Geothermal Energy

Nice quick summary! As with most processes, I believe the cost will decrease and the efficiency increase with practice. Until it's economically feasible to practice the process (i.e. research costs drop or other other energy source costs increase), I don't believe it's worth pursuing.

Thanks,

If they could bring down the cost of drilling the wells Geothermal Energy would look much more attractive as a source of power.

Drilling of geothermal wells is the same processes as most any other wells, the well casings and such are slightly different than some wells, but all are common available materials. The drilling processes that are used have been adapted over hundreds of years for petroleum and deep water. So you really should not expect to much change in the capital cost of construction, at least with regards to the wells which comprise about 50% of the capital cost, since it will always represent a small portion of a already large and relatively well established industry. In essence it is similar to the auto industry developing more biodiesel vehicles, not a lot will change from the cost of existing deisel designs, since the processes remain esssentially the same. however, it may become economically viable as you mentioned when other energy sources become more costly.

I agree with what you're saying, and in Minnesota shallow (horizontal) closed loop home systems are the most common. They can greatly reduce a household's energy consumption, and it looks like their payback is around 5 years.

These domestic systems work toward reducing energy consumption, however I think that the blog was referring to geothermal for large scale energy production. In that case, no I do not think that it can satisfy our energy needs, but it is still part of the renewable energy puzzle. As already demonstrated in some areas, there is definitely merit to exploring geothermal as an energy source.

I did the controls design work for a system in Klamath Falls. It was designed to provide heat for eighteen buildings in the dowtown area and was commissioned in the early 1980's. It consisted of 2 production wells which were capable of providing 500gpm each at up to 270°F. After routing through the heat exchangers, it was reinjected about a mile away from the production wells. The closed loop portion of the system was maintained at 160° and energy was metered for billing purposes at each building. The system had some issues with the CPVC pipe which was used for the closed loop portion.

Every area is different and an engineering study should be performed at each prospective site to determine which system type (if any) would be economically feasable.

Right - my uncles family lived in K Falls in the 50's and İ remember geothermal being used then - this story is kind of off in that respect. Due to various problems use of geothermal is losing it's attraction. Drilling isn't so easy and İ believe the 20% failure rate is highly optimistic. There have been problems with new sites being exploited causing earthquakes. The water coming up is some nasty stuff to handle being loaded with anything soulble that is down yonder. One poster was referring to a geo-exchange system - a ground source heat pump which is a totally different animal. OİT (Oregon İnstitute of Technology) does a lot of work wiht geothermal and is known around the world. When İ was a kid it was OTİ but guess they had to change with the times!

The one problem I have seen with Geothermal is the system we reviewed used a glycol solution. I asked how the system would be tested or checked to be sure they don't dump glycol into the ground and have it show up in the drinking water wells.

No one is in charge of checking the system after it is in use. They have no state or local AHJ that will do any yearly testing.

Ethylene glycol or propylene glycol? One is toxic and one is not.

ANY to date?

"state or local AHJ that will do any yearly testing."

GEO THERMAL any thermal, even just below grade as well