Jubilee Pool: 'Hot rocks' lido will need extra heating

An artist's impression of how the Jubilee Pool could look when it is completed

A lido that was set to become the UK's first to be warmed using geothermal energy will need extra heating due to drilling problems.

Engineers were hoping to reach water of 35C deep underground to heat the Jubilee Pool in Penzance, Cornwall.

But the project encountered problems 0.4km (0.25 miles) down as "a zone of very high water flow" stopped them going deeper.

"Additional sustainable heat pumps" are now needed to keep the pool warm.

"Given the risks of drilling further and potential well collapse, the geothermal team decided to stop drilling and make best use of the hot water zone," the team behind the £1.5m project said.

The pool first opened in 1935 and is one of a few saltwater tidal open air swimming pools in Europe

Engineers had planned to drill 1.4km (0.8 miles) below the surface to reach temperatures of up to 35C (95F).

"We understand this delay to geothermal opening is far from ideal but wanted to do all we could to get the existing pool and other amenities reopened over summer for the community to enjoy," said chief operations officer Abbie Cranage.

"We are doing all we can to work with partners and bring their deadlines further forward where possible."

The pool is set to reopen without heating in July and more work is expected in October when they hope to switch on the heat.