Xcel Energy finds promising results from wind-to-battery project


Frank Novachek,
Director of
Corporate Planning,
Xcel Energy
Minneapolis, MN, U.S.A. — (METERING.COM) — August  4, 2010 – A wind-to-battery storage project being undertaken by Xcel Energy in Minnesota as part of its smart grid strategy has shown promising results, and the bottom line is the technology works.

In October 2008, Xcel Energy began testing a 1 MW sodium-sulfur battery storage system to demonstrate its ability to store wind energy and move it to the electricity grid when needed – the first use of the technology in the United States for direct wind energy storage, according to the company in a statement.
“We have proved that this technology can perform the functions of storage that we were looking for to help us manage the variability of wind energy on our operating system,” said Frank Novachek, Xcel Energy director of corporate planning. “The success of this technology is important to both Xcel Energy and our customers, and we are greatly encouraged by these results.”

The preliminary test results indicate that the battery has the ability to effectively shift wind energy from off-peak to on-peak availability, and to reduce the need to compensate for the variability and limited predictability of wind generation resources. Further, the technology supports both the transmission grid system by providing voltage support, and the regional electricity market by responding to real time imbalances between generation and load.

The technology also may be applicable for solar energy, the results indicate.

Testing will continue to determine the technology’s ability to facilitate integration of larger penetrations of wind energy on the grid. Phase II of the study will also assess the potential value of the various battery system functions and determine the potential cost effectiveness of the technology. A final report is expected in summer 2011.

The project is being conducted in Luverne, Minn., about 30 miles east of Sioux Falls, S.D. The battery installation is connected to a nearby 11 MW wind farm owned by Minwind Energy, LLC.

Collectively, the 20 50 kW battery modules are able to store about 7.2 MWh of electricity, with a charge/discharge capacity of 1 MW.

Xcel Energy purchased the battery from NGK Insulators Ltd. Other partners in the project include S&C Electric, the University of Minnesota, the National Renewable Energy Laboratory, the Great Plains Institute and Minwind Energy, LLC, and Gridpoint.

The project received a $1 million grant from Xcel Energy’s Renewable Development Fund.