March 7, 2008—Xcel Energy soon will begin testing a cutting-edge technology to store wind energy in batteries. It will be the first use of the technology in the United States for direct wind energy storage.
Integrating variable wind and solar power production with the needs of the power grid is an ongoing issue for the utility industry. Xcel Energy will begin testing a one-megawatt battery-storage technology to demonstrate its ability to store wind energy and move it to the electricity grid when needed. Fully charged, the battery could power 500 homes for over 7 hours.
Xcel Energy has signed a contract to purchase a battery from NGK Insulators Ltd. that will be an integral part of a project. The sodium-sulfur battery is commercially available and versions of this technology are already being used in Japan and in a few US applications, but this is the first US application of the battery as a direct wind energy storage device, says Xcel.
The 20 50-kilowatt battery modules will be roughly the size of two semi trailers and will be able to store about 7.2 megawatt-hours of electricity, with a charge/discharge capacity of one megawatt. When the wind blows, the batteries are charged. When the wind dies down, the batteries supplement the power flow.
The project will take place in Luverne, Minn. The battery is expected to go on-line in October 2008.
Partners in the project with Xcel Energy include the University of Minnesota, the National Renewable Energy Laboratory, the Great Plains Institute and Minwind Energy, LLC.
Xcel Energy is testing emerging technology and energy storage devices as part of its overall Smart Grid strategy, which modernizes and upgrades the grid to allow for easier integration of renewable energy sources. The project has been selected to receive a $1 million grant from Minnesota’s Renewable Development Fund, pending Minnesota Public Utilities Commission approval this spring.
For more information visit the Xcel Web site.
