Hugh Pickens writes writes "Josie Garthwaite writes that old electric car batteries degraded below acceptable performance levels for autos still have enough life to serve the grid for at least ten years with a prototype announced by GM and ABB lashing five Chevy Volt battery packs together in an array with a capacity of 10 kilowatt-hours — enough to provide electricity for three to five average houses for two hours. "In a car, you want immediate power, and you want a lot of it," says Alexandra Goodson. "We're discharging for two hours instead of immediately accelerating. It's not nearly as demanding on the system." Deployed on the grid, community energy storage devices could help utilities integrate highly variable renewables like solar and wind into the power supply, while absorbing spikes in demand from electric-car charging. "Wind, it's a nightmare for grid operators to manage," says Britta Gross, director of global energy systems and infrastructure commercialization for GM. "It's up, down, it doesn't blow for three days. It's very labor-intensive to manage." The batteries would allow for storage of power during inexpensive periods for use during expensive peak demand, or help make up for gaps in solar, wind or other renewable power generation. One final advantage of re-using electric car batteries is that the battery—the most expensive part of an electric car—remains an asset beyond its useful life in the vehicle. "If there is a market in stationary power for spent batteries, consumers could recognize this as an increased resale value at end of life, however small," says Kevin See."