Being clever with heat
Combined heat and power systems are increasingly popular, as is heat recovery. It always seems ironic to me that we are developing these technologies when, through better insulation, Passivhaus etc, we are cutting down on a requirements for heating. And when technologies such as solar thermal can easily heat hot water. Still we do need heat at certain times – the problem is that we don’t always need it when it is available.
So it is interesting to see that scientists in Germany have come up with a new way of storing heat, for re-use when it is needed. The storage method, developed by Fraunhofer, is intended in the first instance for use with biogas plants, but since it is is simply a storage method, could presumably be used more widely. The technique, using zeolite spheres, occupies a quarter of the space of heat storage and in water and has the added advantage of not actually storing heat itself. Instead, heat is used to dry out the spheres and, when you want them to emit heat, you allow them to take up water again.
The principle has been known for ages, but the researchers have addressed important practical details. Hooray for science!