Energiewende in Germany - issues and problems - Copernikus Symp., Szczecin, 12.5.2014 1 F. Wagner, Max-Planck-Institut für Plasmaphysik, Greifswald
Introduction 2 Two terms, not to be confused energy (TWh) and power (GW) A machine/system uses energy to do work e.g. steam engine chemical energy thermal energy mechanical energy electricity Generally, heat is produced when energy is converted or transformed into work primary energy (PE): energy content of fuels (chem. energy) net energy: energy in the desired, useful form (electricity) Germany, 2012: PE: 3820 TWh; electricity produced: 630 TWh A human being needs 100 W for his/her metabolism and is able to provide 120 W for steady-state work Average power needs: 3820000000000000 Wh/82000000 people/8760h 5320W/120W = 45 (slaves, working for us)
Use of energy in Germany Copernikus Symp., Szczecin, 12.5.2014 3 Net energy 30 % 16 % 25 % 29 % Industrie Verkehr Handel, Gewerbe Haushalt Industrie industry Verkehr transportation Handel, Gewerbe trade and commerce Haushalt household only ~ 1/3 for households rest: into the sectors of our economic acitivities
Energy carriers of primary energy 4 2012 Coal Steinkohle Lignite Braunkohle Oil Öl Gas Nuclear Kernenergie RE EE rest Rest 80% fossil with CO 2 emission Quelle: AGEB und bdew
Use of Renewable Energies (RE) 5 electricity heat fuel 11.6 % RE
The task of the future 6 replacing coal and nuclear Without nuclear and coal Wind PV Wind PV
power (MW) power (MW) Copernikus Symp., Szczecin, 12.5.2014 Electricity demand during the day 7 Definition: load = demand Tue 31.1.2012 Peak load Base load demand MWh 6:00 12:00 18:00 time (h) time (h) 68 GW x 24 h x 365 days = 600 TWh
power (MW) Copernikus Symp., Szczecin, 12.5.2014 Electricity demand during the week 8 Mo Tue Wed Th Fr Sa Su time (days)
power (MW) Copernikus Symp., Szczecin, 12.5.2014 Electricity demand during the year 2012 9 during the week at the weekend Christmas period J F M A M J J A S O N D time (months)
2013 Copernikus Symp., Szczecin, 12.5.2014 2013 Growth of wind and PV in Germany 10 Growth of installed wind and PV power in Germany onshore wind Won PV 2013: Wind: 32.5 GW; PV: 36 GW
Situation 2012 Copernikus Symp., Szczecin, 12.5.2014 11 utilisation: uf = 82% installed power utilisation: uf = 83% installed power W off = 160 MW in the diagram: multiplied by 200 utilisation: uf = 100% installed power Wind fits well to the annual variation of the demand
power (MW) power (MW) Copernikus Symp., Szczecin, 12.5.2014 Wind und PV power in winter and summer 12 12.-19.2.2012 5.-12.8.2012 Mo Tue Wed Th Fr Sa Su Mo Tue Wed Th Fr Sa Su load wind PV time (days) time (days) Wind is erratic and strong in winter PV is periodic, strong in summer and aligned to the maximal demand there is an optimal mix between wind and PV: ~ 20 % Optimum: residual power is minimum
Comparison: load installed RE power 13 2012 RE have feed-in priority periods with strongly reduced thermal power PV periods with surplus Won
Peak (installed) power and energy production 14 Power: Maximal demand: 83 GW Wind: 32.5 GW; 39 % PV: 36 GW; 43 % Energy: Annually produced electricity: 630 TWh High capacities are necessary to produce energy by RE All components have to be ready to work at high power levels Wind: 50.7 TWh; 8.1 % PV: 26.4 TWh; 4.2 %
Scale 2012 data to higher installed powers and analyse Assumptions: electricity demand will not change (electric cars, saving measures, air conditioning) Hydroelectricty and electricity from waste will not change Biomass will be used for transportation not for electricity production Target: 630 TWh produced 595 used 537 net hydro: 21, waste: 5 TWh Target: reduced load: 500 TWh What next? 15 Term: 100%, optimal mix case: Wind + PV: 500 TWh; W on = 2/3 wind; W off = 1/3 wind; PV = 20%
Scaling to 100% supply by RE 16 Onshore wind Offshore wind PV back-up 2012 reduced load 100% opt. mix
Duration curve: load 17 1 10 5 2012 8 10 4 6 10 4 peak 2000 h 1 middle 1 load 6000 h 4 10 4 2 10 4 base load 0 J 1 F 2 M 3 A 4 M 5 J 6 J 7 A 8 S 9 O 10 11 N 12 D time (months)
Duration curve 18 1 10 5 8 10 4 6 10 4 1 1 2012 1: reduced load 2: back-up 3: Woff x 200 4: PV 5: Won 4 10 4 2 10 4 0 2 63 4 5 J 1 F 2 M 3 A 4 M 5 J 6 J 7 A 8 S 9 O 10 11 N 12 D time (months) grey: fossil power red: nuclear power
Duration curve 19 1 10 5 8 10 4 6 10 4 1 1 2012 1: reduced load 2: back-up 3: Woff x 200 4: PV 5: Won 4 10 4 2 10 4 0 one month 4 63 2 5 half year J 1 F 2 M 3 A 4 M 5 J 6 J 7 A 8 S 9 O 10 11 N 12 D time (months)
Scaling to 100% supply by RE 3 10 5 Last Copernikus Symp., Szczecin, 12.5.2014 advantage of optimal mix 2,5 10 5 100% opt mix 3 10 5 Last 20 2,5 10 5 100% Won 100% opt mix 2 10 5 2 10 5 1,5 10 5 surplus 1,5 10 5 1 10 5 back-up 1 10 5 5 10 4 5 10 4 0 1 2 3 4 5 6 7 8 9 10 11 12 time (months) 0 1 2 3 4 5 6 7 8 9 10 11 12 time (months) - Production of surplus at a high power level - 100%-case: back-up energy = surplus energy - Even for the 100 % case a thermal back-up system is needed as long as storage is not available
The 100% case of Denmark Copernikus Symp., Szczecin, 12.5.2014 21 The 100% case in Denmark: 21.12. 2013 Dk situation 1 24 surplus = net export equal to back-up = thermal power ref. P.-F. Bach
Specification of the 100%, optimal mix case 22 Germany P Won = 176 GW ; P Woff = 33 GW; P PV = 97 GW P RE installed = 306 GW P load = 83 GW; P back-up = 73 GW W Won = 271 TWh ; W Woff = 135 TWh ; W PV = 94 TWh; W RE = 500 TWh W back-up = 131 TWh; W surplus = 131 TWh 12% reduction of back-up power The total installed power (306 + 73 GW) compares with the load of the EU: ~ 400 GW The surplus corresponds to the annual demand of Poland
2012 compared to 100%, opt. mix. - case 23 situation 2012 optimal mix, 100% case The Energiewende is still in its infancy
Back-up system 24 Operation of the Rostock coal power station Anti-correlation of thermal power and wind power (50Hertz) wind level where the power station switches off 3. und 4. Woche Okt. 2010
power (MW) Back-up system Copernikus Symp., Szczecin, 12.5.2014 25 80.000 70.000 60.000 50.000 40.000 30.000 20.000 10.000 0 the last 6 weeks in 2012 Maximum power Base load The power of the back-up system remains high It has to meet the full dynamic range from 0 to nearly peak load The power gradients increase strongly
power (MW) Storage Copernikus Symp., Szczecin, 12.5.2014 26 100%, optimal mix case black: Last red: back-up blue, negative: surplus h 66 90 117 67 27 71 70 83 TWh 3.7-3.5 4.5-2.5 0.5-2.4 0.8-3.4 1,00E+05 8,00E+04 6,00E+04 4,00E+04 2,00E+04 0,00E+00-2,00E+04-4,00E+04-6,00E+04-8,00E+04-1,00E+05 Mo 9.1.2012 Su 12.2.2012
power (MW) Storage Copernikus Symp., Szczecin, 12.5.2014 100%, optimal mix case black: Last red: back-up blue, negative: surplus h 66 90 117 67 27 71 70 83 TWh 3.7-3.5 4.5-2.5 0.5-2.4 0.8-3.4 1,00E+05 8,00E+04 6,00E+04 4,00E+04 2,00E+04 0,00E+00-2,00E+04-4,00E+04-6,00E+04-8,00E+04-1,00E+05 6 4 2 0 storage level (TWh) Mo 9.1.2012 Su 12.2.2012
power (MW) Storage Copernikus Symp., Szczecin, 12.5.2014 28 100%, optimal mix case black: Last red: back-up blue, negative: surplus h 66 90 117 67 27 71 70 83 TWh 3.7-3.5 4.5-2.5 0.5-2,4 0.8-3.4 1,00E+05 8,00E+04 6,00E+04 4,00E+04 2,00E+04 0,00E+00-2,00E+04-4,00E+04-6,00E+04-8,00E+04 6 4 2 storage level (TWh) empty -1,00E+05 0 Mo 9.1.2012 Su 12.2.2012
power (MW) Storage Copernikus Symp., Szczecin, 12.5.2014 29 100%, optimal mix case black: Last red: back-up blue, negative: surplus h 66 90 117 67 27 71 70 83 TWh 3.7-3.5 4.5-2.5 0.5-2,4 0.8-3.4 1,00E+05 8,00E+04 6,00E+04 4,00E+04 2,00E+04 0,00E+00-2,00E+04 storage level (TWh) -4,00E+04-6,00E+04-8,00E+04-1,00E+05 6 4 2 0 Storage capacity in the order of 10 TWh Mo 9.1.2012 Su 12.2.2012
Storage Copernikus Symp., Szczecin, 12.5.2014 Present pumped water storage situation: ~ 50 GWh, ~ 7 GW 30 To replace the back-up system, the 100%, optimal mix case demands a storage of 33 TWh = 650 x presently installed capacity of Germany A target storage value could be: 5 TWh. Only chemical storage possible; technology not available at large scales Such a system would consist of: P RE not changed (P Won = 176 GW ; P Woff = 33 GW; P PV = 97 GW) P storage = -123 (+73) GW; P back-up = 71 GW (-15%) for 42 TWh (131 TWh) Capacity factors of system (%): Won Woff PV storage back-up 18 47 11 22 6 Problem: no component operates economically
Demand-side management Copernikus Symp., Szczecin, 12.5.2014 Principle: shift economic activities into low-cost periods Average of daily variation of load, back-up and surplus 31 low-cost period 9:30 17:30 1 24 Low price period is during the day, not the night!
Demand-side management 32 Comparison winter - summer winter 10:00 16:00 summer 9:30 18:00 23:00 6:00
Use of daily storage Demand-side management 33 Storage capacity: 0.3 TWh Reduction of back-up system: 131 103 TWh 1 24
Demand-side management 34 Situation during weekend 6:00 17:30 1 24
Demand-side management 35 Situation during weekend Full integration of weekends: Additional use of RE: 7.9 TWh Peak-load: 83 63 MW Reduction of back-up system: 131 123 TWh Mo Tue We Th Fr Sa Su Integration of weekends has about 1/3 the effect of a storage which is larger than the present one by a factor of 6
The benefits of an EU-wide grid 36 Average load of Germany compared to the normalised load (normalised to energy) of 8 countries: Spain, France, Irland, UK, Belgium, Germany, Czech Rep., Denmark Average PV power of Germany compared to the normalised PV power of 4 countries: Spain, France, Germany, Czech Rep. 1 24 Result: shift but no strong averaging effect
The benefits of an EU-wide grid 37 Back-up energy needed to produce 1 TWh - in the 8 countries - or jointly in EU Benefit: Back-up energy for EU (TWh) Countries individually: 446 Countries jointly: 323 Total load: 1761 TWh
Phase Shift Transformers define borders 38 recommended and planned in ENTSO-E transmission grids recommended planned Instead of EU-wide integration in electricity supply: des-integration happens
Conclusions w.r.t. intermittent sources 39 Wind and PV electricity is possible in large scales if the necessary space is allocated Large power to be installed comparable to the load of Europe high costs A supply system exclusively by wind and PV: does not seem to be possible Back-up system required in all scenarios: little saving in thermal power Ironically: CO 2 -emission rises in spite of a RE capacity ~ the power demand High surplus power peaks and energies: what to do with? Suppress further degradation of economic operation Use for power-to-gas: high prices of secondary electricity Use for heating: winter production: 76 TWh (private heating: 550 TWh) Use for cooling: summer production: 55 TWh (cooling needs: 20 TWh) Store for electric cars: 100 TWh required
Conclusions w.r.t. intermittent sources 40 Storage (for surplus power): large-scale technology, not yet available operation not economic difficult to motivate from the CO 2 saving point of view Components operation not economic today: no new gas power stations Electricity supply cannot be organised under market rules capacity market Unfavorable operation of all technical systems increased costs and CO 2 CO 2 reduction by RE: not to the levels as already achieved by others in EU No favorable conditions for demand-side management: day-time activities will intensify: maybe, new markets will develop best options: use of weekends storage by car batteries: surplus during the day not the night Supra-national supply improves situation: will it ever be realised?
Technology change Copernikus Symp., Szczecin, 12.5.2014 41 from red to blue Blue: RE, fusion, fission with breeder Dt: costs Increase in world population Increase in energy consumption Increase of CO 2 Keep all options open! Other issues: technology economy system costs competitors now 2050
Conclusions 42 The exclusive use of RE has limitations and leads to shortcomings. Therefore, the most obvious question will be whether and how an electricity system based on intermittent sources can be improved or supplemented. This will be a question classically posed to research and engineering because these disciplines have found the ways in the past to liberate mankind from the imponderabilities and perils of nature.