SustainX Received Key Isothermal Compressed Air Energy Storage Patent

WEST LEBANON, N.H., Jan. 25, 2011 /PRNewswire/ -- SustainX, Inc., a New Hampshire-based startup that is developing a transformational technology for utility-scale energy storage using compressed air, has received its third patent.  U.S. Patent No. 7,874,155 expands the patent portfolio surrounding SustainX's isothermal compressed-air energy storage technology by protecting core elements of the company's heat-transfer technology.

To store energy, SustainX uses electricity to drive pistons that compress air. The basis of the new patent, and a key element of SustainX's energy storage process, is the use of a water spray to keep the air at a constant temperature.  During compression, the sprayed water absorbs heat from the air.  The compressed air is then stored in above ground storage vessels and the heated water is stored in a constant-temperature reservoir.  To produce energy from storage, compressed air is used to drive the same pistons, which in turn drive an electric generator.  Warm water from the reservoir is sprayed into the air during expansion to keep it from cooling.  Keeping the air at a constant temperature during compression, storage, and expansion yields a more efficient storage cycle.

The new patent covers the use of a liquid spray injected into air continuously during compression or expansion and solidifies SustainX's position as a leader in the field of compressed-air energy storage.  This innovation, in combination with other elements of SustainX's patented technology, has enabled the company to increase the round-trip efficiency and reduce the cost of compressed air storage to levels never before achieved.

"This latest patent highlights fundamental innovations which the SustainX team has developed and protects the key enablers of our technology. The addition of this patent solidifies our position as the leader in compressed air energy storage," said president and CEO Thomas Zarrella.

About SustainX

SustainX was spun out of the Thayer School of Engineering at Dartmouth College in 2007 and has received funding from the National Science Foundation (NSF) Small Business Innovation Research (SBIR) Program, the Energy Storage Program at the U.S. Department of Energy (DOE), and equity investments from top-tier venture investors Polaris Venture Partners and Rockport Capital.

The company's transformative energy storage technology, which it terms ICAES™ (for Isothermal Compressed-Air Energy Storage), uses electrical energy to compress air near-isothermally (i.e., at approximately constant temperature), stores it aboveground in commercial gas storage containers, and expands it near-isothermally to generate electricity. No fuel is involved.  The company's competitive advantages stem from its proprietary thermodynamic and hydraulic control innovations, a design centered on mature industrial components, and reliance on ambient-temperature, nontoxic working fluids.

SustainX ICAES is targeting the emerging market for bulk (grid-scale) energy storage being created by the growth in renewable generation, and aims to disrupt costly "peaker" plants that burn natural gas or other polluting fuels.

SOURCE SustainX, Inc.