21, rue d’Artois, F-75008 C1-207 CIGRE 2012 http : //www.cigre.org

Co-development of the Mediterranean transmission grids

L. IMAZ MONFORTE, M. CELOZZI, A. BARDACH, J. KOWAL, Ph. ADAM1 France

SUMMARY

This paper gives first a brief history of the development studies of the Mediterranean transmission grid, and a brief summary of the conclusions of the most recent project studies in the region. Then the paper introduces the Medgrid industrial initiative which aims to promote and facilitate the development of the Mediterranean transmission system to support the implementation of the Mediterranean Solar Plan and to contribute to the recent objectives of the European Commission regarding renewable energies. In connection with other initiatives interested in the development of power exchanges between the countries of the South and East of the Mediterranean and Europe, Medgrid proposes a global approach to coordinate the future transmission infrastructure projects around and through the Mediterranean. This global approach adds value to the bilateral initiatives to build new transmission facilities across the sea, by assessing and comparing the feasibility and profitability of all the possible transmission infrastructure corridors and projects in the Mediterranean region. Medgrid aims to elaborate a Mediterranean grid development plan for the 2020-2025 time horizon which is the horizon set up by the Mediterranean Solar Plan to reach 5 GW exports from the countries of the South and East of the Mediterranean to Europe, out of 20 GW of to be generated in these countries. To achieve this Mediterranean grid development plan, Medgrid is considering the national demand profiles and power generation mixes of all the countries, and the potential benefits resulting from power exchanges between these countries, should the appropriate transmission infrastructures exist. The gains on the global generation mix are compared with the cost of investment and operation of new transmission infrastructures which are necessary to make those gains possible. As a result, Medgrid will propose a list of infrastructures whose expected gains justify their development costs. Several scenarios of evolution of the costs of conventional and renewable energy generation are considered, and an original approach is followed to consider grid corridors rather than individual transmission infrastructure projects.

KEYWORDS: MEDGRID, Mediterranean Solar Plan, HVDC, grid master plan, corridor.

1 [email protected] V2

1. A brief history of the development of the Mediterranean grid

The electric interconnection between Europe and the countries of the southern and eastern shores of the Mediterranean Sea is this ancient idea of a large electric ring around our “Mare Nostrum”. In the year 2000 the study of the Mediterranean electric ring (MEDRING) was launched. The study was co-financed by the European Commission and led by a consortium of partners from Europe and Southern and Eastern Mediterranean Countries (SEMC). The MEDRING study was submitted end of 2003 and concluded its activities with a very positive assessment of economic benefits and the technical viability of the Ring, provided that some technical solutions were adopted to overcome operational difficulties [1] [2]. Furthermore the Second Strategic Energy Review of the European Commission communicated on 13 November 2008 concluded that a Mediterranean energy ring needed to be completed, linking Europe with the Southern Mediterranean through electricity and gas interconnections. In particular the Ring was essential to develop the region's vast solar and wind energy potential. The MEDRING Update study was launched in October 2009 within the framework of the Euro- Mediterranean Energy Market Integration Project (MED EMIP) financed by the European Union. This update study finalized end of 2010, provided recommendations on actions to be undertaken to close the Mediterranean Electricity Ring, thus integrating the power systems of all Mediterranean countries, and on actions to develop North-South links crossing the Mediterranean sea, enabling the direct energy exchanges between the SEMC and the North Mediterranean Countries (NMC) [3] [4] [5] [6] [7]. By the end of 2011 the situation is that the synchronous closure of the Mediterranean ring is not considered as a short or medium terms option as it requires the development of stronger national transmission grids in some SEMC as well as the decision on where including the DC interface in the future interconnected North African power system in order to avoid uncontrolled active power deviations. However the connection of the Turkish grid to the Eastern part of the European Network of Transmission System Operators of Electricity (ENTSO-E) grid is under tests which should be completed by the end of 2012. But the Mediterranean ring is still open at two locations: the border between Turkey and Syria and the border between and Libya. In parallel to the MEDRING update study, bilateral studies have been carried out on the feasibility of new North-South interconnection projects such as the interconnectors between Algeria and Sardinia (), between Algeria and Spain, and between Tunisia and Sicily (Italy), in complement to the existing synchronous interconnection between and Spain.

2. The recent evolution of the energy context in favour of a Mediterranean grid

In December 2008 the European Commission Parliament and Council agreed a binding legislation to implement the so called “20-20-20” targets:  A reduction in EU greenhouse gas emissions of at least 20% below 1990 levels;  20% of EU energy consumption to come from renewable resources;  A 20% reduction in primary energy use compared with projected levels, to be achieved by improving energy efficiency. In November 2008, the Union for the Mediterranean (UfM)2 has defined six large project of general interest, one of them being the Mediterranean Solar Plan (MSP). The objective of the MSP is to add 20 GW of low carbon electricity generation capacity, mainly solar, in the SEMC by 2020. The power will

2 Launched on the 13 July 2008 in the frame of the French presidency of the European Union, UfM promotes a new co-development policy in the Mediterranean region. It unites residents of the Mediterranean states and the member-states of the European Union, 43 countries. [http://www.ufmsecretariat.org/en/projects/]. 2 be used mainly to respond to the national demand, but a part of the green electricity (5 GW) could be exported to Europe where it will be sold at higher prices of the feed-in tariffs.

The EU directive Energy-Climate (2009/2//CE) makes it possible to include the import of green electricity from outside the EU to reach the ambitious objective of renewable energy share. Most countries of the Middle East and (MENA) have now defined and launched their national solar plans as part of their electricity development plan in order to face their increasing consumption needs (about 7% per year) as a result of their economic and demographic growth. The structure of the electricity demand is very different between Europe and the MENA countries, with a consumption peak generally in winter in the North and in summer in the South due to the fast development of air conditioning. The result is a strong interest in exchanging power in both directions at different times of the year to help to secure the supply of electricity throughout the Mediterranean basin, and to reduce the generation costs by using at every moment the cheapest conventional power plants, which are often the most efficient environmentally.

3. The most recent initiatives considering the Mediterranean grid

- industrial initiative (Dii)3 Founded in October 2009, Dii is a private industry consortium working towards enabling the vision of a sustainable energy supply from the deserts in Europe, the Middle East and North Africa (EUMENA). The overall objective of Dii is to create a market for renewable energy from the deserts. The long-term goal, by 2050, is to satisfy both a substantial part of the energy needs of the MENA countries and to meet approximately 15% of Europe’s electricity demand. Dii short term objectives are the creation of a positive investment climate, the development of the technological, economic, political and regulatory framework, thereby attracting interest, as well as enabling investment, in renewable energies and the associated interconnected power grids in MENA countries.

Figure 1 : Dii roadmap towards a self-sustained market – Reference project phase 2011-2020 (source Dii)

- Paving The Way for the MSP4 Started in September 2010 for a three year term, the Paving the Way for the Mediterranean Solar Plan Project (PWMSP) funded by the European Union, addresses nine Southern Mediterranean Partner

3 http://www.dii-eumena.com 4 http://www.pavingtheway-msp.eu 3

Countries5 and will assist them in implementing the MSP. It objective is to support the beneficiary countries, in the harmonization of their legal and regulatory framework, in the transfer of knowledge and capacity building, in the definition of sustainable energy policies, and in investments. In addition, the project aims to assess the Mediterranean grid and the data and information collection for the implementation of the MSP.

- MEDGRID6 Created in December 2010, MEDGRID is a consortium of partners coming from eight countries from the EU and MENA. It combines leading partners from the business of electricity generation, transmission and distribution (operators and technology providers), and of financing of infrastructures and services, from both the public and private sectors. Their common ambition is to open up new pathways for sustainable electricity by studying the feasibility of electricity interconnections and needed reinforcements between the Mediterranean countries, in coherence with the objectives of the MSP. MEDGRID is working closely with the authorities of related countries, the European Commission, the scientific community, banks and development funds and nongovernmental organisations, as well as with the other two initiatives mentioned above (Dii and PWMSP). The MEDGRID industrial initiative aims to promote and to facilitate the development of a Mediterranean interconnection system. Its objective is to design an interconnection Master Plan, which enables the exchanges foreseen for 2020 in the Mediterranean Solar Plan, and to study its feasibility from the technical, economical and institutional points of view. It considers the interest and the opportunities to develop a transmission grid around and across the Mediterranean Sea, based on the existing and on-going economic analyses of consumption and generation forecasts in the concerned countries and on technical studies of transmission corridors [18]. In addition to this Mediterranean Grid Master Plan, MEDGRID aims to (i) promote and develop an efficient regulatory model for investment in transmission infrastructures and open access to the networks; (ii) assess the feasibility of new technologies; and (iii) contribute to the development appropriate financing schemes to achieve the overall targets. The learnings from these actions will provide investors with complete and reliable information to help them in making their decision to invest in new transmission infrastructure projects in the Mediterranean region.

4. The present situation of the capacity of interconnections around the Mediterranean Sea A number of transmission infrastructures already exist in the Mediterranean Sea. With one exception, the existing links use the HVDC technology. This is due to the fact that HVDC is a more economical solution than HVAC in submarine options where distances are greater than about 50 km. The oldest Mediterranean transmission link was commissioned in 1965: the SACOI link between mainland Italy, Corsica and Sardinia, became in 1987 the first multi terminal HVDC scheme by the addition on the 200 MW / +- 200 kV main link of a 50 MW tapping station in Corsica [10]. The mercury arc valves of the old converter stations were replaced in 1992 by thyristor valves when the main converter stations were upgraded to 300 MW [11]. The first interconnection through the Mediterranean Sea is the Morocco-Spain HVAC scheme (2 x 700 MVA / 400 kV) commissioned in 1997 and 2006. The next transmission schemes in the Mediterranean all used HVDC technology: GRITA between Italy and Greece (500 MW / +- 400 kV) commissioned in 2001 [12] [13] [14], SAPEI between mainland Italy and Sardinia (2 x 500 MW /+- 500 kV) commissioned in 2009 and 2011 [15], and

5 Algeria, Egypt, Israel, Jordan, Lebanon, Morocco, Palestine, Syria and Tunisia. 6 http://www.medgrid-psm.com/en/ 4

Romulo between mainland Spain and the island of Mallorca (400 MW / +- 250 KV) commissioned in 2011 [16] [17]. As mentioned earlier, interconnection projects have been studied in the framework of bilateral agreements between the grid operators. The following table 1 summarizes the existing projects, the projects which have been decided (in green) and the projects which have been studied or are under studies (yellow).

Name Voltage Capacity Max. Commission Under water of the project (kV) (MW) depth date length (km) (m) 1 Spain (Mallorca Menorca) 132 AC 50 90 1973 120 2 Spain (Cometa) [16] [17] 250 DC 400 1500 2011 237 Morocco - Spain 1 400 AC 700 630 1997 30 3 Morocco - Spain 2 400 AC 700 630 2006 30 Morocco - Spain capacity increase 400 AC 700 - 3000 630 2025 30 Italy - France (SACOI 1) [10] 200 DC 200 450 1965 118 4 Italy - France (SACOI 2) [11] 200 DC 100 450 1992 118 Italy (SAPEI) 1 [15] 500 DC 500 1650 2009 420 5 Italy (SAPEI) 2 500 DC 500 1650 2011 420 6 Italy - Sicily 400 AC 2013 90 7 Italy - Croatia 400 DC 1000 200 2020 200 8 Italy - Montenegro 500 DC 1000 1200 2015 375 9 Italy - Albania 400 DC 500 2014 290 Greece - Italy (GRITA) 1 [12] 400 DC 500 1000 2001 163 10 Greece - Italy (GRITA) 2 [13] [14] 400 DC 1000 1000 2020 163 Italy Malta 1 [8] 132 AC 400 160 2015 100 11 Italy Malta 2 220 AC 600 160 2020 100 Italy (Elba island) 132 AC 2015 40 12 Italy (Islands : Capri, Ischia, 150 AC 2015 95 Procida) 13 Tunisia - Italy (TUNITA 1) 400 DC 1000 670 2015 194 14 Libya - Italy (LIBITA) 500 DC 1000 600 2020 550 Algeria - Italy (1) [19] 500 DC 500 2000 2016 330 15 Algeria - Italy (2) [19] 500 DC 500 2000 2020 330 16 Algeria - Spain 500 DC 2000 1900 2018 240

Table 1: interconnection projects through the Mediterranean (situation end of 2011): existing (no color), decided (in green) and studied (yellow).

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Figure 2: existing submarine links and potential transmission projects in the Mediterranean basin

5. The interest of a global approach versus bilateral approaches

The MEDGRID approach is different from the previous bilateral approaches of the interconnection infrastructure projects, by its global approach of the development of Mediterranean grid. MEDGRID final proposals on power transfer capacity solutions in terms of location, rating and date of operation, will be the result of updated social welfare benefits which will consider the complete system. Such an approach brings a certain number of advantages like the use of common criteria to assess the technical and economical performances of different infrastructure projects and their implementation dates, to compare their profitability and potential interference. The result of such an approach is a robust development plan of national grids and of interconnections, pointing out a proposed sequence of infrastructure development for a range of possible scenarios of demands, generation mixes and global economic backgrounds. The main difficulty stems from defining accurate enough hypothesis for the calculation of the benefits, because of the large degree of uncertainties on aspects like generation mix evolution and production prices.

6. The MEDGRID optimization process

An important step of the technical-economic analysis is the elaboration of a global model able to assess the benefits, costs and profitability of a given grid development plan in a given scenario of national demand profiles, of national generation mixes including renewable energy sources and their intermittent nature, and of some externalities (CO2 price, oil price, technology prices). To do that, the model will be fed with relevant data regarding the system: - Demand profile forecasts over the complete year in each country in 2020; - Generation mix in each country with a special attention to the expected technical and economical performances of renewable energy sources according to the location and technology used in 2020; - Existing and planned grid data in each country for 2020 including their technical performances (capacity to satisfy most constraining situations, availability).

This global model will use the existing data and updated national generation and grid master plans, opportunities of power exchanges will be studied, and will be able to consider combined generation and transmission investments, exchanges allowed by additional transmission projects, and, in some extend, also the dispatch and reserve rules defined by the transmission system operators. In addition to the export of green power from the south to the north, the assessment of the benefits brought by new transmission links will capture all the potential benefits such as the sharing of power

6 reserve, economic energy exchange in both directions (outside the peak periods), and the improvement of the reliability, resilience and flexibility of the global system. Other criteria as suggested by REALISEGRID study [9] may be considered, such as social and economic welfare, reduction of wind overproduction, of load shedding, of CO2 emissions and of the cost for external fuel, contribution to sustainable development (RES, CO2, energy efficiency), extension of an integrated electricity market. The model will allow an assessment of the maximum expected gains under the theoretical assumption that there are no limitations of power flows by the grids will be made. This gives a first indication of the potential global gain on the generation mix of the region and a limit for the transmission infrastructures costs. As a main result, a global optimization model will assess the economic performance of the global system with the existing and planned infrastructures in the time horizon corresponding to the objective of the Mediterranean Solar Plan (20 GW of renewable energy and 5 GW exported towards Europe). More detailed and specific optimization models used by corridors will allow refining the assessment of the benefits of the development of the potential corridors across the Mediterranean. The Master Plan will be the grid development proposals which will reach the best scores in terms of global expected profitability and risk limitation.

7. The assessment of grid development performance and investment costs An utmost important issue for the construction of the Mediterranean Master Plan responding to the MSP is the definition of the grid development strategies which will be considered. The actual limit of submarine cable manufacturing and laying for deep waters is 1650 meters, reached by the SAPEI link [15] commissioned in 2009. Cable manufacturers consider that extending that limit to 2000 meters should be feasible in the short term. The geography of the Mediterranean Sea, as shown on figure 3, is such that for the time horizon considered (2020 – 2025), a limited number of possible submarine paths can be considered.

Figure 3: Morphology of the Mediterranean seabed; red areas: below 2000 m; yellow areas: in the range 1500-2000 m. (source MED EMIP)

Therefore the Mediterranean basin has been split into three corridors which will be studied separately in order to assess their technical economic and environmental feasibility. Their mutual influence will be considered within the optimization process described earlier. The three corridors can be described as follows (see figure 4):  The west corridor involving Morocco, Algeria, Spain, Portugal and France;  The centre corridor involving Algeria, Tunisia, Libya, Italy mainland and islands, France including Corsica, and Greece;  The east corridor involving Libya, Egypt, Jordan, Syria, Lebanon, Turkey, Greece, Cyprus, Malta, Israel, and the Palestinian Territories.

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For each corridor, the feasibility will define the necessary grid evolutions to increase the transfer capacity between the countries of the corridor by 1 GW, 2 GW and 3 GW in the South-North direction. For each corridor and for each transfer capacity objective, the grid evolutions will consist of a set of individual projects such as new submarine cables, new overhead lines in some national grids or reinforcement of existing national or interconnection infrastructures, necessary to achieve the expected level of net transfer capacity. The most critical issue will be the assessment of the transfer capacities at the borders of the countries concerned, in both directions. National scenarios, issued by the analysis of the yearly dispatching of the corridor, will be considered to integrate the special characteristics of the energy mix and the constraints specific to each transmission system operator. At this stage the involvement of all the transmission system operators of the grids affected by the corridor development requirements is of utmost importance.

Figure 4: the three corridors to be modelled. Existing transfer capacity: Studied interconnection:

8. The technical and environmental feasibility of the corridors The technical and environmental feasibility studies of the corridors will rely on existing transmission technologies and except for the Strait of Gibraltar, the submarine links will use High Voltage Direct Current (HVDC). Two different technologies are available for DC transmission. The line commutated converter (LCC) option is a well proven technology suitable for the transmission of large amount of power up to 7200 MW per circuit over long distances (more than 2000 km). The second is the voltage source converter (VSC) technology which uses power transistors instead of thyristors, and provides more flexibility in supplying power systems with low short-circuit capacity. However the VSC option is limited in power (1400 MW per circuit7) and has higher losses than the LCC option in the conversion process. But VSC it more suitable for multi-terminal links and opens new perspectives for the design of HVDC meshed grids. Converter stations can be economically designed for 1, 2 or 3 GW per circuit. Two main different HVDC submarine cable technologies are available. The mass impregnated (MI) option allows the design of 2 GW per circuit and can be associated with both VSC and LCC converter technologies.

7A circuit can be bipole for both LCC and VSC, or a symmetrical pole for VSC. 8

The other option is the extruded cable (XLPE), more recent and limited to 1 GW per HVDC circuit. Its main advantages against the MI option are a lower cost, a lower weight and the absence of oil leakage risk. But it can only be used with the VSC converter technology. In the context of the Mediterranean, the major challenge is the design of cables to be laid in very deep waters which. The depth of the sea can reach 4500 metres in the Eastern part of the Mediterranean [6]. The needs of HVDC grids in the North Sea, consisting either of multi-terminal links or meshed grids, will push the development of such grids and their standardization. Therefore it may be of interest to develop for the three corridors compatible HVDC solutions in view of their integration within a future Mediterranean HVDC grid beyond the horizon of work of MEDGRID. Standardized solutions for the different corridors will bring additional benefits to the individual projects which will have the possibility to share spare components and maintenance and repair tools. The above considerations apply essentially to the submarine part of the North to South interconnections and assume that the connection points in the existing grids have the capacity to provide the power to the interconnector or to evacuate the power from the interconnector. In case this capacity is not sufficient, several options will be considered: the reinforcement of the existing grids which may imply an important list of additional lines and substations, or the design of an overlay grid to connect the interconnector to a substation within the existing grid, providing the required capacity. Combinations of the above options can also provide adequate solutions.

9. Conclusion

Interconnections in the Mediterranean basin are at a very early stage, presently limited to a Morocco- Spain link. Clearly, all the following key factors are in favour of a large modern grid in the Mediterranean basin: electricity from renewable energies to limit the climate change, exploitation of essential valuable and unlimited renewable energy resources based on sun and wind, drivers for economic and social growth in MENA countries, recent technological and industrial progress. The roadmap of MEDGRID is focusing on 2020, in accordance with objectives of the European energy-climate package and of the South and East countries’ solar plans; the Mediterranean Master Plan of the trans-Mediterranean interconnections by MEDGRID has also got to be designed for the doubling of the electricity consumption in the south and east countries by the date set. MEDGRID is a co-development project, which creates the best conditions for materializing this vision of the future Mediterranean grid and electricity market.

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BIBLIOGRAPHY

[1] CIGRE Session 2002 paper 37-108: “Analysis of operation of the forthcoming Mediterranean ring”, by C. LEMAITRE et alii. [2] CIGRE Session 2004 paper C1-205: “Technical challenges set by the closure of the Mediterranean ring from the dynamic security point of view”, by Bruno COVA et alii. [3] European Union Energy Market Integration Project (EU MED-EMIP) - MEDRING update – Volume 1 – “Overview of the power systems of the Mediterranean Basin”, April 2010. [4] European Union Energy Market Integration Project (EU MED-EMIP) - MEDRING update – Volume 2 – “Analysis and proposals of solutions for the closure of the ring and North-South electrical corridors”, April 2010. [5] European Union Energy Market Integration Project (EU MED-EMIP) - MEDRING update – Volume 3 – “Market Potential and Financial Impact of Solar Power Generation in Mediterranean Partner Countries”, April 2010. [6] European Union Energy Market Integration Project (EU MED-EMIP) - MEDRING update – Volume 4 – “Visualizing the Mediterranean Sea Basin for Electric Power Corridors”, April 2010. [7] CIGRE Session 2008 paper B4-116: “Linking Europe to Africa through long distance HVDC submarine interconnectors: methodology applied to the feasibility study and technical challenges to be overcome”, by Bruno COVA et alii. [8] CIGRE Session 2010 paper B1-104: “HVAC submarine cable links between Italy and Malta. Feasibility of the project and system electrical design studies”, by L. COLLA et alii. [9] CIGRE Session 2010 paper C1-105: “Prospects for the transmission planning in Europe towards a sustainable energy future: the REALISEGRID project”, by G. MIGLIAVACCA et alii. [10] CIGRE Session 1988 paper 14-12: “The SACOI (Sardinia-Corsica-Italy) multi terminal link: commissioning tests of the Corsican station Lucciana”. [11] CIGRE Session 1994 paper 14-107: “System commissioning tests for SACOI-2 HVDC three- terminal link”. [12] CIGRE Session 1996 paper 21-304: “Qualification test program for the 400 kV HVDC deep water interconnection between Italy and Greece”, by A. ORINI et alii. [13] CIGRE Session 2000 paper 14-106: “Investigation of FACTS applications in the Hellenic transmission system considering power flow variations including Greece-Italy HVDC link”, by N.D. HATZIARGYRIOU et alii. [14] CIGRE Session 2002 paper 14-116: “The Italy – Greece HVDC link”, by S. CORSI et alii. [15] CIGRE Session 2004 paper B4-206: “Feasibility of a new long distance submarine HVDC link between Sardinia island and Italian peninsula (SAPEI)” by C. PINCELLA et alii. [16] CIGRE Session 2006 paper B4-104: “Feasibility studies of the HVDC submarine interconnection between the Spanish peninsula and the Balearic island of Mallorca”, by R. GRANADINO et alii. [17] CIGRE Session 2010 paper B4-204: “The RÓMULO project, Spanish peninsula – Mallorca (243 km, 250 kV, 2x200 MW): first Spanish HVDC link”, by J. PRIETO et alii. [18] CIGRE Bologna Symposium paper 273 : “MEDGRID – The development of an interconnection grid between Europe, Middle East and North Africa”, by Ph ADAM et alii. [19] CIGRE Session 2012 paper B4-304: An integrated AC-DC multiterminal grid in the western Mediterranean Basin – Development, planning and design challenges, by L. COLLA et alii.

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