Elon Musk introduced Tesla Energy’s PowerWall. The sleek wall mounted battery storage system is designed to storage the energy solar panels produce during the day. The system allows homeowners to then draw upon the energy at night and during power outages. $3500 price tag is well below what authorities were speculating the price would be. Musk also introduced a gigawatt size battery storage system for utilities and commercial applications. Walmart is already using the larger units to power eleven of their stores. Multiple units can be combined for larger energy storage needs. Up to nine home PowerWall systems can be linked together for larger home solar arrays.