energy storage on the grid: informing future development
DESCRIPTION
Energy Storage on the Grid: Informing Future Development. Eric Hittinger Advisors: Jay Whitacre, Jay Apt Department of Engineering and Public Policy Carnegie Mellon University. This study examines four energy storage technologies and four applications. Energy Storage Technologies: - PowerPoint PPT PresentationTRANSCRIPT
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Energy Storage on the Grid: Informing Future Development
Eric HittingerAdvisors: Jay Whitacre, Jay Apt
Department of Engineering and Public PolicyCarnegie Mellon University
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This study examines four energy storage technologies and four applications
• Energy Storage Technologies:– NaS Batteries– Li-Ion Batteries– Flywheels– Supercapacitors
• Applications:– Frequency regulation provided by energy storage– Peak shaving using energy storage– Wind Integration (Baseload)– Wind Integration (Load-following)
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100 MW Natural
Gas TurbineCharge/ Maintain Energy
Curtailment
“Flat Power” Output (within deadband)
Wind Power vs. Time
Wind + Gas Power vs. Time
Wind + Gas + Battery Power vs. Time
Wind Generation
Sodium Sulfur (NaS)
Battery
A Co-located wind/natural gas turbine/energy storage system can deliver “baseload” power
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Energy storage is used only to smooth the sharpest wind fluctuations
Wind Farm Output
Output After Battery “Smoothing”
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Cost-of-service is conceptually like a production function
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Sensitivity plot for “Regulation” application using flywheels
0% 100% 200% 300% 400% 500%$0
$10,000,000
$20,000,000
$30,000,000
$40,000,000
$50,000,000
$60,000,000
$70,000,000
$80,000,000
$90,000,000
Percent Change from Base Case Value
Cost
of P
rovi
ding
One
Yea
r of 1
00 M
W R
egul
ation
(M
illio
ns)
Module Capital Cost
Fixed Operating Cost
Module Energy Capacity
Lifetime
Property SlopeLifetime 0.23Fixed Oper. Cost 0.28Module Cap. Cost 0.73Module Energy Capacity 0
Sensitivity of NaS battery properties
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Sensitivity of flywheel properties
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Sensitivity of Li-Ion battery properties
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Sensitivity of supercapacitor properties
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Capital cost improvements are still valuable even after current technology targets have been met
Existing Targets• US DOE’s Energy Storage Program: $250/kWh• American Electric Power: $500/kWh• ARPA-E GRIDS Program: $100/kWh
Using $250/kWh:Capital Cost Reduction
Average Change in Sensitivity to Capital Cost
Li-Ion Battery 50% 20%
NaS Battery 30% 12%
Flywheel 50%* 25%
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Research Conclusions
The relative importance of storage properties depends on storage type and application…
…but certain properties, particularly capital cost, are consistently more valuable to improve.
These results can help inform:– Energy Storage Development– Research Funding– Energy Storage Technology Targets
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Questions!
Support for this research has been provided by the EPA STAR Fellowship, the National Energy Technology Laboratory of the Department of Energy, and the Electric Power Research Institute under grants to the Carnegie Mellon Electricity Industry Center (CEIC).
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In the Wind/Natural Gas/Storage systems, storage is used for intermittent sharp spikes
Wind
Natural Gas
Storage
100 MW Gas Turbine67 MW Wind Farm0.7 MWh Battery100 MW Target Power Output
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0% 4% 8%12%
16%20%
24%28%
32%36%
40%44%
48%52%
56%60%
64%68%
$0
$20
$40
$60
$80
$100
$120
$140
$160
$180
Average Cost of Electricity is relatively constant over a wide range of wind penetrations for the Wind/Gas/NaS Battery Systems
Battery Contribution
Wind Contribution
Gas Contribution
Delivered Wind Energy (percent of total delivered energy)
Aver
age
Cost
of E
lect
ricity
($/M
Wh)
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100 MW Natural
Gas TurbineCharge/ Maintain Energy
Curtailment
“Flat Power” Output (within deadband)
Wind Power vs. Time
Wind + Gas Power vs. Time
Wind + Gas + Battery Power vs. Time
Wind Generation
Sodium Sulfur (NaS)
Battery
The “load-following” application is very similar to the “baseload” application
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NaS Battery Properties
NaS Battery Parameter Base-Case Value
Round-trip Efficiency 80%
Module Energy Capacity 0.36 MWh
Module Power Limit 0.25 MW
Module Maintenance (Heating) Power 2.2 kW
Module Capital Cost $240K ($670K / MWh)
Module Fixed Operating Cost $8K / module - year ($22K / MWh-year)
Length of Capital Investment 20 years
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Li-Ion Battery Properties
Li-ion Battery Parameter Base-Case Value
Round-trip Efficiency 80%
Capital Cost of Batteries $500K / MWh
Capital Cost of Power Electronics $300K / MW
Fixed Operating Cost $8K / MW - year
Length of Capital Investment 10 years
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Flywheel PropertiesFlywheel Energy Storage Parameters
Base-Case Value
Round-trip Efficiency 90%
Module Energy Capacity 0.025 MWh
Module Power Limit 0.1 MW
Flywheel Friction Losses 3% of max power (3 kW)
Module Capital Cost $200K
Fixed Operating Cost $5K / module - year
Length of Capital Investment 20 years
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Supercapacitor PropertiesSupercapacitor Parameters Base-Case Values
Round-trip Efficiency 70%
Capital Cost of Supercapacitors $143M / MWh
Capital Cost of Power Electronics $60K / MW
Fixed Operating Cost $13K / MW - year
Length of Capital Investment 20 years