Presentation on theme: "TOE: Grid Energy Storage David Snydacker February 2015 I am a PhD student in Materials Science and Engineering. My."— Presentation transcript:
TOE: Grid Energy Storage David Snydacker February 2015 DavidSnydacker2015@u.northwestern.edu I am a PhD student in Materials Science and Engineering. My research focuses on Li-ion batteries.
100 billion nuclear bombs per second Earth gets 10,000x current demand Plenty of solar energy available. Challenge is delivering energy: WHERE (transmission) and WHEN (storage) it’s needed. Transmission and storage operate in complementary space-time domains, but they often compete!
Geological Storage Worldwide rate of fossil energy storage is roughly one gas station!
Energy Storage Value Streams Desired Features: Power (MW), Energy (MWh) Cheap, Durable, Safe, Efficient Behind-the-meter (customer sited) Markets: Uninterruptable Power Supply (e.g. server backups) Demand charge reduction Distributed generation (PV) integration Rural electrification and grid defection Utility Markets Frequency and voltage Regulation Transmission and distribution deferment Arbitrage Power Plants Ramp Rate Control Generation Firming
Other Markets Xtreme Power, IEEE Presentation 2012
Frequency Response Cody Aaron Hill, Alexis Kwasinski, MSE, The University of Texas at Austin, 2013 Droop Response: %R = 100 * (percent frequency change) / (percent power output change) -30 MW Maui wind farm with 10 MW of Xtreme Power lead acid batteries -When net load increases, historically generators convert interia to boost power and slow down -Battery banks respond within one second with real and reactive power, stabilizing frequency
Ramp Rate Control Xtreme Power, Cody Aaron Hill, Alexis Kwasinski, MSE, The University of Texas at Austin, 2013 When utilities buy electricity from wind and solar generators, the power purchase agreements (PPAs) specify allowable ramp rates (kW/min). Batteries allow renewable generators to meet these ramp rates without curtailing large amounts of power. Solar PV power ouput is particularly volatile because there is little “inertia” 1 MW PV simulation: PV at 4 MW/min, System at 50 kW/min
Generation Firming (Leveling) Xtreme Power, Cody Aaron Hill, Alexis Kwasinski, MSE, The University of Texas at Austin, 2013 Scheduled power delivery increases economic value of power via higher electriciy prices or avoided PPA penalties Power output is forecast every ~15 min and bid into market Batteries help ensure power output meets forecast within +/- 10%
Time Shifting (Arbitrage) Xtreme Power, Cody Aaron Hill, Alexis Kwasinski, MSE, The University of Texas at Austin, 2013 Buy low. Sell high. Requires access to markets with dynamic pricing (Wholesale or Retail) Wholesale prices don’t always reflect supply-demand at the local (circuit) level Need better electricity markets to send price signals to specific circuits
Reactive Power Support Xtreme Power, Cody Aaron Hill, Alexis Kwasinski, MSE, The University of Texas at Austin, 2013 Inductance in lines, transformers, etc absorbs reactor power (lagging power factor) RPS traditionally provided by capacitor banks, but these create switching transients Power electronics enable continuous changing of reactive power w/o transients Power Factor = P / S = cos θ
A Big New Driver for Distributed Storage: Distributed Solar
Opportunity: Supply Intermittency 20 th Century 21 st Century
Grid Energy Storage Technologies Physical Storage: Gravitational Kinetic Pumped Hydro Compressed Air Thermal Chemical Storage: Batteries Liquid Batteries Flow Batteries Electolyzers
Rotational Flywheel Beacon Power Eff = >90% High power Low energy 100,000s cycles For vehicles, too:
Gravitational Energy Cache Gravel Lifts Eff = 72-80% Advanced Rail Energy Storage Train cars
Hot Brick “Storage” (Demand Response) V-Charge Electric Heating, Simple Resistor in hot bricks Low Efficiency compared to heat pumps Simple resistor enables high frequency demand response V-Charge via GTM
Supercapacitor (double layer) Images: Industry Canada, Ioxus Toyota hybrid: 518 hp engine, 475 hp supercap
Batteries Applied voltage moves electrons from cathode to anode Negative charge accumulates in the anode Positive ions are attracted to negative anode and migrate through electrolyte
Stationary Batteries: lifespan is not just a minimum requirement, can drive cycle cost reduction Cycle Cost ( $ / (kWh*cycle) ) Graphite//LiNi 0.8 Co 0.15 Al 0.05 O 2 Graphite//LiFePO 4 Li 4 Ti 5 O 12 //LiFePO 4 Cycle Cost ≈ Battery Cost ÷ Cycle Life rough model for illustration only 31 grid cost
Electrolysis: splitting water into hydrogen image: instructables.com
Electrolysis: Audi e-gas https://www.youtube.com/watch?v=08Y_dTXYQXE
Electrolysis: Jet Fuel Synthesis at Sea Also: Audi e-Fuels including e-diesel
Solar Thermal Overview: Electricity and Fuels direct sunlight concentrated light heat electricit y grid hydrocarbons, or methanol heliostat light absorption, heat transfer, heat strorage thermochemical conversion electrolysis syngas: H 2 /CO 2 Fischer- Tropsch, etc
Romero et al. Energy & Environmental Science (2012) Heliostats C = ~1,000-3,000C = ~200-1,000 C = ~30-80 Roughly half the cost of solar thermal electricity Direct normal incidence (DNI) sunlight is required DNI ≈ 800 kW/m 2 in sun-belt region (+/- 40°) Theoretical max concentration for 3D: C ≈ 11,500 2D heliostats 3D heliostats Heliostat innovation focuses on cost reduction
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