1. Compressed Air Energy
Storage
An Overview of the System and its Advantages
20/08/2013

2. Overview
 CAES Operation
 Compression
 Generation
 Advantages of CAES
 Advantages of CAES in Salt Caverns
 Conclusions
20/08/2013Compressed Air Energy Storage Operation & Advantages 2

3. CAES Operation
Compression
20/08/2013Compressed Air Energy Storage Operation & Advantages 3
Source: http://www.ridgeenergystorage.com/caes_overview.htm

4. CAES Operation
Generation
20/08/2013Compressed Air Energy Storage Operation & Advantages 4
Source: http://www.ridgeenergystorage.com/caes_overview.htm

5. Advantages of CAES
 Reduces the costs in having no storage at all, thus reducing
wind curtailment.
 In 2011, wind farms were paid £25million to not produce
electricity due to extortionately high costs set by the wind farm
operators1.
 This money could be spent on installing CAES systems and so
the turbines would be able to store the energy produced, thus
eliminating costs for shut-down.
 Reduced emissions associated with the energy produced by
conventional methods.
 Storing energy that would otherwise be wasted results in a
reduction in emissions due to needless further production.
20/08/2013Compressed Air Energy Storage Operation & Advantages 5
[1] Source: Daily Mail – “Wind farms paid £25million NOT to produce electricity when it is blustery - and YOU pay”

6. Advantages of CAES
 Quick start-up time.
 0%-100% can be achieved in 10 minutes.
 50%-100% can be achieved in 15 seconds2.
 Vast areas in which the system could be implemented
 80% of US territory has geology suitable for CAES3.
 There just needs to be a proven technology with high
efficiency that could be applied to the possible sites.
20/08/2013Compressed Air Energy Storage Operation & Advantages 6
[2] Source: Arizona Research Institute for Solar Energy
[3] Source: Boise State University - “Overview of Compress Air Energy Storage”

7. Advantages of CAES
 Shift of cheap off-peak energy to expensive peak
energy.
 CAES uses excess energy at off-peak times to compress
air.
 It then generates electricity at times of peak demand,
when electricity prices can be 4 or 5 times as high.
 It is this difference in electricity price that generates income
for the cavern operators.
20/08/2013Compressed Air Energy Storage Operation & Advantages 7

8. Advantages of CAES
Using Salt Caverns
 Flexibility4
 Operate under very high pressure and so can very quickly
accept or deliver large amounts of air and hence can cope with
the intermittency of generation requirements caused by
renewable sources.
 Cycling
 Traditional gas caverns can traditionally only inject in the
summer and withdraw in the winter
 Base Gas
 Caverns must be primed with a base pressure of gas, which is
lower in salt caverns than it is with typical caverns, resulting in a
higher proportion of working gas from the cavern.
20/08/2013Compressed Air Energy Storage Operation & Advantages 8
[4] Source: EIA – “Salt caverns account for 23% of U.S. underground natural gas storage daily deliverability”

9. Conclusions
 Compressed Air Energy Storage provides an
increasingly important solution to the problem of grid
stability and energy storage.
 Once one technology has been proven to work
incorporating a high efficiency, the possibility for
installation globally is very realistic and has huge
commercial benefits whilst also preventing grid
breakdown.
20/08/2013Compressed Air Energy Storage Operation & Advantages 9

10. Thank you
20/08/2013Compressed Air Energy Storage Operation & Advantages 10