New Hampshire-based SustainX has received US$14.4 million from GE Energy Financial Services and other investors to continue developing its compressed air energy storage technology.

GE Energy Financial Services joins Cadent Energy Partners and prior investors Polaris Ventures and Rockport Capital in the new round of venture financing, details of which were not disclosed. A total of $5.4 million in earlier financing for SustainX came from the Small Business Innovation Research programme of the National Science Foundation and from the Energy Storage Program of the US Department of Energy. AES Energy Storage LLC is working with SustainX to demonstrate a full-size system in the field.

According to the company, SustainX technology keeps air at a nearly constant temperature during compression and expansion; this significantly improves efficiency and reduces the cost of compressed-air energy storage below that of other above-ground energy-storage options.