Comic: An Alternative, Alternative Energy

Since when has Geothermal been rarely discussed?

But i think geothermal could help us a lot and it is almost an infinite source of energy right?

Idk?

-THE KID

OK I really think this is the sleeper of the energy Alternative.I speak to many Engineers about this process and different Bits you use and the rigs. It is a real old process I really think the not knowing of people and the unwillingness to learn is so incredible to me.I know from my research we need to rethink our Congress and Senate giving us science lessons.OH Well maybe I hope I have not done this comment for not.
Jim

I seem to recall reading that you can tap geothermal energy anywhere in the country if you only drill deep enough. Go down deep,put a heat pipe in the hole,and circulate a working fluid.The resulting hot fluid could then run a Stirling engine.

The explanation of geothermal energy is only a partial one. Here in Canada, in my immediate neighbourhood (20 mile radius) there are a several companies that sell and install geothermal systems for homes and office buildings. They dig deep trenches and lay pipe horizontally in a closed system.. A fluid is pumped through the pipes, passes through a heat exchanger and the heat is used to heat water or heat the building. You do not have to use a deep vertical pipe system, or have hot springs to achieve a workable system.

Quiet1 - You are correct that it does not take a deep well to create a signifigant heat exchanger for controlling air temperature. Since the fickleness of weather and seasons only penetrates the first few feet of the earth's insulating dirt, underneath you get a constant temperature cooler than most summer temperatures and warmer than most winter. It is, ideed, a wonderful way to conserve energy.

Creating electricity, however, requires a much more agressive system, so needs not stable shallow crust temperatures, but hot radiant core heat from deeper in the earth. This requires not only wells, but wells specifically placed at shallow points in the earth's crust where more heat radiates to the surface.

So, while you can bake a pig in some places just by throwing it in a hole with some pineapples, in other places you would have to drill through signifigant amounts of solid granite.

As the drawing showed, most of the US, particularly the east cost, is not sitting on prime geothermal land. If we looked more like Iceland, we would be hearing much more about geothermal.

"I seem to recall reading that you can tap geothermal energy anywhere in the country if you only drill deep enough."

That's technically true but you'll be sucking ~50 times less energy through this borehole per unit time than a conventional oil well and you'll have to keep drilling new holes as one volume of rock becomes depleted(it will heat back up, but you'll have to leave it alone for a century or two).

It's probably easier to crack nuclear fusion than to develop an economical method to drill as deep as the Kola superdeep borehole for just this trifling amount of power.