Geothermal Energy - Is It Being Underestimated For Long Time?

Replies

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  ISHAN TOPRE

  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.
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  Ramani Aswath

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

  Here's my weird logic - We invent drilling mechanisms so that we can reach the high temperature magma in the Earth's core and get access to all heat energy reserve. Given the figures, I'm quite sure we can take care of all the world's energy needs at least for few centuries.
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  ISHAN TOPRE

  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.
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  Kaustubh Katdare

  Wondering whether we can seek some response from Geothermal Engineers.
• 

  ISHAN TOPRE

  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.
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  Ramani Aswath

  The_Big_K

  Here's my weird logic - We invent drilling mechanisms so that we can reach the high temperature magma in the Earth's core and get access to all heat energy reserve. Given the figures, I'm quite sure we can take care of all the world's energy needs at least for few centuries.

  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.
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  PraveenKumar Purushothaman

  bioramani

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

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

  bioramani

  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.

  That's my point - the prices of this technology are deliberately being kept very high so that the world relies on Petrol. Are there alternative means of reaching out to this energy?
• 

  silverscorpion

  praveenscience

  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..
• 

  ISHAN TOPRE

  praveenscience

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

  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.
  
  

  The_Big_K

  That's my point - the prices of this technology are deliberately being kept very high so that the world relies on Petrol. Are there alternative means of reaching out to this energy?

  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.
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  PraveenKumar Purushothaman

  silverscorpion

  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..

  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... 😀
• 

  Ramani Aswath

  The_Big_K

  That's my point - the prices of this technology are deliberately being kept very high so that the world relies on Petrol. Are there alternative means of reaching out to this energy?

  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.
• 

  ISHAN TOPRE

  bioramani

  Nuclear power has its own drawbacks, now all too well known after the Japan's quake/Tsunami.

  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?
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  Ramani Aswath

  ishutopre

  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?

  We are talking about Geo. The argument is that geo is at a high cost. Apparently cheaper options like fossil fuels and nuclear power have 'hidden' costs like pollution, environment degradation and radiation damage. If these issues are also taken into account, geo thermal can become more attractive even though investments are high.
  I support exploiting geothermal.

• 

  PraveenKumar Purushothaman

  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! 😔
• 

  Ramani Aswath

  praveenscience

  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.
• 

  ISHAN TOPRE

  I just read a news saying Indonesia is going to get a $300m loan for setting out a geothermal plant from world bank #-Link-Snipped-#f 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.
• 

  Ramani Aswath

  ishutopre

  I just read a news saying Indonesia is going to get a $300m loan for setting out a geothermal plant from world bank #-Link-Snipped-#f 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.
• 

  Kaustubh Katdare

  Can we not develop technology to solve this problem? I'm wondering whether any Geothermal engineers are reading this post.
• 

  ISHAN TOPRE

  Some time back I came to know about the scientists at Pacific Northwest National Laboratory. They have developed techniques to tap the low temperature geothermal energy sources economically. I think this would also be useful for countries which are located far away from the earth’s tectonic plate boundaries.
  
  PNNL scientists developed a liquid which rapidly expands and contracts. This is christened as a biphasic fluid as per its properties. The liquid when exposed to heat brought to the surface from water circulating in moderately hot rock at earth’s crust the thermal-cycling (the one seen in normal coal fired power plants) of the biphasic fluid will power a turbine to generate electricity.
  Not only that. The scientists have also tried to increase its efficiency PNNL people have used specially constructed nanostructured metal organic material (MOHC) as heat carriers. People from MIT have estimated that if the technology developed by PNNL is commercially available it would lead contribute to 10% of USA’s energy demand.
• 

  Ramani Aswath

  The_Big_K

  Can we not develop technology to solve this problem? I'm wondering whether any Geothermal engineers are reading this post.

  #-Link-Snipped-#
• 

  ISHAN TOPRE

  Sir,
  i read that article of Myth Vs Fact. But what I am trying to ask, have you worked in this field and found any anomaly in the current technology taking the reference of this article?
  
  As far as i can comprehend, they have only stated myth and facts while giving the possible (appropriate or not) reasons.
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  Ramani Aswath

  ishutopre

  Sir,
  i read that article of Myth Vs Fact. But what I am trying to ask, have you worked in this field and found any anomaly in the current technology taking the reference of this article?
  
  As far as i can comprehend, they have only stated myth and facts while giving the possible (appropriate or not) reasons.

  There is nothing wrong with current technology for geothermal energy harvesting. Wherever it is available near the surface it is a good option. As far as I can see in locations where the hot rock is too far below the surface (like in India) the cost of harvesting is currently too high.
• 

  Slitten

  The_Big_K

  Can we not develop technology to solve this problem? I'm wondering whether any Geothermal engineers are reading this post.

  
  To me one factor why geothermal energy is only advancing slowly, is the mindset that to gain energy from the earth's core, you would have to use mechanical processes. To be able to get the heat required for this, you would have to dig deep, which in turn means that costs are very high indeed.
  
  We might need to look at carbon-based life, if we want to extract some form of energy from the warm, close to surface regions. Abandoned mineshafts might provide the ideal habitat for organisms that require heat and minerals, commonly found in the ground-water of such shafts.
  (Since daylight is not avaiable, these organisms cannot rely on photosynthesis.)
  
  These organisms can than be processed into bio-fuels. Processing algae into bio-fuel is pretty common nowerdays, however finding organisms that can live, and benefit from living in such an environment, and than be suitable for being processed into bio-fuel can be a challenge...
  
  My message: "Geothermal energy is versatile, start thinking."
• 

  Ramani Aswath

  Thermodynamically it is most efficient to harvest heat as heat if possible. Growing biomass for later conversion is a costly process and leads to Carbon Dioxide generation, which adds to the problem. The fact remains that in India the hot rocks are too far below ground level for economic harvesting using existing technologies.
• 

  Slitten

  bioramani

  Thermodynamically it is most efficient to harvest heat as heat if possible. Growing biomass for later conversion is a costly process and leads to Carbon Dioxide generation, which adds to the problem. The fact remains that in India the hot rocks are too far below ground level for economic harvesting using existing technologies.

  Yes, from a Thermodynamics point of view it is.
  But using current technology, it is hardly possible to gain (mechanical) energy from the regions close the the surface. Abandoned mineshafts are normaly only used to dump waste in, eventhough they have alot of potential for geothermal energy.
  
  The current tec. of geothermal energy is mearly suitable for India. For geothermal energy to be used there, the entire concept of it has to be changed from the ground up, that is in my opinion. Drilling is one problem, but pumping water down without causing geological instability is something else. Drilling technology can advance quickly (plasma drilling concepts). But there simply are only a limited amount of concepts for extracting geothermal energy, which means that scientists are only experimenting in places which are ideal for geothermal energy, therefore not alot of thought is spent for regions that are not ideal, but which do however have potential.
  
  I must disagree with you on the cost of harvesting biomass. 😔
  Harvesting biomass can be done cheaply and the prices of bio-fuel can compete against those of fossil fuels.
  
  I'm not an expert on this subject, but as far as i know some algae are even used to filter exaust fumes form factories and power plants, and are futher processed to bio-fuels.
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  Ramani Aswath

  The issue is biomass has low energy density in the raw state. Getting biomass to a state suitable for energy generation is not very cheap. On the other hand, certain algae generate electric power directly by photosynthesis. Some basic work is going on in this area. Far from being a practical proposition. The great advantage is that it consumes CO2 to produce electricity.
  I am all for exploiting biomass for energy. Very long back I had interacted with Dr.AKN Reddy, the founder of ASTRA, IISc, Bangalore and a long time friend, in this area, though for biogas generation.