Energy Storage Projects Take Large-Scale Approach

Staff -- Consulting-Specifying Engineer, 12/1/2005

No longer relegated to backup status, energy storage technologies are expanding into grid-connected applications for peak shaving and frequency regulation. Two recent projects illustrate how energy-storage products are gaining respect as distributed energy resources.

Columbus, Ohio-based utility American Electric Power will be installing a 1.2-MW stationary sodium-sulfur battery-based system at a substation owned by its Appalachian Power operating unit, near Charleston W.Va. Expected to be operational by early summer 2006, it will be able to supply 7.2 MWh of electricity. AEP managers say it will delay the need for equipment upgrades at the facility by six to seven years. The unit is the first megawatt-class sodium-sulfur system to be used on a U.S. distribution system, they add.

The U.S. Dept. of Energy's Sandia National Labs contributed funding to the project, which is intended to demonstrate the technology's use in peak-shaving and equipment upgrade deferral applications. The manufacturer is NGK Insulators Ltd. of Nagoya, Japan. Chicago-based S&C Electric is serving as system integrator.

A utility-scale, flywheel-based energy-storage system was set to be connected to the local grid in San Ramon, Calif., this fall. The unit, designed by Wilmington, Mass.-based Beacon Power Corp. for the California Independent System Operator (ISO), is to demonstrate the potential of flywheel-based frequency regulation as a means for improving power quality across the California grid. Beacon Power is now building a second Smart Energy Matrix for the New York State Energy Research and Development Authority, with plans for winter 2005 delivery.