In a giant sodium sulfur (NaS) battery

One of the greatest challenges producers, transmitters and distributors of electricity have faced is the fact that electricity, once generated, couldn't be stored for times when demand was high or traditional resources were interrupted. That left electricity providers with just one choice - continue to build more and more generation plants to provide the electricity our nation needs. Unfortunately, the cost of building new electricity generation is high - both in dollars and environmental impacts.

Now AEP and its partners are leading the industry in the installation of large-scale, sodium sulfur (NaS) batteries which allow energy to be stored where it's likely to be needed during peak demand periods or for specific circuits during outages (islanding). And because the batteries are connected to the electricity grid, they can charge during periods of low demand and discharge backup or supplemental power when needed.

Following testing at its Dolan Test Center in Ohio, AEP became the first company to deploy NaS batteries by installing and operating a demonstration unit in 2002. In 2006, AEP installed a 1.2 megawatt (MW) stationary NaS battery near Charleston, W.Va. By 2020, AEP will improve service reliability and quality and security by deploying 1,000 MW of distributed energy storage on the grid. Three installations of NaS batteries were completed by AEP in 2008:

Citizens NaS station, Bluffton, Ohio - 2 megawatts - largest utility-scale NaS battery installation in US. Used in light commercial area for peak shaving and islanding. 15-year lifespan

Balls Gap Station - Milton W.Va. - 2 megawatts - residential peak shaving and islanding

East Busco Station, Churubusco, Indiana - 15 miles northwest of Ft. Wayne - 2 megawatts - suburban residential peak shaving and islanding - potential for wind generation connection