Tesla Powerwall is a wall-mounted battery system for storing energy generated by solar power panels and wind turbines. Powerwall is a product of Tesla Energy, a business division of Tesla Motors. Powerwall, which is aimed at the residential market, is designed to store power generated at peak solar time for use during power outages and out-of-peak solar time, including night. The system's slim, modular design is adapted from the technology used in those for Tesla's electric cars and can hold up to 7 kilowatt-hours of energy, which is enough energy to power a typical home in the United States for about 7 hours. A similar product, Tesla Powerpack, is aimed at the business and utility market. Both products are based on lithium ion battery technology. Powerwall will be available in a 7 kilowatt hour (kW) model, designed for daily use applications, and a 10kwh model, designed for backup power. The units weigh about 220 lbs. Total capacity can be upgraded by modular connection of up to nine additional units. Tesla expects to start shipping Powerwall sometime during the summer of 2015. Tesla provides the following specifications for Powerwall: (1) Mounting: Wall Mounted Indoor/Outdoor; (2) Inverter: Pairs with growing list of inverters; (3) Energy: 7 kWh or 10 kWh; (4) Continuous Power: 2 kW; (5) Peak Power: 3.3 kW; (6) Round Trip Efficiency: 92%; (7) Operating Temperature Range: -20C (-4F) to 43C (110F); (8) Warranty: 10 years; (9) Dimensions: H: 1300mm W: 860mm D: 180mm