According to Powermag the UK start up the simplest thermal energy storage systems consisting in two large containers at the opposite temperatures connected by a heat pump.
The surplus of wind power or solar energy is used to heat up the hot tank at the 500 Celsius and to retain that temperature. The other tank also insulated is kept at -160 Celsius. There are no refrigerants, chemicals or water necessary and no other requirement.
Each tank of gas and gravel has the size of a small building, and for this energy storage the heat differential between the containers operates a 6MW heat pump. According to the Jonathan Howes, the company’s chief technology officer, the overall operating efficiency is claimed to be 72% to 80% for the energy storage process.
The large containers could give more energy storage and according to Howes, it will cost about $16 million to test the prototype’s ability to store and release 16 MWh of power at a rate of 2 MW for 8 hours.
California is looking for energy storage and 33% of our electricity is to come from renewable sources by 2020. More energy storage is needed to avoid the intermittency of renewable. To ensure a good match between the rise in renewables and storage a rising percentage of storage on the grid is mandated.
Federal Energy Regulatory Commission (FERC) wants to offer higher payments to fast storage suppliers or at least to incentivize utilities to offer breaks to customers who conserve the environment. The Californian utilities offer incentives to the commercial users in order to give them a break for wasting more energy. The waste of fossil powered energy has an impact on climate change globally; in South being felt as extremely weather.
