(麻豆淫院Org.com) -- Scientists at Newcastle University have completed the first phase of a giant central heating system that will harness heat from deep underground.

A team of scientists and engineers today (23 June 2010) pumped out the first from the depths of Weardale as part of a landmark project to investigate the potential of geothermal as a source of renewable heat.

The twin borehole system is the first of its kind in the UK and will allow warm - heated by the hot granite rocks hundreds of metres below ground - to be continually cycled through a 1,000m underground heating system.

Led by Newcastle University, the geothermal borehole is one of five forms of land-based being considered for the proposed Eastgate eco-village in Weardale.

The University team believe it could not only provide renewable, for homes and businesses, but also some of the natural hot water could be used in a spa - the first such development in the UK since the Romans tapped the hot springs at Bath.

Project lead Professor Paul Younger, of Newcastle University, says that using a twin set of boreholes solves problems which have hindered other attempts to use deep-seated hot water.

鈥淥nce you find hot groundwater then pumping it to the surface through a single borehole isn鈥檛 the problem - it鈥檚 what you do with the water afterwards that has held back ,鈥 he explains.

鈥淲ater from such depths is twice as salty as , so unless you happen to be on the coast, you can鈥檛 let the spent water simply flow away at surface but cleaning the water is both energy intensive and costly.

鈥淚n this system we are re-injecting the water using a second borehole. This means we are able to maintain the natural water pressures in the rocks and allow pumping to continue for many decades to come.

鈥淪o, by recycling the hot water through what is essentially a huge central heating system deep underground, we can produce an almost carbon-neutral source of energy.鈥

Following a grant from the Department of Energy and Climate Change earlier this year, the team has drilled a second - or 鈥榬einjection鈥 - borehole to complement the 995m deep exploration borehole which was originally drilled three years ago.

Water at a temperature of around 30-40潞C is brought up to the surface where it passes through a heat exchanger before being sent back underground to be re-heated.

Used water is reintroduced to the granite at about 420m deep, and heated up again as it flows through a complicated maze of fractures on its way back to the pumping borehole.

Newcastle University鈥檚 Professor David Manning said the Eastgate borehole was a 鈥榞eothermal prototype鈥 that could be used at other 鈥榟otspots鈥 across the UK.

He explained: 鈥淲ater deep underground gets heated by the naturally-occurring low-level radiation that is found in all rocks.

鈥淪ome rocks are far better at producing heat than others - especially granite of the kind we have drilled into at Eastgate. This makes it one of the country鈥檚 鈥榟otspots鈥 - where water starts warming up quite close to the surface.鈥

A spokesman for Durham County Council said the findings by Newcastle University were of real interest and the use of geothermal as a potential energy resource for Eastgate would be considered in due course.

Lloyd McInally, Lafarge Cement UK鈥檚 rating and regeneration manager, said the borehole was an exciting first step for the former cement works site.

鈥淭he plans for the former Lafarge cement works at Eastgate have been developed to provide future generations with real opportunities at the same time as creating a genuine sustainable 'green' legacy for the Dale,鈥 he explained. 鈥淭he twin system is an important and exciting first step.鈥

Professor Younger said the next step was to go even deeper. 鈥淭here is every reason to suppose that if we drill even deeper here in future we will find water at boiling point, which is hot enough to generate electricity.鈥

Provided by Newcastle University