GEOTHERMAL energy has come on stream at United Downs near Redruth and is producing enough energy to power 10,000 houses.

The scheme produces electricity by pumping water 1.5 miles down into hot granite in a fault zone and recovers the water through a second well.

The water/steam attains a temperature of 190 degrees centigrade. This is used to drive turbines that produce the electricity.

The good thing about geothermal energy is that once the wells are drilled and the machinery is installed the ongoing costs are low. There are no times when it does not produce energy as with solar or wind power. There is enough geothermal energy underneath the Earth’s crust to outlast the sun!

We are lucky in Cornwall to have easier access to geothermal energy because of the underlying geology. There is a bonus with the plant in that it is also producing lithium, the essential mineral for the storage batteries that are used in other areas of green energy.

• Air source heat pumps do work and work well! I have a friend who has changed her LPG gas/electric heating system in a three-bedroomed semi-detached house. Her energy costs are considerably reduced and the house has never been more comfortable. If you want to change, I recommend you get in touch with Community Energy Plus who will guide you through the process – cep.org.uk/contact-our-team or 0800 954 1956. There is no charge for the service. They will assess the most suitable heating system for your house.

• The large tortoiseshell butterfly that was thought to be extinct in England has been spotted in Cornwall and in several other sites across southern England. It is thought their disappearance was linked to the loss of elm trees with Dutch elm disease in the 1980s.

CASA (Climate Action St Austell)