When the work is completed a section of the pool will be heated to around 35°C, making it the first facility of its kind in the country to be heated using geothermal energy. The new heated section will open to the public in the summer of 2019.

The project is being undertaken by GEL after securing funding from the European Regional Development Fund. GEL secured a licence from Geon Energy, a joint venture company set up by Arup and GEL for some of the technology used in the project.

Geon Energy has developed the technology which enables the delivery of an efficient, renewable and sustainable heating supply. The process involves drilling a geothermal well and drawing up water that has been heated by the surrounding ground using a small pump. The heat is then transferred to water in adjacent pipes which flow into the pool.

"The use of geothermal energy significantly reduces emissions of greenhouse gases associated with the supply of heat and we hope that the learning and expertise gained from this ground-breaking project will be exported elsewhere, giving Cornwall the chance to be a leader in geothermal technology and installation," said Ryan Law, managing director of GEL.

Dr Matthew Free, director, Arup said: "We have been looking at many possibilities for generating geothermal heat and are pleased that the first operational project will be in Cornwall where we carried out a highly successful trial project two years ago. Not only will the well deliver heat cost-effectively and with practically zero carbon emissions, it should prove an attractive idea for the local community and for visitors. The resulting economic benefits to Penzance should be significant."