Geothermal Energy - Is It Being Underestimated For Long Time?

For a simple reason Biggie,
Geothermal energy is only available in some *special* places. Not indulging in much technicalities unnecessarily, perhaps we do not have advanced means of extracting this energy from places which are not known for geothermal energy extractions.

As of now the economics are against it. Its time will come sometime.

I do not think so. Geothermal energy resources are only feasible (as of now ) in places where earth's heat energy is available on earth's surface.
Digging the earth to massive depth's would not be a good idea (both practically and economically). However, in future, we may develop some other techniques to extract energy from earth's surface.

P.S: If possible let me come with some reliable figures on this topic.

Geothermal power plants the reality:
Geothermal power plants are one of the widely spoken debate topics whenever we talk about eco friendly energy. But instead of composing a big epitaph, I would directly come to my point.
To start from basics, a geothermal power plant works on the principles of heat exchange. It is widely known fact that geothermal energy is extracted from HOT rocks present on earth's surface. The suitable rocks are often found on surface up to a depth of 3 to 5 miles.
This image from Idaho National laboratory shows that the working of a geothermal power plant is similar to thermal and other plants involving the use of superheated steam.


Some IMPORTANT advantages of geothermal powers plant
1. We can have power plants of variable capacities 30 TO 2000GW.

2. It is one of the CLEANEST SOURCE OF ENERGY and till we have earth, we will have this energy (let us hope so )

The major disadvantages of Geothermal power plant are:

1.Hardness of rocks is one of the limitation factors in tapping these renewable sources of energy. If the rock is hard, we cannot drill through it.

2.The locations might be odd like poles or mountains. Also they are mostly situated at places with highest risk of earth quakes and volcanic eruption i.e.; near at the mouth of tectonic plates.

3.It cannot be transported. For example, we can have a coal powered thermal power plant in say Koradi and the coal is supplied from another location say Chandrapur.
The power in this case is only limited to the surrounding areas.

4.IT IS UNRELIABLE, yes, the power plant may stop functioning abruptly for months may be years and you may require to shut up the plant.

5. Safe disposal of harmful gases present in earth's crust are more often a problem.

My view point.
The above disadvantages are mostly limited by economical factors, and metallurgical factors of drilling machines. The same factors have prevented this source as a conventional source of energy. A proper approach in countering natural factors would help us in getting through metallurgical factors. The economics will naturally will come down if we are able to provide cheaper alternative to do the same thing. The energy has a lot of potential and if we neglect its first cost, I do not think that operating cost will be very tough to manage. The reason being we are only circulating cold water and getting fuel (energy for FREE).
In my opinion, the major hurdle is however the unreliable nature of power generation.
The following Image gives the possible locations of geothermal power plants


If possible I will try to mention the list of operational geothermal power plants of world.

There is no need for all that. At most places in the world there is dry hot rock just about 10 KM below the surface. Existing drilling technology is sufficient to reach this and exploit the geothermal energy using pumped water.

It is only the economics of harvesting that is currently preventing more widespread exploitation of this clean energy.

What is the economic issue? Is it anything about funding from the Government?

No.. It's not about finding.

I think "economic issues" here means the cost of harvesting the geothermal energy.

Keeping the amount of power generated constant, I think cost per watt of power if coal or natural gas or oil is used will be many times cheaper than cost per watt of power in geothermal energy.
So, to generate the same amount of power using geothermal energy will be costlier than using coal or oil. I think this is what is meant by economic issues..

Well funding from government will be a very good idea. But we should also get the output with respect to the amount of money invested.

But yes I too feel that the issue should come into picture.

But what if technology is not that much developed? Can this be a point? I mean we should be able to extract energy so that the money can be recovered. After all any project is dependent on investment done in it. and even so, it is also unreliable. Your plant may stop working for months, then what will you do?

I am more inclined towards the bolded part (technical) above.

What if the reserves of coal and natural gas gets exhausted? I mean, at least after a few decades? What would be the Govt's decision? Why I said this is, the GeoThermal energy seems promising...

While countries like Indonessia are already using Geothermal power, India has not begun on this. It is also true that Indonesia has geo thermal resources near the surface of the earth and it is cheap to harvest. In India we may have to reach down to the hot rocks to get any substantial power. As of now this will be expensive.

When we talk about costs and economics we sometimes miss out on total costs and look at just price/KWHr. There are hidden costs of long term damage to the environment, green house gas emission and anthropogenic global warming that is associated with power from fossil fuels. All of which must be considered. Nuclear power has its own drawbacks, now all too well known after the Japan's quake/Tsunami.

The government of the country, which has to address such larger issues is otherwise busy.

Geothermal must receive its attention soon in India. We can at least start with the known hot springs in Hrishikesh area.

Sir, but we are talking about geothermal energy. How is it related to Nuclear energy? Is it just a typographical error? or is it some way related?

Okay, now the issue is like, Geo Thermal is easy to get but costlier than Non Renewable resources. What can our country or this world do to avoid the crisis of NRR? Is there really an alternate? I see Solar Energy is rendered hopeless!

The way things appear, geothermal energy(GTE) should be pushed. Though there is an initial investment, the plant is no different from existing steam turbine generators. Since all the boiling happens underground, only a smaller foot print is needed above ground. The steam will be condensed to liquid water that goes back. Negligible waste and virtually zero pollution. Some heat has to be released to the ambient because of second law of thermodynamics. However, this will be far below what fossil fuel plants release.

In the early 70s MIT developed a solar 'Hot plate' using sodium nitrate crystals in a sealed container, melting the salt using solar collector with a parabolic concentrator and bringing this into the house for use as a hotplate. The latent heat of fusion of the salt worked as a constant temperature hot plate. Since heat is used directly as heat much higher efficiencies are realized. The problem with current solar photovoltaic cells is their low efficiency and short life.

By combining GTE with such direct solar heat use it can be a win win situation.

I just read a news saying Indonesia is going to get a $300m loan for setting out a geothermal plant from world bank http://www.newenergyworldnetwork.com/investor-news/renewable-energy-news/by-region/asia/indonesia-gets-300m-world-bank-loan-to-expand-geothermal-capacity.html

If anyone follows market, is there any possibility that a corporate house will invest money in this technology? As we can see almost every corporate house from Reliance to Adani has powerplants.

I am currently in Washington DC. Just returned from a visit to the Museum of Natural History. One exhibit is on hot spots of the world, which shows locations where geothermal activity is at the surface of the earth. Remembering your post I looked up Indonesia and India. Indonesia is prominently in the hot spots. Unfortunately India is shown completely isolated in a cold zone, which means that we have to dig deep to reach the hot rocks.

Corporates look for quick ROI.