Really disruptive technologies tend to be fairly rare in the renewable energy market. However, the heat batteries developed by Sunamp, which specialises in this area, look to be capable of being more disruptive than most of the innovations one sees in this space. Andrew Bissell, the CEO of Sunamp, claims that his products are highly likely to make conventional hot water cylinders obsolete in a relatively short space of time. The technology is now in its third iteration and is barely a third of the size of a typical hot water cylinder, such as households use for hot water. However, the company is currently prototyping much larger versions capable of scaling up to provide the heating needs of commercial companies from palette-sized to container-scale. In 2013, the Department of Energy and Climate Change gave Sunamp a contract to put the thermal storage system, alongside off-peak electricity and air-source heat pumps, into seven homes as a proof of concept trial. That was very successful heating the homes at half the cost of natural gas. The Sunamp put heat batteries into 650 homes. These were in two housing associations, East Lothian Housing and Castle Rock Edinvar.