HomeCoal FiredEquipmentCompressed air energy storage makes use of space in underground caverns

Compressed air energy storage makes use of space in underground caverns

OLEAN, N.Y., Aug. 1, 2001 à‚– From rolling blackouts in California to skyrocketing prices in New York, America is bracing itself for what the White House considers “the most serious energy shortage since the oil embargoes of the 1970s.” Fortunately, an economical and environmentally friendly solution may be right under our feet.

Compressed air energy storage (CAES) is a method of economically converting electric energy, storing it, then retrieving it for later use.

Air is compressed and stored underground during off-peak hours for electricity, usually at night or on weekends. Then during peak hours when demand is greatest, the compressed air is returned to the surface to drive equipment that generates more electricity.

“Essentially, CAES is a type of battery,” explains David Hargreaves, business development manager for Dresser-Rand Company. Dresser-Rand helped develop the CAES technology and custom-engineered the equipment for a facility in McIntosh, Alabama, USA, the only one of its kind in the U.S.

“Air is compressed into an underground salt cavern at night at a cost of one to two cents a kilowatt-hour, then withdrawn to generate electricity when the demand for power is high. Using off-peak power to compress the air is the key to cost savings.”

For the past decade, CAES technology been in use at the Alabama Electric Cooperative facility in McIntosh.

It has successfully produced up to 110 megawatts of electrical power within 15 minutes of start-up at a cost that is considerably less than power generated by gas turbines. CAES plants can be built in multiples of 110 megawatts, depending on power needs and potential underground storage capacity in a particular geographic area.

Air storage options include caverns in salt formations, aquifers and mined hard rock caverns. Geology suitable for one or more of these options is available throughout much of the world.

“As the price of fuel used to generate electricity increases, it looks better and better for compressed air,” said Dr. Robert Schainker of the Electric Power Research Institute (EPRI). Schainker is product sector leader, transmission and substations, for EPRI, an energy and environmental research organization based in Palo Alto, Calif.

Dr. William Lang’s Strata Power Co. of Aurora, Illinois, owns the reservoir rights to several aquifers within power transmission distance to Chicago. Lang, who held the original patent on the process of compressed air storage, sees the day when it will provide answers to managing power grids during periods of peak demand. “It’s both for peaking power and intermediate power up to 10 to 12 hours a day,” he says. “It’s very economical. The nation needs it. It’s the only thing at hand.”

According to engineers and consultants, CAES plants could be a quick fix with long-term potential. Compared with the four to eight years it takes to build a traditional fossil fuel plant, a CAES plant can be built in less than three years.