A new thermal energy storage material dubbed ChainStore has potential applications from heating and cooling of buildings and greenhouses to thawing frozen football pitches.
The technology uses biodegradable materials and can be made in large quantities easily, said Professor Saffa Riffat, President of the World Society of Sustainable Energy Technologies and head of Nottingham University’s Buildings, Energy and Environment Research Group, who led the research team.
With the world’s requirement for electrical power growing rapidly, and because of the intermittent nature of most renewable energy sources, the need for efficient technology for energy storage is increasingly urgent.
Thermal energy storage (TES) technology allows energy to be stored by heating or cooling a medium such as water, or causing a phase change in a material such as wax. The energy can then be recovered at a later time.
Professor Riffat said most TES technologies are expensive and have poor heat transfer capabilities – it is not easy to get the heat in or out of the storage medium.
ChainStore uses a low-cost biopolymer material which is biodegradable and edible as its outer cover. The material can be formed into bubbles to contain the energy storage medium. “It can be made very quickly in long chains or to cover large areas, at low cost,” said Prof Riffat.
The energy storage medium is a composite crystalline material, of which details are not currently being released because it is in the process of being patented. Prof Riffat said, however, that it has very high energy storage capacity compared with water.
Applications are expected to include cold storage, where the store, including the ChainStore material, would be cooled when renewable or cheap-rate electricity was available. At times of peak electricity rates or when renewable energy was not available, the material would absorb heat and keep the store cool.
Installed on ceilings in buildings it would absorb heat and reduce the need for air-conditioning during the day, and release heat at night. The material could be hung in greenhouses so that energy stored during the day would protect plants from frost during the night.
For sports pitches an “active” version of the product, with electric heating elements built in, would be pre-warmed, then unrolled over the pitch. This would be much cheaper than under-soil heating systems, which only the biggest clubs can afford, said Prof Riffat.