A Goad for Geothermal?

In spite of the fact that I spent 15 years in the role of fuel technologist in fossil-based fuels and personally believe that the rhetoric about the impact of fossil fuels on GW is a hoax, I am gratified to see serious consideration is being given to the development of geothermal energy. I have commented numerous times that geothermal and hydrothermal power are the only practical alternatives to fossil fuels unless nuclear power installations will be allowed by the public.

"Geothermal is the most efficient renewable energy alternative"...But this does not deal with the fact that appropriate sites for major grid-sized generating plants are few and far between, and that the environment at the bottom of the "hole" is most likely going to be very, very nasty and corrosive. There is a lot more to viable than efficiency...

With regards to wind, wind will not replace conventional power generation any time soon, if ever. The problem is, one needs to maintain alternative generating capability on standby for when the wind stops blowing- you need twice the capacity (actually more like three times the capacity, since wind normally only give you about 1/3 or less of the rated capacity). Unless, of course, you have really, really big storage systems that can see you through an extended period of calm...

With the government rapidly going broke, I can think of a whole lot more practical things to spend the money on, like natural gas systems, nuclear power, or a manned Mars mission. You get a whole lot more bang for the same bucks...

Geothermal can be applied at the home level using a heat-pump. There are various configurations but they all use the earth as an almost infinite heatsink. This multiplies the electrical energy supplied to the heat-pump compressor by about 3X. This might not be as sexy as a big power station but if a few percent of the homes were equipped with this, the energy savings would be significants.

I have such a system at home which cut my overall energy bill in half while enjoying central heating, cooling, and a heated swimming pool with an extended season using the heat dumped by the AC at no extra cost.

This technology is available and pays for itself in two to five years. It can be installed on small lots with vertical wells or on larger lots with horizontal loops less than two meters deep. I have the later with 1000m of pipe for a five tons heat-pump. I could have used a four tons unit.

Any home owner replacing its central furnace / AC should consider this.

IMHO you haven't done enough reading on residential geothermal systems yet. The freon never goes in the ground, the subsurface pipes are plastic.

Hey everyone else... "geothermal" is a loose term a lot of people seem to throw around, not understanding what system they're talking about. If you're using steam from deep underground that's one thing. If you're using a brine filled closed loop system to use the thermal mass of the ground under your feet as the thermal source/sink for you heat pump system then this is an entirely different. Just because there are issues with the large scale production of electricity from geothermal sources does ABSOLUTELY NOTHING to disprove residential geothermal systems from being a very efficient and safe way to heat your house!

New natural gas furnaces are very efficient but unless there's a pipe nearby it might not be the obvious answer that some people think it is. I'm also in Quebec Canada, the land of milk-and-honey if you crave cheap electricity, but in spite of my desire to get connected to a natural gas line that is only a block away, I would be PERSONALLY charged for the expense of tearing up two blocks of road to bring the line to my house. It's like gas isn't considered necessary infrastructure and simply not added when roads are built or resurfaced.

When I dump my current old school oil/heat pump arrangement I'm going geothermal because it's really my only choice if I'm after efficiency and a reasonable ROI.

I have to admit, I'm someone looking for clarification on geothermal issues. The original article in the 7/20 Science Daily on research at the DOE Pacific NW National Laboratory spoke of a rapidly expanding and contracting biphasic fluid powering a turbine. It is intended to extract energy from "low-temperature" geothermal resources. I've read several articles on extracting energy from coal mines. I have to assume that the closed loop system was used, although the articles I've read (and one that I've cited in another entry) speak of geothermal to supply energy for entire communities.

This is not the same thing as producing energy for export. What I want to know is - what is the low temperature threshold for the biphasic fluids? With this method how much energy could be produced from coal mines and could it be economically viable? I'm assuming here that deleterious environmental impacts would be more readily ameliorated than those associated with deep geothermal wells.

Is there an expert out there? (I'm asking engineers!? Hoo-Boy)

It is difficult to see how geothermal classes as "renewable", if it doesn't use energy income. If it were truly renewable, how is the replacement heat to be captured and stored at depth for future re-use in the geothermal systems?

Good point. If we don't completely screw things up it's reasonable to assume that man is going to be around on this planet for a couple of billion years. In the future we're going to look back on this era as a "blink in time" when we squandered all the fossil resources: it's frightening to think that we may be looking back realising that in a slightly longer period we completely messed up the planets thermal stability.

EDIT

When I submitted this comment Globalspec presented me with this quote:-

"The greater the obstacle, the more glory in overcoming it." -- David Hume (Scottish Philosopher)

It just struck me that it had a somewhat ironic relevance .

Do you really believe man will be around for a couple of billiojn years? I find that highly unlikely.

In post #9, I didn't go into any detail of how they're ( at the N. Ca. Geyser's Project) renewing their water supply to generate the steam, but the surrounding counties now pump " treated" waste water to the projects to be injected into the production steam wells. I'm still not quite sure if this is a good thing or not. The studies have not been public that I know of. I guess it's better dumping it into a river flowing into the Ocean.

This all seems to work, as long as the Earth's inner core stays in the molten state

A few million people using electricity produced geothermally (accelerating the release of heat from the bowels of the Earth) might not be noticed. Billions of people drawing on that heat source and releasing it into the atmosphere, talk about global warming!

Thanks for the post, very interesting

James Renewable Energy Potts

I live in WV where deep mine drilling is already in place -yes there is acid mine drainage - but the environmental damage done thereby palls in comparison to the heinous destruction of land, species, communities and the utter obliteration of our precious aquifer, due to mountaintop removal.

Geothermal seems to me like a way forward for us since our economy has traditionaly been based on energy production.

I also live in West Virginia. Mountaintop removal has done SOME damage to our environment, but overall it has been great for our economy. The older "strip mining" methods were not environmentally friendly at all, but the newer methods of replacing the top soil and replanting is showing success. Those who come to our state to see the devastation created by mountaintop removal are immediately shown "Kayford Mountain". It is one of the oldest strip mine sites in the USA. It is not fair to show that one and not the ones with lakes full of fish and water fowl and fields packed with deer and other wildlife. Geothermal is way too far in the future to allow spending on it when clean coal is probably less than a decade into our future.

If we were spending on geothermal it wouldn't be so "far into the future". Also, a plethora of native species, mushrooms, orchids, many arthropods etc. cannot be readily propagated nor will they adapt to alien environments. Restored strip mine sites are like the "native wildflower" patches planted by the Interstate, where the soil is leveled, sprayed with herbicides and replanted with species native to the midwest. There may be those for whom homogenous ecosystems are sufficient. Certainly homogeneity is more easily "administered" in many contexts. But there are others of us who value the fragile complexity of the whole of life, and certainly don't agree to blithely sacrifice it for what is, as often as not, frivolous, excessive consumption. The artificial economics of coal subsidies promulgate this type of energy use.

I was thinking that geothermal may be a good thing until I read #9. This guy made me realize that there are hazards involved that are much worse than hydro or wind and even mountaintop removal.

I'm wondering if dj95401's scenario is true of all sites, or only of those @ a certain depth or near fault lines?

Maybe our cleanest and most viable new energy option will turn out to be the most far-fetched - "Pigs in Space" - space based solar.

It could potentially resolve some current issues, political and economic. To avoid terrorism and bear the expense, such facilities would have to be international cooperative efforts. And solving the logistical problems could contribute to further space exploration.

I have to say, as a Star Trek fan, space based solar is my dark horse favorite alternative energy option.

Geothermal steam fields are usually associated with fairly shallow volcanic activity.

Volcanic Activity = Earth Quakes!

Ever been to Yellowstone National Park, here in the States?

Try looking up Sweden's attempt at drilling deep bore holes for their Geothermal exploration, and the end results. Allot of Shake, Rattle and Roll

Wasn't there a Sci Fi movie, years ago, about cracking the earth's mantle?

It's still a hot topic around here!

Try to stay cool

My interest in using existing deep mines differently was sparked by an article in the Pittsburgh Post-Gazette. This is the link - http://www.post.gazette.com/pg/08306/924549-52.stm .

I understand that in the Netherlands, Germany & Denmark similar systems make use of geothermal energy from old coal mines. These are heat pumps, but they are of greater capacity than home systems. Also, they are cleaning up the contaminated mine water.

In any case, WV isn't prone to much in the way of earthquake activity.