Making the energy transition in Germany successful by pumped storage expansion

Transcription

1 Making the energy transition in Germany successful by pumped storage expansion Dr. Klaus Krüger, Voith Hydro Holding, November 11th 2014, Brasilia Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro PSP Goldisthal, 1060 MW, head: 300m, 8,5 GWh 1 el

2 Content German energy transition in the power market ( Energiewende ) Study on a pumped storage expansion with renewable energy production shares of 60% in 2030 and 80% in 2050 Pumped storage plant (PSP) contribution for reliable available capacity and for avoiding curtailments of renewables Economic and ecological benefit of a PSP expansion Conclusions of the study Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 2

3 What has basically changed? In previous German energy transitions (e.g. coal to oil in the 60s- 70s; oil & coal to nuclear in the 70s- 90s ) just the primary energy carriers have been exchanged while the system architecture for electrical energy remained unchanged. In the past system architecture, energy storages were not of central importance for system stability because thermal power plants offer sufficient reliable available capacity and the residual load was never below zero. So far energy storage has been undertaken by nature by means of the primary energy carriers coal, gas, uranium or oil. The power generation followed afterwards as needed, i.e. the sequence has been first storage and after that generation. Electricity from wind and solar is generated intermittently and this generation is detached from the demand. The sequence of energy storage and generation has been changed. Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 3

4 Forecasted break-down for installed power plant capacity 2020, 2030 and 2050 *) in Germany 250 German national peak-load: 83 GW GW 46 GW 56 GW 57 GW 65 GW 80 GW solar wind hydro biomass CHP geothermal conventional CHP 50 gas black coal lignite 2014: wind 35,4 GW, solar 36 GW (peak), nuclear: 12,6 GW (will be shut down until 2022) *) Nitsch, J., et al.: Pilot study of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), 2010 Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 4

5 German energy transition: a new phase started 2000 due to subsidization of wind & solar StrG: Stromeinspeisegesetz / former German Electricity Feed-in Act EEG: Erneuerbare-Energien-Gesetz / German Renewable Energy Act Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 5

6 ... but with a negligible contribution to reliable available capacity ( potencia assegurada ) MW installed wind & solar power by the end of 2011 and their contribution to reliable available power installed power reliable available capacity Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 6

7 Principles for Generation Adequacy Analysis *) Reliable available capacity = net generating capacity - system reserves - outages - overhauls - not usable capacity Reliable available capacity share of the nominal power: 90% fossil & nuclear power plants, 70% to 90% storage and pumped storage power plants 5-8% wind farms off-shore 1% wind farms on-shore 0% solar *) ENTSO-E: System Adequacy forecast SAF Online: Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 7

8 Problems lie with what many view as the solution: electricity from wind and solar power *) Ecologically speaking, there are strong arguments in favor of new renewable energies. But they also entail technical risks: Electricity from solar and wind power is generated intermittently. If we want a 30% share of this weather-dependent electricity, we get 100% in good conditions but 0% when conditions are bad. It's a case of feast or famine! This may lead to an unstable and costly electrical energy system because we need: much more transmission grid capacity, still lots of reserve & backup thermal power plants and storage capacities and flexibility to compensate the volatility of wind & solar. *) View of a Swiss utility on the German energy transition. Source: Hans E. Schweickardt, Chairman of Alpig Holding SA, Switzerland: The energy transformation in Germany multiple implications for Swiss utilities, PLATTS European Power Summit, Berlin, April 28th,

9 Why does Germany need new transmission grid capacity? 9 Decentralized feed-in of wind & solar has to be integrated into the existing electricity system, which was designed for a different scenario Main wind sources are in the North, main consumers are located in the South of Germany 300 GW 200 Generation Scenarios (by German regulator) Reference A B C B Nuclear Lignite Hard coal Natural gas Mineral oil Pump storage Misc. conventional Wind on-shore Wind off-shore Solar Biomass Hydro Wind Solar Source: IAEW

10 10 Consequences & related investment cost 51 projects to be realized until 2022 have been approved 2,900 km within existing line corridors 2,800 km within new line corridors Pilot projects 8 HVDC projects 2 HVDC on-shore cable projects 1 high temperature conductor project 4 HVDC transmission corridors Transmission capacity: 28 GW Line length: 3,100 km Total investment costs of 20 bn. Open questions Realization of the projects until 2022? Technical challenges?

11 Feed-in / load Generation Scheduling requires increasing Flexibility Demand Compare German RE 2014 and 2034 exemplary week 80 GW GW MO TU WE TH FR SA SU MO TU WE TH FR SA SU Windenergie Photovoltaik Solar Nachfrage Demand Wind and solar feed-in will exceed demand temporarily in future Additional must-run on top E. g. biomass, combined heat and power plants Grid network constraints due to network topology and operations Besides, renewable generation capacity rarely fits the demand Flexibility and reliable available capacity are crucial to cover volatile residual load

12 Marginal generation costs 12 German Merit Order 2013 effect Renewables (RE) do not have appreciable marginal generation costs National subsidies leading to demand-independent renewable feed-in, which distorts the energy market. Lots of sun and wind drive market prices down. MWh load/ demand generation/ supply supply curve shifted, due 5 GW RES Equilibrium with 5 GW RES Equilibrium without RES nuclear lignite hard coal natural gas oil Accumulated thermal generation stack Conventional generation are pushed out of market and earn decreasing prices However: Conventional fossil generation still needed for system adequacy MW

13 The study Voith Hydro has contracted the Institute of Power Systems and Power Economics*) of RWTH Aachen with a scientific study in 2013 **). The simulation was based on the entire German power plant park modelled by IAEW using a dedicated plant scheduling optimization tool. The following scenarios were considered: 2030: 60 % of renewable energies (RE) in the generation 2050: 80 % of renewable energies (RE) in the generation Evaluation of the pumped storage (PSP) as multifunctional power plant for short-time storage purposes (e.g. daily cycling) providing reliable available capacity Further ancillary services like spinning reserve, compensation of RE forecast errors, congestion management, etc. have not been considered or evaluated. *) Institut für Elektrische Anlagen und Energiewirtschaft (IAEW), Prof. Moser, RWTH Aachen **) Moser, A., Rotering N., Schäfer, A.: Unterstützung der Energiewende in Deutschland durch einen Pumpspeicherausbau Potentiale zur Verbesserung der Wirtschaftlichkeit und der Versorgungssicherheit (im Auftrag der Voith Hydro). IAEW RWTH, Aachen, 4. April 2014, Online: 13

14 Questions which the study answers: 1. To which extent can pump storage plants (PSPs) prevent curtailments of wind and solar generation? 2. To which extent can PSPs provide reliable available capacity in order to reduce the necessary conventional thermal power plant fleet backup? 3. Does an expansion of PSP in Germany pay off macro-economically? The target of the study was the minimization of the total costs for investments in power plants and fossil fuel consumption, considering all power plants in Germany and using a dedicated plant scheduling optimization tool. Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 14

15 Assumptions and used data basis for the study No national transmission grid limitations Germany as an island, i.e. import/export = 0 for electricity Other consumption based on ENTSO-E data *) RE production based on the IWES **) model and 2007 weather data RE installation costs and fuel cost model based on the 2010 BMU ***) pilot study Perfect foresight of wind & solar generation with hourly resolution Investment costs for PSP expansion: 1000 /kw (power section) and 50 /kwh (storage section) Evaluated ratio energy storage to power for PSP extension: 3 / 5 / 7 Wh/W, storage cycle efficiency: 80%, service life: 60 years Mixed interest rate on capital of 4% *) ENTSO-E: Consumption Data, Online: **) Fraunhofer Institute for Wind Energy and Energy System Technology: Model " Virtual electricity supply systems", Kassel, 2012 ***) Nitsch, J., et al.: Pilot study of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU),

16 Methodological sequence for two scenarios: 60% RE (2030) and 80% RE (2050) expected load and power plant fleet (RE & thermal) Estimation of an economic storage power expansion based on the ETG study *) expected residual load Evaluation of PSP to supply reliable available capacity Reduction of the gas fuelled power plants Operation & scheduling analysis for the entire year considering the complete conventional power plant & PSP fleet Cost & CO 2 emission assessment *) Energietechnische Gesellschaft im VDE (ETG), Energy storage for the energy transition study, Frankfurt am Main, Online ww.vde.com/de/fg/etg/arbeitsgebiete/v2/aktuelles/oeffenlich/seiten/ StudieSpeicherungsbedarf 16

17 Estimation of an economic PSP capacity expansion based on assumptions as outlined in ETG study *) ø full load hours vs. PSP power t [h] Additional pump storage power 60% RE (2030): + 8 GW 80% RE (2050): + 16 GW % 80% P [MW] PSP power through expansion Assumption: PSP expansion is feasible if on average more than full load hours per year in turbine operation can be achieved Add. utilization hours & earnings for PSP come on top by additional ancillary services like: spinning reserve, peak load supply, balancing energy for compensation of RE forecast errors, grid congestion management,... *) Energietechnische Gesellschaft im VDE (ETG), Energy storage for the energy transition study, Frankfurt am Main, Online ww.vde.com/de/fg/etg/arbeitsgebiete/v2/aktuelles/oeffenlich/seiten/ StudieSpeicherungsbedarf 17

18 Methodology to calculate the necessary energy storage capacity vs. reliable available capacity supplied by PSP residual load Lower upper reservoirs refill upper reservoirs 18 18

19 PSP contribution for reliable available capacity Energy storage demand vs. reliable available capacity 400 E [GWh] P [GW] 20 Energie RE 40% 40 % Energie RE 60% 60 % RE Energie 80% 80 % Germany today, 7 GW PSP power & 40 GWh 7 GW reliable available capacity by PSP fleet 2030, PSP-expansion of 8 GW & 96 GWh 13 GW reliable available capacity by PSP fleet The provision of reliable available capacity through PSP can increase to 13 GW in 2030 to 16,6 GW in 2050 and substitute fossil power plants with the same power. Evaluated ratio energy storage to power for PSP extension: 3 / 5 / 7 Wh/W. The potential for provision of reliable available capacity by PSPs increases with a growing share of RE while the required energy storage capacity decreases. 2050, PSP-expansion of 16 GW & 152 GWh 16,6 GW reliable available capacity by PSP fleet Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 19

20 Typical load profile for a week in 2030 (60% RE) without PSP curtailment of RE MO TU WE THUR FR SA SU with PSP avoidance of RE curtailment by basin filling lowering upper basins 9:00 16:00 8:00 17:00 01:00 smoothening peak shaving MO TU WE THUR FR SA SU thermal filling of up. basins curtailment of RE RE & Must-Run lowering of up. basins load profile 20

21 Main results for the 60% RE scenario (2030) 15 GW pump storage plants (7 GW existing + 8 GW expansion) with a total storage volume of 96 GWh substitute up to 13 GW of gas power plants % of the surpluses of RE generation can be stored (in total 6 TWh) and later re-cycled by this PSP fleet. 1 Mio. t per year CO 2 emissions reduction because PSP re-cycles RE generation which substitutes fossil fuels. The whole pump storage fleet is well utilized and the savings of variable generations costs (fossil fuels + CO 2 certificates) surpass the annualized investment costs of PSPs. Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 21

22 Impact of pump storage plants 2030 (60% RE) 6 TWh curtailment of renewable electricity can be replaced or avoided by: 6 TWh = annual production of 900 wind turbines with 2.5 MW each. Pump storage with 15 GW: 7 GW existing + 8 GW-expansion avoids thermal power plants with 13 GW Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 22

23 Typical load profile for a week in 2050 (80% RE) without PSP curtailment of RE MO TU WE THUR FR SA SU avoidance of RE curtailment by basin filling with PSP lowering upper basins smoothening peak shaving MO TU WE THUR FR SA SU thermal filling of up. basins curtailment of RE RE lowering of up. basins load profile 23

24 Main results for the 80 % RE scenario (2050) 23 GW pump storage plants (7 GW existing + 16 GW expansion) with a total storage energy of 152 GWh substitute up to 16.6 GW of gas power plants % of the surpluses of RE generation can be stored (in total 17.6 TWh) and later re-cycled by this PSP fleet. 2 Mio. t per year CO 2 emissions reduction because PSP re-cycles RE generation which substitutes fossil fuels. The whole pump storage fleet is well utilized and the savings of variable generations costs (fossil fuels + CO 2 certificates) surpass the annualized investment costs of PSPs. Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 24

25 Worst case scenario: December 2050 (80% RE) 2-weeks with less or no wind conditions, less sunshine [MW] without PSP Contribution of wind & solar drops almost to 0 MW in this situation! Run-of-river, geothermal and biomass have some contribution. [MW] with PSP PSP avoids inefficient short term operation of thermal power plants. Maximum peak load for the thermal power fleet in this year, which is approx. 10% lower in the scenario with PSP. thermal filling of up. basins curtailment of RE Smoothening and peak shaving effects using PSP are also in this scenario obvious. RE lowering of up. basins load profile 25

26 Impact on investments and on the levelized cost of electricity (LCOE) in Germany 1500 Mio. / a ,8 added value = investment in D 775,6 fuel cost savings bonus / malus effect for consumers ,4 374, ,2 102,5-102,5-179, ,2 102, ,1-184,4 179,2 102, Investment Investitionen for in gas Gaskraftwerke power plants Investitionen in Pumpspeicherkraftwerke Investment for PSP Gesamtinvestitionen in Total Deutschland investment Variable Einsparung energy variabler costs Stromgestehungskosten savings due to PSP durch storage Speicherzyklen cycling Veränderung der Stromgestehungskosten Change of LCOE in Deutschland 2030 mit with PSW PSP 2050 mit with PSW PSP 2030 ohne without PSW PSP 2050 ohne without PSW PSP Hydropower Development Europe 2014, , Porto Making the energy transition in Germany... K. Krüger 26

27 Conclusions of the study PSPs have to be recognized as an important connecting & completive element between the fluctuating renewable energies and the conventional energy generation with thermal power plants. PSPs can substitute up to 16.6 GW fossil power plant reserve capacity in 2050 with 80% RE. RE expansion with a PSP fleet expansion can reduced the thermal power plant capacity reserve. But RE expansion without PSPs cannot! The PSP fleet is able to compensate the volatility of the renewable energies and allows a more economic & smoother operation of the remaining thermal power plant fleet. As a result, the Demand-Side-Management of consumers in industry and private house-holds can be mainly avoided. Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 27

28 Conclusions (continued) The key to success factor of the shown results is that the multi-functional pumped-storage power plants are a perfect combination of large-scale energy storage, provision of reliable available capacity for peak demands and enormous flexibility for positive and negative loads! pump mode turbine mode Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 28

29 negative balancing energy positive balancing energy 9 day load regime of a pumped storage complex compensating the volatility of wind & solar in minutes averaged load values Pumped storage is the only mature and feasible technology to provide such cycle-intensive services for the high voltage grid stability! turbine mode ( MW) pump mode ( MW) Source: Peter Matt, Vorarlberger Illwerke AG: Defining the Role of Hydropower in the European Energy Mix. Conference paper during the Hydropower Development, Porto, 17th-18th September Owner: Vorarlbeger Illwerke EG in Austria. Name of pumped storage complex: Werksgruppe Obere Ill Lünersee: Obervermutwerk (29 MW), Obervermutwerk II (360 MW) under construction. Vermutwerk (156 MW) Kopswerk I (247 MW) Kopswerk II (525 MW) Lünerseewerk (232 MW), Rodundwerk I (198 MW), Rodundwerk II (276 MW) 29

30 Dr. Klaus Krüger Head of R&D Voith Hydro Holding Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 30

31 Consequences for the thermal power plant fleet PSPs can provide additional ancillary services and quickly compensate the daily fluctuations in the generation or consumption. Remaining thermal power plants plus the PSP fleet must be able to compensate the load for time periods with less or almost no RE generation (e.g. wind calms). All in all less thermal power plants are needed. Existing conventional plants run until the end of their lifetime, are better utilized and run smoother and more efficient. Their fossil fuel consumption can be reduced, which also means that Germany can reduce a part of its fossil fuel dependence. CO 2 emissions reduction is about 2 Mio. t per year in the 2050 (80% RE) scenario. Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 31

32 Influence and magnitude of RE forecast errors Quelle BMU Leitstudie 2011 S. 187, RMSE: Root Mean Square Error Die Energiewende erfolgreich gestalten: Mit PSW Krueger

33 Die Energiewende gestalten: Mit Pumpspeicherkraftwerken Dr. Roland Münch Juni

34 34

35 35 Impact on Transmission Network during High Wind Feed-In Wind speed Wind feed-in Network utilisation Changing transportation needs leading to more congestions Network upgrades

36 market price ( / MWh) Pumped storage operation is getting unprofitable PSP business model got lost due to decreasing spreads summer day 2012 summer day 2012 hour source: 36

37 Reliable available capacity via PSP PSPs can in fact provide reliable available capacity if the entire PSP fleet is operated as described in the study, i.e. used as short-term storage for max. 2 to 3 days, and the "filling" of the storage basins is carried out depending on the residual load by RE and/or the thermal power plant fleet. thermal filling of up. basins curtailment of RE RE lowering of up. basins load profile Of course, PSPs are not capable of covering the base load in the way thermal power plants can. The maximum national load relevant for the dimensioning of the reliable available load, however, is always composed of the base load and a variable peak load. Consequently, PSPs can very well reduce the reliable available capacity of fossil-fuel power plants by covering the peak load! A requirement for this is that the installed capacity of thermal power plants during nighttime is always enough to cover the load and, in addition, to fill the upper basins of the PSPs even if and this is of crucial importance in this context no RE input at all is available. 37

38 Breakdown of the LCOE for the German energy transition ( Energiewende ) 35 Billion / year Invest PSP Variable energy costs Invest conventional CHP Invest gas plants Invest black coal plants Invest lignite plants Invest geothermal Invest run-of-river Invest biomass CHP Invest solar Invest wind fuels CO 2 certif % RE (2030) 80 % RE (2050) CHP: Combined Heat and Power Based on Nitsch, J., et al.: Pilot study of the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU),

39 Integration von EE-Überschüssen durch PSW 2030 Lastgang 2 einer Woche ohne PSW 2030 (60% EE) Abregeln von EE MO DI MI DO FR SA SO Lastgang 2 einer Woche mit PSW 2030 (60% EE) 10:00 15:00 07:00 00:00 05:00 02:00 07:00 11:00 18:00 08:00 09:00 17:00 23:00 06:00 01:00 01:00 17:00 09:00 00:00 06:00 17:00 23:00 09:00 16:00 04:00 01:00 08:00 17:00 Win-Win EE + PSW MO DI MI DO FR SA SO 2 Beispielhafter Lastgang bezogen auf Gesamtdeutschland aus der IAEW-Studie Die Energiewende erfolgreich gestalten: Mit PSW Krueger Quelle: IAEW / RWTH Aachen, Dr.-Ing. Niklas Rotering 39

40 Batteriespeicher: Speichertechnologie mit hoher Leistung jedoch mit niedrigen Energiemengen, welche ins/aus dem Niederspannungsnetz ein- und ausspeichert. PSW: Speichertechnologie mit hoher Leistung und hoher Energie, welche ins/aus dem Hochspanungsnetz ein- und ausspeichert. Achtung: Bei den Batteriekosten in dieser Darstellung sind die Kosten für Umrichter und Transformatoren um ins/aus dem Hochspannungsnetz ein- und auszuspeichern nicht enthalten. Der Vergleich mit Pumpspeichern hinkt also! Die Energiewende erfolgreich gestalten: Mit PSW Krueger

41 Tail water Hydraulic short circuit operation Head water During this operation mode the motorgenerator is permanently synchronized which allows extremely fast switching from no load running to nominal load in pump or turbine mode. Same direction of rotation in T/P Allows very steep load gradients (+/-) The grid sees only the difference between turbine power and pump load The stabilization of the grid has a higher priority than the efficiency Hydraulic short circuit operation at the three machines set in Kops II (175 MW in turbine mode, 150 MW in pump mode) 41

42 Principles for Generation Adequacy Analysis *) Reliable available capacity = net generating capacity - system reserves - outages Potencia assegurada - overhauls - not usable capacity Reliable available capacity share of the nominal power: 90% fossil & nuclear power plants, 70% to 90% storage and pumped storage power plants 5-8% wind farms off-shore 1% wind farms on-shore 0% solar potencia assegurada *) ENTSO-E: System Adequacy forecast SAF Online: Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 42

43 Impact on investments and on the levelized cost of electricity (LCOE) in Germany 1500 Mio. / a ,8 added value = investment in D 775,6 fuel cost savings bonus / malus effect for consumers ,4 374, ,2 102,5-102,5-179, ,2 102, ,1-184,4 179,2 102, Investment Investitionen for in gas Gaskraftwerke power plants Investitionen in Pumpspeicherkraftwerke Investment for PSP Gesamtinvestitionen in Total Deutschland investment Variable Einsparung energy variabler costs Stromgestehungskosten savings due to PSP durch storage Speicherzyklen cycling Veränderung der Stromgestehungskosten Change of LCOE in Deutschland 2030 mit with PSW PSP 2050 mit with PSW PSP 2030 ohne without PSW PSP 2050 ohne without PSW PSP Seminário Técnico sobre Usinas Hidrelétricas Reversíveis no Setor Elétrico Brasileiro Making the energy transition in Germany... K. Krüger 43