Homes could be kept warm with giant “heat batteries” developed by a British start-up that has won backing from the government and external investors. Caldera, based in Hampshire, uses cheap off-peak power and electrical elements to heat a huge highly-insulated block of material called Warmstone, made from recycled metals and aggregate. A coil of water pipes pass through the block, heating up water that can then be used in a conventional central heating system with radiators and a hot water tank. Weighing 1.7 tonnes and measuring 1.7 metres tall by 1 metre diameter, the heat battery is intended to be installed outside a property and to be used primarily as a replacement for oil or LPG boilers. They are used in more than a million of the homes that are not on the gas grid. Oil heating systems are due to be phased out in coming years to meet climate targets but switching to electric-powered air-source or ground-source heat pumps is likely to prove challenging in older properties with solid walls and poor insulation. Heat pumps can cost anywhere from £5,000 to more than £15,000 to install depending on type but insulation and other changes to make them work efficiently could increase the total bill to more than £27,000 in some solid wall properties.
Times 17th May 2021 read more »