World’s first liquid air energy storage plant uses Atlas Copco 12 September 2011

Atlas Copco compressors are performing an essential role in an innovative cryogenic process developed by Highview Power Storage to store off-peak electric energy by liquefying air.

Using cheap, off-peak electricity, the CryoEnergy System pilot plant operates by extracting ambient air from the surrounding environment.

Rob Morgan chief technology officer at Highview, explains that the gas is cleaned, compressed and then cooled until it liquefies. Liquefied air is then stored in an insulated tank at -196° C.

When power is required, liquid air is drawn from the tank and pumped to high pressure, he says. Ambient, or above ambient, waste heat is applied to the liquid air via heat exchangers, resulting in a phase change from liquid air to a high pressure gas, which is then used to drive a turbine and power generator.

The liquefaction stage is accomplished by integrating Atlas Copco compressors within Highview's 300kW/2.5MWh CryoEnergy system. An oil-free ZR 700 VSD water-cooled screw compressor, with specially modified inlet pipework, operates within the recirculation system, while the main air feed for the liquefaction plant is supplied by a ZR 250 VSD variable speed drive rotary screw compressor. Atlas Copco also supplied a low-pressure ZS45+ VSD blower.

"The screw compressors supplied by Atlas Copco offered the best compromise in price, performance and delivery," comments Morgan. "Atlas Copco also provided us with excellent support during the selection of the machines."

"With the drive for a low carbon economy, there is increasing emphasis on wind and solar sources," observes Gareth Brett, CEO of Highview Power Storage. "However, these forms of generation are intermittent and thus there is a need for a viable energy storage method to act as a buffer … and release [energy] to the grid at peak times."

Highview's CryoEnergy system pilot plant is being hosted by SSE's (Scottish and Southern Energy), Slough heat and power plant, using commercially available components throughout.

Highview plans to scale up the system to a 10MW 40MWhs commercial demonstrator: "As we scale up the technology, we will certainly be discussing with Atlas Copco how their advanced compressor technology can support our projects in the future.," comments Morgan.

Brian Tinham

Related Companies
Atlas Copco Compressors

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.