Why don't we have more Geothermal Plants?

Why do we have so few? There is a massive source of energy a few miles below the surface of the planet, no matter where we are. Technically there is heat energy even at the surface, but in a small amount, so why can we not build more Geothermal plants? In some places there is shallower sources of heat, so could we not use more of them? For example in Bath, England, there is a hot spring in use. This implies that there is hot ground water readily available there, and so why can't we use it?

The system of geothermal energy simply uses the water which is already heated in the ground (or if necessary, waste water which is suitable), which is then bought up to the surface, and used to either turn turbines or to be put through a heat exchanger in order to generate electricity. The used water is then put back into the earth in order to be heated again.


image source: http://geothermal.marin.org/GEOpresentation/images/img037.jpg


this image shows the basic layout of a geothermal plant and how it works. We have considerable problems due to the continued use of fossil fuels, so it would make sense to replace fossil fuel power plants with Geothermal ones, in order to reduce this problem.

For example, Coal and Gas made up 0.23 ZJ (Zetta, 10^21, yes big isn't it ) of the energy produced in 2004, whereas Geothermal, wind solar and wood produced only 0.006 ZJ.

Here is an image I found of the areas which use Geothermal energy. Why not more of the Pacific Ring of Fire at least? It makes no sense to me.


image source: http://www.power-technology.com/projects/mokai/images/mokai3.gif

from what i understand ( and i understand only a little ) is that even though we live on a big ball of fire only a few locations are shallow enough to access easily enough to make them economically feasible. having said that there is also the cooling problem, if you bring heat up from depth is dissipates and is not sufficient to the task. the last problem is 2 fold one is that geothermal site are not very neat looking projects at least the one's I've seen and 2 the geothermal site at the geysers destroyed the hot springs and the baths ( by cooling the surface water). but all this having been said it is a source that should be used more and I'm sure that if more research was done it could be significantly improved. i last note is that if you check the map of possible locations for geothermal plants they are also the location of the most active earthquake zones.

[edit on 26-2-2007 by wcssar]

I lived very close to a geothermal research facility and one of their main problems was the clogging of pipes due to the heavily mineralized water from the production wells. The facility has sense been closed.

Still I think geothermal along with other alternative energy sources should be researched to lessen the impact of oil and gas based energy generation.

I have never heard of a Geothermal plant being blocked up by the mineralised water before.

I know that the best places are commonly earthquake zones, but as long as they are designed well they shouldn't suffer much damage, same goes for most buildings. I remember once seeing a video of a Geothermal plant in Iceland where a Lava flow had only just missed it, but I don't know whether it was abandoned or not afterwards.

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Thre aren't more geothermal plants for the same reason there aren't more solar plants and wind plants, or tidal plants, etc.

Because none of them are as cheap and efficient as burning fossil fuels, whether its coal, oil, or gas.

Thanks Majic, I wasn't expecting that!



The sad nature of quite a lot of things, be it to do with safety features on aircraft, or this context. Still when considering the considerable of climate change, something which doesn't contribute as much to greenhouse gases should be used, even if it isn't as efficient.

But the problem with cost and efficiency is that people won't buy it if its not cheap and effective. Peopel would freak out if their electric bills were as high as they'd be if all energy was alternative, or even a large percentage was alternative.

Consider that the public COULD dramatically reduce greenhouse emissions, if they simply purchased hybrid cars. They're more expenseive, but on the other hand, they use less gas so there's even a trade off. And yet they STILL don't purchase them in large numbers.

True, people would do that, but people will also probably complain immensely when it is obvious that some natural disaster happens that probably wouldn't have occurred if Global warming hadn't been triggered. What will happen if we do run out of fossil fuels? I think everyone will complain a lot then, even if they did nothing to stop Global warming.

Great question. Why not answer it and become rich by constructing geothermal plants all over the world?

Or other alternatives for that matter:

EnviroMission Limited - The Solar Tower Project is designed to provide large scale renewable energy with zero emissions, reducing green house gas emissions while providing continual electricity production.
www.enviromission.com.au...

Atmospheric Vortex Engine
www.vortexengine.ca...

www.google.com...

www.startram.com...

www.google.com...

Since the easy oil has already been found, it makes sense to me to drill a dry well a few more miles/kilometers and use geothermal heat to either create electricity or drive a reaction that starts with water, heat and some intermediaries and ends with hydrogen, oxygen and the original intermediaries.

You mean subsidized, it part by invading up to 60 countries? Why give depetion allowances? The land and natural resources were stolen in battle and through enclosure movements and other various schemes several hundred years ago.

Are you a Real Libertarian, or a ROYAL Libertarian?
by Dan Sullivan
wealthandwant.com...

Besides, to get the remaining oil means drilling deep and pumping far.



Oil companies see big Gulf of Mexico discovery
www.msnbc.msn.com...

[edit on 23-7-2007 by autumnofburnoutcommie67]

[edit on 23-7-2007 by autumnofburnoutcommie67]

Since it is already 2007 and such (and other various other) changes haven't happened yet, I am inclined to believe that their is/are something(s) fundamentally wrong -- and that it is a world-wide phenomenon.

Someone would have aready "stood up to the plate by now" -- without getting murdered.



--Stand Up (Let's Get Murdered) by P.O.S.

Hearts of champions: The Plastic Constellations + P.O.S.
by Steve McPherson
www.pulsetc.com...



[edit on 23-7-2007 by autumnofburnoutcommie67]

reply to post by apex

---

another website i was on last year had an artical about trying to make use of geothermal power in swizerland--everytime they injected massive amounts of cold water in the borehole they ended up causing earthquakes 4or 5 on the richter scale under/near a swiss city---they were forced to stop experimenting by their government until they can figure out what they're doing wrong

A word on price of geothermal. There is some dispute apparently.

Here's one source: willprice.blogspot.com...



But the funny thing is that the government doesn't seem to see it that way anymore, even though he claims his numbers came from the DOE.

www1.eere.energy.gov...




We can compare this to coal-fired power plants.

en.wikipedia.org...



And although that first blogger has the government projecting coal in 2015 to be 5 cents per kilowatt hour, that's not where it is now according to the State of Kentucky.

www.coaleducation.org...



There is also a by-state breakdown at that site. Coal costs 15 cents per kilowatt hour in Hawaii, 12 in New York, 11 in California, and 10 or more in 7 other states as well.


That means that if you build a 0.5 Mw coal plant and a 0.5Mw geothermal plant side by side, the coal plant will cost you $650,000 an the geothermal plant will cost you 2 Million.

That means the coal plant is $1,350,000 cheaper. But for how long?

At a savings of 2 cents per kilowatt hour for the geothermal power, times 500 kilowatt capacity, you make up 10 dollars an hour with the geothermal plant. That means it will take 135,000 hours for the goethermal plant to pay for itself (assuming that the price of coal doesn't go up). 15.4 years if the plant is being run at full capacity full time. Obviously that's not practical but that gives you a baseline.

California has geothermal plants that have been operating for 48 years. There are geothermal sources that have operated for over a century without being overtapped. It would work out.

Lets not forget, that was using the national average. How long would it take geothermal to pay for itself in California? At a savings of 7 cents per hillowatt hour times 500kw you'd make up 35 dollars an hour. Thats 38571 hours to break even. That's about 4 years if it's running full bore all the time.

So realistically, in may places, geothermal stabilizes prices immediately, helps the environment immediately, hurts the saudis immediately (i realize the saudis are producing oil, not coal, but oil is also used, and its even more expensive than coal) and starts yielding a net profit in less than 10 years.

Yes, the question is not so much price per kilowatt, but more price for total energy, in which case geothermal is extremely cheap, though not immediately. not such a great option, really with coal when you think about it, it has a constant running cost and new fuel needed, not to mention exhaust. Geothermal needs the heat of the earth, which is pretty much constant if you go down a little way.

Not to mention the lack of massive mines and vehicles transporting fuel. It maybe more expensive in countries like Britain, but for the Pacific rim, this must surely be a great idea? if not a great idea, at least a simpler method than elsewhere. Yes there is earthquake risk but the heat is likely closer as well, and it's not like it will meltdown is it?

Good post Vagabond.

To the best of my understanding of what I've read, you mainly run into the earthquake thing when you inject hot dry rock. It seems to make sense. Ever been camping and see what happens to granite left in the fire pit- Much less if you pull it out and throw it in cold water?

Rock expands and contracts depending on temperature, and rock also has a small elasticity (which accumulates when you have a lot of rock) which will store energy until such point as the rock is broken- like a rubber band. I'm sure that problem gets even worse if you have unknown faults in the area- if you make the rock contract you're going to pull it back a bit and reduce friction at the fault, making it discharge early.

Nice thing about that problem however is that it ain't very hard to find hot dry rock, so you can pretty much build such plants out of the way and build the plant to cope.

Of course the little catch with injecting hot dry rock is that you provide the water. Sort of a problem in some areas. Take my area for instance. We've got a shallow geo-thermal source, but we're having a bit of a water crisis as it is.

On the other hand, it would be possible to kill two birds with one stone if we piped in sea water. You're producing steam anyway, so the plant can double as part of a water desalination program (I'm not sure but I think their doing that in Iceland). In our area that would be particularly convenient since we also have a lake of certain regional importance going dry not far from our geothermal source.

So long story short, in certain areas you'd have to be a wee bit creative about making it feasible, but as you say, in the pacific rim it's pretty much nothin' doing. There's very little reason that California and Hawaii should not be all over this. Ditto Japan.