Each of the four new plants is expected to supply 5MW of electricity to the National Grid and 20MW of heat to the local area.
The electricity from all four plants will power 45,000 homes. The plants will take 18 months to build and are expected to be operational in 2026.
The United Downs plant is now producing geothermal steam which will be converted to deliver approximately 3MWe of power to the National Grid starting in 2022.
The Cornwall Geothermal Distillery Company is in the approval processes to utilise 2.5MW from the plant, and has plans for a £4million research centre.
Up to 10MW of heat is also expected to be used in a large housing development planned at Langarth.
Two wells will be drilled for each plant. Water is then pumped from the deepest well where temperatures are expected to be about 180C. The steam produced is then fed through a heat exchanger at the surface and water is then re-injected into the ground to pick up more heat from the rocks in a continuous cycle.
The electricity and heat energy produced by this type of low carbon, renewable energy source is continuous as geothermal energy does not generate in peaks and troughs as many other sustainable power sources are subject to.
“Over the next 20 years, our target is to produce in excess of 500 MW of power from geothermal resources making this one of the most significant and reliable baseload power sources in the UK,” says Geothermal’s md Ryan Law.