The city of Presidio, Texas, has only one aging transmission line connecting it to the US electric grid, so power outages are very common.
To battle chronic power outages and electrical fluctuations, the city is coming up with an unusual solution: a Texas-sized battery backup!
The hoped-for remedy is a battery, a Texas-size battery, which could eventually end up playing an important role in wider use of green power generation such as solar and wind. The U.S. $25 million system, which is now charging and is set to be dedicated April 8, will be the largest use of this energy storage technology in the United States.
The four-megawatt sodium-sulfur (NaS) battery system consists of 80 modules, 8,000 pounds (3,600 kilograms) each, constructed by the Japanese firm NGK-Locke. They were shipped to Long Beach, California, in December and transported to Texas aboard 24 trucks.
The cost of the battery system includes $10 million just to construct the building in which it will be housed and the new substation it requires.
Completed in December 2003, the BESS is one of GVEA's initiatives to improve the reliability of service to GVEA members. In the event of a generation or transmission related outage, it can provide 27 megawatts of power...
http://www.gvea.com/about/bess/
4MW is probably best served by full sized turbines.