The Sonnen energy storage system stores energy from solar-powered homes that’s generated during off-peak times for use during high-demand times, thereby reducing energy costs. The German-based system’s 4-kilowatt-hour battery incorporates self-learning software that increases a home’s solar consumption, manages time of use, and supports grid services, according to the manufacturer. With more than 30,000 installations worldwide, the technology has been used for years in Europe.

In the U.S., Phoenix-based Mandalay Homes has been an early adopter, including the battery in its recent Discovery Home, then taking the concept standard in its 2,900-home Jasper master planned community in Prescott Valley, Ariz. Combined with a six-panel solar array, the Sonnen system will make each of these homes almost completely energy-independent.