SLOVENIAN NETWORK DEVELOPMENT PLAN 2021–2030

SLOVENIAN NETWORK DEVELOPMENT PLAN 2021–2030

ELES, d.o.o. Chief Executive Officer Aleksander Mervar, MSc INDEX

ABBREVIATIONS USED 6

1. INTRODUCTION 10

2. BASES FOR PREPARING THE NETWORK DEVELOPMENT PLAN 14 2.1 Realisation of the previous development plan 15 2.2 Analysis of the previous period 16 2.2.1 Electricity demand on the transmission network 16 2.2.2 Distributed energy generation in the distribution network 17 2.2.3 Electricity generation on the transmission network 18 2.2.4 Electricity dependency of Slovenia 19 2.3 Transmission network operation in the past 20 2.3.1 Trends of Transmission Network Loading 21 2.3.2 N-1 Security in the Slovenian Transmission Network 22

3. ELECTRICITY DEMAND AND GENERATION SCENARIOS OVERVIEW 26

4. ELECTRICITY DEMAND AND PEAK LOADS FORECAST 30 4.1 Electricity demand forecast at the transmission level 31 4.2 Peak loads and minimal loads forecast 33

5. COVERING THE ELECTRICITY TAKEN OVER AND POWER FROM THE TRANSMISSION NETWORK 36 5.1 Generation evolution in the transmission network 36 5.2 Covering electrity demand 39 5.2.1 Electricity balance forecast 40 5.2.2 Adequacy of ensuring capacities of generation units 41 5.2.3 Projection of achieving energy and climate targets by 2030 42 5.3 Projection of ancillary services and power reserves 43 5.3.1 Scope of power reserves in the Slovenian EPS 43 5.3.2 Reactive power control 44 5.3.3 Black start service 44 5.4 Regional electricity exchange 45 6. TRANSMISSION NETWORK DEVELOPMENT PLAN 48 6.1 Situation in the transmission network by 2030 48 6.2 Slovenian transmission network development in the next 10-year period 50 6.2.1 Investments into the primary electricity equipment 50 6.2.2 Secondary equipment 54 6.2.3 Acquisition of 110 kV transmission network owned by other companies 55 6.3 Other investments priorities in the next 10-year period 56 6.3.1 SINCRO.GRID project 56 6.3.2 NEDO project 56 6.3.3 SUMO project 56 6.3.4 ELES Beričevo Technology Centre 57 6.3.5 Battery Energy Storage Systems 57 6.3.6 Compensation devices for voltage control 57 6.3.7 Construction of an advanced infrastructure for the provision of flexibility services from electric vehicles - the E8 concept 58 6.4 Research and development activities 59 6.4.1 OSMOSE project 59 6.4.2 FlexPlan project 59 6.4.3 INCIT-EV project 59 6.4.4 OneNet project 59 6.4.5 Interrface project 60 6.4.6 BD4NRG project 60 6.4.7 Activities in the Area of Demand Response and Distributed Generation 61 6.4.8 System reserve from DG sources of uninterrupted power supply – diesel electric generators 61 6.4.9 WAMPAC 61 6.4.10 Council for research and scientific activity 61 6.5 Assessment of investments by 2030 62 6.6 Long-term transmission network development 63

CONCLUSION 68

LITERATURE AND SOURCES 74 6

Abbreviations used

aFRR AUTOMATIC FREQUENCY RESTORATION RESERVE CCGT COMBINED CYCLE GAS TURBINE CEF CONNECTING EUROPE FACILITY CEP CLEAN ENERGY PACKAGE CHP COMBINED HEAT AND POWER PLANT CL CABLE LINE CRO CROATIA DEG DIESEL ELECTRIC GENERATOR DG DISTRIBUTED GENERATION DN DISTRIBUTION NETWORK DTR DYNAMIC THERMAL RATING EC EUROPEAN COMMISSION EIMV ELECTROINSTITUTE MILAN VIDMAR ELES ELES, D.O.O. EMS ENERGY MANAGEMENT SYSTEM ENS ENERGY NOT SUPPLIED ENTSO-E EUROPEAN NETWORK OF TRANSMISSION SYSTEM OPERATORS FOR ELECTRICITY EPS ELECTRIC POWER SYSTEM EU EUROPEAN UNION EV ELECTRIC VEHICLE EZ-1 ENERGY ACT FCR FREQUENCY CONTAINMENT RESERVES HEP-ODS HRVATSKA ELEKTROPRIVREDA - OPERATOR DISTRIBUCIJSKOG SUSTAVA D.O.O. HOPS HRVATSKI OPERATOR PRIJENOSNOG SUSTAVA D.O.O. HPP HYDRO POWER PLANT HSE HOLDING SLOVENSKE ELEKTRARNE 7

HU HUNGARY HVDC HIGH-VOLTAGE DIRECT CURRENT IT INFORMATION TECHNOLOGY ITA ITALY LCL LOGISTIC CENTER LJUBLJANA LOLE LOSS OF LOAD EXPECTATION MARI MANUALLY ACTIVATED RESERVES INITIATIVE mFRR MANUAL FREQUENCY RESTORATION RESERVE MSCDN MECHANICALLY SWITCHED CAPACITOR WITH DAMPING NETWORK NECP NATIONAL ENERGY AND CLIMATE PLAN NEDO NEW ENERGY AND INDUSTRIAL TECHNOLOGY DEVELOPMENT ORGANIZATION NPP NUCLEAR POWER PLANT NTC NET TRANSFER CAPACITY OHL OVERHEAD LINE OPGW OPTICAL GROUND WIRE PCI PROJECTS OF COMMON INTEREST PICASSO PLATFORM FOR THE INTERNATIONAL COORDINATION OF THE AUTOMATIC FREQUENCY RESTORATION PROCESS AND STABLE SYSTEM OPERATION PSP PUMPED STORAGE POWER PLANT REE RED ELÉCTRICA DE ESPAÑA RES RENEWABLE ENERGY SOURCES RS REPUBLIC OF SLOVENIA RTE RÉSEAU DE TRANSPORT D'ÉLECTRICITÉ SAFA SYNCHRONOUS AREA FRAMEWORK AGREEMENT SCADA SUPERVISORY CONTROL AND DATA ACQUISITION SI SLOVENIA SO GL System Operation Guideline SODO ELECTRICITY DISTRIBUTION OPERATOR SONPO NETWORK CODE FOR THE ELECTRICITY TRANSMISSION SYSTEM SPP SOLAR POWER PLANT SS SUBSTATION TEŠ THERMAL POWER PLANT ŠOŠTANJ, D.O.O. TE-TOL COMBINED HEAT AND POWER PLANT LJUBLJANA TN TRANSMISSION NETWORK TPP THERMAL POWER PLANT TR POWER TRANSFORMER TSO TRANSMISSION SYSTEM OPERATOR TYNDP TEN-YEAR NETWORK DEVELOPMENT PLAN UMAR INSTITUTE OF MACROECONOMIC ANALYSIS AND DEVELOPMENT WPP WIND POWER PLANT VSR VARIABLE SHUNT REACTOR WAMPAC WIDE AREA MONITORING PROTECTION AND CONTROL SYSTEM 8 9

01 INTRODUCTION 10

Introduction

The present document is a summary of the document “Slovenian Network Development Plan from 2021 to 2030” [1], which ELES drafted on 19th November 2020. The summary shortened the content of the original document, and it contains all the information and data that are needed for making a presentation to the broader expert public and electricity market participants.

The main purpose of the development In order to ensure a high reliability of the plan [1] is to present the necessary in- network and therefore supplying quality vestments into the transmission network electricity, challenges need to be tack- The main purpose (hereinafter: TN) in the next ten years, led in the development process brought of the development which will be ensure adequate transmis- forward by the increased demand for plan is to present the sion capacity of the Slovenian electricity electricity and peak loads, ageing infra- network and its reliability. Users of the structure, spatial restrictions and the re- necessary investments electric power system (hereinafter: EPS) lated siting issues, environmental issues into the transmission will therefore be provided with a long- and dispersed generation, new technolo- network in the next ten term reliable and quality electricity sup- gies, etc. On the other hand, the EU has ply. The long-term goal of developing been adopting measures and develop- years. the TN is to improve the quality of elec- ing strategies for the establishment of tricity supply as much as possible for the a sustainable economy for many years, lowest possible cost, the highest possible with which it hopes to change the cli- utilisation of the existing devices, the mate and environmental challenges into efficiency of investments and the lowest opportunities in all areas of the policy possible impact on the environment. and enable a transfer that will be just and inclusive for all. This goal is at the centre of the European Green Deal [9], in which the EU hopes to become a climate neutral economy by 2050 with zero net greenhouse gas emissions. 11

The first and main step in achieving the [4] and other appropriate documents company itself. Due to the unexpected set goals at the EU level in the energy that have an impact on the preparation crisis conditions, additional element of sector is the creation of an appropriate of the development plan. It should be uncertainty in planning and managing electricity network development strate- pointed out that, in line with the Euro- transmission network appeared. ELES gy. In line with Article 30 of the Energy pean regulation [8], the adoption of the updated the development scenarios by Act EZ-1 [2], the Decree on the award- Integrated National Energy and Climate considering the expert assessments of ing of a concession and on the method Plan of RS (hereinafter: NECP), which is a the European Commission (EC) [16] and of provision of a service of general eco- strategic document that sets goals, poli- the Institute of macroeconomic analysis nomic interest – electricity transmission cies and measures of Slovenia for the pe- and development (hereinafter: UMAR) system operator [3] and Article 22 of riod up to 2030 (looking ahead to 2040) [17]. ELES also considered the impact Directive 2009/72/EC of the European at the five dimensions of the energy of the Covid-19 epidemic in future com- Parliament and of the Council of 13 July union, is of extreme importance for Slo- pany revenues based on the currently 2009 concerning common rules for the venia [5]. It is for this purpose that ELES known assumptions and corrected the internal market in electricity and repeal- considered the guidelines and goals assessments accordingly. The conse- ing Directive 2003/54/EC [4] a transmis- defined in NECP in the process of mak- quences of the pandemic may lead to a sion system operator (hereinafter: TSO) ing the new network development plan, short-term weakening of the electricity must create transmission network de- which, in addition to the energy policy, demand growth and may therefore have velopment plans for at least a ten year it considered to the highest extent possi- a positive impact on postponing certain period every two years. When preparing ble when designing the scenarios. investments. However, the realisation of its ten-year network development plan, the infrastructure projects in the energy a TSO forms reasonable assumptions on It is also important to note that as this sector will have a great impact on the the development of the generation, sup- document was in the creation stage, recovery from the pandemic, whereby ply, consumption, and exchanges with the Covid-19 epidemic was declared, investments will need to be directed into other countries. It also considers the which will have consequences on a glob- the direction of clean energy and sus- investment plans for regional networks al scale, including the economy and the tainable development. 12 13

02 BASES FOR PREPARING THE NETWORK DEVELOPMENT PLAN 14

Bases for preparing the network development plan

Transmission network planning is based on the various established approaches and methodologies that also consider the current state of the transmission network as one of the input parameters.

For this purpose ELES considers the his- torical electricity demand and its trends in the process of network development plan preparation, as well as the electrici- ty conditions in the transmission system, the state of the transmission system and the current state of the previously planned investments in the transmission network, and therefore makes an as- sessment as to whether previous invest- ments achieved or are achieving their expected results. An important starting point is also the fact that planning must be considered as an important part of managing assets in their life cycle. 15 2.1 REALISATION OF THE PREVIOUS DEVELOPMENT PLAN

The analysis of the realisation of the new facts. 1% of projects were stopped, previous development plan has shown 27% of investments were extended and that ELES managed to complete 16% 9% of projects are being delayed due to of investments in the last two years, ap- external factors over which ELES has no prox. 42% are being implemented with- control. Figure 2.1 shows the status of in the schedule and 5% of investments project realisation. will be concluded prematurely due to the

Investments Investments implemented Figure 2.1: The realisation implemented as prematurely of investments in the scheduled 5% 42% development plan for the Delayed period of 2019 - 2028 investments 9%

Postponed investments Completed 27% investments 16% Stopped investments 1%

ELES managed to conclude some impor- • Double circuit OHL 400 kV Beriče- • Partial relocation of the OHL 110 kV tant projects in 2019-2020 that increase vo-Okroglo – line conductor replace- Kočevje-Ribnica; the reliability of operations and facilitate ment; • Completion of the interphase spac- company operations. The most impor- • SS Pekre - commissioning of the bat- ers installation at OHL 2 x 110 kV tant realised projects are: tery energy storage system in the Beričevo-Grosuplje and OPGW instal- scope of the SINCRO.GRID project; lation at OHL 110 kV Grosuplje-Ribni- • SS Divača – commissioning of the • Complete renovations of SS Sloven- ca-Kočevje; second transformer 400/110 kV; ska Bistrica, SS Plave and SS Pekre; • ELES Diagnostics and Analytics Cen- • SS Podlog - commissioning of the • Commissioning of SS Vojnik with con- tre; transformer 400/110 kV; nections; • other investments or reconstructions. • SS Divača - commissioning of the • Renovation of OHL 110 kV Mari- variable shunt reactor (VSR) and the bor-Cirkovce; mechanically switched capacitor with • Renovation of double circuit OHL damping network (MSCDN) at SS 110 kV Cirkovce-Zlatoličje and the Divača in the scope of the SINCRO. improvement of the reliability of op- GRID project; erations; 16 2.2 ANALYSIS OF THE PREVIOUS PERIOD

2.2.1 ELECTRICITY DEMAND ON THE TRANSMISSION NETWORK

The bases for planning electricity trans- than figures show when looking from weather conditions. Due to the above, mission networks are electricity needs transmission network side. There is a fair the largest increase in peak demand and power needs. Based on the review of amount of distributed generation (DG) occurred in winter 2017 due to low tem- the previous ten-year period of electric- located in distribution network (DN) peratures. This implies that there is a ity demand from the transmission net- which is reflected as reduced demand of high load and temperature dependency, work (figure 2.2), a slow recovery can be distribution companies from the TN. If which will be increasing in the future, seen after the drop due to the economic distributed generation was not present, due to the increasing amount of heat crisis that was present in Slovenia until then the electricity demands on the TN pumps. It needs to be noted that the 2014. Only after 2014 can it be seen level would be even larger. periods of extremely low or high temper- that the electricity demand began to in- atures are short on an annual level, how- crease more significantly, coming to the The peak demands in the TN reflect even ever the TN must be able to withstand 2007 levels in 2017. It needs to be noted greater dynamic than the electricity de- these extremes. that the real generation share is higher mand, which is mostly dependent on

Total electricity demand at the transmittion level [GWh] Peak Demand [MW] 18,000 2,300 Figure 2.2: Total electricity demand on TN and annual 16,000 2,100 peak demand in the last ten years 14,000 1,900

12,000 1,700

10,000 1,500

8,000 1,300

6,000 1,100 Peak demand 4,000 900 Transmission losses PSP – pumping 2,000 700 Locations of direct consumption Distributions – TOTAL 0 500 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 17

2.2.2 DISTRIBUTED ENERGY GENERATION IN THE DISTRIBUTION NETWORK

The insight into the volume and type At the end of 2019, the solar power of DG units in DN is very important for plants (SPP) had the highest installed ELES, because it has a direct impact on power, approx. 276 MW [13], which is the amount of electricity offtake of dis- approx. 50% of all installed generation tributions companies from the TN. The sources in DN (figure 2.3). Despite the analysis of previous years has shown highest total installed power, the SPP that the installed power of DG in DN were placed third based on the genera- is slowly increasing, which is why ELES tion of electricity, behind the combined is carefully studying the impact on the heat power generation units (CHP) and safety and reliability of the EPS’ func- the small HPP, which can also operate tioning. In 2019, a total of 601.3 MW of during night time and therefore have DG were connected to DN, which gener- higher capacity factors. ated 1,364.7 GWh of electricity or. ap- prox. 10% of the total generation in TN, amounting to 13,697 GWh.

Installed capacity [MW] Annual electricity generation [GWh] 300 600 Figure 2.3: The installed 276 capacity and the generated 501 250 500 electricity from the various DG source types in DN in 2019 [13] 412 200 400

150 270 139 300 126

100 20

101 50 39 75 100 Installed capacity [MW] 16 3 6 2 0 Annual electricity generation [GWh] 0 0 Small Solar CHP Biogas Biomass Wind Other Hydro

The growth of the new SPP was reduced With the increased RES penetration in significantly recently, however, an in- the future, controlling transmission sys- creased penetration of RES is expected tems will be an even bigger challenge, in the future in line with the environ- for which appropriate solutions will have mental policy of the EU and the NECP to be found in the sense of storing elec- policies [5]. The Slovenian Development tricity, the additional system reserves, Strategy 2030 [12] defines the same tar- compensation devices, etc. Such solu- get share of RES by 2030 as determined tions will directly increase costs for sys- in NECP [5], i.e. a 43-percent share of tem services and transmission network RES in the electricity sector, 41-percent charges. The final consumers who are share in the heating and cooling sector already financially supporting the incen- and a 21-percent share in traffic. tives for the RES will therefore have to pay even more through higher network charges. 18 2.2.3 ELECTRICITY GENERATION ON THE TRANSMISSION NETWORK

The quantity of generated electricity and Lower Sava River, Avče Pumped Stor- eration units connected to the Slovenian an overview of the net installed capacity age Power Plant (PSP), gas units at the transmission network had a net total in- of units in the past ten years show that Šoštanj Thermal Power Plant (TPP)). The stalled capacity of 3,335 MW, of which previous investments in the Republic of only investment in base-load units was 696 MW in the Krško Nuclear Power Plant Slovenia were made primarily into peak the new Unit VI at the Šoštanj Thermal (NPP Krško), 1,459 MW in TPPs, 1,000 units Hydro Power Plant (HPP) on the Power Plant. At the end of 2017, the gen- MW in HPPs, and 180 MW in PSPs [14].

Table 2.1: The installed capacities at NPP, TPP, HPP and PSP in the last ten years in MW [14] 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

NPP (total) 696 696 696 696 696 696 696 696 696 696 Thermal 1,296 1,296 1,296 1,296 1,275 1,764 1,654 1,654 1,707 1,459 Hydro 901 901 913 952 952 952 952 1,000 1,000 1,000 PSP 180 180 180 180 180 180 180 180 180 180

TOTAL 3,073 3,073 3,085 3,124 3,103 3,592 3,482 3,530 3,583 3,335

Figure 2.4 shows the electricity genera- in the change of the measuring system, ed at NPP (shown as the Slovenian and tion of units connected to the TN, where- because only the offtake at the offtake Croatian share, divided) and TPP was by the “other” category includes minor locations where digit measurements are more equal, while there were larger de- industrial co-generation at locations of placed is considered for locations of di- viations in the annual generation at HPP direct offtake, which are no longer visible rect offtake. Due to the baseload opera- due to the hydrological changes. on the figure as of 2016. The reason lies tion of such units, the electricity generat-

Electricity generation [GWh] Net installed capacity [MW] 16,000 4,000 Figure 2.4: Electricity 273 generation of HPPs, TPPs and 184 144 293 278 14,000 187 271 188 202 3,500 NPP Krško and net installed 282 capacity in the last ten years 4,064 3,218 3,453 12,000 5,520 4,015 4,233 3,000 3,543 4,187 4,022 3,426 10,000 2,500

4,787 4,262 8,000 4,795 3,242 4,401 2,000 4,636 4,381 3,809 4,049 3,946 Net installed capacity 6,000 1,500 Other generation on TN 3,030 2,983 2,949 2,763 PSP 4,000 2,686 2,616 2,685 2,712 2,741 1,000 2,512 Hydro Thermal 2,000 500 2,949 3,030 2,983 2,686 2,616 2,512 2,685 2,712 2,741 2,763 NPP CRO (1/2) NPP SLO (1/2) 0 0 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 19 2.2.4 ELECTRICITY DEPENDENCY OF SLOVENIA

Table 2.2 shows the annual electricity de- 1,212 MW. It needs to be noted here tricity is leased from lower-priced gener- pendency in RS, which shows the import that only 50-percent of NPP Krško is con- ation units abroad. The dependency, as dependency that is generally between sidered, and that the import dependen- a share based on the final consumption, 17 and 20%. In the last two years, Slo- cy did not occur due to the insufficiency is therefore between 16.1% and 19.6% venia imported electricity approx. 83% of the system or the lack of generation and is present between 72% to 86% of percent of the time in order to cover its units, but rather due to the electricity the time during the year. needs, whereby the largest import was market, whereby the major share of elec-

Table 2.2: Energy dependency in RS at an annual level

Deficiency, Year Deficiency Deficiency Deficiency percentage of [GWh] [%] [h] time [%]

2019 2,445 17% 7,093 81% 2018 2,355 16% 7,440 85% 2017 2,557 1% 7,451 85% 2016 1,652 12% 6,346 72% 2015 2,750 2% 7,526 86%

To ensure safe and reliable operation of electricity at certain times for covering import dependency in the year reached the transmission system, the essential the needs of domestic consumers. In up to 74%, which was still managed by information is the hourly import depend- 2019, the dependency was larger than ELES and owing to the Slovenian TN be- ency. This shows (Figure 2.5) that RS the annual average 51% of the time, ing strongly connected with European also imported up to 81% of the required which amounted to 20% this year. The EPS.

Electricity deficiency at the hourly level [%] Figure 2.5: The share of 80% electricity dependency in RS at the hourly level in the last five 60% years

40%

20%

1000 2000 3000 4000 5000 6000 7000 8000 9000 0

-20%

-40%

-60% 2019 (annualy 17%) 2018 (annualy 16%) -80% 2017 (annualy 18%) 2016 (annualy 12%) -100% 2015 (annualy 20%) 20 2.3 TRANSMISSION NETWORK OPERATION IN THE PAST

Below is a graphical representation of state (hypothetical state in the network The map of Slovenia in Figure 2.6 shows the most heavily loaded transmission when one transmission system element the most loaded transmission lines that lines based on the power measurements fails) in 2019. have a 95% probability of loading oc- as well as the trends of transmission line curring above a rated capacity of 60%. movements, voltages and loads in N-1

Figure 2.6: The most loaded transmission lines based on the 95-percent probability threshold

Kainachtal

Obersielach (Na Selu) Ravne Maribor

Cirkovce Šoštanj

Okroglo Podlog Žerjavinec

Beričevo Kleče

Redipuglia Krško (Sredipolje) Tumbri

Padriciano Divača (Padriče) Rated capacity above 70% Rated capacity between 60% and 70% Rated capacity between 50% and 60% Pehlin Melina 21 2.3.1 TRENDS OF TRANSMISSION NETWORK LOADING

Figure 2.7 shows the trend of transmis- A significant increase of the load trend a change or reduction of the economic sion network loading between 2014 and at the 110 kV voltage level was detect- activities (thus the reduction of electric- 2019, where the increase or decrease de- ed in previous development plans in the ity consumption); the reason may be notes a change expressed in percentag- area of south Gorenjska region, whereby the opposite, namely an increase of in- es based on the rated line capacity. Fig- loads elsewhere either dropped or stag- vestments into better energy efficiency ure 2.7 is especially revealing, even more nated (Pomurje region). The most recent or energy-saving technologies or that so because no load drop was recorded trends in the 110 kV network show that power flows shifted due to the construc- on the 220 kV and 400 kV voltage level. network loading is stagnant; there is tion of a new energy infrastructure in the On the contrary, these transmission lines only a slight drop of the network loading vicinity. show an increase of network loading, at the north Primorska region. It needs with 220 kV OHL Podlog-Obersielach be- to be pointed out that stagnation or a ing the most exposed and with a signifi- lower growth trend of the loads at a cer- cant increasing loading trend. tain location does not necessarily mean

Figure 2.7: Transmission network loading trend based on the five-year measurements

Kainachtal

Obersielach (Na Selu) Ravne Maribor

Cirkovce Šoštanj

Okroglo Podlog Žerjavinec

Beričevo Kleče

Redipuglia Krško (Sredipolje) Tumbri

Padriciano Divača (Padriče) Over 3% increase per year 1% - 3% increase per year 1% - 3% decrease per year 3% decrease per year Pehlin Melina 22 2.3.2 N-1 SECURITY IN THE SLOVENIAN TRANSMISSION NETWORK

The basic criterion for network planning Figure 2.8 shows compliance with the These obvious issues in the Slovenian and operating requirements foresees N-1 criterion on the basis of simulations, transmission network were already cov- that the N-1 security criterion must be whereby the analysis assumed all the ered in previous transmission develop- ensured at all times. The goal of ensur- Slovenian and interconnection lines and ment plans, where networks were sup- ing this criterion is to prevent the occur- longer sections of double circuit trans- posed to be strengthened in order to rence of major disturbances and their mission lines. The Figure shows that ensure quality electricity supply to con- spread due to the failure of any individ- most of the problems may be expect- sumers in the future and an increased ual element. ed in the Primorska region, where high resilience to any disturbances that may loading occur in the most unfavourable occur in the transmission system. states. The latter is high also in the Po- murje region. The dark coloured lines run toward radial powered areas that are left without a power supply in case of line outage, such as, for example, the Bela Krajina region.

Figure 2.8: Line loading in a N-1 situation

Kainachtal

Obersielach (Na Selu) Ravne Maribor

Cirkovce Šoštanj

Okroglo Podlog Žerjavinec

Beričevo Kleče

Redipuglia Krško (Sredipolje) Tumbri

Padriciano Divača (Padriče) Above 100% rated capacity 80% - 100% rated capacity 60% - 80% rated capacity Line causing partial autage Pehlin Melina 23 24 25

03 ELECTRICITY DEMAND AND GENERATION SCENARIOS OVERVIEW 26

Electricity demand and generation scenarios overview

Creating scenarios allows us to think about the future in the sense of alternative possibilities, where the highest challenge will undoubtedly be the adoption of appropriate decisions. This task will not be easy, because decisions will need to be made in a significantly more unpredictable environment.

This task will not be easy, because deci- The scenarios concerning the future sions will need to be made in a signifi- electricity demand and transmission cantly more unpredictable environment. network loading were designed to con- 2.1–2.6% Scenarios are an efficient approach to sider, to the maximum extent possible, creating a common understanding in the requirements as defined in ENTSO-E the framework of joint challenges and TYNDP ([6], [7]) and scenarios in NECP agreements on environmental issues as [5] and include the most recent findings Estimated long-term well as on defining the required func- in the energy area. growth of gross tioning in order to achieve the strategic goals. domestic product.

This development plan addresses four other goals of the EU and RS or pursu- generation expansion, development of scenarios, whereby scenarios Sc1 and ing the energy policy of the country to technical and technological parameters, Sc3 have been designed on the basis the largest extent possible in line with yields, energy efficiency, etc. Figure 3.1 of the bottom up approach, whereas NECP [5]. The scenarios differ from each provides an overview of the starting scenarios Sc2 and S4 were designed other based on their parameters, i.e. the points of each scenario that logically on the basis of the top-down approach rate of the future economic activity, en- connects the following policies: and are realising the environmental and ergy product prices, the rate of new RES 27 • Scenario 1 (Sc1) assumes a lower is more ambitious and considers a very ergy [7] and the state goals defined growth of the economic development high growth of electric vehicles and in NECP [5] but still assumes a higher and development in achieving the heat pumps. The RES and CHP match growth of the economic development energy policy goals, while major con- the growths as defined in NECP. Due to compared to Sc2. It is assumed that sequences of the Covid-19 epidemic the more efficient investments in new in order to achieve the goal of re- make additional contributions to its technologies, the consumption of all ducing emissions by 80% at the EU reduction. The final energy consump- final energy types is very low, where- level by 2050 compared to 1990, the tion and even electricity is increasing as electricity demand is higher than national goal of having 100-percent slowly. The usage of petroleum prod- in scenario Sc1 but still lower than in coverage with non-carbon sources has ucts is being moderately reduced in scenarios Sc3 and Sc4, which are sim- been set for the electricity generation the traffic sector, being replaced by ilar to Sc2 in terms of their energy de- by 2050. The Sc4 scenario considers natural gas. The introduction of elec- mands but with a higher projection of more favourable macroeconomic con- tric mobility and gas fuels has been the economic development. ditions, which is why the number of assessed based on the technical and • Scenario 3 (Sc3) includes policies and heat pumps is significantly increased. financial capabilities, whereby the EU measures adopted on the EU level and Consequently, traffic intensity is also goals regarding the reduction in Slovenia. It is similar to Sc1 in terms on the rise, where the introduction of • Scenario 2 (Sc2) matches the ENT- of its assumptions, whereby it assumes e-mobility is the most intensive. Due SO-E scenario National trends [7] and a higher growth of the economic devel- to more efficient investments in new the national goals defined in NECP opment, leading to higher growth of technologies, consumption of all final [5] in terms of its goals, however it as- new technologies, such as heat pumps, energy types is reduced; however, elec- sumes a lower growth of the economic EV, RES, etc. Even the consequences tricity demand is increased the most. development and major consequences of the Covid-19 epidemic are less visi- The construction of HPP in all scenar- of the Covid-19 epidemic, whereby the ble. Thus, traffic intensity is also rising, ios is moderate and in line with NECP consumption of all final energy types leading to a high growth of natural gas [5], whereby the most likely scenario is is low. It considers the goals as are de- consumption. Increased electrification the construction of HPP Mokrice. Sc4 fined for the entire EU on the basis of at various areas is also reflected as a is more ambitious in this context be- the policies for 2030. There are addi- higher electricity demands, whereby cause it assumes additional construc- tional demands for electricity due to growth of all final energy types re- tions of power plants on the Sava River the extensive usage of heat pumps. mains relatively moderate. and the construction of PSP Kozjak, The reduced consumption of petrole- • Scenario 4 (Sc4) assumes goals de- and it also assumes the construction um products in transport has been con- fined for the entire EU on the basis of of a new nuclear power plant unit in sidered with the gradual replacement policies for 2030, whereby it matches Krško in 2030. with natural gas, however, unlike Sc1, it the scenario ENTSO-E Distributed En-

Final energy demand Figure 3.1: Development Electric vehicles Electricity demand scenarios overview

Electricity consumption in Heat pumps households

Peak demands in Solar power plants transmission network

Wind power plants Transmission losses Sc1 Sc2 Sc3 Hydro power plants Distribution losses Sc4 (Drava, Sava, Soča, Mura)

It needs to be noted that scenarios are scenario assumptions be realised. When technical and technological parameters neither plans nor predictions. The sce- future electricity demand is planned, will not provide appropriate results if nario assessments are used solely as then these assumptions are linked to the assumptions on the expected future indicative values with which we describe the demographic and especially to the economic development are not at least the future happenings and conditions economic development. Even the best roughly correct [15]. that we may expect should the core and most sophisticated planning of the 28 29

04 ELECTRICITY DEMAND AND PEAK LOADS FORECAST 30

Electricity demand and peak loads forecast

Electricity and power demands serve as the basis for planning networks for the transmission of electricity.

The electricity consumption forecast is carefully and expertly considered in the ten-year development plan in line with the internationally established ap- proaches and models for the long-term assessment of electricity needs. The re- sults of the development forecasts have a certain measure of uncertainty that cannot be avoided, but they can be re- duced with a prudent and accurate ap- proach. 31 4.1 ELECTRICITY DEMAND FORECAST AT THE TRANSMISSION LEVEL

When determining the TN needs, the tion companies at the transmission lev- Slovenia EPS. Most DG will be installed generation of the distributed generation el. Figures 4.1 and 4.2 show that, in line in DN, whereas the TN only assumes the (DG) in DN and losses in TN and DN also with the assumptions of each scenario, connection of wind farms. need to be predicted, which is reflected the installed capacity of DG is persistent- as a reduced total demand of distribu- ly increasing and with it their impact on

Net installed capacity [MW] 3,000 Figure 4.1: Scenario assessment of the amount of the installed capacity of DG in DN and TN in 2,500 2030

2,000

1,500

1,000 Geothermal Solar Wind 500 Biomass Hydro CHP 0 Sc1 Sc2 Sc3 Sc4 Sc1 Sc2 Sc3 Sc4 Sc1 Sc2 Sc3 Sc4 2019 DG in TN in 2030 DG in DN in 2030 Total DG in Slovenia in 2030

Electricity generation [GWh] 4,000 Figure 4.2: Scenario assessment of the electricity 3,500 generation from DG in DN by 2030 [15] 3,000

2,500 Sc1 (all DG) Sc1 (DG only in DN) 2,000 Sc2 (all DG) Sc2 (DG only in DN) 1,500 Sc3 (all DG) Sc3 (DG only in DN) 1,000 Sc4 (all DG) Sc4 (DG only in DN) 500 2021 2022 2023 2024 2025 2026 2027 2028 2019 2030 32 Figure 4.3 shows the forecast of electric- line is increasing in all scenarios as the consequences. The quick return of con- ity needs in TN by 2030 (solid curves). years go by, because the DN assumes sumption to the pre-crisis levels depends The dotted curves represent the full elec- more inclusions of DG. The most visible mainly on the development of events tricity needs in Slovenia (including losses difference is in scenarios Sc2 and Sc4, on the global scale and on the preven- in TN and DN), because consumption, where the growth of dispersed genera- tive measures of the state. In 2030, we viewed from the transmission level, is tion can be seen. In 2020, a certain drop may expect demand in TN (without PSP) seemingly lower due to the generation can be seen in the expected demand, between 13.1 and 14.6 TWh, which is a of DG and co-generations in DN and because projections in the year of the 1 to 11.6-percent increase compared to connections of major consumers. The draft of this document show a signifi- 2019. difference between the solid and dotted cant impact of the Covid-19 epidemic

Electricity demand [GWh] 18,000 Figure 4.3: Scenario assessment of electricity 17,000 demand in TN by 2030 [15]

16,000

Previous period 15,000 Sc1 Sc1' (without DG) 14,000 Sc2 Sc2' (without DG) 13,000 Sc3 Sc3' (without DG) 12,000 Sc4 Sc4' (without DG) 11,000 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 33 4.2 PEAK LOADS AND MINIMAL LOADS FORECAST

The trend of peak load and minimum visible decrease due to the Covid-19 epi- The peak load is assumed mainly to oc- loads in the next ten-year period for all demic. If the DG continue to produce the cur in winter time, presumably in Janu- four scenarios is shown in Figures 4.4 predicted amount of electricity, then the ary, whereby minimal load is assumed and 4.5, where each scenario also shows trend of the annual peak loads in TN can to occur during the May holidays, when the impact of DG on the peak load or be expected between 2,273 MW (Sc1) most of the generation is not in opera- minimum load trend. In addition to the and 2,560 MW (Sc4). It is interesting to tion and the heating needs are low. In demand growth, the growth of TN peak observe the minimum load trends where these and similar conditions, the DG on load is also expected in the coming ten- these, in terms of TN, begin to drop sig- DN still operate and reduce the already year period, whereby there is another nificantly in three scenarios. low demand.

Peak demand at the transmission level [MW] 2,800 Figure 4.4: TN peak loads 2,750 forecast by 2030 [15] 2,700 2,650 2,600 2,550 2,500 2,450 2,400 2,350 Previous period 2,300 Sc1 2,250 Sc1' 2,200 Sc2 2,150 Sc2' 2,100 Sc3 2,050 Sc3' 2,000 Sc4 1,950 Sc4' 1,900 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030

Min. demand at the transmission level [MW] 1,200 Figure 4.5: TN minimal loads 1,150 forecast by 2030 [15] 1,100 1,050 1,000 950 900 850 800 750 700 650 600 550 500 450 Previous period 400 Sc1 350 Sc1' 300 Sc2 250 Sc2' 200 Sc3 150 Sc3' 100 Sc4 50 Sc4' 0 2010 2012 2014 2016 2018 2020 2022 2024 2026 2028 2030 34 35

05 COVERING THE ELECTRICITY TAKEN OVER AND POWER FROM THE TRANSMISSION NETWORK 36

Covering the electricity taken over and power from the transmission network

5.1 GENERATION EVOLUTION IN THE TRANSMISSION NETWORK

For the purposes of preparing forecasts into other generation sources. The of the evolution of generation units in presence of RES in the transmission the transmission system according to network is low, only 9 MW of solar Past experience show individual development scenarios, ELES power plants. that building of new has obtained from generation compa- • Sc2 considers investments in gener- infrastructure is not nies the relevant data on planned new ation units that can be realistically generation units and decommissioning expected. However, due to siting dif- easy and investors plans for existing units, shown in Table ficulties, delays in the completion of face many obstacles 5.1. Based on their current status, in- construction are particularly frequent which result in lengthy dividual units were placed in different in HPPs. The scenario therefore as- scenarios, considering also the NECP [5] sumes a delay in the construction of procedures. provisions, as follows: new HPP (mainly on the middle Sava • Sc1 considers only those new genera- River), while the opinion of the inves- tion unit that are already in the con- tors is also considered [14]. In addi- struction phase, have obtained the tion to the generation sources includ- building and environmental permit ed in Sc1, this scenario also assumes and whose probability of implemen- the construction of HPP Mokrice and tation is high (TPP Brestanica PB7, 81 MW of wind power plants included CCGT CHP Ljubljana units 1 and 2). in the transmission network. In line With the exception of the aforemen- with NECP [5], the installation of the tioned generation, the scenario does carbon capture and storage technol- not assume any new investments ogy is planned at TEŠ 6 after 2030. 37

• Sc3 assumes a similar realisation of Compared to the previous develop- the construction of power plants as ment plan, most changes in the set of Sc2, except that no additional HPP planned generation units in TN in the are planned to be constructed out- 2021–2030 period can be found in the side the ten-year development peri- year of their construction and not their od. After 2025, only HPP Mokrice is selection or number. The list still includes constructed of the large HPPs. 60 MW TPP Trbovlje, because its liquidation of wind and 10 MW of solar power was terminated on 1st January 2018. plants is installed in the transmission line with the adopted business plan of network in 2030. the HSE Group, the storage of petrole- • Sc4 is the most ambitious scenario um products will be carried out at this in the sense of generation units. All location within the scope of compul- investments of NECP [5] are realised sory emergency reserves prescribed by as well as investments announced by the state and ancillary services in the the investors [14]. It includes the con- electric power system. For this purpose, struction of PSP Kozjak in 2028 and two gas units have been preserved at the construction of NPP2 in 2030. In this location. The modernisation of the addition to HPP Mokrice, additional high-pressure turbine is planned for HPPs are constructed near the end 2021 at NPP Krško, which will increase of the ten-year period, namely HPP its net capacity by approximately 1%. Trbovlje, HPP Suhadol and HPP Učja. In the previous development plans, the The Sc4 scenario also has a large po- possibility of constructing the second tential for the construction of HPP on block of the nuclear power plant at Krško Idrijca. Similarly to the Sc2 scenario, was also mentioned, which the investor the carbon capture and storage tech- is currently planning to carry out at the nology is installed at TEŠ after 2030. end of the ten-year period, i.e. in 2030. It In total 102 MW of wind and 11 MW is assumed that unit 5 at TPP Šoštanj will of solar power plants are connected operate until the end of 2027 in accord- to the transmission network in 2030. ance with the plans of its owners. This scenario is based on the assump- tions that Slovenia will achieve by 2030 all energy climate goals as per NECP [5]. 38 Table 5.1: Overview of the planned electricity generation units in the TN in the upcoming ten-year period (MW) [14] Power units in TN 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 Scenarij

HYDRO POWER PLANTS Dravograd 26 26 26 26 26 26 26 26 26 26 Vuzenica 56 56 56 56 56 56 56 56 56 56 Vuhred 72 72 72 72 72 72 72 72 72 72 Ožbalt 73 73 73 73 73 73 73 73 73 73 Fala 58 58 58 58 58 58 58 58 58 58 Mariborski otok 60 60 60 60 60 60 60 60 60 60 Zlatoličje 126 126 126 126 126 126 126 126 126 126 Formin 116 116 116 116 116 116 116 116 116 116 ČHE Kozjak 420 420 420 Sc4 HPPs on the Drava River 587 587 587 587 587 587 587 1,007 1,007 1,007

Moste, Moste Završnica 21 21 21 21 21 21 21 21 21 21 Mavčiče 38 38 38 38 38 38 38 38 38 38 Medvode 25 25 25 25 25 25 25 25 25 25 Trbovlje 36 36 Sc4 Suhadol 44 44 44 44 44 Sc4 Vrhovo 34 34 34 34 34 34 34 34 34 34 Boštanj 32 32 32 32 32 32 32 32 32 32 Arto-Blanca 39 39 39 39 39 39 39 39 39 39 Krško 39 39 39 39 39 39 39 39 39 39 Brežice 48 48 48 48 48 48 48 48 48 48 Mokrice 28 28 28 28 28 28 Sc2,3,4 HPPs on the Sava river 276 276 276 276 304 348 348 348 384 384

Doblar I 30 30 30 30 30 30 30 30 30 30 Doblar II 40 40 40 40 40 40 40 40 40 40 Plave I 15 15 15 15 15 15 15 15 15 15 Plave II 20 20 20 20 20 20 20 20 20 20 Solkan 32 32 32 32 32 32 32 32 32 32 PSP Avče 180 180 180 180 180 180 180 180 180 180 Učja 34 34 34 34 Sc4 HPPs on the Soča river 317 317 317 317 317 317 351 351 351 351

HPPs on the Idrijca river 78 Sc4

Total HPPs 1,181 1,181 1,181 1,181 1,209 1,253 1,287 1,707 1,743 1,821

THERMAL POWER PLANTS

TEŠ unit V 305 305 305 305 305 305 305 TEŠ gas unit 51 42 42 42 42 42 42 42 TEŠ gas unit 52 42 42 42 42 42 42 42 TEŠ unit VI 539 539 539 539 539 539 539 539 539 539 TPP Šoštanj 928 928 928 928 928 928 928 539 539 539

Gas unit I+II 58 58 58 58 58 58 58 58 58 58 TPP Trbovlje (HSE - EDT) 58 58 58 58 58 58 58 58 58 58

Gas unit 1 23 23 23 23 Gas unit 2 23 23 23 23 Gas unit 3 23 23 23 23 23 23 23 23 23 Gas unit 4 114 114 114 114 114 114 114 114 114 114 Gas unit 5 114 114 114 114 114 114 114 114 114 114 Gas unit 6 53 53 53 53 53 53 53 53 53 53 Gas unit 7 50 50 50 50 50 50 50 50 50 50 Sc1,2,3,4 TPP Brestanica 400 400 400 400 354 354 354 354 354 331

Unit III coal, wood. biomass RES 45 45 45 45 45 45 45 45 45 45 CCGT-TOL1 57 57 57 57 57 57 57 57 57 CCGT-TOL2 57 57 57 57 57 57 57 57 57 Sc1,2,3,4 TE-TOL 45 159 159 159 159 159 159 159 159 159

Total TPPs 1,431 1,545 1,545 1,545 1,499 1,499 1,499 1,110 1,110 1,087

NPP Krško 703 703 703 703 703 703 703 703 703 703 NPP Krško 2 1,100 Sc4 Total NPPs 703 703 703 703 703 703 703 703 703 1,803

TOTAL 3,315 3,429 3,429 3,429 3,411 3,455 3,489 3,520 3,556 4,711 39 5.2 COVERING ELECTRITY DEMAND

Electricity demand at the transmission tions within the entire ENTSO-E system. all scenarios is shown in Figure 5.1. The level is covered by generation sources NPP Krško operates at full capacity with curve on the Figure represents the entire connected to the transmission network. its low generation price of electricity. This electricity demand in transmission net- The annual quantities of electricity gen- also applies for Unit 6 of TPP Šoštanj, work and includes the take-off of distri- erated from these sources are calculated which operates even during the high- bution companies from the transmission according to the climatic conditions in an est market prices and covers its variable network, the energy of large consumers average year, i.e., by taking into account costs. Electricity generation at the Ljublja- on the transmission network, electricity the average precipitation and tempera- na Combined Heat and Power Plant (TE- consumption of pumped storage power tures in the calculations. The quantity of TOL) is a side product, since its primary plants and transmission network losses. electricity generated from RES is entirely role is supplying most of Ljubljana with Most of the DG will be connected to dis- dependent on weather conditions, while heating energy and industrial steam. The tribution network and are reflected as the the main role in electricity generated quantity of electricity generated at PSP reduced take-off of distribution compa- from TPPs is played by the electricity mar- Avče is assessed on the basis of its previ- nies from transmission network, with only ket. As a rule, the quantities of energy ous operation and amounts to 250 GWh. a smaller share of solar and wind power generated from conventional sources are The covering of electricity demand from plants connected to the transmission net- obtained with the help of market simula- the transmission network by 2030 and for work.

Figure 5.1: Covering of electricity demand from transmission network by 2030 for all four scenarios

Electricity [GWh] Electricity [GWh] 16,000 16,000 Sc1 Sc2 14,000 14,000

12,000 12,000

10,000 10,000

8,000 8,000

6,000 6,000

4,000 4,000

2,000 2,000

0 0 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030

Electricity [GWh] Electricity [GWh] 16,000 16,000 Sc3 Sc4 14,000 14,000

12,000 12,000

10,000 10,000

8,000 8,000

6,000 6,000

4,000 4,000

2,000 2,000

0 0 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030

Demand at transmission level Storage Wind Solar PSP Hydro Thermal NPP Krško (50%) + NPP Krško 2 40 Results indicate a deficit in domestic Šoštanj, the generation mix in these of supply, because the first former focus- generation in the first three scenarios three scenarios does not change signif- es on the produced electricity, while the is at a similar level, which is mainly the icantly. The largest generation increase latter focuses on the currently available consequence of uneconomical opera- and thus the positive balance of Slovenia power. The ability of the system to cover tion of the available domestic gener- by 2030 can be expected only in scenar- the needs of end users is measured with ation. The difference will be covered in io Sc4, which assumes the construction the LOLE indicator, which is presented in the market with the import of electric- of PSP Kozjak and NPP Krško 2. It needs Chapter 5.2.2 for the Slovenian EPS. ity from abroad. With the exception of to be noted that covering electricity de- the decommissioning of Unit 5 at TPP mand must not be equated to reliability

5.2.1 ELECTRICITY BALANCE FORECAST

The electricity balance is defined as the ciency in the domestic generation, also difference between electricity demand due to the uneconomical operation of and generation at the transmission level, the available domestic units, which will where only half of the energy obtained have to be compensated with imports % from NPP Krško (Slovenia owns 50%) from abroad. The highest dependence in 24 is taken into account in the calculation. 2030 is in Sc3 in the amount of 4,056 The results show a negative balance GWh, which would require an import of throughout the entire observed period 463 MW throughout the year. The pro- Maximal expected for three scenarios. Only the fourth sce- jection results for the next ten-year peri- Slovenian energy nario is significantly positive after the od are shown in Table 5.2. construction of the new NPP Krško 2. dependency in 2040. The negative balance denotes a defi-

Table 5.2: Electricity balance forecast and import dependence at the transmission level for all four scenarios in the upcoming ten-year period (GWh) 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030

Electricity balance (GWh) Sc1 –1,780 –1,754 –2,040 –2,199 –2,348 –2,511 –2,674 –3,436 –3,570 –3,733 Sc2 –1,758 –1,668 –1,888 –1,904 –1,809 –1,860 –1,911 –2,562 –2,584 –2,636 Sc3 –2,051 –2,139 –2,539 –2,672 –2,696 –2,854 –3,011 –3,769 –3,898 –4,056 Sc4 –1,987 –1,996 –2,317 –2,348 –2,268 –2,218 –2,213 –3,085 –3,038 5,155

Deficiency (%) Sc1 12.9 12.4 14.1 15.0 15.9 16.8 17.6 22.4 23.0 23.8 Sc2 12.7 11.8 13.0 13.0 12.1 12.3 12.4 16.4 16.3 16.3 Sc3 14.5 14.7 16.9 17.6 17.5 18.2 18.9 23.3 23.7 24.2 Sc4 14.1 13.7 15.4 15.4 14.7 14.0 13.7 17.8 17.2 –28.7

Considering the fact that no large ad- namely in 2030 between 16% (Sc2) and its policy in the sense of new innovative ditional generation units will be built 24% (Sc1 and Sc3). Even the accelerat- schemes for subsidizing new RES instal- in Slovenian EPS in the next ten-year ed implementation of RES under Sc4 on lation. The current self-sufficiency goal is period (with the exception of the possi- the distribution network will not change given in NECP [5] and assumes at least ble construction of NPP Krško 2 in Sc4) the balance for the better. Should Slo- 75% supply of electricity from sources in and considering the electricity demand venia wishes to decrease its electricity Slovenia in 2030. growth, Slovenian energy dependency dependence, it will need to either con- may be expected in the future as well, struct NPP Krško 2 or thoroughly reform 41 5.2.2 ADEQUACY OF ENSURING CAPACITIES OF GENERATION UNITS

Adequacy is the indicator of the system’s tor, which presents the probability that quired import needs to be determined to ability to cover the consumers’ needs for the domestic generation capacities, with achieve this criterion. electricity and power in all the expected consideration given to the energy from operating situations by considering the abroad or without it, will not be suffi- The adequacy analysis for Slovenia planned and unplanned unavailability of cient to cover the total system consump- shows that the LOLE value, without con- EPS elements. The important part is also tion and provides a statistically calcu- sidering the energy import from abroad, the adequacy of generation units, which lated number of hours in the year when is very high, which means that without is a criterion for assessing whether suf- consumption at the estimated available electricity import, generation units lo- ficient electricity generation is assured aggregates and, considering the statisti- cated in Slovenia cannot meet Slovenian in a certain operating state for covering cal probability of their failure, will not be electricity demand at all times. The cal- the needs of electricity consumers. If covered. The limit value of the indicator culation of the LOLE reliability factor for sufficient generation are not available, in countries across the world is not har- 2030, where a sensitivity analysis was then this may lead to power outages for monised; the most often used value is made at the expected consumption for consumers, which can be minimised with 10 hours/year. The value of LOLE, which Sc3 and where many different develop- appropriate measures. is lower than the target value, usually ment variants of the Slovenian genera- signals that it is possible to assume that tion fleet were analysed, is provided in The adequacy assessment for EPS Slove- the system has enough reserve power to Table 5.3. nia has been made by focusing on the ensure reliable operation; if the situation LOLE (Loss of Load Expectation) indica- is reversed, then the amount of the re-

Table 5.3: The LOLE reliability factor and the energy not supplied (ENS) in 2030 without considering imports from abroad

LOLE (ur/leto) ENS (GWh)

Variant A Low installed DG capacity 1.422 342 Variant B High installed DG capacity 336 49 Variant C Low installed DG capacity, NPP Krško 2 in operation 70 30 Variant D High installed DG capacity, NPP Krško 2 in operation 34 6 Variant E Low installed DG capacity, two gas units (250 MW) 0 0 42

For continuous operation of the power future that will ensure appropriate trans- However, there is also the possibility of system with an appropriate reliability mission capacities or that will increase using smart solutions which include the level, Slovenia will be forced to import the resilience of the transmission system use of DG sources and active consumers electricity; the most unfavourable condi- to various events. The reduction of the that have the option of adjusting con- tions are to be expected in winter times LOLE indicator will be possible in the fu- sumption (e.g. electric vehicles, active when the hydrology and solar radiation ture without considering imports only if demands response, battery energy elec- is low and energy demand is high. With new generation capacities are construct- tricity storage systems in combination its cross-border connections, Slovenia is ed, whereby the solar power plants, due with solar power plants, heat storage relatively well integrated in the pan-Eu- to their inability of storing electricity, will solutions) for ensuring ancillary services, ropean EPS, which is why it can import not have such a large impact on the im- thereby reducing the LOLE values. Some the required electricity at any given provement of the indicators as conven- of these technologies are still in the de- moment. However, activities and invest- tional power plants. velopment phase but show great poten- ments will need to be carried out in the tial and will be of great use in the future.

5.2.3 PROJECTION OF ACHIEVING ENERGY AND CLIMATE TARGETS BY 2030

In line with the European regulation on Figure 5.2 shows the scenario assess- managing the energy union and climate ment of the final electricity coverage measures, the government of the Repub- share with RES by 2030. The projections 1,866 MW lic of Slovenia adopted Slovenian NECP show that Slovenia will be very close to [5] that defines the goals, policies and the set goals of Sc2 and Sc4 in 2030. measures for the period up to 2030. One These are also the scenarios that re- of the key goals defined in the NECP is alise the NECP [5] goals to the highest Ambitious assessment to achieve at least a 27-percent share of extent possible. On the other hand, Slo- of installed photovoltaic renewable sources in the final energy us- venia would fail to achieve the Sc1 and age by 2030 and the following indicative Sc3 goals in 2030. It needs to be noted generation in 2030. sectoral goals: a 43-percent RES share here that the projections depend heav- in the electricity sector, 41-percent RES ily on the electricity demand forecasts, share in the heating and cooling sector which may have a positive impact on the and a 21-percent RES share in traffic. aforementioned goals at a lower growth. Based on the various scenarios, Slovenia will require additional generation from RES between 400 and 1,750 GWh of electricity in 2030.

Share of final electricity demand covered with RES 50% Figure 5.2: Share of final electricity demand covered with RES for all four scenarios 45% 43%

40%

Sc1 35% Sc2 Sc3 30% Sc4 Sc4 without NPP Krško 2 Energy-climate target 2030 25% 2019 2021 2023 2025 2026 2028 2030 43 5.3 PROJECTION OF ANCILLARY SERVICES AND POWER RESERVES

The balancing reserves of Slovenian EPS, chronised area of continental Europe voltage control is meant to maintain the reactive power reserve for voltage con- and to balance deviations in the Slove- voltages in the Slovenian transmission trol and black start service are ancillary nian EPS. They include frequency con- network, while the black start service is services provided by qualified provid- tainment reserve (FCR), the automatic meant for quick network restoration fol- ers for ensuring such services with their frequency restoration reserve (aFRR) lowing its collapse. units. The aim of the balancing services and the manual frequency restoration is to maintain the frequency in the syn- reserve (mFRR). The system service for

5.3.1 SCOPE OF POWER RESERVES IN THE SLOVENIAN EPS

With the implementation of the Rules, the cooperation of ELES in the FCR coop- the International Coordination of the terms and conditions for balancing ser- eration, with 10 TSO purchasing FCR in a Automatic frequency restoration pro- vices providers on the ELES balancing uniform market. The uniform market of cess and Stable System Operation) for market [20], a new, more flexible and the FCR cooperation covers half of the forming a uniform European platform united local market for balancing servic- necessary reserve for continental Europe for exchanging the aRFF energy. An in- es emerged in 2020, which ensures equal - 1,500 MW. Based on the expected en- crease of the necessary aRFF scope is ex- terms and conditions for all qualified ser- ergy situation and planned investments, pected in future years, from +/- 60 MW vice providers, regardless of the connec- ELES does not expect any significant to +/- 72 MW, mainly due to the increase tion voltage level and used technologies. changes in the required amount of FCR of the share of RES, while at the same Currently, the aFRR and mFRR markets by 2030, and will for Republic of Slovenia time an increase is also expected of the are fully established, whereby the FCR remain between 14 and 17 MW. qualified amounts of aRFF from these market is in the phase of being estab- same sources. Increase of new aRFF ser- lished (purchase with negotiations). A In the future, two projects will be essen- vice providers is also expected, mainly substantial change is planned for the tial for ELES in the area of international aggregation providers with sources from start of 2021, when ELES expects the collaborations in line with the require- the distributed generation and flexible approval of the new version of the Rules, ments of the Regulation [19]: MARI demand in the distribution network and terms and conditions for balancing ser- (Manually Activated Reserves Initiative) sources that are based on new battery vice providers on the ELES balancing for forming a uniform European plat- storage technologies. market and establishment of the fully form for exchanging the mFRR energy functional FCR market, which will allow and the PICASSO project (Platform for 44

The size of the necessary system servic- synchronised area of continental Europe for distributing reserves for the recovery es defined by ELES are in line with the are determined with the Synchronous of the frequency between partners in guidelines on electricity transmission Area Framework Agreement (hereinaf- such block. ELES is part of the SHB block system operation (Commission Regula- ter: SAFA [29]). In terms of dimension- (includes Slovenia, Croatia and Bosnia tion (EU) 2017/1485 [21], hereinafter: ing Slovenian reserve size, the operating and Herzegovina), which is why the di- SO GL) and the technical requirements agreement of the block for regulating mensioning of the necessary reserve size of the Slovenian legislation (SONPO active power and frequency, concluded is determined at the level of the entire [22]), while additional policies regarding in line with the provisions of SO GL [21], SHB block and not just in the Slovenian the reserve dimensioning of the entire is also essential as it defines the method regulation area.

5.3.2 REACTIVE POWER CONTROL

An adequate voltage control is required whereby the minimisation of costs is sub- the SINCRO.GRID project, with which it for the safe and stable operation of the ordinate to the fulfilment of the security will establish a coordinated and joint volt- transmission network. ELES plans to have of operation condition. The multi-level age control together with the Croatian a comprehensive modernisation of the voltage control will fulfil all the reliability system operator (HOPS) and acquire mul- voltage control from the lowest level of criteria and ensure an appropriate re- tiple devices for controlling voltage in the voltage control of individual generation sponse is made to disturbances, while the 220 kV and 400 kV network. With these units to the main central control of the maintenance of the cost-efficient voltage devices, at the concurrent cooperation of transmission network in the coming years. profile will be made in phase two. the generation units in the 400 kV, 220 kV The purpose of the comprehensive mod- and 110 kV network, ELES will we able to ernisation is to minimise the costs of the With the implementation of changes in actively optimise the voltage in the Slove- generation and transfer of reactive power, the control structure, ELES also devised nian EPS.

5.3.3 BLACK START SERVICE

Black start service is a specialised service In the future, with updates to the strat- toration. Further strategy updates will meant for the establishment of opera- egy for system restoration, it will be also be made possible by reactive power tions with own sources and is therefore possible to include battery energy stor- sources that ELES is integrating in the linked to specific sources in Slovenian age units next to the classic generation framework of the SINCRO.GRID project EPS. The Black start service is a special- sources. There are more and more of and smart grid solutions at users. These ised service meant for the establishment these units emerging in the system and solutions will be studied thoroughly and of operations with own sources and is may, due to their rapid response, improve only those that will enable appropriate therefore linked to specific sources in the stability and resilience to disturbanc- responses will be included in the restora- Slovenian EPS. The service needs are es in the starting phase of system res- tion plan. defined in the network code NC ER [28] and in the System restoration plan [30], in line with the aforementioned network code and the national legislation.

When performing network restoration after a collapse, two goals need to be realised. As a priority, conditions for con- nections with neighbouring networks that mainly run on the 400 kV and 220 kV voltage level need to be ensured and provision of electricity to vital users in the Slovenian EPS. 45 5.4 REGIONAL ELECTRICITY EXCHANGE

A high growth of electricity generation ities in practice, which is based on the ly changed today. For Slovenia, this is es- from RES, mainly solar and wind power, so-called power flows. The final result is pecially true for the Italian and Austrian presents new challenges to the TSOs, expected to reduce the differences be- borders, the countries with an extremely which they try to tackle with a higher tween flows that are the consequence of high growth of RES. coordination level in mutual activities. commercial contracts and actual physi- The key change in this area is the intro- cal flows. Regardless of the challenging condi- duction of two network codes regulating tions, ELES managed to increase the im- the allocation of transfer capacities and The expected result of implementing port and export transmission capacities the management of transmission net- new methodologies will also be higher in recent years. The increase is mostly work congestion. The two mentioned volatility of the available transmission due to the Italian and Croatian borders, documents ([23], [24]) present very clear paths and capacities, especially for day- whereas conditions on the Austrian bor- requirements and guidelines to TSOs re- ahead and intraday. If, only a few years der are significantly more complex, due garding the manner of coordinating and ago, the determination of NTC values to which the realised values in the last developing the specified methodologies. was the subject of an annual agreement couple of years have been, on average, The implementation of new methodol- and any changes during the year were somewhat lower than planned. ogies introduces a completely new con- the consequence of extraordinary oper- cept of determining transmission capac- ating events, the situation has complete-

Table 5.4: Maximum NTC values, the physical capacity, and physical flows at Slovenian borders in 2019 ITA AT CRO

Rated capacity of interconnections [MW]* 1,488 2,860 4,716 NTC value - winter 2019 (import/export) [MW]** 660/760 950/950 1,500/1,500 NTC value – summer 2019 (import/export) [MW]** 680/620 950/950 1,500/1,500 Maximum flow in 2019 (import/export) [MW] 1,224/1,662 1,564/1,045 1,497/1,356 Average flow in 2019 (import/export) [MW]*** 229/638 710/284 528/235 No. of hours of physical flow in direction 2019 (import/export) [h] 741/8,019 8,239/521 3,576/5,184 * Calculated at cos = 0,95. φ ** Maximum planned hourly NTC value at individual border. *** Yearly average of hourly physical power flows in a certain direction.

Despite the strategy of increasing NTC transmission capacities in the amount values, a higher increase in future can of 70% of the thermal capacities at the By observing the N-1 only be expected with the construction border in the event of a failure of a criti- of new cross-border connections and cal element for electricity trading needs. criterion, the Slovenian investments in critical points, primarily A positive impact can be expected on the electric power in neighbouring electric power systems. transmission capacities size, but there is system is still able to The calculation shows that by observing a probability that the costs of ensuring the N-1 criterion, the Slovenian electric these measures will increase significant- considerably raise the power system is still able to consider- ly for TSOs. Table 5.5 shows the assessed maximum NTC values ably raise the maximum NTC values future NTC values on Slovenian borders, above the current ones. above the current ones. With the imple- which are only indicative and are not mentation of the new CEP, there is an harmonised with the neighbouring SO additional uncertainty surrounding the for the target year of 2030. requirement for ensuring cross-border

Table 5.5: The indicative NTC values at Slovenian borders in 2030 Indicative NTC values in MW (import/export) Year ITA CRO AT HU

2030 680/800 2,000/2,000 1,200/1,200 1,200/1,200 46 47

06 TRANSMISSION NETWORK DEVELOPMENT PLAN 48

Transmission network development plan

6.1 SITUATION IN THE TRANSMISSION NETWORK BY 2030

ELES pursues the ENTSO-E guidelines • locations with a shortage of future and methodology for drafting develop- electricity generation; ELES is as a member ment plans, whereby it introduced the • inadequate electricity supply (e.g. approach of identifying the transmission LOLE, ENS); of ENTSO-E constantly

system future needs system in its own • areas with high CO2 emissions; upgrading and development plan preparation process, • bottlenecks - between countries and improving the network which is based on [27]. It initially per- also internal, etc. forms market analyses for the target year planning guidelines. in the future, whereby the entire planned One of the main purposes of the network generation fleet and the expected de- development process is to eliminate the mand are considered. It then performs detected problems with various measures network analyses based on the market and new network reinforcements, which results. In this scope, the transmission requires extensive calculations in simula- network topology also considers the ex- tion tools. The results of such a process isting network state or the so-called refer- for the Slovenian EPS, which is based on ence state without reinforcements or new the demand and generation scenarios, connections in the network and without are given in Figure 6.1. The results show operating measures. Such an approach the status of N-1 criterion in 2030 for the allows the company to detect: Sc1 scenario. 49

Figure 6.1: The conditions of the reference network in the N-1 state in 2030 (without the planned reinforcements)

Kainachtal

Obersielach (Na Selu) Ravne Maribor

Cirkovce Šoštanj

Okroglo Podlog Žerjavinec

Beričevo Kleče

Redipuglia Krško (Sredipolje) Tumbri

Padriciano Divača (Padriče) Above 120% rated capacity 100% in 120% rated capacity 80 in 100% rated capacity Pehlin Melina

The results show that if no investments the strengthening of the network), be an In this context, an extensive analysis of are made into the transmission infra- important segment in a reliable network the status of ELES owned power trans- structure in the target year 2030, then operation. formers was made, showing a part of the there will be certain sections in the net- power transformers will be at the end of work where the security of supply will In addition, next to the analysis shown their lifetime in the next ten-year period. not be met. As has already been men- in Figure 6.1, there are also other devel- For this purpose, ELES made an optimum tioned, the operational measures (e.g. opment related aspects for investing in strategy for their replacement in line tap variation of phase-shifting trans- the transmission infrastructure, such as, with the status of the power transform- formers, switching operations) are not for example, market movements for re- ers or their remaining lifetime and the considered in the process of identifying ducing price differences between areas expected loads in the future and placed the future needs of the transmission sys- or the establishment of additional op- them in the set of investments into the tem. The operational measures may, in tions for exchanging power reserves, re- transmission network of Slovenia. certain operating conditions (as a pre- placement of the worn-out equipment, liminary alternative of solutions prior to expired lifetime of electricity elements. 50 6.2 SLOVENIAN TRANSMISSION NETWORK DEVELOPMENT IN THE NEXT 10-YEAR PERIOD

6.2.1 INVESTMENTS INTO THE PRIMARY ELECTRICITY EQUIPMENT

Baselines for the set of investments in addition to improving reliable and safe and the new 4 km long double circuit the Slovenian transmission network are operations of the Slovenian transmis- 220 kV OHL Zagrad–Ravne, which will be based on the energy policy goals and sion network, will allow access to the connected into the existing 220 kV OHL were prepared on the basis of results eastern electricity markets and will in- Podlog-Obersielach, and the replace- from own analyses, analyses conducted crease security of supply in all situations. ment and commissioning of new large by external institutions, development cri- The investment is the largest individual power transformers meant for supplying teria, plan of overhaul and technological investment in the history of ELES. In power to large areas of consumers in renovation of electric power elements addition to the above, ELES plans to the Republic of Slovenia. In the 110 kV in transmission network facilities, needs complete the implementation of the transmission network, one of the priority of electricity producers and customers, international project SINCRO.GRID in investment areas is the northern Primor- criteria for secure and safe operation of the next five-year period which, among ska region, where the construction of the the transmission network, international other things, assumes the integration double circuit 110 kV OHL Divača-Gori- agreements and international contracts. of the various compensation devices on ca running through the village of Renče the 400 kV voltage level at substations will significantly increase the safety and Of all the planned investments into Beričevo, Cirkovce and Divača and also reliability of operations. The focus in the the primary electricity infrastructure, separately in the network of Croatia. next five years is also on supplying pow- the construction of the double circuit One of the essential investments for en- er to the coastal part of Slovenia, the 400 kV OHL Cirkovce-Pince will be key suring an adequate level power supply Mura region, the Koroška region and the in the coming period at the 400 and by 2030 will also be the construction of central part of Slovenia. 220 kV voltage level by 2025, which, in the new 220/110 kV substation Ravne 51

Based on the starting points, ELES will, in 400 and 220 kV substations and • Complete refurbishment of 110 kV the coming ten-year period, focus on the transformers (TR): OHL Hudo–Kočevje, 110 kV OHL Gor- following prominent investments into • Compensation devices in substations ica–Ajdovščina, 110 kV OHL Koper– the primary electricity equipment in the Divača, Beričevo and Cirkovce (within Buje, 110 kV OHL Vuhred–Podvelka transmission network by 2030: the scope of the SINCRO.GRID pro- and 110 kV OHL Podvelka–Ožbalt, ject); 110 kV OHL Kidričevo–Ptuj–Formin, 400 and 220 kV connections: • 400 kV substation Cirkovce (link with double circuit 110 kV OHL Ormož– • Double circuit 400 kV OHL Cirk- the investment double circuit 400 kV Ljutomer and double circuit 110 kV ovce-Pince OHL Cirkovce-Pince); OHL Vuhred–Pekre. • Double circuit 220 kV OHL Zagrad– • 220/110 kV substation Ravne (link Ravne. with the investment double circuit 110 kV substations and TR: 220 kV OHL Zagrad–Ravne); • Battery energy storage systems in In addition to the abovementioned in- • TR 400/110 kV at Beričevo substation substation Okroglo and substation vestments, activities are also under way (new TR 411) and the gradual tran- Pekre (within the scope of SINCRO. in connection with the potential new sition of Beričevo substation to the GRID project); high-voltage direct current interconnec- transformation of 400/110 kV; • New substations 110/20 kV Izola, tion line between Slovenia and Italy, • TR 400/110 kV at Maribor substation 110/20 kV Hrpelje, 110/20 kV Do- which is still in the study phase and a de- (replacement of TR 41); bruška vas, 110/20 kV Zreče, 110/20 cision on its execution has not yet been • replacement of TR 220/110 kV at Di- kV Luka Koper and 110/20 kV LCL adopted. Its realisation depends on vača substation; through co-investments with the vari- market conditions and the attainment • TR 220/110 kV at Podlog substation ous distribution companies; of an adequate level of social welfare. (replacement of TR 212); • full renovation of substations In the past, ELES was also intensively • TR 220/110 kV at Kleče substation 110/20 kV Tolmin, 110/20 kV Trbov- engaged in carrying out the upgrade (replacement of TR 211). lje, 110/20 kV Ajdovščina, 110/20 of the 220 kV transmission network to kV Selce, 110/20 kV Lipa, 110/20 the 400 kV voltage level, initially on the 110 kV connections: kV Brežice, 110/20 kV HPP Formin, Divača-Beričevo section, which was sus- • Double circuit 110 kV OHL Di- 110/20 kV HPP Doblar and 110/20 pended in 2017 due to difficulties with vača-Gorica (completion of the miss- kV Velenje; the permitting procedure and siting pro- ing section at the village of Renče); cess of OHL in physical space. Thus, in • connecting line 2 x 110 kV for HPP Tables 6.1 and 6.2 show the provision of the present development plan ELES does Mokrice; the N-1 security criterion and the desired not foresee any upgrade to the 400 kV • double circuit 110 kV OHL Brestani- years of including individual investments voltage level on any section. The devel- ca–Hudo; into the Slovenian transmission network opment plan does, however, foresee the • connecting 110 kV line for SSok Luka by 2030. The specified investments are beginning of a longer-lasting process of Koper substation; both of local and national importance renewal of the entire 400 and 220 kV • 110 kV cable line (CL) Koper-Izola-Lu- and need to be realised in the given pe- networks. ELES will conduct the neces- cija; riod in order to secure safe and reliable sary studies for project execution in the • Double circuit 110 kV OHL Divača– operation of the entire power system. next few years and subsequently decide Pivka–Ilirska Bistrica; However, due to difficulties in obtain- on the beginning of its implementation. • Double circuit 110 kV OHL Dra- ing permits and state spatial planning vograd-Velenje (the placement of ca- documents, which are outside of ELES’s bles from pillar no. 126 to SS Velenje); jurisdiction and on which it has no in- • Double circuit 110 kV OHL Divača-Ko- fluence, it is realistic to expect delays in per (upgrading of single circuit OHL project realisation that may lead to the to double circuit); unreliability of the network in future, • 110 kV OHL + CL Moste–Jeklarna– and consequently to the non-supply of Železarna–Jesenice; electricity to customers. The entire scope of investments in all areas in the period leading to 2030 is shown in [1] in Table 7.8 (chapter 7.5). 52 Table 6.1: Necessary investments in the Slovenian transmission network by 2030 Object 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030

400 and 220 kV voltage level OHL 2 x 400 kV Cirkovce-Pince* OHL 2 x 220 kV Zagrad-Ravne* OHL 2 x 400 kV Hrenca-Kozjak (connection of PSP Kozjak)* TR 400/110 kV Cirkovce* TR 400/110 kV Beričevo* TR 400/110 kV Beričevo* TR 400/110 kV Maribor* TR 220/110 kV Kleče* TR 220/110 kV Ravne* TR 220/110 kV Podlog* TR 220/110 kV Divača*

Central Slovenia and Zasavje region 110 kV 110 kV CL TETOL-PCL** 110 kV CL TETOL-Center-PCL (replacement)** *** Connecting OHL for connection of SS Brdo** Connecting OHL for connection of SS Rudnik** *** OHL 2 x 110 kV Polje-Vič** *** OHL 2 x 110 kV Potoška vas-Vodenska** Connecting OHL for connection of HPP Suhadol** Connecting OHL for connection of HPP Trbovlje** 2 x 110 kV CL Šiška-Vrtača*** *** 2 x 110 kV CL PCL-Vrtača*** *** Connecting OHL for connection of SS Vižmarje*** *** Connecting OHL for connection of SS Vevče*** ***

Dolenjska, Bela krajina and Posavje regions 110 kV OHL 2 x 110 kV Brestanica-Hudo (reconstruction)* OHL 2 x 110 kV Grosuplje-Trebnje** *** OHL 110 kV Kočevje-Hudo (reconstruction)** Connecting OHL for connection of SS Dobruška vas* Connecting OHL for connection of SS Mokronog** Connecting OHL for connection of HPP Mokrice* OHL 2 x 110 kV Kočevje-Črnomelj*** ***

Primorska region 110 kV OHL 2 x 110 kV Divača-Nova Gorica* OHL/CL 110 kV Koper-Izola* OHL/CL 110 kV Lucija-Izola* OHL 2 x 110 kV Divača-Koper (reconstruction)* OHL 2 x 110 kV Divača-Pivka-Ilirska Bistrica (reconstruction)* OHL 2 x 110 kV Pivka-Postojna (adding a second system)* OHL 2 x 110 kV Žiri-Logatec** *** OHL 110 kV Koper-Buje (reconstruction)* OHL 110 kV Gorica-Ajdovščina (reconstruction)* Connecting OHL for connection of SS Hrpelje*/** Connecting OHL for connection of SS Luka Koper*/** Connecting OHL for connection of SS Divača*** *** Connecting OHL for connection of SS Kras*** ***

Koroška and Savinjska Valley regions 110 kV OHL 2 x 110 kV Dravograd-Velenje* 110 kV CL SS 220/110 kV Ravne-Železarna Ravne*/** Connecting CL for connection of SS Vojnik* Connecting OHL for connection of SS Zreče*/**

Gorenjska region 110 kV OHL 2 x 110 kV Kamnik-Visoko** 110 kV CL Jeklarna-Železarna-Jesenice* Connecting OHL for connection of SS Brnik** Connecting OHL for connection of SS Trata**

Štajerska and Pomurje region 110 kV OHL 110 kV Murska Sobota-Lendava** OHL 2 x 110 kV Lenart-Radenci** OHL 2 x 110 kV Maribor-Murska Sobota (adding a second system)** OHL 2 x 110 kV Maribor-Sladki Vrh** Connecting OHL for connection of SS Dobrovnik** * Investment in ELES’ domain. ** Investment in the domain of another company. *** Investment in domain of other company and has been placed on the list of the required investments in the event of an extensive electrification and integra- tion of additional RES (ambitious variant of distribution companies). */** Investment in domain of ELES and other company (co-investment) 53 Table 6.2: Necessary investments in new substations by 2030 Object 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030

400 in 220 kV voltage level SS 400/110 kV Cirkovce* SS 220/110 kV Ravne*/** SS PSP Kozjak**

Central Slovenia and Zasavje region 110 kV SS LCL*/** SS Brdo** SS Rudnik** *** SS Vodenska** SS 110/20 kV Vrtača*** *** SS 110/20 kV Vižmarje*** *** SS 110/20 kV Vevče*** *** SS 110/20 kV Komenda*** ***

Dolenjska, Bela krajina and Posavje regions 110 kV SS Dobruška vas*/** SS Mokronog**

Primorska region 110 kV SS Hrpelje*/** SS Izola*/** SS Luka Koper*/** ENP Črni Kal** SS Divača*** *** SS Kras*** *** SS Kobarid*** ***

Koroška and Savinjska Valley regions 110 kV SS Zreče*/**

Gorenjska region 110 kV SS Brnik** SS Kranjska Gora** SS Trata**

Štajerska and Pomurje region 110 kV SS Dobrovnik** SS Kidričevo*** *** SS Murska Sobota 2*** *** * Investment in ELES’ domain. ** Investment in the domain of another company. *** Investment in domain of other company and has been placed on the list of the required investments in the event of an extensive electrification and integra- tion of additional RES (ambitious variant of distribution companies). */** Investment in domain of ELES and other company (co-investment) 54 6.2.1.1 Projects of common interest (PCI)

The Projects of Common Interest are • Italy–Slovenia interconnection between Slovenia-Italy« (financial incentive of energy infrastructure projects of Euro- Salgareda (ITA) and Divača-Beričevo EUR 200,000). In November 2016, ELES pean importance, which, in addition to (SI) region; applied for the second time for CEF their importance in terms of the nation- • SINCRO.GRID project from the thematic funds, with the 1st phase of project SIN- al economy, present key projects for the area of smart grids. CRO.GRID, for which it received EUR 26.9 development of the European energy million. ELES applied to the CEF tender network, establishment of an internal The projects of common interest are en- again in September 2018 and was suc- electricity market and pursuing goals titled to financial assistance in the form cessful with two applications. The first of the European energy policy. On the of non-reimbursable aid for studies, work application was the 2nd phase of the basis of Regulation (EU) No 347/2013, and projects in the area of smart grids. project SINCRO.GRID; it obtained EUR the list of projects of common interest is For this purpose the Connecting Europe 1.6 million of funds for the project, while made every two years. In line with the Facility (CEF) was established to provide the second application was in the area delegated Commission Regulation (EU) European Union funding. of works for construction of the double 2020/389 of 31 October 2019, the fol- circuit 400 kV OHL Cirkovce-Pince and lowing ELES projects are included on the In 2014, ELES applied, for the first time, substation 400/110 kV Cirkovce. For this list of projects of common interest: to the first tender of the CEF program purpose, ELES was approved co-financ- with the project Italy-Slovenia intercon- ing of EUR 48.2 million. • Interconnection between Cirkovce (SI) nection and with the study titled “Study and Žerjavinec (CRO) / Heviz (HU) – dou- and validation of the optimal technolo- ble circuit OHL 400 kV Cirkovce Pince; gies for submarine/terrestrial line HVDC

6.2.2 SECONDARY EQUIPMENT

In addition to investments into new Due to the acquisition of energy infra- lines, connections and substations, in- structure from generation and distri- In addition to vestments into the secondary equip- bution companies and from direct con- ment are also essential in order to main- sumers and its inclusion into company’s investments into tain the necessary level of operational control system, ELES also plans imme- primary eletrical reliability. In the coming ten-year pe- diate urgent equipment adjustments in equipment, riod, ELES plans reconstructions of the line with EZ-1 [2] and the Decree on the secondary equipment at substations division of the 110 kV network into the investments into the Krško, Okroglo, Gorica, Dekani, Cerkno, distribution and transmission systems secondary equipment Vrtojba, HPP Medvode, Sežana, Pivka, [26]. Reconstructions of secondary sys- are essential in order to HPP Boštanj, HPP Blanca, HPP Krško, HPP tems following the acquisition will be Mavčiče, Radeče, Brežice, PSP Avče, Bres- necessary at substations HPP Vuzenica, maintain the necessary tanica, Moste, Laško, Rače, Ruše, Ptuj, HPP Ožbalt, HPP Vuhred and HPP Dra- level of operational Breg, TE-TOL and Koper. vograd. reliability. 55 6.2.3 ACQUISITION OF 110 KV TRANSMISSION NETWORK OWNED BY OTHER COMPANIES

ELES already purchased the major part • 110 kV switchyards: HPP Doblar, HPP of the 110 kV transmission devices and Formin, HPP Dravograd, HPP Fala, the corresponding transmission network HPP Ožbalt, HPP Vuhred, HPP Vuzeni- between 2014 and 2020 and also made ca, Železarna Jesenice, Jeklarna; a proposal to the Ministry of Infrastruc- • 110 kV transmission lines: 110 kV ture and the Ministry of Finance in the OHL Moste–Železarna, 110 kV OHL framework of the EZ-1 amendment to Moste–Jeklarna and 110 kV OHL extend the deadline for the remaining Jeklarna–Železarna; network acquisition from three to eight • objects that will be listed in the years. Despite the proposal, ELES is plan- amended Decree on the division of ning to continue taking over those 110 the 110 kV network into the distribu- kV transmission devices which appraisal tion and transmission systems [26]. values will be equal to or lower than the current book values. These are: 56 6.3 OTHER INVESTMENTS PRIORITIES IN THE NEXT 10-YEAR PERIOD

6.3.1 SINCRO.GRID PROJECT

The SINCRO.GRID project is the Europe- countries in the region. The project in- of which EUR 40.5 million was obtained an project of common interest (PCI) in cludes the deployment of compensation from the CEF (Connecting Europe Facility) the area of smart grids of the two neigh- devices, an advanced dynamic thermal fund and EUR 59.3 million EUR is ELES’s bouring countries of Slovenia and Croatia rating system, a battery energy storage share in the entire project. SINCRO.GRID (ELES, HOPS, SODO and HEP-ODS) and system, integration of distributed RES, is divided into 11 activities and has been offers an innovative system integration and a virtual cross-border control centre on-going since 2015; it is currently in the of mature technologies whose synergy with pertaining information and telecom- completion phase of its implementation, will benefit the electric power systems munications infrastructure. The value which will be completed in 2022. of Slovenia and Croatia, as well as other of the entire project is EUR 88.6 million,

6.3.2 NEDO PROJECT

In November 2016 the representatives of of cooperation within the framework utilise available sources from all voltage the Slovenian Government and ELES on of the Slovenian-Japanese partnership. levels for effective operation of the com- one side, and the Japanese New Energy The NEDO project is designed to set up plete system. The substantive focus of the and Industrial Technologies Develop- advanced network management and project is on secondary voltage control us- ment Organization (NEDO) and the Hi- operating systems that combine all volt- ing battery energy storage systems, volt- tachi company on the other side, signed age levels of the power system into an age control, and the inclusion of active official agreements on the beginning efficient whole, and whose purpose is to consumers.

6.3.3 SUMO PROJECT

The SUMO project integrally connects the transmission capacities regarding current operator to transparently use the results. Dynamic Thermal Rating (DTR) technol- and forecasted atmospheric conditions In the period from 2017 to 2020, SUMO ogy with N and N-1 security analyses. It and loading of the transmission network. enabled the network’s operation above provides the transmission system oper- SUMO project results are integrated in the static thermal limit more than a few ator with a transparent assessment of SCADA/EMS, which allows the network dozen times. 57 6.3.4 ELES BERIČEVO TECHNOLOGY CENTRE

The new Technology centre ELES Beričevo and ensure the possibility of the future ELES also plans the implementation of represents a strategic, technological and development of ELES’ activities. The first the third phase, which represents the con- development centre of ELES with which phase of the project was already conclud- tinuation of the concept of constructing the company will ensure a higher level ed in 2018, while the second construction the Technology centre ELES Beričevo as of reliability of Slovenian power system, phase is currently in progress, which as- a whole and combines all phases, except reduce the number of equipment out- sumes the construction of areas for the for the phase of constructing a central ages, faster elimination of transmission critical technological part that represents warehouse. The expected start of the infrastructure failures, reduce risks relat- the national and regional operation cen- third phase is in 2022 and is expected be ed to the existing location at Hajdrihova tre and additional office and technologi- completed by 2030. 2 and the existing inappropriate objects cal areas.

6.3.5 BATTERY ENERGY STORAGE SYSTEMS

ELES encounters problems primarily in solutions to such problems, ELES has fo- project. Within the scope of this project, the areas of secondary control of active cused on modern battery energy storage ELES will install 10 MW of advanced lithi- power and frequency, for which there are systems and set the long-term goal of um-ion battery storage system. Alongside insufficient quantities of reserves in the installing electricity storage systems that the SINCRO.GRID project, the installation Slovenian power system, while the qual- will participate in secondary frequency of battery energy storage system is also ity of such services is not satisfactory, control. Battery energy storage systems planned within the scope of NEDO pro- primarily due to the technical limitations are one of the main building blocks of the ject. of generation sources. In searching for international SINCRO.GRID smart grid

6.3.6 COMPENSATION DEVICES FOR VOLTAGE CONTROL

Voltage control compensation devices The classic sources of ancillary system and flexible way. After devoting numer- are a technically advanced and tested services are often not up to the challenge, ous activities to the concept of installing solution for ensuring quality electricity. which is why, to avoid critical situations, compensation devices in the past, ELES The implementation is the answer to in- ELES is establishing a long-term autono- started implementing the concept within creasingly frequent voltage fluctuations mous control of the voltage profile with the scope of the European/international and extreme situations introduced into its own sources and the coordinated man- SINCRO.GRID project, expected to end in the network by new generation technol- agement of these sources, which will pro- 2022. ogies, operating events and social factors. vide for their coordinated, cost-efficient 58 6.3.7 CONSTRUCTION OF AN ADVANCED INFRASTRUCTURE FOR THE PROVISION OF FLEXIBILITY SERVICES FROM ELECTRIC VEHICLES - THE E8 CONCEPT

By implementing its own pilot project in project, ELES is establishing a suitable experience that it may then share with electromobility, the activities of ELES are environment for the sustainable develop- other stakeholders related to the develop- mainly focused on ensuring sustainable ment of electromobility and for achieving ment of electromobility and also encour- mobility and restricting the negative im- the national goals in this area. By being age other companies and potential users pacts of electric vehicle charging on the engaged in and developing own guided of the charging infrastructure to imple- power system operation. With the pilot charging algorithms, ELES will obtain the ment guided charging stations. 59 6.4 RESEARCH AND DEVELOPMENT ACTIVITIES

ELES successfully completed a series of its • Defender project research and development projects in the (https://defender-project.eu/) past two years: • TDX-ASSIST project • FutureFlow project (http://www.tdx-assist.eu/) (https://www.futureflow.eu/) • MIGRATE project The chapter presents the new research (https://www.h2020-migrate.eu/) and development projects that are cur- • BioEnergyTrain project rently on-going at ELES. (http://www.bioenergytrain.eu/)

6.4.1 OSMOSE PROJECT

The OSMOSE project (https://www.osmo- 21.85 million (ELES’ share: EUR 654,431, of solutions and sources of flexibility. The se-h2020.eu/) is a four-year international of which EUR 458,101 is co-financed by demonstration, coordinated by ELES and research project that includes 33 partners the EU). The system operators (RTE, REE, which includes TERNA and RTE, is direct- from nine European countries. The value TERNA and ELES) that are part of the ed towards cross-border cooperation in of the entire project is EUR 28 million, of OSMOSE project will conduct four demon- exchanging flexibility sources between which the European Union, through its strations in order to increase the tech- energy markets close to real time. Horizon 2020 programme, finances EUR no-economic potential of a wide range

6.4.2 FLEXPLAN PROJECT

The FlexPlan project (Horizon 2020, is EUR 4.4 million. The main purpose of technologies for ensuring network flexi- https://flexplan-project.eu/) is a three- the project is to establish an innovative bility, which will enable the reduction and year international development project methodology and tools for network plan- optimisation of the network development that includes 13 partners from eight Eu- ning. In addition to classic investments, costs in the future. ropean countries; the value of the project the tool will consider the inclusion of new

6.4.3 INCIT-EV PROJECT

The INCIT-EV project (Horizon 2020, with the comprehensive infrastructure is also to research the behaviour of elec- https://www.incit-ev.eu/) is a four-year in- development concept for mass charging tric vehicle users by using the most ad- ternational research project that includes of electric vehicles E8, developed by ELES, vanced neuroscience techniques. Based 32 partners from eight European coun- which is why ELES is part of the work on the acquired results, the partners will tries. The main purpose of the project, the package that is meant to develop the prepare recommendations that will serve total value of which is EUR 18.6 million, application and services for managing, the decision-makers in the electric mobili- is to demonstrate friendly electric vehicle controlling and optimising the charging ty area as the starting points for planning charging solutions to users to promote infrastructure in order to ensure friendly and developing a user-friendly charging mass usage of electric vehicles in Europe. charging and driving of electric vehicles infrastructure. The project has been designed in line to users. An important part of the project

6.4.4 ONENET PROJECT

The OneNet project (Horizon 2020) is for a coordinated cross-border operation and flexible architecture that will help a three-year international project that of the transmission and distribution elec- reshape the European electricity system includes 72 partners from 21 European tricity network system operators by es- that is currently managed on national or countries, the value of which is EUR 28 tablishing new markets of flexibility. The regional levels. million. The partners will seek solutions aim of the project is to develop and open 60 6.4.5 INTERRFACE PROJECT

The Interrface project (Horizon 2020, ket adopted by the EC that promote the of solutions and placement of demonstra- http://www.interrface.eu/) is a four-year collaboration between operators in ensur- tion pilot projects, while it also cooperates international research project that in- ing electricity balancing market services, tightly with the Energy Agency regarding cludes 42 partners from 16 European managing transmission network conges- the option of establishing flexibility mar- countries; the value of the project is EUR tions and other system ancillary services. kets on the distribution level in the future 20 million. The project is an answer to the ELES is cooperating in the project as an and their impact on the operation of the legislative proposals on the energy mar- observer and assessor in the development transmission system and its stability.

6.4.6 BD4NRG PROJECT

BD4NRG (Big Data for Next Generation complete; its assessed value is EUR 11.8 management. We will explore the flexi- Energy) is a project of a consortium that million. ELES is bringing professional com- bility and ways in existing workflows for includes more than 30 companies and re- petencies from system operations and abstract improvements and the possible search institutions from the EU member high-voltage infrastructure management, integration of market transaction needs states in the framework of the research and a digital laboratory for pilot testing in defining infrastructure maintenance and innovations programme Horizon into the project. The project will combine schedules and predictive activities. 2020. The project is set to start in Jan- the advantages of modern business ana- uary 2021 and will take 36 months to lytics with the activities of physical asset 61 6.4.7 ACTIVITIES IN THE AREA OF DEMAND RESPONSE AND DISTRIBUTED GENERATION

At ELES we are devoting intensive efforts • the inclusion of electricity consumers • the SINCRO.GRID project – an inter- to the development of new solutions, as and small DG devices in annual pur- national project designed to upgrade the potential of demand response and chase of ancillary services; the steering and control platform for dispersed generation is an important • the eBADGE project – a pioneer pro- demand control and DG; factor in ensuring the reliability of oper- ject of adapting consumption in Slo- • construction of ELES’ own system re- ation and balancing power system. The venia, the results of which are already serves from diesel electric generators solutions or measures in exploiting the implemented in practice by the sys- (DEG); potential of managing the adaptation of tem operator and other companies; • the construction of an advanced in- consumption that have been or are being • the FutureFlow project - an inter- frastructure for the provision of flex- implemented are the following: national project where ELES and its ibility services from electric vehicles partners researched solutions and (the E8 concept), which includes the encouraged consumers and the dis- introduction of electric mobility and tributed generation to ensure flexible guided charging of vehicles as one services for power system needs; of the options for offering flexibility services.

6.4.8 SYSTEM RESERVE FROM DG SOURCES OF UNINTERRUPTED POWER SUPPLY – DIESEL ELECTRIC GENERATORS

A minor technological upgrade and ag- the successful testing on one DEG and In 2021, ELES plans to upgrade the DEG gregation of DEG into a virtual power acquiring a positive opinion from the En- fleet. The IT platform, which, in addition plant and the establishment of a connec- ergy Agency, ELES is continuing activities to the aggregation and management of tion in the management system would for establishing a source of mFRR from 15 sources, also ensures integration with all increase the utilisation of these devices, DEGs in a total nominal active power of the back-end information systems, has because DEG would also offer mFRR in 4.188 MW. been completed and is ready for the in- addition to its basic function. Following clusion of the remaining DEG.

6.4.9 WAMPAC

The purpose of the WAMPAC (Wide Area displaying the information of the event reduce or limit the impact of disturbanc- Measurement, Protection and Control Sys- to the operator in a clear and transpar- es. The WAMPAC system will also be of tem) is to detect and locate disturbances ent way. It is planned that the WAMPAC great assistance in the system restoration in EPS on the basis of the high resolution system will carry out pre-set measures in from islands and coupling networks from and synchronised phasor measurement case of detected disturbances (stability is- a de-energised state. units and advanced algorithms, while sues and system oscillations) and by this

6.4.10 COUNCIL FOR RESEARCH AND SCIENTIFIC ACTIVITY

As a response to the modern trends in secondary and tertiary education and entific achievements into the economic the international electricity sector, ELES ensure sustainable financing sources for environment to promote technical, tech- established the Council for research and Masters degrees and candidates of doc- nological and life sciences among young scientific activity. The tasks of the Coun- toral study programmes in areas related people and to strengthen education in cil are to establish an organised system to the company. ELES is committed to Slovenian schools and faculties. of long-term exchange of expertise with an intensive transfer of research and sci- 62 6.5 ASSESSMENT OF INVESTMENTS BY 2030

In this network development plan for the est source are long-term loans. An im- and company business operations. The period from 2021 to 2030, ELES is plan- portant 12-percent share in sources of fi- common denominator of all the planned ning to invest EUR 528 million by 2030. nancing is represented by financial grants investments in the development plan Taking into consideration the needed obtained from European funds. The esti- is that they are all directed towards im- financial resources for the acquisition of mated investments for the next ten-year plementing ELES’ mission, vision and the 110 kV transmission network owned period until 2030 are shown in Figure 6.2; values. The realisation of the planned by other companies, the total investment the entire set of investments in all areas investments will have an impact on the value is EUR 530 million. ELES is thus in the period leading to 2030 is shown in reliability of the supply and the price of entering into its largest investment cy- [1] in Table 7.8 (chapter 7.5). electricity, on the higher production of cle since its establishment, whereby it is the Slovenian economy and on the in- focusing on completing a series of large Investments have multi-layered impacts crease of the gross domestic product. In investment projects and research and de- both for the domestic economy and addition, the realisation of the planned velopment activities of smart grids and electricity network users as well as for investments will increase the competi- concepts for increasing the utilization of the European energy infrastructure, for tiveness of the Slovenian economy on the the existing transmission network. The the strengthening or preserving of the global market, which means that higher bulk of the financing sources are from national electricity network, meeting positive economic effects can be expect- company equities, while the second larg- the set environmental and energy goals ed at the increased realisation.

Investments [mio EUR] 160 Figure 6.2: The estimated investments for the period from 140 2021 to 2030

120 Primary equipment - substations 400 kV, 220 kV, 110 kV 100 Primary equipment - power lines 400 kV, 220 kV, 110 kV 80 Other planned investments 60 Major investments in operations

40 Telecommunications and improvements in information services 20 Secondary equipment (protecton, management, measurements) 0 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 63 6.6 LONG-TERM TRANSMISSION NETWORK DEVELOPMENT

ELES, as transmission system operator primary source of electricity is strongly strategy foresees that in order to increase of the Slovenian transmission network subjected to weather conditions. the operating reliability on one side and to and member of ENTSO-E, contributes ensure sufficient network capacity margin significantly to the development of the Based on the calculations of ENTSO-E on the other side, it will first be necessary trans-European electricity network. One [25], Slovenia is expected to retain its to establish the currently missing connec- of ENTSO-E’s primary goals is to ensure transit status in future and will foreseea- tion with Hungary, which will increase the the transparency of the electricity net- bly be even more exposed to cross-border reliability of the Slovenian transmission work and support decision-making on the power flows in all directions, particularly network, as well as give the option of im- regional and European levels. at the borders with Austria and Italy. In porting and exporting electricity and the favourable meteorological conditions, additional option of exchanging the bal- Based on the projections [15], the most in- mainly due to wind power plants, we can ancing power, thus leading to decreased tensive scenario (Sc4) can lead to 26 TWh expect high, albeit short-term loads at costs of the balancing and the option of of consumed electricity in RS by 2050, the Croatian border. It will be possible to introducing additional competition on which is an 86% increase compared to control these power flow fluctuations to a the ancillary services market. At the same 2018. The transmission network needs will certain extent by means of FACTS devic- time it should be noted that the Sloveni- be lower in this scenario and, based on the es for power flow control or other meas- an transmission network has significantly predictions, they will amount to 16 TWh, ures. However, it should be noted that if higher thermal capacities in comparison which is 27% more than in 2018. The the anticipated extensive development with NTC values, and that the calculations lower value in the transmission network is of the European electric power is realised, of NTC values under the N-1 criterion are due to the large scope of DG in the distri- additional transmission infrastructure will higher for Slovenia than those calculated bution network that assumes the installa- have to be ensured in the next couple of in neighbouring transmission networks tion of 7,700 MW of solar and 500 MW of decades. - these are, in this sense, malnourished, wind power plants. The scope of DG in the which is why ELES is adopting decisions next 30 years will therefore significantly The concept of developing a high volt- with neighbouring system operators on surpass all the current levels, which will age network in the Republic of Slovenia all development activities that extend be- require greater power system flexibility in by 2030 has already been presented in yond the ten-year development plan, and the future. The network of the future will Chapter 6.2 and is based on the clearly set is coordinating timeframes for the con- have to be capable of withstanding rapid long-term strategy of the development of struction of new transmission capacities fluctuation changes in generation, which the ELES company and the electric power with foreign partners is characteristic of energy sources whose network of the Republic of Slovenia. The 64 In line with all of the aforementioned the necessary studies regarding the are presented and shown in the expla- changes in the European power system, method and form of the renovation in nation of the Spatial Planning Strategy ELES is actively studying the possibility the period between 2021 and 2023. In of Slovenia. for developing the network. TERNA and the scope of the renewal process and ELES are thus studying the possibility depending on the neighbouring system Although the construction of a new of establishing a new HVDC connection operators and by considering the Euro- overhead line or transformer still repre- between Slovenia and Italy on the Slo- pean vision regarding the opening of sents a basic function of the transmis- venian-Italian border, which is currently borders, with the accelerated construc- sion network that will remain so in fu- in the study phase, and an additional tion of projects in priority corridors in ture, the time needed for the execution strengthening of the existing connec- the framework of PCI and the increases of such investments is too long to keep tions (installing conductors with a high- of the interregional transmission ca- up with the rapidly changing energy er transmission capacity). pacities, ELES will also study the long- sector. For this reason one can expect term possibilities of replacing the 220 an increasingly expressed need for op- In the event that aforementioned in- kV interconnections with 400 kV. If the timising the utilisation of the existing vestments are realised, additional 400 kV parts of the network will require electricity network while modernising loading can be expected on the inter- a renovation in the long-term period, its management and utilisation logic, nal transmission network of Slovenia, then the possibilities for partial join- and conferring an active role on the which, in line with growing needs, will ing of electricity corridors will also be operation of the electricity network of be solved by upgrading the internal studied as well as the abandonment the future. Figure 6.3 represents the 220 kV network to the 400 kV voltage of the unnecessary corridors. For the long-term development options of the level – initially in the corridor between construction of 400 kV transmission Slovenian transmission network, which Beričevo and Divača, and then in the lines and for the upgrade from the 220 will have to operate in symbiosis with Beričevo-Podlog-Cirkovce corridor. ELES to the 400 kV voltage level, which will the other advanced technologies, both also placed the start of the process for require additional investments in the in the form of storing energy as well as renewing the entire 400 and 220 kV future, the existing buffer zones or par- in intersectoral linking. network into its current development allel reserved corridors will need to be plan, whereby ELES plans to carry out used to the highest extend possible, as

Figure 6.3: Long-term development options of the Slovenian transmission network

PSP Kozjak SS Ravne SS Maribor

SS Cirkovce TPP Šoštanj

SS Okroglo SS Podlog

SS Kleče SS Avče SS Beričevo New object – in 10-year development plan SS Okroglica Object – upgrade SS Krško New object Object – existing SS Hudo 400 kV – new/parallel line 400 kV line – upgrade from 220 kV SS Divača 400 kV – new line HDVC New line – in 10-year development plan 400 and 220 kV – existing network 65 66 67

07 CONCLUSION 68

Conclusion

One of the main purposes of the Network Development Plan of the Republic of Slovenia from 2021 to 2030 is to present investments in the various parts of the Slovenian transmission network that will provide adequate transmission capacities and network conditions, ensuring the reliable and high-quality supply of electricity to end users and the fulfilment of the European and Slovenian energy and climate goals.

During the preparation of this develop- The planning has taken into account the ment plan, the Covid-19 epidemic was long-term projections of the growth of The adequacy of the declared, which completely changed the electricity off-take from the transmis- habits of people and introduced new un- sion network, the foreseen construction planning is reflected certainties into the electricity demand of new generation units, the expansion in the fact that the forecasts, not dealt with in the past. It of the distribution network and the transmission network, will leave a mark on the global scale as planned and projected changes in the well as on the economy and society as European transmission network. ELES despite the Covid-19 a whole, whereby the final consequences also considered the guidelines and goals pandemic, operates on the state prosperity and the remain- defined in NECP [5], which, in addition smoothly and provides ing segments cannot yet be predicted. to the European energy policy ([9], [10], Due to the Covid-19 epidemic, which, in [11]) and included them to the high- living and working addition to the existing challenges, intro- est extent possible in the development conditions for the duced an additional element of uncer- scenarios. To achieve the set goals and population, social tainty in planning and managing power to ensure an undisturbed access to the systems, ELES prepared four different de- transmission system and quality elec- systems and the velopment scenarios in its development tricity to all end users of the Slovenian economy. plan by considering expert assessments transmission system, ELES plans to in- and the impact of the epidemic based vest EUR 528 million by 2030. Taking on the currently known assumptions. On into consideration the needed financial the other hand, the Covid-19 situation resources for the acquisition of the 110 made it clear, again, as to how extremely kV transmission network owned by other important the stability and reliability of companies, the total investment value is power system operation is for ensuring EUR 530 million. living conditions, work conditions, social systems and the economy. 69 The costs of ancillary services and the in addressing this issue and has sought establishment of the cross-border ex- solutions in the installation of compen- changes of ancillary services, in line sation devices for voltage profile control, with the network codes, as well as the installation of battery energy storage increase of their scope due to the possi- systems, additional amount of reserves, 530 ble commissioning of new power plants etc (solutions within the framework of MILLION EUR represent another uncertainty in the the SINCRO.GRID and NEDO projects). coming period. In the recent period, Such solutions will also directly increase we have seen the decommissioning of costs of ancillary services and network generation from conventional sources tariffs for the electricity transmission, Amount of investments that, in contrast with the harder-to-pre- which will present an additional direct in the transmission dict RES, were the only ones capable of burden for the end users in the future. network by 2030. providing the ancillary services for se- It needs to be noted here that part of cure and reliable operation of the entire the costs for promoting expensive and power system until today. Thus, there is hard-to-predict RES could be avoided in already a lack of ancillary service provid- the future by including new HPP in the ers in the Republic of Slovenia. Based on transmission network of the Republic of the environmental and energy policy of Slovenia. Slovenia still has an unexploit- the EU, an increase of the RES (mainly ed hydro-potential in this area (middle wind and solar) is to be expected in the Sava river, Mura river, small HPP), how- future, which will result with an even big- ever the activities in this area are being ger challenge for managing the power carried out relatively slowly. system operation. ELES is already active 70

The expected trend of transfer capacity Terms such as microgrids, battery energy needs and the increasingly more difficult storage systems, digitalisation, electric Rapid changes in the siting of power lines will in future require mobility, blockchain technology, flexi- better utilisation of existing overhead bility and other modern terms are being energy sector dictate line routes, using the existing buffer intensively introduced in the energy sec- the search for new zones or parallel reserved corridors. The tor and are outlining the silhouette of a solutions for managing future power system will also need to modern world in which the only constant operate in symbiosis with the other ad- is rapid change. Such a rapidly changing the operation of the vanced technologies, both in terms of environment is a particular challenge for power system, with energy storage as well as in intersectoral the electricity system, which has always an emphasis on new linking. In the future new technologies been seen as more conservative and will gain importance, such as HVDC con- predictable. If, until recently, the energy technologies and nections, implementation or develop- sector was still considered a more tradi- operating concepts, ment of smart grids, upgrade of single tional branch with few changes, the dy- which ELES is actively circuit into two or multi circuit overhead namic pace of changes in past years has lines, introduction of new technologies revealed that precisely the opposite is developing and of compacting overhead line elements, true. With the skills, experiences and the introducing. the implementation of modern tech- know-how that we possess, we will need nologies for reducing the environmental to form a sustainable energy sector for impacts and the technologies of high the benefit of the generations of today temperature low sag conductors. and tomorrow. 71 72 73

08 LITERATURE AND SOURCES 74

Literature and Sources

[1] ELES, Slovenian Network Development Plan from 2021 to 2030, Ljubljana, 19 November 2020. [2] Energy Act EZ-1 (Off. Gaz. of RS, No. 17/2014, 81/2015). [3] Decree on the awarding of a concession and on the method of provision of a service of general economic interest – elec- tricity transmission system operator (Off. Gaz. of RS, No. 46/15). [4] Directive 2009/72/EC of the European Parliament and of the Council of 13 July 2009 concerning common rules for the internal market in electricity and repealing Directive 2003/54/EC. [5] The Government of the Republic of Slovenia, Integrated National Energy and Climate Plan of the Republic of Slovenia, https://www.energetikaportal.si/fileadmin/dokumenti/publikacije/nepn/dokumenti/nepn_5.0_final_feb-2020.pdf [6] ENTSO-E, Ten-Year Network Development Plan 2018, 2018. [7] ENTSO-E, Ten-Year Network Development Plan 2020, 2020, https://tyndp.entsoe.eu/. [8] Regulation (EU) 2018/1999 of the European Parliament and of the Council of 11 December 2018 on the Governance of the Energy Union and Climate Action, https://eur-lex.europa.eu/legal-content/SL/TXT/PDF/?uri=CELEX:32018R1999&from=sl. [9] European Commission, European Green Deal, https://ec.europa.eu/info/strategy/priorities-2019-2024/europe- an-green-deal_en (accessed on 21 October 2020). [10] European Commission, Paris Agreement https://ec.europa.eu/clima/policies/international/negotiations/paris_en. [11] European Commission, European Climate Law, https://ec.europa.eu/clima/policies/eu-climate-action/law_en. [12] RS Government, Slovenian Development Strategy 2030, 2017, https://www.gov.si/assets/vladne-sluzbe/SVRK/Strategi- ja-razvoja-Slovenije-2030/Strategija_razvoja_Slovenije_2030.pdf. [13] Energy Agency, Report on the status of the energy sector in Slovenia in 2019, Maribor, 2020. [14] ELES, Information obtained from producers on the existing and planned generation units by 2030, Ljubljana, 2020. [15] EIMV, Updating the predictions of developing the electricity offtake at the transmission network of the Republic of Slovenia by 2054, Ljubljana, 2020. [16] EC, “Spring 2020 Economic Forecast: A deep and uneven recession, an uncertain recovery,“ EC, Brussels, May 2020. [17] UMAR, COVID-19 Scenario, Ljubljana, April 2020. [18] EIMV, Electricity generation adequacy in Slovenia, Ljubljana, 2018. Evropska komisija, Pariški sporazum (Paris Agreement) https://ec.europa.eu/clima/policies/international/negotiations/par- is_en. 75

[19] Regulation (EU) 2017/2195 on establishing a guideline on electricity balancing, https://publications.europa.eu/en/publica- tion-detail/-/publication/39af0e7c-d408-11e7-a5b9-01aa75ed71a1/language-sl, November 2017. [20] ELES, Rules, terms and conditions for balancing service providers on the ELES balancing market, Ljubljana, May 2018, https://www.eles.si/Portals/0/Novice/avkcije/sistemske%20storitve/T%26C%20za%20PSI/Pravila%20in%20pogoji%20 za%20PSI.pdf. [21] Regulation (EU) 2017/1485 of 2 August 2017 on establishing a guideline on electricity balancing, https://eur-lex.europa.eu/ legal-content/SL/TXT/PDF/?uri=CELEX:32017R1485&from=sl. [22] ELES, Network code for the electricity transmission system, http://www.pisrs.si/Pis.web/pregledPredpisa?id=NAVO1112, 7 May 2016. [23] Commission Regulation (EU) 2015/1222 establishing a guideline on capacity allocation and congestion management, http:// publications.europa.eu/en/publication-detail/-/publication/b91aa370-3293-11e5-9f85-01aa75ed71a1/language-en, July 2015. [24] Commission Regulation (EU) 2016/1719 establishing a guideline on capacity allocation, http://eur-lex.europa.eu/legal-con- tent/EN/TXT/?uri=CELEX%3A32015R1222, September 2016. [25] ENTSO-E, Completing the map – Power System Needs in 2030 and 2040, https://eepublicdownloads.entsoe.eu/tyndp-doc- uments/IoSN2020/200810_IoSN2020mainreport_beforeconsultation.pdf. [26] The Government of the Republic of Slovenia, Decree on the division of the 110 kV network into the distribution and transmis- sion systems, (Official Gazette of RS, No. 35/15), http://www.pisrs.si/Pis.web/pregledPredpisa?id=URED6103, 2015. [27] ENTSO-E, Identification of system needs methodology, Brussels, Belgium, 2019. [28] European Commission, regulation on establishing a network code on electricity emergency and restoration (NC ER), 2017, https://eur-lex.europa.eu/legal-content/SL/TXT/PDF/?uri=CELEX:32017R2196&from=EN. [29] ENTSO-E, The Synchronous Area Framework (SAFA) for the ENTSO-E Regional Group Continental Europe, 14 April 2019, Brussels. [30] ELES, System Restoration Plan, December 2018, Ljubljana Title: SLOVENIAN NETWORK DEVELOPMENT PLAN 2021–2030 Issued by: ELES, d.o.o., Hajdrihova 2, 1000 Ljubljana Production: AV studio d.o.o. Photographs: Arhiv ELES, d.o.o., Boštjan Barl, archive Naš stik, Dobran Laznik, Marko Kolenc, Samo Vidic Date of production: 19 November 2020 Date of issue: June 2021 EXISTING AND PLANNED ELECTRICAL TRANSMISSION NETWORK IN THE REPUBLIC OF SLOVENIA

RTP Mačkovci

Kainachtal

RTP Sladki Vrh RTP Dobrovnik

RTP Murska Sobota RTP Koroška vrata RTP Radenci RTP Dravograd Obersielach HE Vuzenica (Na Selu) ČHE Kozjak HE Mariborski RTP Tezno RTP HE Dravograd otok RTP Radvanje Melje RTP Lenart RTP Vuzenica HE Vuhred HE Fala RTP Ravne HE Ožbalt RTP Lendava Heviz RTP RTP Podvelka RTP RTP Ljutomer Dobrava Pekre Pince Žerjavinec RTP Železarna Ravne RTP TP TP RTP Ruše Maribor RTP Slovenj Gradec Karbid Korund RTP Kranjska Gora HE Zlatoličje 1x RTP Jesenice RTP Rače 35 k V RTP Ptuj HE Formin RTP Železarna Jesenice RTP Jeklarna Jesenice RTP Ormož RTP Slovenska RTP Cirkovce RTP TE Šoštanj RTP Zreče Bistrica HE Moste RTP Velenje V k RTP Slovenske 0 2 x 1 RTP Kidričevo RTP Ptuj RTP Mozirje Konjice RTP Tržič Breg Nedeljanec V k

0 2 RTP x 2 Radovljica kV RTP 0 x2 RTP Zlato polje RTP Nazarje 1 Podlog-DES RTP Vojnik

RTP Bohinj 1x110 kV1 RTP Trnovlje x1 RTP RTP Rogaška Slatina 10 RTP Okroglo k V RTP Kobarid V k 20 Brnik 2x RTP RTP Podlog Žerjavinec RTP Železniki RTP 1x20 kV 1x10 kVPrimskovo 1x110 kV RTP Lava 1 Komenda x35 k RTP Žalec RTP Lipa V RTP Kamnik 1x RTP Selce

20 kV RTP Labore

1

1 x

RTP x 1

2 RTP Šentjur 1

1 0 0

x

3 k

5 k k Trata V

RTP Tolmin V HE Mavčiče V RTP RTP Mengeš RTP Laško RTP Škofja Loka Vodenska V k 20 RTP Črnuče 1x kV 0 RTP Domžale 11 RTP Potoška vas 1x HE Medvode RTP Hrastnik ČHE Avče HE Doblar RTP Vižmarje HE TE RTP Kleče RTP Cerkno Trbovlje Trbovlje RTP Anhovo RTP Beričevo HE RTP Litostroj RTP Žiri Suhadol RTP Radeče RTP Šiška RTP Polje RTP Bežigrad RTP Litija HE Vrhovo HE Plave RTP Žale RTP Vevče HE Boštanj RTP Brdo RTP RTP TE RTP Idrija TE-TO RTP Sevnica RTP Vrtača LCL Brestanica HE Solkan RTP Ljubljana LEGEND RTP Vič Rudnik RTP Center SUBSTATIONS (SS) RTP Nova Gorica HE Arto-Blanca RTP PCL Switching SS 110 kV HE Krško RTP Vrhnika RTP Grosuplje JE Krško Distribution SS 110/X kV RTP Mokronog RTP Krško-DES Planned new SS 110 kV Planned new SS 110 kV - ambitious scenario Redipuglia RTP Logatec (Sredipolje) RTP Ivančna RTP Krško Traction SS RTP Vrtojba Gorica RTP Trebnje HE Brežice Planned traction SS RTP Brežice Redipuglia Planned new SS 220 kV (Sredipolje) RTP Dobruška HE Mokrice Tumbri RTP Ajdovščina vas Upgrade of SS 220/110 kV to SS 400/(220)110 kV SS 400/110 kV

RP Hudo kV RTP Kras 20 RTP Ločna Planned new SS 400/110 kV RTP Bršljin SS 400/220/110 kV RTP Cerknica Phase shifting transformer

RTP Gotna vas LINES

RTP Postojna RTP Ribnica 1

1 110 kV OHL

x

x

1

2

1

0

0

k

k Planned new 110 kV OHL

V V Upgrade of 110 kV OHL to double 110 kV OHL RTP Sežana RTP Divača Double 110 kV OHL Planned new double 110 kV OHL ENP Planned new 110 kV line - ambitious scenario Divača Padriciano RTP Pivka RTP Kočevje 110 kV cable line (Padriče) Planned new 110 kV cable line Zaule RTP Metlika 220 kV OHL (Žavlje) Planned new double 220 kV OHL RTP Hrpelje 400 kV OHL RTP Luka Double 400 kV OHL Koper ENP RTP Ilirska Bistrica Planned new double 400 kV OHL Črni Kal RTP Črnomelj RTP Izola POWER PLANTS V RTP Dekani 2x20 kV k 20 1x Hydro/pumped storage power plant kV ENP 0 V 11 x20 k 1x 1 kV Thermal power plant 1x110 RTP Dekani RTP Lucija Koper Nuclear power plant Planned new hydro/pumped storage power plant Planned new thermal power plant Matulji Melina Pehlin

Source: ELES, d.o.o., distribution and generation companies Map: Surveying and Mapping Authority of the Republic of Slovenia Buje Year: 2020

0 10 20 30 40 km NETWORK PLANNING DEPARTMENT