High Capacity Large Scale Electrical Power Storage

A long-time problem in electrical power systems has been efficient and cost-effective storage of electric power. This would allow demand peaks to be satisfied by electricity generated during off-peak times. This can reduce the infrastructure requirements of power systems and can make better use of wind power. Because strong winds often occur at night when demand is low, battery storage can make more power available from wind farms by storing it until it is needed.

In the past the problem has been in the cost or efficiency of very large batteries. They tend to wear out quickly and also only return a fraction of the energy put into them.

Sodium-Sulfur batteries may provide a solution to this problem.

American Electric Power (AEP),
one of the largest U.S. utilities, has been using a 1.2 megawatt NaS
battery in Charleston, W.Va., the past year and plans to install one
twice the size elsewhere in the state next year. Dozens of utilities
are considering the battery, says Dan Mears, a consultant for NGK
Insulators, the Japanese company that makes the devices.

"If you've got these batteries distributed in
the neighborhood, you have, in a sense, lots of little power plants,"
Walker says. "The difference between these and diesel generators is
these batteries don't need fuel" and don't pollute.(More)