Large-Scale Energy-Storage Systems – Technologies and Applications. E. Peled, Tel Aviv University France - Israel Energy Meeting, Tel Aviv, 10-11, November, 2010 1
Benefits of Energy Storage • • • • • •
•Generation –Spinning Reserve –Capacity Deferral –Frequency Regulation –Load Leveling –Renewable Support
• • •
•Transmission & Distribution –Line and Transformer Deferral (Solar / wind farms will be located far from the customers) –Grid stability
• • • •
•End-Use –Power Quality/Reliability –Peak Load Reduction –Distributed Generation Support
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100GW of pumped-hydro storage already installed world-wide
Electrical Energy Storage can be Connected in Several Strategic Locations:
At the Load
At Conventional Power Plants
At Transmission Nodes At Renewable Energy Sites
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.... Flexible Deployment 10/29/2009
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• Shifting capacity night to day. • Lowering need for spinning reserve. • Lowering the need for new installations.
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Energy Storage in Solar Without Storage
3000
Solar Power storage reduces conventional generation requirements
With Storage
(3000MW
2000
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2000MW)
Fast power fluctuations for a 4.6 MW solar PV array in Arizona (10 sec resolution)
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7 days power fluctuations for a 4.6 MW solar PV array in Arizona (1min resolution)
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Wind Farm Applications: ¾Peaking Power Component:- Firming (6 to 12 hours of storage) ¾Frequency Regulation Component:- Stabilization (smoothing)
Peak Power Services Frequency Regulation Services – stabilization of Power through fast response smoothing
v
v
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Energy Storage – Wind Applications • •
• • •
Overcome intermittent nature of wind power “Capacity Firming” – Avoid penalties (power below forecast) – Utilize power above forecast – Price arbitrage / profit maximization Power supply at slow wind Enable increase in wind penetration (>20%) Stabilization of power through fast response smoothing
Better power smoothing requires larger ESS system
32MW farm using 4MW 1.5hour VRB ESS – Sapporo-Japan
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Wind energy cost approaching conventional energy cost
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Annual Wind Installation
$19.5B
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Wind accounted for 40% of all global renewable energy investments in 2005
Geographic Penetration
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Competitive analysis 10,000
$ / kWh
1,000
VRB 100
10 100 13 Energy Storage Association Source:
300
1,000
$ / kW
3,000
10,000
EnStorage ESS system based on HTB RFC (based on technology developed at my group) Hydrogen
Electric Power
Regenerative Fuel Cell Regenerative Fuel Cell (FC & Electrolyzer)
aqueous Hydrogen hydrogen Aqueous Bromine tribromidesolution solution Bromide
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3HBr
H2+HBr3
• • • •
Totally sealed system No emissions or solid waste Infinite electrolyte life >75% total efficiency Power Generation 250kW to 1GW Proprietary Membrane: 3x higher power density Î 3x lower cost/kW
Energy Storage 1MWh to 10GWh lower cost chemicals Î 4x lower cost/kWh
Comparison between Enstorage ESS and pump hydro ESS • Pumped - Hydro storage technology – – – – –
Larger than 100MW units The lowest cost ESS Usually in conjunction with hydroelectric generation Generally not economical otherwise Israel Electric Company evaluating 800MW installations (~8% of peak demand)
EnStorage ESS based on Hydrogen Three Bromide RFC - advantages over pumped-hydro storage: – – – – – 15
Similar or lower cost Faster response time (1mS vs. 10 seconds for pump hydro) Short term peak: up to 2-3x average output Lower footprint No dependence on topography • can be located in proximity to customers • Applicable to distributed storage
EnStorage energy storage system (ESS) Pump
HBr + HydrogenTribromide solution tanks
Hydrogen tanks 20 kW stack
Compressor
20kW stack
Dryer
Expander
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Single or multiple storage tanks
50-100 Stacks in Parallel
EnStorage energy storage concept HBr/HBr3 solution tanks
HBr To HBr3
H2 Cylinder
Charge mode: 1. Power is supplied to Regenerative Fuel Cell. 2. HBr is converted to HBr3.
RFC
3. Hydrogen is generated.
3HBr
H2+HBr3
Power in
HBr/HBr3 solution tanks
HBr3 to HBr
H2 Cylinder
Discharge mode: 1. Power is generated by the Regenerative Fuel Cell 2. Hydrogen is consumed.
RFC
3. HBr3 is converted back to HBr.
3HBr 17
Power out
H2+HBr3
HBr3solution
HBr3solution 18
PEM FC stack
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Enstorage Membrane Production: Continuous Coater • 33cm wide sheet • 15m2/h (30kW/h)
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World record in power density 1.5W/cm2 Peak power
0.2W/cm2 operating point 21
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Flow Batteries
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Main concept: 1. Based on Vanadium Red-Ox chemistry. 2. Vanadium solutions are circulated both on anode and cathode. 3.
Storage capacity (Energy) is based on tanks volume. Power is based on the size of the active electrodes .
4. Membrane is used for separation between anode and cathode. 24
5. Cation exchange membrane is used. EnStorage Confidential
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•Expensive salts •Membrane price •High cycle # Tanks
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Stacks
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•Expensive organic complex •limited cycle # • requires 100% DOD ever few cycles. •Capacity & power conjoined
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EnStorage (HTB RFC)
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Summary • There is a large need for electric energy storage systems for grid applications and for wind and solar (PV) farms. • In many cases the solar and wind generation sites are far from the customers, thus storage is critical. • Each 5MW wind turbine needs a 1MW - 6 hours ESS. • At present the only technology that meets the cost goal is pump hydro (100 GW installed). • All batteries are too expensive, have too short cycle or calendar life, thus applicable for a short time
storage only. • The Enstorage Regenerative Fuel Cell ESS is expected to meet the performance requirements and the cost goal, especially for large systems and many hours of storage. 29
Thank you for your attention
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