Compact heat storage

Research & Development

Building & Testing

Market Replication

Major Results

Compact heat storage

Seasonal storage of heat produced during summer for usage in winter is a step forward to gain independence on non-renewable energy sources. For short storage times an easy and cheap way of storing heat is in water boilers. For seasonal storage, however, the loss of heat has to be minimalized and the storage density has to be improved.

An average low-energy household has an energy demand in the winter of about 6.7 GJ/year. For the storage of this energy in water (?T = 70 K) a volume of 23 m3 would be needed, which is not possible for most households. Salt hydrates have a storage density of a minimum of 1 GJ/m3 (depending on operating conditions) and no loss of heat occurs during storage. Using salt hydrates, a storage volume of 4 – 8 m3 would ideally be sufficient. The energy density of the thermochemical material will determine the precise volume of the storage system, the cost and the storage capacity.

Especially for the long term, compact thermal storage is of the utmost importance. In 2050, over 70% of the current dwellings will still be present! This means that the existing houses today will have to be retrofitted with thermal storage installations in order for them to be energy neutral in 2050. Compact thermal storage is inevitable!

“Through cooperation and perseverance we will achieve breakthrough technology for thermal energy storage”
Christophe Hoegaerts, TNO
4th MERITS newsletter - April 2015
The fourth MERITS newsletter has been released, including news on thermal storage material, component, and system level developments. In addition, a sneak preview is given on the construction of the MERITS demonstrator container being built at the moment. Check it now!
MERITS in IEA Solar Update June 2013