Tesla’s Powerwall, with its unique design, has already sold 2.500 units
Energy storage is important for renewable energy not because green power is unpredictable, but mainly because it is intermittent: strong winds in the early hours do not coincide with the peak demand of the evenings, and solar panels produce power in the daytime when sunlight is strong but most families are away from home and do not get to use the power from their panels. Storage units allow excess energy to be time-shifted to when it is needed, maximizing the benefits of windfarms and solar arrays. According to a report titled ‘The Role of Energy Storage in the PV Industry’, edited in 2013 by IHS Inc. Cambridge Energy Research Associates (IHS CERA), the energy storage business could grow from $200 million in 2012 to a $19 billion industry by 2017!
To address this growing demand for energy storage, Tesla launched the Powerwall last year, a lithium-ion battery with an energy storage capacity of 6.4 kWh, sufficient to power most homes during the evening using electricity generated by solar panels during the day. The Powerwall was first designed for installation with SolarEdge inverters, but it is now also compatible with inverters from SMA, the world’s largest inverter manufacturer by revenue and second largest by shipments. Tesla has also produced a similar product suited for utilities, the “Powerpack”, a 100kWh battery block to help them smooth out their supply of wind and solar energy - which is generated intermittently - or to pump energy into the grid when demand soars. In the company’s financial update for the first quarter of 2016, Tesla confirmed it had shipped 25 MWh of storage capacity to customers in four continents. “We delivered over 2,500 Powerwalls and nearly 100 Powerpacks in the quarter throughout North America, Asia, Europe and Africa”, they report in a letter to shareholders.