Designing a 100% renewable energy system

Transcription

1 Designing a 1% renewable energy system a low regret energy strategy to meet security, climate and air pollution objectives A preliminary development for illustration only Mark Barrett, Ed Sharp group (run presentation to see animations) 1

2 Policy objectives Renewable energy can be the foundation for an integrated, low risk, reversible and long term energy policy for: Social well being Energy security Climate stabilisation Air pollution Geographical extent Global Genetic loss (permanent) Many renewables do not incur long term, spatially expansive environmental impacts. SPACE =======> Regional Acid rain Global warming Radioactive Local Air pollution Indefinite TIME Years to reverse impacts ============>

3 Qualitative aspects of low carbon supply options Qualitative aspects are major drivers of social and political technology choice, as exemplified by concerns about nuclear power, shale gas and carbon sequestration. Mass produced renewables are the reversible, low risk, low cost option. Relative subjective marks: 1 good Renewables Nuclear Fossil Hydro river Carbon Biowaste Sequestration Solar Wave Tidal barrage Wind Tidal flow Hydro reservoir Biocrop Reversibility Risk Climate change mitigation Other environment Potential impact outside UK Consumption global resources International political impact Political security Transparency Certainty costs and performance

4 UK renewable electrical energy technical and economic potential Estimates based on current costs. Wind and solar: mass produced technologies resource vast Uncertain commercial cost Tidal, wave, (nuclear) An advantage of tidal is that it is predictable, and output can be partially controlled from barrage schemes with storage. 4 Hydro H Biomass Bio Biowaste Bw Land Fill Gas LF Sewage Sew Wind-on Won Wind-off Woff Tidal barrage Tb Tidal flow Tf Wave Wa Solar PV PV Nuclear N p/kwh Wind and solar resource potentially much larger => 1. PV: S Bw: 1 PV: L H: M Won: 2Woff: Won: 3 Woff: 2 Woff: 5 Woff: 6 Bio 5. 1 Sew Won: 1 Woff: 3 Woff: 4 H: S LF: 12 H: L TWh Generation only: excludes system balancing Discount rate: 5 %/a Tf Wa: 1 Tb N Wa: 2

5 DynEMo Evolution of electricity system dynamics (wait for animation) 215 to 255, increasing demand and uncontrollable renewables absorbed with storage, dispatchable renewables and trade. CHP increases and declines. 5 winter spring summer autumn days

6 DynEMo Evolution of electricity system dynamics 255: all electricity provided with renewable generation - biomass district heating CHP the main dispatchable plant 6 GW GBR: 255: 4 days, 1 d/mth, mths 1,4,7,1; t=1m winter spring summer autumn days ImportEle_GW WaveEle_GW SolarPVEle_GW WindOff1Ele_GW WindOn1Ele_GW TideEle_GW HydroEle_GW SupEleDisp_GW LiqEle_GW SolEle_GW GasEle_GW NucEle_GW EleSysStoreOut_GW CHPEle_GW EleSuppReq_GW EleSysStoreIn_GW EleWasted_GW TradeEle_GW EleGen_GW

7 Energy system dynamics: simple hourly model Sample 2 days and 2 weeks days Power (GW) Wind index / Heat pump COP Dem: ele for heat Dem: ele specific Dem: heat non space Dem: space heat Dem: heat Ren: Controllable Wind On Wind Off Solar Ren: Uncontrollable 21 m1d11wd2h1 21 m1d12wd3h1. Ren: Total COP Wind index weeks Power (GW) Wind index / Heat pump COP Dem: ele for heat Dem: ele specific Dem: space heat Ren: Controllable Wind On Wind Off Solar Ren: Total Wind index COP 7 21 m1d11wd2h1 21 m1d12wd3h1 21 m1d13wd4h1 21 m1d14wd5h1 21 m1d15wd6h1 21 m1d16wd7h1 21 m1d17wd1h1 21 m1d18wd2h1 21 m1d19wd3h1 21 m1d2wd4h1 21 m1d21wd5h1 21 m1d22wd6h1 21 m1d23wd7h1 21 m1d24wd1h1

8 How much storage is needed? (Simple model: assuming 1% renewables and no trade) Average (GW) Month Storage (TWh) Dem: ele for heat Dem: ele specific Dem: heat non space Dem: space heat Wind On Wind Off Solar Ren: Controllable Ren: Total Store TWh For year 2, from 31 years of hourly meteorology and wind power generation from Dr Ed Sharp Energy (TWh) Dem: cumulative Ren: cumulative Net demand-renewable cumulative 1. Model hourly demands and renewables across the year 2. The minimum storage is the maximum difference between cumulative demand and supply m12d26wd6h 24 m1d25wd1h m2d24wd3h2 24 m3d26wd6h6 24 m4d25wd1h16 24 m5d26wd4h2 24 m6d25wd6h12 24 m7d25wd1h22 24 m8d25wd4h8 24 m9d24wd6h18 24 m1d25wd2h4 24 m11d24wd4h14

9 Annual demand and renewable supply variation over 31 years Considerable inter-annual variation in wind generation (about +/-2% on shore; +/- 1% off-shore) Less variation in total demand (about 5%) because the weather driven component of electricity demand is small (in scenario) Large variation in storage required. For a 7 TWh/a demand/supply system around 7 TWh of storage is required, i.e. 1% of annual demand. Storage can be a mix of heat, EV batteries, chemical, biomass, fossil etc Dem: ele for heat Energy (TWh) Storage (TWh) Dem: ele specific Dem: space heat Ren: Controllable Wind On Wind Off Solar 2 2 Ren: Total Store TWh

10 Some (electrically connected) storage options for system management - for UK, excluding bioenergy and fossil energy stores Power (GW) and time (hours) energy storage potential 25 Potential storage with upwards of 2 GWe power and 5 TWh energy. Ammonia/hydrogen and district heat stores can be very large. System electricity storage (batteries etc.) relatively costly and inefficient. GW Vario water Off peak bricks Pumped Number Max Time Dom HW STORAGE tanks Restriction GW hrs GWh Efficiency 2 Current Pumped storage Nondom HW % used Electric heating Industy/services Various % Water industry water pumping % Building fabric Total % In place Domestic Off peak bricks Winter 1 M % 15 need controls HW tanks 5 M % HW Industy/services? HW tanks.5 M % tanks General Electric heating Winter.5 M % Total % 1 Future Building storage Building fabric Winter 3 M % EV battery additional HW tanks 2 M % Electric vehicles battery 2 M % District heating heat pumps/chp Winter % Synthetic fuels H2, NH % 5 Total future additional DH heat 95% pumps/chp Total future % 1 Syn fuels:h2, NH Hours

11 International trade Transmission evens out the variations in demands and renewable supplies so that the demandsupply matching problem is reduced and less storage is needed. The UK now has 4 GW interconnection, and another 8 GW is planned, so perhaps 12 GW by 225. How will international trade flows vary hour by hour? Need to model all the countries/regions. What can we rely on importing in time of need? And exporting in time of surplus? What is the best balance between storage, transmission and trade? 11

12 What is the best balance between storage, transmission and trade? System consists of : Nodes with Demands heat and electricity Intermediate conversion district heating, heat pumps Renewables variable uncontrollable Renewables dispatchable (hydro, biomass) Stores heat and electricity LEGEND Conne ction ====> e d Node u Transmission links with certain capacity (GW) Demand a t i t L Uncontrollable Nodes can be individual countries or groups of countries. Dispatch Store The further apart nodes are, the more meteorology, demands and renewables are smoothed so less storage is needed. 12 Transmission link L o n g i t u d e ==>

13 What is the best balance between storage, transmission and trade? First scope Europe, but databases global A. For each country 1. Collect hourly meteorology and renewable resource 2. Collect base year data for demand and supply 3. Project scenario demands 4. Project initial generation, storage and transmission capacities History Meterology Demand Supply Scenario Meteorology Demand Supply B. Optimise iterate simulation changing decision variables (generation, storage and transmission capacities) to find least total capital and running cost of system For each country, for each hour across year, simulate: Simulation 1. demands using social activity patterns and meteorology 2. uncontrollable renewable energy solar, wind 3. flows to country demands 4. flows to country stores of heat and electricity 5. flows from countries with surplus to countries with deficits 6. generation by dispatchable sources (hydro, bioenergy) to meet remaining deficit Decision variables Demand Supply Storage Transmission Optimisation Results Energy flows Costs Emissions Simulate and optimise for different weather years to find extreme weather that stresses the system 13

14 Country by country data Historical hourly generation and trade Example: Norway 14

15 Bioenergy Bioenergy is a premium renewable: Has carbon (!) and can be used to make liquid transport fuels Has integral energy storage and may be a critical component of high renewable systems TWh UK bio and primary energy scenarios CHPBio FoodToConsumers But: Can compete with food production Has complex environmental impacts Is scarce, e.g. UK waste bioenergy perhaps enough to make <5% aviation fuel Causes combustion and othr emissions 15 TWh 5 TBioInp TBioFue SolPri LiqPri 2 GasPri BioPri 15 WaveEle SolarPVEle WindOff1Ele 1 WindOn1Ele TideEle HydroEle 5 NucEle SSolPassGainUse SSolCollToTank DSolPassUse DSolCollToTank

16 Non CO2 global warming: aviation, methane and biomass Global warming (NB different time horizons) from: high altitude aviation Natural/bio gas leakage (pipe, LNG, flare, etc.) bioenergy (sequestered carbon loss, CH4, N2O, etc.) Very uncertain but a significant fraction of total GW, perhaps 5-7% in low carbon scenarios. (And aviation growth will make it difficult to control air pollution around airports.) 16 Mt Mt % 9% 8% 7% 6% 5% 4% 3% 2% 1% UK energy related global warming scenarios % TAirAltGW BioCropCO2e MethGasGenCO2e MethDistCO2e RefLiqCO2 LiqEleCO2 SolEleCO2 GasEleCO2 CHPCO2 SGasCO2 ISolCO2 ILiqCO2 IGasCO2 DLiqCO2 DGasCO2 TTint TAir TF TPLandFos TAirAltGW BioCropCO2e MethGasGenCO2e MethDistCO2e RefLiqCO2 LiqEleCO2 SolEleCO2 GasEleCO2 CHPCO2 SGasCO2 ISolCO2 ILiqCO2 IGasCO2 DLiqCO2 DGasCO2 TTint TAir TF TPLandFos

17 Development Implications for air pollution from fossil combustion 1. General reduction in annual emission 2. Emissions will be more variable in space and time (hours to seasons) as dispatchable bioenergy is used to when other renewables low, so relatively high energy related emission episodes might remain 3. There will be correlations between meteorology, and demand, renewables and atmospheric pollutant processes 17

18 How long might the cables be? Regular east-west diurnal, and seasonal, variations in demands and renewables Match varying demand and supply with transmission as well as storage Energy exchange enhances political security 18

19 DynEMo Designing a national renewable energy system A system which will operate hour by hour across the days, months and years. 1. Demand 2. Supply 3. Integration 4. Operation 19

20 Energy system dynamics: simple hourly model Monthly cumulative supply-demand variation for each of 31 years (Modelling based on 31 years of hourly meteorology and wind power generation from Dr Ed Sharp) Considerable monthly variation in cumulative supply-demand resulting in minimum and maximum of about -/+ 7 TWh, or 1% of annual demand Cumulative supply-demand (TWh) Average

21 DynEMo Electricity system stress examples over 3 days WINTER-5 oc. No wind, no trade. SUMMER. 35 oc. No wind, no trade. GW GBR: 255: 3 days, 3 d/mth, mths 1; t=7.5m District heating: energy current and projected Deg C DHBoiHeat_GW DHHPHeat_GW CHPHeat_GW DHHeatInput_GW DHHPEleIn_GW DHHeatStoreT_C National electricity system Electricity: bio CHP and fossil gas main supplies. 1 GW DH: CHP at maximum. Boiler used when DH store empty and more heat required gas heating used to manage the electricity system GBR: 255: 3 days, 3 d/mth, mths 1; t=7.5m ImportEle_GW WaveEle_GW SolarPVEle_GW WindOff1Ele_GW WindOn1Ele_GW TideEle_GW HydroEle_GW SupEleDisp_GW LiqEle_GW SolEle_GW GasEle_GW NucEle_GW EleSysStoreOut_GW CHPEle_GW EleSuppReq_GW EleSysStoreIn_GW EleWasted_GW TradeEle_GW EleGen_GW GW DH: CHP fills store to maximum then just tops up GW GBR: 255: 3 days, 3 d/mth, mths 7; t=7.5m What if DH were used for cooling? District heating: energy current and projected Deg C CHPHeat_GW DHDel_GW DHHeatInput_GW CHPGas_GW DHHPEleIn_GW DHBoiFuel_GW DHHeatStoreT_C Electricity: Solar, CHP then fossil gas when DH store full ImportEle_GW WaveEle_GW SolarPVEle_GW WindOff1Ele_GW WindOn1Ele_GW TideEle_GW HydroEle_GW SupEleDisp_GW LiqEle_GW SolEle_GW GasEle_GW NucEle_GW EleSysStoreOut_GW CHPEle_GW EleSuppReq_GW EleSysStoreIn_GW EleWasted_GW TradeEle_GW EleGen_GW

22 Conclusions It is possible to design 1% renewable systems that will function hour by hour in different meteorological conditions. Detailed spatiotemporal modelling is needed to explore functioning systems. There is abundant renewable electrical energy potential. If demand is higher then renewables, storage etc. can be scaled up. Biomass energy resources are uncertain and may be insufficient for aviation. Risky, irreversible nuclear is unnecessary and fossil CCS is insufficient for near zero carbon. District heating and synthetic fuels have important management roles through storage and multi-fuelling. Aviation growth is probably incompatible with UK climate change mitigation targets. 22

23 Thank you for listening. Questions? 23