Compressed Air Energy Storage (CAES)

Max Dunn — Thu, 30 Oct 2008 08:10:00 -0800

Much of the criticism of solar and wind energy is that they don’t produce power all the time and that we don’t have any good way of storing electricity. There is some pumped hydro storage, but it is only able to contribute less than 3% of the power, and it is not likely that we will be able to build more.

However, another way of storing energy is to compress air underground. There are a lot of areas that can be used for this underground air storage including underground aquifers, carved out salt caverns, depleted natural gas wells and old mines.

The air is compressed using an electric turbine which can be driven by solar, wind or even off-peak electricity. Then when it is needed, the compressed air is fed into a natural-gas fired electric plant which normally would need to use a lot of energy to compress the air. This makes CAES systems almost 3 times more efficient than single cycle gas-fired plants, and almost twice as efficient as combined cycle plants. In addition, CAES equipment is simpler and has lower operating costs.

Currently there are two CAES plants in operation around the world. A 290 MW plant in Germany operating since 1978, and a 110 MW plant in Alabama operating since 1991. Now, there is a third 200 MW CAES plant being built in Central Iowa (ISEP) that received a federal funding earmark in 2009 for $1.5 million.

CAES is a very promising technology that can make sustainable energy much more practical and we should be working harder and faster and devoting more money to develop this technology.

References:

Eschew Obfuscation: Compressed Air Energy Storage (CAES)

Compressed Air Energy Storage (CAES)