Earthed

How far deep in to the earth core one has to bore/dig to ge the benifit of Geothermal power?

How far down the earth core one has to dig/bore into to get the benifit of the geothermal power?? Can this be done in any ground or is there a special site (like oil drilling) to get the benifit??

Public Comments

1. I don't know the details of the process, but i think it does require special sites. I think it works like oil, but is renewable, and is somehow related to geysers and hot springs. That's all I can remember about it.
2. If you dug into the earth's core you would be in, pardon the pun, deep shit! The very deepest mines and bores do not go anywhere near the core! We are quite literally, scratching the surface.
   
   I think you are confused, you no not need to tap the core to encounter geo-thermal heat.
3. The temperature is always increasing with depth, but it increases at a different rate depending on the layer of the Earth. So, in the upper part of the Earth’s crust, the temperature is increasing at about 25 degrees Celsius per kilometer (or 72 degrees Fahrenheit per mile).
   
   
   
   So really a good 3km would be sufficient.
   
   In reply to the above comment they main sites chosen are places with fault lines as there's already a geological weakness making it easier to dig. Also hence the geysers and such.
   
   
   
   New methods in several countries is something called EGS.
   
   The key characteristic of an EGS (also called a Hot Dry Rock system), is that it reaches at least 10 km down into hard rock. Faster heating making energy production a lot faster.
   
   
   
   *edited: As per the above comment. The earths crust is 120km thick in some places. In contrast the deepest hole ever dug is 12km. The earths crust is compared to the skin of an apple (the entire earth been the apple!). Below the crust is the mantle and then the core.
4. It really depends on what you mean by benefit.
   
   
   
   If you just want to save energy for heating at home it is sufficient to use the fact that the floor at a depth of about 2 meters has typically average year temperature, which is much warmer than a cold winter is. This difference can be technically used to safe heating energy.
   
   
   
   For creating electricity or high energy heating, however, you should find a site with high geothermal gradients (increase of temperature with depth). Those high gradients occur in the proximity of tectonic ridges or volcanoes.
5. About 2000 kilometres below the earth's crust, lies the molten part (which itself is about 3000 kilometres thick) that surrounds the solid centre.
   
   
   
   But you don't have to bore/dig that deep, there are geysers spurt out and hot springs well up, eg, Iceland, else no energy problem, just housing and farmland problem.