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Drilling to begin on Newcastle geothermal energy scheme

An exploration team in Newcastle plan to drill through old mining tunnels to search for geothermal energy under the city centre.

Researchers from Newcastle University who are leading the project hope it could initially provide up to 5MW of thermal energy, with potentially more heat and electricity from future boreholes.

This would provide heat for a new campus that will combine research facilities with affordable housing, while some energy may be siphoned off the power a nearby shopping centre.

Drilling is expected to begin next week, pending a number of official permissions, on an exploratory 2km borehole at the planned 20-acre Science Central campus, the site of the former Scottish and Newcastle Breweries.

The borehole will be the deepest ever drilled in a UK city, according to scientists from the Newcastle Institute for Research on Sustainability, who believe that water will be pumped out at a temperature of 80oC.

The Institute’s director, Paul Younger, said the project would be a flagship for the city’s plan to become an exemplar for sustainable urban environments.

‘The vast majority of the world’s population for many decades to come will be in existing cities, not in small eco-developments, so the real challenge is increasing the sustainability of old industrial cities,’ he told The Engineer.

If successful, the borehole will access water heated by naturally occurring low-level background radiation found in the granite that underpins the landscape surrounding Newcastle.

Rather than tapping into the granite directly, the borehole will drill into sandstone under the city connected to the granite by a major inactive geological fault, which allows heated, mineral-rich water to circulate through the rock strata.

The borehole will also have to pass through a layer, a few hundred metres deep, of coal mining tunnels that sit directly beneath the city centre. This presents particular challenges for the company managing the project, County Durham-based Drilcorp.

‘We’ll be drilling with a mud flush, which means we keep the borehole full of mud, and that disappears if we hit a hole,’ said Drilcorp’s contracts manager, Matthew Dale.

‘We can seal it with a steel tube but if there are lots of layers of holes it restricts the size of the borehole each time you put a tube in. The other option is to effectively seal up the seam with concrete.’

The mud flush is necessary to seal the borehole against potential gas leaks as drilling progresses, and gas monitoring is required all the way down.

‘The mines are unknown so we don’t know how long it will take to go though them – we might never even encounter them,’ said Dale. ‘We hope we’ll do it within 12 weeks.’

The project was funded with £400,000 from the Department of Energy and Climate Change’s Deep Geothermal Challenge Fund, with another £500,000 coming from the university and Newcastle City Council.

If the first project is successful, future boreholes may be able to provide tens of megawatts of thermal energy and could even provide a source of power for electricity generation, said Younger.

‘You have to get water to probably about 120ºC so we’d need to go even deeper for that, maybe to about 3km. If we did do that you could probably rely on each megawatt of electrical energy providing you with about 5MW thermal.

‘That’s one of the nice things about geothermal: it does produce a hell of a lot of useful heat energy.’


Readers' comments (11)

  • This is an interesting project and I hope successful. The University Science Campus could be totally green in energy needs. This may also expalin why Geordie girls do not seem to feel the cold at weekends!! Maybe they draw on this heat source naturally!!

    Joking aside the local Newcastle council could turn green and produce reductions in community charges, as if this would happen. I can say these things as I lived in the North East for 49 years.

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  • Nothing is free, has anyone conducted a study into the long term effects of the localised cooling effect of tapping into this heat source?

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  • Why all the bally hoo? A similar scheme was developed in Southampton aeons ago. It still provides heat for parts of the city centre. The wheel re-inventing itself or a lot of self publicity?

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  • I have read elsewhere that minor earth tremors are a probability with this type of power generation, as in Basel in December 2006. I hope this has been taken acount of!

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  • The effect of drawing off thermal energy from the rocks at that depth will be negligible. The surrounding rock will have an enormous thermal mass as well as direct energy input from pressure, radioactivity, etc

    http://theenergylibrary.com/node/11484

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  • This is an excellent idea, but caution needs exercising when drilling through old coal workings. Methane and other gases are released through the coal cutting operation, and after coal cutting has finished.
    Potentially it could cause underground explosions which could devastate the local geology.Cutting into mine workings will invariably mean considerable amounts of mud will leak away into them, and there could be miles of old roadways.

    Such geothermal schemes are a good idea, Ikea industrial park at Giltbrook has one to heat the retail parks buildings. They use no energy in their heating, and have a free fuel source when the initial costs are recouped.

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  • I have always been curious about this. Just how far do you need to drill in the UK before you get to seriously hot areas (200c +) heated by the core and therefore unlikely to ever diminish over time? Or even just running one or more power cables from areas like Iceland and supporting much bigger power generation projects from there. I know with oil and gas we go down quite a long way already.

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  • Coal mines under the City centre, fill em with concrete!
    Last week I visited a City in China called Tangshan, also undermined by coal mines, in 1976 during an earthquake the city fell into the mines, now a beautiful... Lake!
    Officially 240,000 people killed, locals say 700,000!

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  • @ Alan P. Is that a troll? Simple google searches show Tangshan to have been re-built and is now home to 3 million people, who, presumably, are not all aquatic creatures. There is also no mention of the devastation of the city being any more than the result of a particularly severe earthquake of around 7.8 on the Richter scale. As for the lake, it must be recent because it wasn't there 6 years after the quake.

    http://earthquake.usgs.gov/earthquakes/world/events/1976_07_27_eib_1983.php

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  • Can we have an informed explanation of the source heat from an experienced geologist, please? The Cornish geothermal project (first one) failed because so much water was lost in fractured rock.

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