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Author Topic: Using drilling technology to generate electricity  (Read 2391 times)

Offline stevewillie

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The earth is a ball of molten material with a thin solid crust. It seems we would drill to depths where water boils and harvest this vast energy resource rather relying on a few active geothermal locations. The system could also take advantage of the force of water dropping down a 10km deep hole. The resulting steam could run generators provided the steam conduits are sufficiently insulated against heat loss. The water could then be recaptured and recycled. Mother earth does all the work through gravity and thermal energy.


 

Offline graham.d

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Using drilling technology to generate electricity
« Reply #1 on: 25/08/2008 23:15:18 »
There is a lot of energy available in geothermal sources but I think there are technical difficulties in generally making it cost effective unless there are special circumstances (a thin crust and/or volcanic activity) that mean that the hot stuff is not too deep. Drilling down over 10km is not a cheap activity and the world record is about 13km so far. The other factor is getting the energy out. A single bore hole wouldn't work. Most schemes seem to involve two holes, one where water is pumped in and another where steam comes out. I think there has to be some natural fissuring to allow the water to move between the two holes and heat up in transit. A single man made connection between them would limit the flow for best efficiency because of the local conductivity of the rocks - the water would cool the rocks locally unless it flowed across a large surface area.
 

lyner

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Using drilling technology to generate electricity
« Reply #2 on: 25/08/2008 23:35:18 »
I believe there have been several schemes which involve pumping water around subterranean porous rocks. Apparently, one major problem is silting up and the flow tends to get less and less. There is also the fact that the achievable temperature difference isn't very great and this limits efficiency ('=' output power) of any heat engine which makes use of the heat source.
 

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Using drilling technology to generate electricity
« Reply #2 on: 25/08/2008 23:35:18 »

 

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