This is an excerpt from EERE Network News, a weekly electronic newsletter.

March 31, 2004

Utah Power Installs Innovative Battery Energy Storage System

The first vanadium-based battery energy storage system in the United States began operating in late March in Castle Valley, Utah. Vanadium is a commercially available metal commonly used as an additive to steel. The pilot project consists of tanks that hold solutions of vanadium ions in two forms, one more positive and one more negative than the other. The two solutions are brought together in a fuel cell stack, where they react to produce electricity. Electricity can also be fed into the fuel cell stack, reversing the reaction and storing the electrical energy in chemical form in the vanadium solutions. The device is sometimes called a regenerative fuel cell, because it can both store and produce electricity, or a flow battery, because the chemical solutions are pumped through the fuel cell stack.

Utah Power installed the battery energy storage system, which is capable of generating 250 kilowatts of power for eight hours. The system was constructed by VRB Power Systems, Inc. and will be used to improve reliability for Castle Valley customers, who are located at the end of the utility's longest electrical distribution line. See the press releases from PacifiCorp, Utah Power's parent company, and VRB Power (PDF 130 KB). Download Acrobat Reader.

VRB Power has previously installed its energy storage systems in Australia and South Africa. For a more detailed technical description of the system, see the company's "Executive Summary" (PDF 422 KB).

Despite their advantages, battery energy storage systems are rare in the United States. The world's largest, located in Alaska, uses nickel-cadmium batteries and is capable of generating 27 megawatts of power for up to 15 minutes. Installed by the Golden Valley Electric Association (GVEA) and completed in January, the system earned a 2004 Technology Achievement Award from the Electric Power Research Institute (EPRI) in February. It has already prevented a number of power outages for GVEA's customers. See the EPRI press release and the GVEA Web site.