The same legendary Panasonic battery technology that powers the world's most advanced electric cars is now available to power your home. EverVolt? stores the excess power your solar panels generate during the day for use during grid outages, or to sell to your local utility. Available in a four- or six-battery configuration, this AC-coupled storage system works with or without solar and delivers clean usable energy capacity ranging from 11.4 kWh to 17.1 kWh.