conventional sources. Solar radiation is the worlds most abundant and permanent energy source. The amount of solar radiation intercepted by the Earth is much higher than annual global energy use. Large-scale availability of solar energy depends on a region’s geographic position, typical weather conditions, and land availability. Solar electricity is produced from sunlight shining on photovoltaic solar panels. Solar heating systems are far more efficient than solar electricity, requiring far smaller panels to generate the same amount of energy. Solar electricity is often referred to as photovoltaic solar. This describes the way that electricity is generated in a solar panel. The design of many technical apparatuses such as coolers, heaters, and solar energy electricity generators in the form of photovoltaic cells, requires terrestrial irradiation data at the study area. Scientific and technological studies in the last three decades tried to convert the continuity of solar energy into sustainability for the human comfort. Solar energy is referred to as renewable and/or sustainable energy because it will be available as long as the sun continues to shine. Wind Energy

It is one of the most significant and rapidly developing renewable energy sources all over the world. Recent technological developments have reduced wind energy costs to economically attractive levels, and consequently, wind energy farms are being considered as an alternative energy source. Wind energy is the most difficult renewable recourse to capture. The wind, driven by natural cycles, originating from the sun, is an abundant and renewable resource. Wind resources can be exploited mainly in areas where wind power density is at least 400 W/m2 at 30 meters above the ground, and therefore selection of sites for wind energy projects depends on accurate meteorological measurements, wind energy maps, site measurements, etc. Even on the best sites, the wind does not blow continuously and can never achieve the 100% load factor. In most systems, wind would be able to attain some 23-28% factor. In recent decades the significance of wind energy has originated from its friendly behavior to the environment so far as air pollution is concerned, although there is, to some extent, noise and appearance pollution from the modern wind farms. Wind power is now a reliable and established technology which is able to produce electricity at costs competitive with coal and nuclear power.

Geothermal energy

Geothermal energy is generally defined as heat coming from the Earth. It has large theoretical potential but only a much smaller amount can be classified as resources and reserves. But like other renewable resources, geothermal energy is widely dispersed. Geothermal use is commonly divided into two categories: electricity production and direct application. The technology to use geothermal energy is relatively mature. The conversion efficiency of geothermal power plants is rather low, about 5 to 20 percent.

Hydropower Energy

Hydropower is the world’s largest source of renewable energy used for power generation. Hydropower today accounts for about one fifth of the world’s electricity production (some 2,700 TWh), with more than 720 GW installed capacity worldwide.2 Hydropower is an already established technological way of renewable energy generation. In the industrial and surface water rich countries, the full-scale development of hydroelectric energy generation by turbines at large-scale dams is already exploited to the full limit, and consequently, smaller hydro systems are of interest in order to gain access to the marginal resources. Wilbanks et al. (2007) stated that hydropower generation is likely to be impacted because it is sensitive to the amount, timing, and geographical pattern of precipitation as well as temperature (rain or snow, timing of melting).

2 Source World Energy Council 59

In regions, where hydropower potentials are still available, and also depending on the current and future water balance, this would increase the competition for water, especially if irrigation might be a feasible strategy to cope with climate change impacts on agriculture and the demand for cooling water by the power sector is also significant. Hydropower leads to the key area of mitigation, energy sources and supply, and energy use in various economic sectors beyond land use, agriculture, and forestry.

Biomass Energy

Biomass can be classified as plant, animal manure or municipal solid waste. Forestry plantations, natural forests, woodlands and forestry waste provide most woody biomass, while most non- woody biomass and processed waste comes from agricultural residues and agro-industrial activities. Overall 14% of the world’s energy comes from biomass, primarily wood and charcoal, but also crop residue and even animal dung for cooking and some heating. Especially, in developing countries biomass is the major component of the national energy supply. Although biomass sources are widely available, they have low conversion efficiencies. A large variety of raw materials and treatment procedures make the use of biomass a complex system that offers a lot of options. Biomass energy conversion technologies can produce heat, electricity and fuels (solid, liquid and gas). Fuels from biomass are most often proposed as substitutes for fossil fuels, in order to meet present and future shortages. It should be noted that biomass energy is not used primarily for electricity generation. Direct use for heating and bio-fuels for transportation is widely spread, mostly in developing countries. The potential of biomass is very large, and some forecasts up to 2025 envisage approximately 2.6 3 GTep based on biogas energy. Increasing use of biomass should however be carefully balanced with the risks of deforestation. Also, many of the raw materials used to produce renewable diesel are edible, or compete with arable land used to grow food. This creates potential conflicts over the use of biomass for food or for fuel.

Renewable and Climate change policies

Concerns about environment, the perceived dangers to humanity from the uncontrolled increase of greenhouse gas (GHG) emissions, have focused international efforts on the promotion of clean, environmentally friendly policies, which almost without exception also promote renewables. During the last 10-15 years, the growing understanding of the importance of renewable energy and its role in sustainable energy development, in diversification of energy supplies and in curbing of global warming led the decision makers in the developed countries to introducing various incentives and policies to promote renewable energy.

3 www.worldenergy.org 60

International GHG Emissions Trading and Renewables projects

The World Energy Council clearly recognizes the importance of the Climate and states: “Climate change is a serious global concern, calling for changes in consumer behavior, but offering potential win-win opportunities. These include increased transfer of efficient technologies from industrialized to developing countries and incentives to investment through emerging voluntary and regulated emissions trading and other mechanism”.

In order to comply with emission reduction targets, there are three separate market mechanisms for managing GHG Emissions:

• Quantified Emissions Limitation and Reduction Obligation Trading (QUELRO) which allows trading in assigned amounts of GHG emissions among emissions-capped Annex I countries (developed countries and economies in transition). • Joint Implementation (JI) – emission trading implemented between two Annex I countries which allows the creation, acquisition and transfer of “emission reduction units” (ERUs). • Clean Development Mechanism (CDM) – applicable in developing countries, by allowing the developed countries projects there to generate “certified emission reductions” (CERs).

Several emissions trade schemes are designed to boost renewable energies in developing countries. The Clean Development Mechanism (CDM) can be used to promote renewable projects in developing countries to off-set emission reduction commitments under the Kyoto protocol in developed countries which by investing in developing countries can earn credits. The potential market for GHC emissions could be huge. A study by Deutsche Bank suggests that the GHG emission trading is going to be the biggest market of the century. The study estimates its value at US $100 billion annually. The market will boost clean energy, including renewable energy projects, and will generate movement of funds for environmentally friendly projects from the developed world to developing countries. The environmental benefits of using renewable energy support global efforts to decrease greenhouse gas (GHG) emissions and also have a positive influence on world environment and on public health.

Conclusion

Production of renewable energy, particularly biomass, can provide economic development and employment opportunities, especially in rural areas. Renewable energy can thus help reduce poverty in rural areas and reduce pressures for urban migration. Growing biomass for energy on degraded lands can provide the incentives and financing need to restore lands rendered nearly useless by previous agricultural or forestry practices. Although lands farmed for energy would not be restored to their original condition, the recovery of these lands for biomass plantations would support rural development, prevent erosion, and provide better habitat for wildlife. Renewable energy technologies, such as methanol or hydrogen for fuel cell vehicles, produced virtually none of the emissions associated with urban air pollution. Renewable energy use does not produce carbon dioxide and other greenhouse emissions that contribute to global warming. The carbon dioxide released when biomass is burned equals the amount absorbed from the atmosphere by plants as they are grown for biomass fuel. Energy importers are able to choose from among more producers and fuel types and this is less vulnerable to monopoly price manipulation or unexpected disruptions of supplies. The growth in world energy trade would provide new opportunities for energy suppliers. Finally, new renewable energy sources offer huge benefits to developing countries, especially in the provision of energy services to the people who currently lack them.

References:

[1] Energy and Climate Change, World Energy Council, 2007

[2] IEA, World Energy Outlook, 2006

[3] Investing in a Low-Carbon Energy Future in the Developing World, World Business Council for Sustainable Development, 2007

[4] Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, Working Group III, 2007

[5] JOHANSSON, T.B., KELLY, H., REDDY, A.K.N. & WILLIAMS, R.H. (eds.). 1993. Renewable energy: Sources of Fuels and Electricity. Washington, DC: Island Press

[6] Renewable energy projects, Handbook, World Energy Council, 2003

[7] The Economics of Climate Change, Stern Review, 2006

[8] WILBANKS TJ, ROMERO LANKAO P, BAO M, BERKHOUT F, CAIRNCROSS S, CERON J-P, KAPSHE M, MUIR- WOOD R, ZAPATA-MARTI R (2007) Industry, settlement and society. In: PARRY ML, CANZIANI OF, PALUTIKOF JP, VAN DER LINDEN PJ, HANSON CE (eds) Climate change 2007: impacts, adaptation and vulnerability. Cambridge University Press, Cambridge, UK, pp 357–390

[9] ZEKAI SEN, Solar Energy Fundamentals and Modeling Techniques - Atmosphere, Environment, Climate Change and Renewable Energy, Springer, London, 2008

[10] www.worldenergy.org

Storage of Energy

NIKOLA PETKOVSKI

Faculty of Electrical Engineering and Information Technologies Rugjer Boshkovik bb, PO Box 574, 1000 Skopje Republic of Macedonia [email protected]

Abstract

Renewable energy sources such as the solar and the wind energy are time dependent energy sources, their periods of availability varying widely with time. Our energy demands usually do not match these periods, which imposes the need of establishing a form of energy storage, to enable a more efficient exploitation of the renewable energy sources and to meet our energy demands. This paper presents a layout of conventional and modern technologies for storing energy.

Key words: Renewable, energy, storage of energy.

Introduction Energy can be stored in the form of heat, such as the sensible heat of a material, or in the form of a latent heat of a material that can undergo a phase change within a suitable temperature range. In addition, heat can be stored in the chemical bonds of materials that release or take heat by

64 taking part in a chemical reaction. The energy can further be stored in a battery, in the form of electrochemical energy, which is a more ordered form of energy than the heat, and it can be converted in other forms of energy with higher efficiency. Other forms of energy storage include storage of mechanical (kinetic) energy in a rotating flywheel, energy storage in a compressed air and storage of energy in hydrogen, which is often generated by way of electrolysis and is used as a clean green fuel. A more exotic way of storing energy is in the magnetic field of a superconductor. All of the above mentioned ways for storing energy have both their advantages and faults. The price of the storage system is often the greatest disadvantage.

1. Heat energy storage 1.1 Water medium storage The water has proved to be a perfect medium for storing the useful heat. The advantage thereof lies in the fact that the heat energy may be added to and retrieved from the water medium, in addition to the fact that the water contemporaneously serves for transporting the heat, thus avoiding temperature drop, i.e. the losses registered during the transfer of the energy from the carrying medium to the energy storage medium. A system of forced circulation of water (see Fig. 1), in addition to the system implying normal circulation may be used as well.1

Fig. 1. Layout of a system wherein the water is used as a solar heat energy storage medium.

The formula presented below shows the capacity of storing energy into the water: = ( ) wherein denotes the heat capacity for a specific temperature change , denotes the 푄푠 푚퐶푝 푠∆푇푠 water mass being heated and cooled, and denotes the specific heat capacity of the water. 푄푠 ∆푇푠 푚 Regarding water storage absent stratification, i.e. implying a complete blending of the water in 퐶푝 the store absent any separation to levels per different temperature of the water (see Fig. 2), the law for energy conservation specifies the following equation:

( ) = ( ) ( ) 푑푇푠 wherein and denote the푚 퐶received푝 푠 and푄푢 the− 퐿 푠released− 푈퐴 푠energy,푇푠 − 푇푎 from the collector and to the consumer, accordingly, per unit of time푑푡 (power), whereas denotes the ambient temperature 푢 푠 of the water푄 storage,퐿 i.e. entirely including the final article of the equation it shows the energy 푎 flow directly into the surrounding area of the storage (losses).푇 The operation of the system within a prolonged period will be perceived by way of integration over time of the above equation.1

Fig. 2. Non-stratified storage operating at temperature Ts, under the ambient temperature Ta.

1.2 Packed bed storage The packed bed (gravel) storage or optionally another fine granulate material possessing high specific heat capacity, non compacted, i.e. loosely placed in a specific storage is often used for storing the heat energy. A fluid, usually air, is used to add and extract heat from the storage. Such system is shown schematically in Fig. 3.

Fig. 3. A packed bed storage unit.

The storage consists of a container, a wire grating to hold the material, a grating support and an inlet and outlet aperture. During operation, the flow goes in one direction when the heat is being added into, and in the opposite direction when the heat is being extracted therefrom. It should be noted that contemporaneous action of adding and extracting heat could not be effected, as opposed to the water storages wherein such actions are possible1. A good storage preferably implies the following characteristics: high coefficient of heat transfer between the air and the solid substance, cheap container and material suitable for storing heat, low heat exchange when there is no air flow and low pressure variation through the storage. The high degree of stratification is the major feature of the storage1 (see Fig. 4).

Fig. 4. Temperature distributions in a pebble bed while charging with inlet air at constant temperature. The differential equations for the temperature of the fluid (air) and the granulate substance read as follows: ( ) ( ) = + ( ) 휕푇푓 푚퐶푃 푓 휕푇푓 휌퐶푃 푓휀 − ℎ푉 푇푏 − 푇푓 ( 휕푡) (1 ) 퐴 = 휕푥 ( ) 휕푇푏 wherein denotes the void fraction휌퐶푃 of푏 the− storage,휀 andℎ푉 푇푓 −denotes푇푏 the volumetric coefficient of the heat transfer between the granulate and the휕푡 fluid (the usual coefficient of heat transfer per 푉 unit area휀 multiplied with the area of granulate per unit volume).ℎ These equations shall be solved by use of complex numerical methods presented by Highes in 1975.

1.3 Storing heat energy by way of phase change of the substance Substances subjected to phase change within a specific temperature range are convenient for storing energy purposes. The phase change shall be followed with a high latent heat that the substance emits, i.e. receives. In addition the phase change process shall be a reversible type process that may be repeated in a large number of cycles causing no decomposition of the substance. It is necessary to provide storage compatible for storing the substance and a convenient way for extracting and adding heat. Ultimately, one shall also consider the price of the material, as well. Once the above requirements have been met, the heat storage systems based on the phase change may operate within a very narrow temperature range, and are characterized with a relatively small volume and mass, as well as a great storing capacity (relative to the other types of heat energy storages). The heat storing capacity of the substance undergoing a phase change at the temperature , which ranges between the temperature and , is equal to the sum of the sensible heat transferred∗ to the solid substance, in order to have it warmed to the 1 2 temperature up to the te푇mperature (where the phase change occurs푇 unto),푇 then the latent heat of the phase transition of the substance∗ and the sensible heat being conveyed to the next 1 phase of the 푇substance to warm it up to푇 the temperature . The relevant expression will have the following presentation: 2 = [ ( ) + + 푇( )] ∗ ∗ 푄푆 푚 퐶푆푂 푇 − 푇1 휆 퐶퐿퐼 푇2 − 푇 67 wherein m denotes the mass of the substance, and denote the specific capacities of the solid and the liquid phase of the substance, respectively, and denotes the latent heat of the 푆푂 퐿퐼 phase transition per unit mass. 퐶 퐶 휆 1.4 Chemical storage of heat The chemical storage of heat is based on the use of compounds that release and receive heat during a chemical reaction. It should be mentioned that no practical utilization of such compounds has been effected so far whatsoever.1 The compounds convenient for such thermo- chemical reactions include, for instance, the ones that will be decomposed to their products during an endothermic chemical reaction. The products resulting from such reaction shall be readily separable and shall be kept in separate storages. Certainly, in order to provide for the restoration of the input energy, one shall ensure the reaction is reversible, to ensure recovering of the starting compound by way of an exothermic reaction. The schematic view of these reactions is presented as follows: + heat + Unfortunately, compounds to act as serious candidates for such reaction at temperatures that may be provided from the solar processes퐴퐵 have n↔ot퐴 been퐵 discovered, yet. Compounds entering into such type of thermo-chemical reaction include, for instance, the metal oxides of some compounds. The advantage of this type of reactions reflects in the fact that the oxygen generated during the reaction, may be used for other purposes, whereas the reverse reaction may be performed by use of the oxygen taken from the atmosphere1. An example of such reverse reaction is the decomposition of the potassium oxide: 4 2 + 3 The above reaction occurs at temperatures between 300°C and 800°C, producing heat of 2.1 퐾푂2 퐾2푂 푂2 MJ/kg during the decomposition thereof.

2. Storing of electricity The electricity is a highly ordered form of energy and this feature makes it useful for various purposes. The electricity may be transformed into heat or mechanical energy at almost 100% efficiency. The heat on the other hand, is a disordered form of energy in atoms and therefore, it is transferred into electricity with lower efficiency. Accordingly, the efficiency of a conventional thermal electric plant combusting a fossil fuel is less than 50%. The disadvantage of the electricity is seen in the fact that it can not be readily stored in large quantities.

2.1 Storing into a battery The battery enables storing the electricity in an electrochemical form and it is often used for various applications. The electrochemical energy exists in a semi-ordered form between the electrical and the thermal form of stored energy. The one-way conversion efficiency varies between 85% and 90%. There are two types of electrochemical batteries - primary battery and secondary battery. The electrochemical reaction occurring in the primary battery is an irreversible reaction and the battery is disposed once it has been entirely discharged. This type of battery is used when a single application of high power density is required. The secondary battery is also known as a rechargeable battery. The electrochemical reaction occurring in the secondary battery is a reversible reaction. Once it has been discharged, it may be recharged by way of injecting a direct current from an external source. This type of battery converts the chemical energy into

68 electricity during discharge. When it is being loaded, it converts the electricity into a chemical energy. In both modes of operation, one portion of the energy is converted into a heat. The efficiency of one cycle of loading and discharge varies between 70% and 80%. The battery comprises positive and negative electrodes in the form of plates, in addition to the distance isolators including a chemical electrolyte therebetween. The two groups of electrodes are connected to the two external terminals fixed on the battery housing. The cell stores electrochemical energy of low electric potential of few volts. The capacity of the cell is marked C, and it is expressed in terms of Ampere-hours. The internal construction of a typical electrochemical cell is shown in Fig. 5.

Fig. 5. Internal structure of a typical electrochemical cell.

There are few types of rechargeable batteries, including lead-acid (Pb-acid), nickel-cadmium (NiCd), nickel-metal hydride (NiMH), lithium-ionic (Li-ion), lithium-polymeric (Li-poly), zinc-air etc. All of them differ by their storing capacity and by their price. The energy densities of various batteries, as measured by the Wh capacity per unit mass and unit volume, are compared in Fig. 6.

Fig. 6. Specific energy and energy density of various electrochemistries.

Despite its lowest capacity per unite volume and unit weight, the lead-acid battery is the most commonly used battery of the reload types of battery, due to its lower price in comparison with the other types of batteries.2

2.2 Storing in a superconductor

The energy E that is stored in a coil conducting the current I, is presented as follows:

= (J/m3) or = (J) 2 1 퐵 1 2 퐸 2 μ 퐸 2 퐼 퐿 wherein: B denotes the density of the magnetic field generated coil (T) -7 (H/m) L denotes the inductivity of the coil (H) μ denotes the magnetic permeability of the air, 4 π 10 The coil shall have a current flowing there through, in order to generate the required magnetic field. The current needs a voltage, applied to the coil ends. The relation between the current flowing through the coil I and the voltage V is presented as follows:

= + 푑퐼 푉 푅퐼 퐿 wherein R and L denote the resistance and the inductivity푑푡 of the coil, respectively. A stable storage of energy may be achieved, provided the second article in the above equation is zero. Then, the voltage required for the flow of current is simply V = RI.

The resistance of the coil is subject to the temperature. In most of the conductive materials, the resistance grows with the rising of the temperature. If the temperature falls, the resistance declines, too. In certain substances, the resistance declines abruptly down to zero, at a certain

Fig. 7. Resistance vs. temperature with abrupt loss of resistance at the critical superconducting temperature.

critical temperature. In Fig. 7, this point is marked with TC. Below this temperature, no voltage is required to enable the flow of current in the coil, therefore, the ends of the coil may be joined together. The current will continue to flow within the short-circuited coil for an indefinite time, and the relevant energy will remain stored for an indefinite time. They say the coil has reached a superconductive condition - a condition having zero resistance. In that case, the energy in the core will be "frozen". Although the superconductive phenomenon has been discovered few decades ago, the industrial interest for practical applicability thereof has commenced in the early 1970-ies. During the 1980-ies, the Administration of current in Bonneville, Portland, constructed a system for superconductive storage of energy connected to a network. In the course of one million cycles of loading and discharging, the system demonstrated satisfactory electrical, magnetic and structural features.2 Conceptual designs have also been developed regarding the large superconductive systems for storing energy up to 5000 MWh for general application.

As far as the superconductive system for storing energy is concerned, the main expenditures relate to maintenance of the coil at temperature that is below the critical superconductive temperature. The efficiency of the entire cycle of loading and discharging is very high (95%).

3. Storing mechanical energy in a flywheel The flywheel enables storing kinetic energy within the rotating mass thereof (occurrence of inertia). Such energy may be converted from and to electricity with high efficiency rate. This manner of storing energy is an old idea, which has now become commercially applicable due to the improvements in the manufacture of composite rotors of high strength and low weight. The efficiency of the conversion within one cycle in the system of large flywheel may reach up to 90%, which is a much higher rate than it is the case with the battery. The storage of energy in the flywheel is limited due to the mechanical stress induced by the great centrifugal forces at high speed. The aim of the future development of the flywheel is to provide five-fold greater density of the stored energy relative to the one with the batteries.

The energy stored in the flywheel having a moment of inertia J and rotating at an angular speed

ω is presented as follows: 1 = 2 2 퐸 퐽휔 A good system incorporating flywheel consists of composite fiber-epoxy rotor, supported with magnetic bearings, rotating under vacuum conditions, and being mechanically connected with an electrical machine operating as an engine or a generator. In the flywheel system configuration, the rotor can be located radially outward, as shown in Fig. 8. It forms a volume- efficient packaging.2

Fig. 8. Flywheel configuration with rotor outside enclosing the motor generator and the bearing.

Flywheels comprising composite rotors have already been produced and tested and they may endure more than 10.000 cycles of complete loading and discharge. This is one order of magnitude higher than any battery known today could support.

4. Storing energy within a compressed air

The compressed air stores the energy by way of pressure variation. It may store the excess of energy of one electric power plant - thermal, nuclear, wind operated or photovoltaic - and to release it as necessary, for instance, in case of greater demand. The system for storing energy within a compressed air consists of the following:

- Air compressor; - Expansion turbine; - Electric motor - generator; - Storing reservoir (cistern) or buried pit.

Assuming P and V denote the air pressure and the volume, respectively, and assuming the n compression of the air from P1 to P2 complies with the gas law PV = constant, then the work required to achieve such compression shall be the energy stored within the compressed air. It is presented as follows: ( ) Energy stored = 2 2 1 1 1 푛 푃 푉 − 푃 푉 The temperature upon completion of the compression 푛is− presented as follows:

= ( ) 푛−1 2 2 푇 푃 푛

푇1 푃1 The value of n under normal conditions is about 1.3.2 When the air having higher temperature upon compression under a constant volume has been cooled, one portion of the pressure is lost, accompanied with a proportionate reduction of the stored energy.

Electricity is generated by way of releasing the compressed air through the expansion turbine driving the generator. The compressed air system may operate under a constant volume or at a constant pressure. Regarding the compression under a constant volume, the compressed air is stored in a cistern under pressure, a pit, an exhausted oil or gas field or in abandoned mines. Such systems possess a large capacity for storing energy. Nevertheless, they do have a disadvantage, too. The air pressure is reduced with the consumption of the compressed air from the storage and the power of the electricity is decreased with the reduction of the air pressure. Regarding the compression under constant pressure, the air storage may be affected in a ground situated cistern of variable volume, or in an underground cavity filled with water. The cistern of variable pressure shall maintain a constant air pressure by the application of the weight over the enclosure of the cistern. If a buried pool is used, the pressure shall remain approximately constant, whereas the storing capacity shall be increased due to the movement of the water through the surrounding rocks. During the generation of electricity, the pressure and thereby the power are approximately constant.

The costs for such system shall also include the cooling of the compressed air. The total energetic efficiency of such system within the entire cycle has been estimated to about 50%. Compressed air electric power plants of 300 MW capacity, have already been constructed in Israel, Maroco and other countries. Two power plants of 150 MW - one in Germany and the other one in Alabama, have been operating for more than ten years.2 A Houston-based company, CAES, has proposed the use of abandoned limestone mines in Norton, OH (see Fig. 9). The 10-million- m3 mines can store enough compressed air to drive 2700 MW capacity turbines.

Fig. 9. System for storing energy within a compressed air, scheduled for construction in Ohio. The air would be compressed during off-peak evening hours and released to drive power-generating turbines during peak daytime hours. The power plant will be built in units brought on line in increments of 300 megawatts as units are completed. Ultimately up to about 2,700 megawatts will be built, which will be enough generating capacity for about one million homes.3

5. Storing hydrogen

The discrepancies between the supply and demand for energy may be controlled by storing hydrogen and fetching it for consumption at a time when it will be required as an energy source. The hydrogen may be stored in large quantities under the ground in cavities filled with water, in the exhausted oil fields or natural gas reservoirs, as well as in artificial pits created as a result of mining. The latter method is mostly practiced in some countries. The hydrogen may be conveyed to the locations of its consumption in the form of gas through buried penstocks, whereas in the liquid form it may be conveyed by supertankers. The hydrogen may be stored in fixed or mobile storing systems at the location of consumption, subject to the manner of utilization thereof. It may be stored in the form of pressurized gas, in a liquid form, or taking advantage of some of its unique physical and chemical properties - in the form of metal hydrides and in activated coal. The hydrogen may be used as a substitute for the fossil fuels practically for any purpose - as a fuel for generating heat and production of electricity in combusting cells, or indirectly, by the use of steam operating generators.

The hydrogen may be converted in electricity by electrochemical route, in fuel cells with high efficiency. The Tokyo Electric Utility has been making experiments using a combusting cell of 4.5 MW, product of United Technologies, for several years already. Now they have connected an additional cell of 11 MW.4

The hydrogen based power system has the potentiality to meet the major energy challenges of to-day: decrease the dependence on the oil import and decrease the pollution and the emission of gases causing the greenhouse effect.

Conclusion

This paper presents few methods for storing energy. They all have their advantages and disadvantages, which makes impossible to tell the "best" way for storing energy. The costs for the implementation of a specific storing system often have the decisive role in the ultimate selection. For instance, the electricity is most often stored using lead-acid batteries which despite their lower specific energy and energy density as opposed to other types of batteries are preferably used due to their lower price. On the other hand, regarding the compressed air storing method, the costs for storing are subject to the selection of the storing location. For instance, the possibility for free utilization of abandoned mines significantly reduces the costs for storing. Some other methods for storing energy, such as the chemical storage of heat and the superconducting storage, will have to sustain further improvement of specific materials, regarding the temperature range at which they operate. The hydrogen is often considered the future of energy storing, due to its characteristic of being the cleanest fuel, being non-toxic with virtually no environmental problems during its production, storage, and transportation. Yet, it necessitates further technological improvements in the area of production and utilization as a source of energy.

References [1] John A. Duffie, William A. Beckman.: Solar engineering of thermal processes. United States of America.: John Wiley & Sons, Inc., 1991. ISBN 0-471-51056-4

[2] Mukund R. Patel.: Wind and Solar Power Systems. United States of America.: CRC Press Taylor & Francis Group, 2006. ISBN 978-0-8493-1570-1

[3] Sandia National Laboratories.: News releases: Solution to some of country’s energy woes might be little more than hot air. [online]. http://www.sandia.gov/media/NewsRel/NR2001/norton.htm

[4] Zekai ¸Sen.: Solar Energy Fundamentals and Modeling Techniques. London .: Springer-Verlag London Limited, 2008. ISBN 978-1-84800-133-6

Geothermal Energy as Source for Heating in Kosovo

Pellumb GJINOLLI Environmental Engineering BSc [email protected] MSc cand. Renewable Energy in Central and Eastern Europe

Presented in

Implementing Energy Efficiency through Renewable Energy Solutions - are Southeast European Countries on track? - Positive examples, barriers to overcome, proposed measures and policies

Abstract

Kosovo traditionally used coal or wood as heating sources because it has a large basin of brown coal, naturally good heating source for the population of which 50% is unemployed. Although fossil sources seem economically feasible in short-term, they definitely are not in long term, apart from that they are not environmentally friendly since by burning it, a lot of harmful emissions are released. Alternative heating sources recently started to be applied in Kosovo, the last project that has involved alternative heating source is a location near Pristina a community called “International Village” and this source was geothermal heating application. Reasons why this project is done in this location at first might look like coincidence because firstly the digging was done for sanitary water and it was realized that water that is taken form there in 203 m was 23 °C and was according to standards of geothermal heating. This project has involved a lot of specialists from Germany, Croatia and Kosovo. The equipments used for drilling and boilers were mainly from Germany. After several tests and discussions with German specialists it was decided to start with this project, which is still going on, the sample house however was heated successfully. There are 110 houses and for these houses it is planned that 140 km of sonde pipe will be used.

Key words: geothermal energy, pilot project, advantages, disadvantages.

Acknowledgment:

In completing this project I had the honour to work with specialist Ing. Dipl. Xhavit Krasiniqi who always found a portion of his valuable time, to provide me with information about the project and geothermal energy in general. So I would like to thank him again for his patience and help. I was provided with help also from “Mega-Term” company who was directly involved in this project and International Village officials who I would like to thank once again, because without their information, to complete this project would have been much harder.

Introduction

What is geothermal energy?

When translated from Greek, word geothermal means earth heat. The earth’s core is extremely hot, mainly as a result of the decay of radioactive materials with half lives measured in millions or billions of years. On the average, the temperature increases by about 28 °C for every kilometre, while in some locations temperature rises faster or slower according to earth’s formation. With today’s technology you can go as deep as you want with drilling where you can reach rocks that can boil water and get steam, and that is the key for geothermal energy generation. The best locations for this energy generation are volcanic regions, but can we say that the places that are not in this type of regions cannot generate this type of heat? Of course there are always exceptions to the rule. So by this we can say that geothermal energy can be generated from everywhere, but the main thing that we should look for is the earth’s thermal flux, which can vary according to earth’s formation whether it is: Dry Clay, Wet land, Granite-Rocky or Granite-Marble. I will speak about this in upcoming chapters. Geothermal energy is applied for a long time and best places in Europe for generation are: Iceland, Hungary, Turkey etc. As of 2004, approximately 70 countries made direct use of a total of 270 PJ of geothermal heat in 2004. More than half of this energy went for space heating, and another for third heated pools. The remainder supported industrial and agricultural applications [1]. The project that I am going to talk about has to do not with geothermal energy production but geothermal heat generation for domestic use that is going to be applied to 110 houses of different size in a community called “International Village”.

Why Geothermal Energy?

Apart from being economical in long-term usage, geothermal energy enters the renewable energy category, because no harm is caused to environment as long as excessive water is not pumped into the earth in one location in too short time[2]. Therefore in these days where Global Warming is being discussed and where country officials are seeking for solution to it, using geothermal energy might be a part of this problem’s solution.

1. Alternative Energy in Kosovo.

Since past times Kosovo used coal as source of heating and energy. Now being independent country and preparing to be part of EU community Kosovo should consider its energy policy toward energy efficiency measures and the increase in use of renewable energy. Ministry of Energy and Mining has taken several steps, like measuring solar radiation in specific zones of Kosovo, also measuring wind speed and looking for more hydro-power projects and also recently starting with energy efficiency awareness raising campaigns.

Apart from that Kosovo has two small hydro power plants which can be considered the only project regarding renewable energy that was done from country officials. Historically Kosovo used coal as primary energy source, since it lies in very large basin of brown coal and we may say that there are the largest reserves of coal in region. There are some private projects about renewable energy sources like solar-thermal, wind energy and lately the geothermal heating application that I am going to talk about.

2. Project Description.

2.1 Project development.

Location where this project is being implemented is 2 km away form Pristina, capital city of Kosovo.

Fig. 1 Location’s map

This community consists of 110 houses which are classified according to their area; there are three types of houses A, B, C type houses. Main reason for implementing geothermal heating to this part of the city is because there were some drills done for supply of sanitary water, but the water that came out form there in depth of 203 m was 23 °C and contained minerals.

At that location temperatures of water were conform standards which means in every 10 m depth there is rise of 1 °C. As we all know, for usage of geothermal energy one of the most important parameters is its thermal flux, and in this area the thermal flux was 45 watt/m (depth) and the result is still the same after one year. It is important for geothermal project appliers that parameters required for usage to be in harmony with parameters that earth will supply. There should be a pause given to the source for regeneration of thermal flux.

Fig. 2 Scheme of geothermal heating system (pictures from Mega-Term)

Technical parameters for heating system temperature (T in entrance and T in return) should be suitable with fluid’s temperature in sonde (T in entrance and T in return). In this project there were 3 different drills done: 1) 130 m deep (130 x 45 watt) with 8 kW pumps 2) 2x110 m deep (220 x 45 w) with 10 kW pumps 3) 2x100 m deep (200 x 45 w) with 14 kW pumps There were 140 km of polyetilen 100 SDR 11 type of sonde pipe used for 110 houses, for 1 house approximately there was 2 sondes and 100 m x pipes used.

Fig. 3 During drilling

Fig. 4 Preparation of sonde before installation in a house

The realization of geothermal heating system for one house, approximately lasts 6-7 days, where: 3 days for drilling, 1 day for preparation of equipments and 2-3 days for preparation of the heating system. Method used in this project is to provide heating from the floor. Not only during the winter but also during the summer this system is designed to provide cooling till 19°C thanks to the reverse cycle in the earth. Once again to have effective heating/cooling of the building we need to have a well-isolated building which will prevent loss of heat/cool in respective seasons.

Fig. 5 Scheme of the system (pictures from Mega-Term)

Generally this system has high efficiency where: from 1 kWh of spent electricity, 4 kW heat or cooling is produced which means that the system is 75% energy efficient, economical analysis will be shown in later chapter. If we were to mention about some facts related to the system, I would probably mention that during February 2009, when outside temp. was registered -21°C, thermal pump managed to generate 3.9 MW energy from the ground during that month.

Fig. 6 A finished system with pump and boiler

In the above picture there is a finished system shown, where you can see both pump and boiler from a famous European producer Vaillant.

3. Economical Analysis.

Since geothermal energy is a renewable energy source, apart form being highly efficient and environmental friendly it also has some disadvantages since the initial investment is high and usually the return is between 6-10 years. Like in any other project, for this project also there was economical analysis conducted. After discussions with specialists form Europe more particularly from Germany and Switzerland it is observed that implementation of geothermal heating system in Kosovo might be done with half of the price that is done in EU. So, in Europe price for applying this type of heat is approx. 135 €/m2, while in Kosovo it was done with 65 €/m2. Average cost for thermal pump without any drill, sonde or other equipments is from 8.800- 10.700€. Below you may find some economical analyses that were done to show if this project is feasible:

Table 1. Total installed energy and type of the houses

In the above table three types of houses and their total energy including alternative energy consumption are shown, in the third column it is shown the energy that we get from earth, in fourth energy from electricity and in fifth, total energy.

Table 2. Heating with geothermal system and type of the houses

In the second table total costs for three types of houses are shown, where in the third column it is shown the energy that we get from earth, in fourth energy from electricity, fifth column shows the price of electricity for households and respectively according to those prices the daily cost for heating up these houses.

Note: Type A house is of 419 m2, B is of 325 m2 and C is 261 m2

4. Advantages & Disadvantages of Geothermal Energy.

Like in every project there are pro’s and con’s, but to take the decision to do or not do the following project, most of the time it’s the advantages that are important, especially if they exceed the disadvantages.

I have analyzed some of the advantages and disadvantages which I will present below.

Advantages:

- The supply of geothermal energy is vast, although not infinite. It can be considered renewable, as long as excessive water is not pumped into the earth in one location in short time. - As mentioned before it is highly efficient when compared to other technologies - Apart form heating it can provide cooling during the summer, thanks to the earth cycle - During the heat production there is not any emission released since there is not any burning as result - Not any significant noise emission.

Disadvantages:

- High initial cost due to the high price of the pump, drillings and other equipments.

Results & Discussion

Discovering alternative sources of energy and separation from the dependency on energy imports that has existed until now is very important fact that we should be dealing with during this century. Energy is a condition for progress but at the same time it creates pollution. This is a result of the energy sources that are currently used and which are harmful for our planet. Apart from being harmful to our planet, fossil fuels and other frequently used energy sources are scarce and lessening with each passing day. The question that arises is quite logical in nature, “Can we produce energy that won’t give any harm to environment but at the same time to be renewable”? The answer is very straightforward and it has been proven. So my point one more time is to prove that Kosovo has capacities to use every kind of renewable energy sources, thanking its geographical position. Reason for doing this project is to have a look at the Kosovo’s market in field of RES. Although Kosovo has put some feed-in tariffs for hydro and wind, I consider that it is at an early stage. There is so much work to be done from officials and the main handicap is the lack of professionals in these areas, therefore good experiences might be taken from countries like Iceland and Hungary regarding Geothermal Power. Although this project was done privately, I think that the lessons learned were very significant for the future of implementing new techniques in using RES in Kosovo. Also the company that dealt with it, in a short time will start to implement new projects around the country which is a good indicator for the future of geothermal energy in Kosovo. From the results, it was seen and proven one more time that Kosovo does have the capacity to generate geothermal energy.

References:

[1] Geothermal power http://en.wikipedia.org/wiki/Geothermal_power [2] Alternative Energy, Stan Gibilsco Other references by: Energy and Environment, Robert A. Ristinen & Jack P. Kraushaar Notes from Master Studies in Vienna Technical University, Geothermal Lecture in Gyor, 2009.

Possibilities for Exploiting Solar Energy in Macedonia

SLOBODAN PARIZOSKI University of Ss. Cyril and Methodius, Faculty of Electrical Engineering and IT Technologies Karpos 2, BB Skopje Macedonia [email protected] [email protected]

Abstract This paper will present the opportunities, practice and potentials that Macedonia offers as a country in the field of exploiting solar energy. Moreover, the most economical ways that Macedonia can use to harvest solar energy will be thoroughly presented, most of which by means of solar water heating and small stand – alone photovoltaic systems. Furthermore, their basic working principle and also their positive and negative features will be depicted. In addition, the preface will describe how the geographical position of Macedonia on the world map offers potential for harvesting solar energy, the current situation about installed water heating systems, the recently acquired practice and experience and the possibilities for future improvement. Finally, the paper will discuss the experience of the Macedonian companies in the particular field, they being equipped and willing to follow the state – of - the – art technology in the field of solar energy.

Keywords: solar energy, solar water heating systems, photovoltaic systems.

Acknowledgements

The author wishes to thank the Faculty of Electrical Engineering and Information Technologies in Skopje for arranging the visit of the “eco-house” and photovoltaic power plant in Kadino, municipality Ilinden near Skopje and also to his dear friend Tatjana Jovanoska for editing spell and grammar errors after the first writing of this paper.

Introduction

The Sun is a real blessing for the Earth and the mankind. It warms us and it gives the plants the necessary sunlight so that they can produce food for humans and animals. Every life form is in some way driven by the power of the Sun. In similar way the fossil fuels are also products of the Sun because they consist of decayed plants and animals about millions of years ago, whose existence is due to the power of the Sun. Nevertheless, nowadays our planet is becoming more and more polluted as a result of the fossil fuels such as coal, oil and natural gas, which are turning into depletion. For that reason the mankind is forced to explore and search for new energy sources especially renewable sources. The Sun’s energy is one type of renewable energy source for which we know that it will surely exist for the next 4-5 billion years. Our task now is to find a way to exploit this energy and to search for additional technologies that will allow us to exploit the sunlight efficiently. However, the sun rays are not equally scattered on the Earth. The regions around the equator get most of the Sun’s energy and as you move towards north and south there is less sun radiation. But even in the countries that are close to the Arctic than the equator there is enough sun radiation for exploiting such as Germany and the Czech Republic. Macedonia is located on the Balkan Peninsula, in southeast Europe, northern hemisphere. As it is shown on the map bellow, Macedonia has a very good incident solar radiation (insulation) between 1600 and 1800 kWh/m2. Unlike northern countries in Europe such as Denmark, United Kingdom, Norway, Sweden, Baltic countries, Poland etc., Macedonia has excellent geo-position for exploiting solar energy for both photovoltaic and solar thermal systems. As one of the sunniest countries in the region Macedonia has annual solar energy value of 10 GWh [1].

Figure 1-Part of the map: "Photovoltaic electricity potential of European countries"-property of European Institute for Environment and Sustainability.

It is estimated that Macedonia has 2000-2400 sunny hours during the year and this generation potential can satisfy at least 75-80 percent of the annual needs for heating and for hot water. Currently its usage is limited to water heating. In Macedonia there are only 7.5 m² solar panels on every 1000 people, or 15000 m² installed solar panels. At the end of 2006 the total collector area in operation in Macedonia was 17,118m². From 500 000 households in Macedonia only 2500 – 3000 are using solar systems for water heating. This represents only 0.5 % of the total market for solar panels [2]. By 2010 this numbers are slightly increased. Because of the low economic standard of living, for now in most of the cases solar energy is used in solar water heating systems (SWHS) for households, with great potential for use in industrial heating systems and photovoltaics for direct producing electricity from sunlight. Macedonia is a developing country and foreign investments in the field of solar energy are rare and just starting. The purpose of this paper is to contribute for future development of solar energy technologies by domestic and foreign investments.

1. Solar water heating systems The most economical way for exploiting solar energy is the solar water heating systems. Especially for countries like Macedonia which makes the first steps in the field of solar technology. These systems are easy to install and use and most importantly, the investment is returned in a couple of years. The following text will disclose the principle of working.

1.1 Basic principles The idea of SWHS is to use some heat-conducting material with flat surface that can extract the heat of sunlight and efficiently transfer it to the system of pipes with some heat-transferring fluid. Depending on construction and needs there are two basic types of SWHS: active and passive. Passive systems are cheaper and with less constructive issues. They use earth gravity in so called siphon effect when cold and warm fluid has different density (relative mass) and then the warm fluid with less density is rising up and the cold fluid with more density is falling down because of the gravity forces. As it’s shown on the Fig. 2 main parts of a passive system are:

1. Solar Figure 2-Passive solar water heating system collector 2. Thermally insulated hot water storage tank 3. Pipes, valves and connecting elements

Active systems are more expensive because, unlike the passive systems, they include additional control elements like pump, electronic control unit, sensors etc., but these systems are often used in areas where in winter air temperature drops

Figure 3-Active solar water heating system below 00C, like Macedonia. The circulation pump is actuated by a differential temperature controller, which interrupts water circulation in the system when the water temperature at the outlet from the collecto differences between inlet and outlet of solar collector are assumed to prevent unnecessary switching on and off of ther falls pump. below [3] a speciﬁed value. Appropriate dead bands for temperature

1.2 Practical example Macedonia is located exactly between 40°5' and 43° north latitude, where intensity of solar radiation, according to measurements so far, has high solar constant and average of 2400 solar hours annually. For objective and accurate presentation bellow is shown table with average daily and monthly amount of solar energy for 12 months in the year for three cities-Kochani, Skopje and Bitola. Analysis is performed with flat panel thermal collectors with one pyral and 1,5 l of fluid. It is important to remark that today’s last generation collectors has 12 pipes with 4,5 l of fluid. With this upgrades today’s solar collectors are more efficient by 20 %. This means that

with every m2 of solar collectors we can expect 1000 to 1100 KWh energy saving annually. One average solar collector with dimensions 195x95x10 cm can save up to 2000 KWh energy. If you have 3 collectors on your roof the math is simple: • 3 collectors with dimensions 195x95x10 cm with 2000 KWh annually save equally up to 6000 KWh;

• Momentary commercial price of energy for households in Macedonia is around 2, 45 denars. That means annual saving of energy costs of around 14 700 denars or 240 €;

• One complete solar water heating system with 5-6 m2 heating surface costs 1000-1300 €. This means that your investment will surely be returned in about 5-6 years. After that you have pure profit because an average lifetime of quality solar water heating systems is about 25-30 years.

1.3 Solar collector’s production in Macedonia

There are dozens of companies in the solar energy business in Macedonia that offer complete solutions for solar water heating systems such as Ekosolar doo, Ekokonsalting dooel, Sofkin ltd and Euroterm. One of the leading factors in solar energy businesses in Macedonia and in the region is the “Euroterm” company located in the “Biljana” industrial zone in Prilep. Euroterm has its own production line of solar collectors for SWHS. The production is fully automated with machines-product from another Macedonian company- “Mikrosam” also located in Prilep. Euroterm is producing selective collectors with highest commercially accessible efficiency for residential types of applications. These types of collectors release up to 50 % more power by m2 than conventional collectors. The materials that are used are reliable and tested: tempered glass, selective foil, embossed back side metal sheet and strong aluminum profile, enabling reliable functioning. The company has implemented quality standards such as ISO 9001 and SOLAR KEYMARK E DIN. 1. Aluminum batten 2. Solar glass 3. Flat absorber 4. Copper pipes frame 5. Insulation 6. Rear side 7. Collector body

Figure 4-Selective solar collector of the Euroterm-Prilep production line

Figure 5-Automated production of solar collectors in Euroterm - Prilep Most of the needed

equipment for SWHS is produced by Macedonian companies although there is some import from foreign countries such as Israel, China, France, etc. However, Macedonian companies are fully equipped for production, have the knowledge in engineering, design and installation practice of SWHS and are able to satisfy most of the solar energy market in Macedonia. 2.4 Current situation

Although Macedonia has a great potential for exploiting solar energy the fact is that it‘s not completely used. In the past two years the Government of Macedonia intervened as a subsidizer for solar water heating systems for households in amount of 30 % of the investment but not more than 300 €. This opportunity was a chance for a lot of Macedonian families who decided to install SWHS in their homes. Also this was opportunity for Macedonian companies to be included in this action and this was beneficial for all parties. Households were able to feel the sun’s energy in their homes and companies for manufacturing, designing and installing of solar water heating systems were quite busy. However for unknown reasons the Government decided that this year (2010) there will be no more subsidies for SWHS. This was explained as a part of economical measurements because of the world finance crisis. In the more expensive part of the solar energy business, photovoltaics, there are still some difficulties for foreign investors. Most of these difficulties are in the field of law like various permits and licenses and landowners issues. Although legislative according to EU and international renewable energy standards is inducted still the practice is something else. However, Macedonia is a developing country and EU-candidate and its abundance of sun is a real magnet for solar energy investors, domestic and foreign. The solar energy technology in Macedonia is yet to come.

2. Photovoltaic systems In this part of solar energy technology Macedonia, unfortunately, is far beyond developed countries like Germany, USA, Japan, etc. Technology for research and producing of solar cells is very expensive and still is a privilege of the wealthy countries. Quite interesting is the fact that the countries that have all known well developed technology and knowledge for producing solar cells today are also the countries with most installed photovoltaic capacities. Macedonia as a developing country with great solar energy potential in near future has a task to attract some of the countries mentioned above to invest in some research or producing facility. For now the use of photovoltaic panels for producing electricity directly from sunlight is limited only for small stand-alone applications like park chandeliers, traffic lights etc. The great example for this is a small stand-alone photovoltaic system with 18 panels located near the faculty of Technology and Metallurgy in Karpos municipality in Skopje. It is used to power the near crossroads traffic lights: The bigger photovoltaic systems like grid- connected that produce larger amount of energy enough to transfer it to the public energy grid are still experimental and on Figure 6-Small stand-alone photovoltaic system for traffic lights located paper. For now the one and only grid- in Karpos municipality in Skopje connected photovoltaic system is a small plant with 10 KW installed power located in village of Kadino, municipality Ilinden near Skopje. This plant is a private investment by the company Sieto from Skopje. The photovoltaic plant is on a parcel that contains additionally one wind turbine and a so-called “eco house”. It is built with latest construction technologies and materials as well as with a solar water heating system

94 on the roof. This project was realized with no help from relevant institutions in the country and it is a fully private project. The aim of the Sieto chairman was to show to the public in the country and in the region that Macedonia has a great renewable energy potential and it must be used for the benefit of all. Below there are some photos of the site:

Figure 7-Grid-connected photovoltaic plant, wind turbine and eco-house with SWHS located on the same site in Kadino, Ilinden municipality near Skopje

All other larger photovoltaic plants are still just projects on paper that are waiting for better days for financing and/or landowner licenses. Many foreign investors were forced to cancel their projects because of these issues. Currently, there is a project for solar photovoltaic plant located near Demir Hisar in the south-west part of Macedonia, which has best chances for realizing. As was mentioned before on the map above this part of Macedonia has great solar energy potential. This project is fully designed by Macedonian company; it has complete law papers, a landowner license, a construction license and an official accordance with MEPSO (Macedonian energy- transfer system operator) and EVN (Austrian company for distribution of energy in Macedonia- former ESM).

Conclusion To conclude, Macedonia has full potential for exploiting solar energy. Perhaps, for the moment it is far from building large photovoltaic plants like that one in Germany, European leader in solar energy. However it has great potential in developing the solar water heating systems. Macedonian companies have a great expertise, human and technology resources to enhance better energy efficiency and large use of free solar energy either for hot water for households, industrial heating or auxiliary water heating for central heating systems. For something extra help will be needed also from the Government, commercial banks with favorable credits and maybe foreign investors.

References [1]. Strategy for energetic development in Republic of Macedonia until 2030, Ministry of Economy, Skopje 2010. [2]. Renewable energy in Macedonia-Focus on ‘green’ electricity production, Analityca, December 2008. [3]. Geographic variation of solar water heater performance in Europe, Y.G.Yohanis, O.Popel, S. E. Frid, and B. Norton, October 2005.

Dye-sensitized Solar Cells

TANJA IVANOVSKA Faculty of Electrical Engineering and Information Technologies Rugjer Boshkovic, Skopje Macedonia [email protected]

Abstract

The dye-sensitized solar cells belong to the third generation thin film solar cells. They are efficient, low-cost solar cells based on dye-sensitized mesoporous nanostructured films. The dye-sensitized solar cell (DSC) generally consists of three parts: transparent fluorine doped tin dioxide (SnO2:F) anode, wide bandgap semiconductor typically titanium dioxide (TiO2) and photosensitive dye also called molecular sensitizer. Within the operation of the DSC there is a separation of the optical absorption and the charge transportation process. The sunlight enters the cell through the anode and is absorbed by the sensitizer, which is attached to the surface of the semiconductor. Charge separation takes place at the interface via photo-induced electron injection from the dye into the conduction band of the solid. For efficient operation of the device it is essential that the semiconductor oxide film has a nanocrystalline morphology. The nanocrystaline film in combination with sensitizer with a broad absorption band permits harvesting a large fraction of incident sunlight. While the DSC has relatively low maximum efficiency of about 11%, given that the cell is composed of low-cost materials and does not require a very specific manufacturing process or equipment, it is attractive for development and mass production. The unique characteristics of dye-sensitized solar cells include luminousness, shimmering color and flexible shapes; offer a wide range of applications from conventional electric generators to building materials, which is why it has been forecast that the DSC will be a significant contributor to renewable electricity generation by 2020.

Key words: solar cells, low-cost, nanostructured, dye, sensitizer

Introduction

Photovoltaic solar cells are traditionally made out of two differently doped crystals that form p-n junctions, where the charge separation occurs at the interface of the two materials. In thin film solar cells these solid state materials that have different conducting mechanisms are usually made of silicon, cadmium telluride (CdTe) or copper indium gallium diseledide (CIGS). This generation of solar cells has been dominating the industry because of the material availability, experience and existing technology in the semiconductor industry. Even though silicon solar cells have operating efficiency of 12-15% and 25% in laboratory modules, still the manufacturing process is very expensive and requires very distinct conditions. In order to minimize the fabrication cost emerged the possibility of using mesoscopic inorganic or organic semiconductors that have interconnected three-dimensional structure. These materials offer a low-cost fabrication process without expensive and energy intensive techniques. The interpenetrating networks of mesoscopic semiconductors have shown strikingly high conversion efficiencies and even more show that it is possible to completely depart from the classical solid-state junction device, by replacing the contacting phase to the semiconductor by an electrolyte, liquid, gel or solid. This allows the separation of two main mechanisms: the optical absorption and the charge separation process [1]. The prototype of this family of devices is called dye-sensitized solar cell and it is invented in the Laboratory of Encole Polytechnique Federale de Lausanne by Michael Gratzel. DSC has also several very attractive features alongside low-cost fabrication that facilitate market entry.

1. Operation principle of the dye-sensitized nanocrystalline solar cell (DSC)

The dye-sensitized solar cell is a third generation solar cell; it is constructed of a large bandgap semiconductor typically an oxide such as TiO2, sensitizer called dye, electrolyte and anode.

Sunlight enters the cell through transparent fluorine doped tin dioxide (SnO2:F) anode. Figure 2.1 shows the working principle of the DSC.

Figure 2.1 Energy band diagram of the DSC. Light absorption by the dye (S) produces an excited state (S*) that injects an electron into the conduction band of a wide bandgap

semiconducting oxide, such as TiO2. The electrons diffuse across the oxide to the transparent current collector made of conducting glass. From there they pass through the external circuit performing electrical work and reenter the cell through the back contact (cathode) by reducing a redox mediator (ox). The reduced form of the mediator (red) regenerates the sensitizer closing the cyclic conversion of light to electricity[2].

The photons strike the sensitizer that is attached to the surface of the large bandgap semiconductor. The photons with enough energy excite the dye and as a result an electron is ejected into the conduction band of the oxide, from where it moves by diffusion to the transparent anode at the top. This mechanism explains the separation of the two functions, the optical absorption and charge transportation. The dye is regenerated by accepting an electron from the electrolyte, usually an organic hole conductor or an electrolyte, such as an ionic liquid containing most frequently the iodide/triiodide couple as a redox system. If electron donation does not occur the dye will decompose. The regeneration of the sensitizer by iodide intercepts the recapture of the conduction band electron by the oxidized dye. This basically means that the regeneration of the dye via electron from the electrolyte occurs more quickly compared to the recombination of the ejected electron with the dye. This “favorable kinetics” is one of the reasons for good efficiency of the DSC. The iodide is then regenerated by the reduction of triiodide at the counterelectrode, the circuit is completed via electron migration through the external load. The voltage generated under illumination corresponds to the difference between the Fermi level of the electron in the solid and the redox potential of the electrolyte. Overall the

99 device generates electric power from light without suffering any permanent chemical transformation [1]. The DSC has two coupled redox cycles involved in the generation of the electricity (Figure 2.2 a)). The light provides electron injection initiating charge flow from the sensitizer via the conduction band of the oxide semiconductor to the external circuit. The dye is then regenerated by electron donation from iodide producing iodine or triiodide. The triodide diffuses to the counter electrode where the electrons injected into the circuit by the sensitizer reduce it back to iodide thus closing the two redox cycles involved in the energy conversion process. The turnover frequency of the sensitizer is 25 s-1 in full sunshine and during 20 years of outdoor service it must support 100 million turnovers [2].

Figure 2.2 a) The two coupled redox cycles involved in the generation of electricity from light in a dye-sensitized solar cell;

b) Transmission electron microscope picture of a mesoscopic TiO2 (anatase) film. The average particle size is 20 nm. [2]

One of the most important features for efficient work of the DSC is the nanocrystalline morphology of the semiconductor oxide thin film. A monolayer of sensitizer can absorb at most a few % of the incident light. Only the molecules that are in direct contact with the oxide will be photoactive so in order to increase the surface of the dye the structure of the TiO2 layer has to be mesoscopic (anatase), which means the particles have an average size of 20 nm (Figure 2.2 b))

[2]. This way the dye penetrates the nanocrystalline structure of the TiO2 film providing a larger contact surface between the dye and the oxide. Employing such oxide nanocrystals covered by a monolayer of sensitizer as light harvesting units allows one to overcome the notorious inefficiency problems. A has surface area is over 1000 times greater than the projected one. 10 μm thick mesoscopic oxide film composed of 20 nm sized particles 2. Photovoltaic performance of the dye-sensitized solar cell

This section will present the performance data obtained with this newtype of thin film photovoltaic cell. A DSC used for experimental measurements is showed in Figure 3.1.

100

Figure 3.1 Cross-sectional view of the embodiment of DSC used in the laboratory for photovoltaic performance measurements. [2]

Both the front and back contact of the cell are made of soda-lime float glass covered by a transparent conducting oxide. The latter material is fluorine doped tin dioxide (FTO) having a sheet resistance of 10– /m2 and an optical transmission of 80–90% in the visible, including reflection losses. The back contact is coated with a small amount of Pt to catalyze the interfacial 15 Ω 2 electron transfer from the SnO2 electrode to triiodide, the typical loading being 50 mg/m . The nanocrystalline TiO2 film is deposited by screen printing onto the FTO glass serving as the front electrode followed by a brief sintering in air at 450°C to remove organic impurities and enhance the interconnection between the nanoparticles. Absorption of the sensitizer monolayer occurs from solution by self assembly. The cell is sealed using a Bynel (Dupont) hotmelt. Redox electrolyte is introduced by injection through a hole on the back contact. The nanocrystalline

TiO2 film is typically composed out of 15 to 20 nm sized anatase [2]. The nanostructured morphology has enormous influence on the performance of the DSC. The incident photon-to- current conversion efficiency (IPCE) or external quantum efficiency is plotted as a function of wavelength. The IPCE value obtained with the single crystal electrode is only 0.13% near 530 nm, while it reaches 88% with the nanocrystalline electrode as shown in Figure 3.2.

Figure 3.2 Conversion of light to electric current by dye sensitized solar cells. The incident photon to current conversion efficiency is plotted as a function of the excitation wavelength. Left: single crystal anatase cut in the (001) plane. Right: nanocrystalline anatase film. [2]

One of the most important measures that characterize the solar cell is the overall conversion efficiency. This gives the total amount of electrical power produced for a given amount of solar power that reaches the cell. The conversion efficiency of the DSC is determined by the

101 photocurrent density measured at short circuit (JSC), the open circuit photovoltage (VOC), the fill factor of the cell (FF) and the intensity of the incident light (IS): η = JSCVOSFF/IS

Figure 3.3 Photocurrent density versus voltage curve for a DSC employing the N-719 dye adsorbed on a double layer of nanocrystalline TiO2 and scattering particles.The iodide/triiodide based redox electrolyte employed a mixture of acetonitirel and valeronitrile as a solvent. The conversion efficiency in AM 1.5 sunlight was 11.18 %. [2]

2 Under full sunlight (AM1.5 global, intensity IS = 1000W/cm ), short circuit photocurrents 2 ranging from 16–22 mA/cm are reached with state-of-the-art ruthenium sensitizers, while VOC is 0.7 to 0.86 V and FF values 0.65–0.8. A certified overall power conversion efficiency of 10.4% was attained in 2001[2]. A new record efficiency over 11.2% was achieved recently and Figure 3.3 shows the current voltage curve obtained with this cell [3].

3. Experimental results

One of the biggest disadvantages of the DSC is the use of liquid electrolyte which means that there are some stability issues with temperature variations. At low temperatures the electrolyte can freeze, whereas at high temperatures it can expand making sealing the panels a serious problem. Even so, tests made with N3 type ruthenium complexes sensitizers show good stability at high temperatures. Hermetically sealed cells with K-19 sensitizer in conjunction with decylphoshponic acid were used for long term thermal stress tests of cells stored in the oven at

80°C. As shown in Figure 4.1 a), the VOC of such a device drops only by 25mV over 1000 hours aging at 80°C and the device maintained over 98% of its initial conversion efficiency after 1000 hours aging at 80°C. While no change was observed for the fill factor, after 1000 hours aging, the 2 2 measured JSC of 15.38 mA/cm was even higher than its initial value of 15.16 mA/cm . The opposing changes of JSC and VOC probably reflect a small positive shift of flat band potential of the mesoporous titania film under the thermal stress, which can result in a net enhancement of photoinduced charge separation efficiency in DSC. film (Preservation Equipment Ltd, UK), as a UV cut-off filter (up to 400 nm), were irradiated at open circuit and 60°C in a Suntest CPS plus lamp (ATLASCells covered GmbH, with 100 amW/cm 50 μm 2thick). As shownpolyester in Figure 4.1 b), device showed an excellent stability under the dual stress of heating and visible light soaking, retaining 97.7% of its initial power conversion efficiency. Impressively, the 2 measured JSC of 15.53 mA/cm after 1000 hours aging, was still higher than the initial value of

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2 15.15 mA/cm while a 16 mV drop in VOC and less than 3% decrease in fill factor were observed [2].

Figure 4.1 a) Temporal evolution of photovoltaic parameters (AM1.5 full sunlight) of the device during continued thermal aging at 80 °C in the dark; b) Temporal evolution of photovoltaic parameters (AM1.5 full sunlight) of the device during continued one sun equivalent visible light soaking at 60 °C. [2]

Conclusion The DSC technology is a very attractive concept for developers and manufacturers of solar cells. The materials are inexpensive, abundant and non-toxic (titania is widely used in toothpastes, sunscreen, and white paint) and the cells are easy for production. Their structure and fabrication allows for a wide range of available colours and transparency. Because DSC are normally built with only a thin of conductive plastic on the front layer they are able to radiate heat much easier, and therefore operate at lower internal temperatures, meaning that they have a wide range of operation temperatures. The favorable kinetics enables the dye-sensitized solar cell to efficiently work in low illumination conditions and with diffuse light. All this makes the DSC extremely appropriate for application in building integration (windows, walls and roofs of varying colour and transparency that will simultaneously generate electricity in addition to whatever other function they serve)[4]. Several manufacturing companies are intensively involved in research and development of the DSC and are promising market availability in near future. Companies like Dyesol from Australia, Konarka form the USA, Sony Corporation, Aisin Seiki in collaboration with Toyota Central R&D Labs, SolarPrint in Ireland and G24 Innovations from the USA are some of the pioneers in working with this technology [2]. In fact the first ever commercial shipment of DSC photovoltaic modules was announced on 12.10.2009 by G24 Innovations for a backpack manufacturer from Hong Kong [5]. The advantages of the dye-sensitized solar cells make them significant future renewable energy contributors. The enormous potential of these cells to be utilized in various applications has driven the scientific and industrial community to further better their properties. Efforts have been made to minimize some of their disadvantages, like the stability problem and the relatively low efficiency. In order to increase the efficiency and improve stability, research has mainly been focused towards developing new, more compatible sensitizers, creating solid state dye- sensitized solar cells and configuring tandem cells. The recent development of the dye-sensitized

103 solar cell holds additional potential for further cost reduction and simplification of the manufacturing process

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References

[1] Gratzel M.: Dye-Sensitized Solar Cells. In: Journal of Photochemistry and Photobiology. C: Photochemistry Reviews 4 (2003), pp. 145 – 153. [2] Gratzel M.: Nanocrystalline Injection Solar Cells. In: Poortmans J., Arkhipov A. (Eds.) Thin Film Solar Cells. Fabrication, Characterization and Application. West Sussex, England: John Wiley & Sons, 2006. ISBN-13: 978-0-470-09126-5, pp. 363 – 385. [3] Schmidt-Mende L., Bach U., Humphry-Baker R., Horiuchi T., Miura H., Ito S., Uchida S., Gratzel M.: Organic dye for highly efficient solid-state dye-sensitized solar cells. In: Journal of Advanced Materials. Vol. 17, (2005), pp. 813–815. [4] Pagliaro M., Palmisano G., Ciriminna R.:Working principles of dye sensitized solar cells and future applications. In: Photovoltaics International journal. Edition 3 (Feb., 2009). [5] Web reference [available online at http://www.g24i.com].

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