Borehole project in Newcastle strikes hot water

[dave50]

Is is hoped this hot water can be used to heat local homes. The question is, will it ever run out? If not where does it come from?

[Hopkirk]

When it runs out the earth will die. It's from the same place that volcanoes come from - the molten core of the earth.

[jomifl]

surface water drains down through fissures in the rock. The rock is hotter further down. If the water can get down far enough it will get quite hot.How quickly the water drains down and what area of rock it is taking heat from determines how sustainable it is.

[gen2]

Other factors that will determine how long the source will last is the themal conductivity of the rocks and the surface area exposed to water. If the cold water being pumped down chills the rocks faster than fresh heat can be conducted towards it, then the efficioncy will rapidly drop off.

There have also been suggestions that pumping water into deep rocks could lubricate them enough to release tension as earth tremors.

[gen2]

Apology for typos
. . . ARE the thermal . . .
. . . EFFICIENCY . . .

[wildwood]

No need for apologies gen2. Nobody expects a gentoo penguin to spell perfectly.

[gen2]

@wildwood: The bairn can spill but the flippers can't.

[beso]

The heat comes from radioactivity in the rock. It is often a large body of granite.