CAES technology has been in use for over 20 years. The first CAES plant,
a 290 MW facility, was started up in Huntorf, Germany in 1978, and a 110
MW plant commenced operation in McIntosh, Alabama in 1991. Both of these
facilities have compression trains that are linked to the generation train
via a common motor-generator and sets of clutches.
The McIntosh plant made improvements to the Huntorf
design by incorporating a recuperator (air to air heat exchanger) to preheat
air from the cavern with waste heat from the turbines. Since overcoming
some startup issues, the plant has functioned with over 95% reliability.
The successful operation of the McIntosh and Huntorf plants has demonstrated
the technical viability of CAES technology in supplying ancillary services,
load following, and intermediate power generation.
Despite its success from a technological standpoint, CAES was not deployed
in other installations during the 1980's and 1990's for a number of reasons:
- Since regulated utilities grew through an increase in invested capital,
there was no economic incentive to add CAES, which increases the efficiency
of existing plants and decreases the total capital required to serve
a given load.
- Independent power producers in the US did not develop CAES because
CAES did not qualify for PURPA contracts, which were available only
for renewable power plants or for cogeneration facilities.
- Even during the boom in power plant construction in the late 1990's, a lack
of available equipment prevented the development of new CAES plants. Until very
recently, major turbine manufacturers had sold out production capacity
and had not been willing to invest in the development of CAES turbines.
As deregulation proceeded and market conditions evolved, CAES technology
became more commercially viable. The value of shaped power and time of
delivery were no longer bundled with the total price of power, and their
worth became more apparent. High volatility in power pricing demonstrated
the value of electricity storage options, while the development of ancillary
services markets provided additional opportunities for revenues from CAES
A number of developers, including Ridge Energy, have
now invested resources to develop, finance, and construct CAES plants.
Today, CAES is still relatively young as a commercial venture, but it
is well on its way to establishing itself as a vital component of an efficient
and flexible power industry.
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