The Role of Energy Storage in
Renewable Power Integration
Emily Fertig
Sharon Wagner
Carnegie Mellon University
Energy storage can facilitate renewable
energy integration
Source: http://www.celgard.com/
Source: http://www.environment-green.com
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Source: http://technorati.com/
Key energy storage research areas include:
•
Technology-specific issues
– Mechanical storage
– Electrical storage
– Thermal storage
•
3
Valuation of energy storage
Mechanical storage options include:
•
•
•
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Compressed air energy storage (CAES)
Pumped hydroelectric storage
Flywheels
CAES can enable wind to supply quick,
reliable energy
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Source: http://www.shpegs.org/cawegs.html
CAES has been operating for over 20 years:
• Huntorf, Germany: 290 MW (1978)
• McIntosh, Alabama: 110 MW (1991)
• Iowa Stored Energy Park: 2700 MW (2011)
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CAES has many benefits for renewables
• Large storage: smoothes daily variability
Key
research
area:
• Ramps
quickly:
smoothes hourly variability
The economic effect of integrating CAES in different
• More cost-effective that batteries at GWh
electricity markets and varying levels of renewable
scalepenetration
energy
• Many locations with suitable geology in U.S.
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Pumped hydro is limited by location
Key research area:
Run-of-river hydro storage (all aspects)
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Source: http://www.tva.gov/power/pumpstorart.htm
Flywheels can help with grid angular stability
and voltage support
• Produce 100-2000 kW for 550 seconds
• Best for high-power, low
Key
research
areas:
energy applications
•Materials development
•Cost reduction
•Improved manufacture techniques
Source: http://www.powergenworldwide.com/
9
Key energy storage research areas include:
•
Technology-specific issues
– Mechanical storage
– Electrical storage
– Thermal storage
•
10
Valuation of energy storage
Batteries are wonderful for renewables,
but expensive
• Store and release power
across
a broad range
of time
Key
research
areas:
scales
•Large-scale demonstration projects
• Smooth rapid fluctuations
•Cost reduction
• Mitigate daily variability
Source: http://www.greencarreports.com/blog/
11
Plug-in hybrid electric vehicles could act as
distributed grid storage
• Daily load leveling
Key
research
areas:
• Frequency
regulation
• Reserve the public and private benefit of using
•Quantify
• Large-scale
use: reduce battery
PHEV’s
for arbitrage
costs through competition and
•Identify
policy incentives necessary to align
mass production
consumer behavior with maximum social welfare
Source: http://keetsa.com/
12
Key energy storage research areas include:
•
Technology-specific issues
– Mechanical storage
– Electrical storage
– Thermal storage
•
13
Valuation of energy storage
Thermal storage can be hot or cold
Source:
http://www.tehrantimes.com/index_View.asp?code=20
1948
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Source:
http://www.kelcroft.com.hk/news/ice_storage2004103
0.htm
Demand-side “hot” storage is usually used
with solar collectors
Key research areas:
decrease in electricity demand
••Quantify
Store heatpotential
energy in hot
water
for later use use
from
wide-spread
••Determine
Reduce electricity
demand
optimum
system size for max
for hot water
economic
returns
•ID policy initiatives to encourage more
deployment
Source:
http://www.conservationhalton.on.ca/uploads/solar%20water
%20heating.gif
15
A “cold” storage system generates ice to
chill water for air conditioning
Key research areas:
•Quantify potential shift in electricity demand
Shift electricity demand for
from air
wide-spread
useday to
conditioning from
•Determine
optimum system size for max
night
economic returns
•ID policy initiatives to encourage more
deployment
Source:
http://www.solarthermalmagazine.com/2010/04/1
2/storing-thermal-energy-a-cool-new-way/
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On the supply-side, storage is usually
coupled with CSP
Source: http://www.volker-quaschning.de/articles/fundamentals2/index.php
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CSP-TES has been operating commercially
for 2 years
Key research areas:
Andasol 1 in Spain: 50 MW (2008)
•Reduce costs
••Quantify
Smoothes hourly
variation from
long-term
effect of TES in CSP O&M
clouds
costs
• Extends plant operation into
nighttime peak
hours
•Evaluate
thedemand
profitability
of different configurations
•Evaluate the effect of different policy initiatives on
decision to use TES with CSP
•Compare economic & environmental implications
Source:
of TES for different CSP technologies
http://www.scientificamerican.com/article.cfm?id=how-touse-solar-energy-at-night
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Key energy storage research areas include:
•
Technology-specific issues
– Mechanical storage
– Electrical storage
– Thermal storage
•
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Valuation of energy storage
An accurate valuation of energy storage
should consider:
• Air quality and economic benefits of offset generation
capacity
• Firming of renewable power to help fulfill RPS requirements
• Avoided construction of new transmission capacity and
transmission congestion relief from renewables
• Relief of ramping requirements for base-load generators
• Overall reduction in cost of ancillary services
• Deferral of substation upgrades
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Overall, we recommend that the
Renewelec Project should:
• Quantify storage potential, costs and benefits
for different energy storage technologies
• Identify how grid and power plant operators
need to adapt to support storage
• Examine market and regulatory strategies
needed to support storage implementation
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Emily Fertig: efertig@andrew.cmu.edu
Sharon Wagner: sjwagner@andrew.cmu.edu
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