IT is reported that old coal mines in Holland are being used to produce hot water from the latent heat deep in the earth. This hot water is used to heat homes.

The counties of Devon and Cornwall are full of deep holes left over from the mining industry. These could be deepened to reach very hot areas. Cold water is pumped into the mines and pumped out again when it is very hot.

After use the water could be returned to the mines for reheating.

The project could revitalise old mining areas and reduce CO2 emissions. We already know that there are hot springs in some old mines — in the Luckett area, for example.

Geoffrey Willetts

Grenville Drive

Tavistock