For years, automakers have looked for ways to reuse the batteries from electric cars, which retain significant storage capacity even after they are no longer useful for transport.
Now, those efforts are beginning to bear fruit. On Monday, Nissan executives announced a partnership with Green Charge Networks, an energy storage provider, to sell stationary systems built around used Leaf batteries to businesses. And on Tuesday, General Motors said it had a similar setup using Volt batteries that is helping to make a testing campus in Milford, Mich., practically energy independent. The company said it planned to sell its systems eventually.