Whatever happened to geothermal energy production?

[n01]

I've become nauseated with the recent obsession with colonizing Mars, mining the moon or asteroids, and spending resources on intermittent power production from wind, solar, and batteries.

I've looked at numerous sources of energy production and have come to the conclusion that instead of looking to the sky, one ought simply dig deeper.

The Earths mantle is essentially an inexhaustible source of energy via injecting water for high-pressure steam extraction. Furthermore, we have barely begun mining deep into the Earth core for heavier elements and other resources, which are imperative for economic growth and prosperity. Energy is carbon neutral available 24/7 and there's no need for the expensive and labor intensive production of batteries to store energy. A third issue that gets solved is desalinization of water if there is such a need, which there is. On so many levels this seems like the most cost-effective and cheap and abundant source of energy just lying below our feet.

I would be interested in getting to know why hasn't the simple issue of drilling holes as deep as possible and extracting energy via heat never taken off?

 

[davenn]

I would be interested in getting to know why hasn't the simple issue of drilling holes as deep as possible and extracting energy via heat never taken off?

mainly because in most areas, the mantle is well below easy/economical drilling depth

geothermal sites around the world are mainly located in areas where the crust is very thin ... less than ~ 5km
so this immediately decreases possible good locations for such generating activities

The www site gives the top 10 geothermal generating sites around the world

http://www.power-technology.com/features/feature-top-10-biggest-geothermal-power-plants-in-the-world/ Dave

 

[n01]

mainly because in most areas, the mantle is well below easy/economical drilling depth

geothermal sites around the world are mainly located in areas where the crust is very thin ... less than ~ 5km
so this immediately decreases possible good locations for such generating activities

The www site gives the top 10 geothermal generating sites around the world

http://www.power-technology.com/fea...biggest-geothermal-power-plants-in-the-world/Dave

Well, we can build rockets and go to the moon, but can't invest in solving a simple engineering problem of drilling holes deeper. I mean, we have the natural talent and expertise to get the job done (think the multitude of oil/fracking companies in the U.S)...

Does this simply boil down to the fact that there isn't that much money (incentive) to get the job done? If so, please shoot me.

 

[davenn]

Well, we can build rockets and go to the moon, but can't invest in solving a simple engineering problem of drilling holes deeper

what I'm telling you is that it ISN'T simple engineering else it would be getting done all the time

the deepest borehole drilled only went to a tad over 12 km, that doesn't even make it 1/2 way to the mantle under most continents. And that is why geothermal bores are limited to geothermal regions where the crust is much thinner

we have the natural talent and expertise to get the job done (think the multitude of oil/fracking companies in the U.S)...

fracking and the likes only goes down a km or so

 

[n01]

what I'm telling you is that it ISN'T simple engineering else it would be getting done all the time

the deepest borehole drilled only went to a tad over 12 km, that doesn't even make it 1/2 way to the mantle under most continents. And that is why geothermal bores are limited to geothermal regions where the crust is much thinner
fracking and the likes only goes down a km or so

The case I'm trying to make is that from an economic perspective you get multiple birds with one stone.

1. Spur investment in novel mining techniques that can go deeper to utilize the heat found at those levels.
2. With the investments and thus technological and engineering hurdles overcome, have access to resources previously inaccessible, spurring growth.
3. Provide clean energy that is carbon neutral and virtually limitless.
4. Utilize facilities to produce desalinized water, possibly lowering costs to those who need it most.

 

[Vanadium 50]

Reasons that you want something are not the same as reasons that it is possible.

 

[n01]

We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win.— John F. Kennedy, May 25, 1961

 

[russ_watters]

We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win.— John F. Kennedy, May 25, 1961

I think you are missing the point/problem: Even if we assume that the effort will just be "hard" and we can do it if we choose to, it will certainly be fabulously expensive. Kennedy didn't care about Apollo being fabulously expensive because it was a one-time, 'lets just see if we can do it' project. Geothermal power would be a long-term program tied to the economy and the economics matter, if for no other reason than that there are lots of other options that geothermal has to compete with.

To say it more succinctly: the biggest problem with your idea isn't that you assume it will be easy it is that you assume it will be cheap. It won't be, and that matters.

 

[n01]

Geothermal power would be a long-term program tied to the economy and the economics matter, if for no other reason than that there are lots of other options that geothermal has to compete with.

I see this as saying that there ain't enough profits in geothermal energy to make it a reality. Is that what you are implying?

To say it more succinctly: the biggest problem with your idea isn't that you assume it will be easy it is that you assume it will be cheap. It won't be, and that matters.

I must be missing something here. Geothermal costs are negligible. You don't have to mine the stuff or control it as, say, nuclear reactors. The energy is constant and non-depletable. The only moving parts are just the turbines and we already have some geothermal plants working in the West. The only engineering obstacle is digging deeper holes, does that really sound like a problem as compared to something like putting solar panels in space etc. ?

 

[berkeman]

The www site gives the top 10 geothermal generating sites around the world

http://www.power-technology.com/fea...biggest-geothermal-power-plants-in-the-world/

The first one on the list is right in my back yard!

http://www.power-technology.com/projects/the-geysers-geothermal-california/

 

[russ_watters]

I see this as saying that there ain't enough profits in geothermal energy to make it a reality. Is that what you are implying?

There isn't enough profit (or savings) to make people choose to do it over something cheaper.

Geothermal costs are negligible.

Just like solar power is free, wind power is free and hydroelectric power is free? C'mon, don't be intentionally dense here: they are only free except for the parts that cost a lot of money!

Geothermal energy is "free" in exactly the same way that gold and oil are "free": They are all sitting there under the ground for anyone to take; all you have to do is dig them up!

 

[n01]

I think you are missing the point/problem: Even if we assume that the effort will just be "hard" and we can do it if we choose to, it will certainly be fabulously expensive.

How are you deriving that qualification on geothermal being 'fabulously expensive'? Af far as I know, the cost of maintenance and virtual full automation of such a geothermal facility is significantly lower than nuclear. If you consider the long-term costs (maintenance, no need tor transport of materials to facility, labor) would make economic sense in the long run despite possibly high initial costs.

If digging deep is really that much of a problem, then why not utilize places like Yellowstone where the magma chamber there is 8 km underground.

Here's my logic in a nutshell:
Either way, we're going to have to dig deeper into the Earth's crust to find new sources of materials that any economy needs for growth. There is an absolute comparative advantage over such bombastic ideas of mining the moon or asteroids no matter how low launch costs go down. If, that is true then why not get started earlier than later? Obviously, this will never happen with our entire economy still stuck with oil and natural gas and the special interest groups or if we can extract what we need from the ocean, efficiently.

Oh, well.

 

[Bystander]

Geothermal costs are negligible.

... until you look at "make-up water" for spinning the turbines.

 

[davenn]

I must be missing something here. Geothermal costs are negligible.

you are ... they are not negligible

I see millions upon millions in a geothermal installation like this
cost of the bores, many 10's of km of pipping large buildings, turbines and generators and the maintenance thereof
and this is where the energy source is less than 1000m deep

and that is only a small portion of the overall installation that can be seen

Dave

 

[Astronuc]

Geothermal costs are negligible.

What is the basis of such a statement?

http://geo-energy.org/geo_basics_plant_cost.aspx
According to this publication, nuclear is not much more expensive than geothermal. Like natural gas-fired or wind plants, one needs many units to provide the same power as a single nuclear unit. That means many turbines, generators and transformers. The infrastructure cost is not negligible.

From US DOE - https://energy.gov/eere/geothermal/geothermal-faqs

Geothermal sources are often not in locations where people live, so transmission systems are necessary, same as for nuclear plants that are often built away from metropolitan areas.

Simply digging deep is not necessarily the answer, and comparing geothermal energy with space exploration (e.g., sending rockets to the moon, or mining asteroids) is not a productive discussion. They represent two very different aspects of human economy. There are plenty of elements available on Earth for terrestrial application, while mining the moon or asteroids would support space exploration, not terrestrial projects.

Desalination is usually done near coastlines, which are not necessarily conveniently located near geothermal sites.

For some dated numbers of geothermal development/utilization, see - https://www.iea.org/publications/freepublications/publication/Geothermal_Essentials.pdf

And there is the matter of location of generation (and water), location of load (use) and competing generation, e.g., hydropower
http://www.usgeothermal.com/About/FAQ.aspx

Why has there not been greater development of US Geothermal capacity?
The development of geothermal power thorough the 1990s has been impeded by two factors: location and cost. In respect of location, most geothermal reservoirs are located in the Western States and specifically in areas which enjoyed excess electrical capacity. For example, Raft River in Idaho and the Newberry Caldera in Oregon are within the Bonneville Power Authority (BPA) system, which distributes hydropower from the Columbia River dams. Local electrical distributors like Idaho Power, and Pacific Power could service their clients by purchasing from the BPA the lowest cost electricity in the USA.

In respect of costs, prior to recent technological advances, the cost of developing geothermal reservoirs, building generators and operating them was between 6 cents and 8 cents per kilowatt hour (Kwh). The major sources of new electrical power generation in the 1990s and until recently was coal and natural gas. These sources were competitive in the 4 to 6 cent per Kwh range.

One must also consider the temperature of the geothermal formation (e.g., 100 to 370°C, or ~ 200 to 700°F).
http://geo-energy.org/Basics.aspx#directuse

If one were to simply pump water into a geothermal source, then in addition to steam production, one would also be concerned with the chemical reaction between water and the minerals/rock formation. One could use a different working fluid in a closed loop, but then one has to be concerned with subsequent leaks due to erosion/corrosion over the lifetime of the loop.

 

[n01]

http://geo-energy.org/geo_basics_plant_cost.aspx
According to this publication, nuclear is not much more expensive than geothermal. Like natural gas-fired or wind plants, one needs many units to provide the same power as a single nuclear unit. That means many turbines, generators and transformers. The infrastructure cost is not negligible.

Maybe we're reading two different papers; but, this was the conclusion from the link provided:

California Energy Commission (CEC) analysis examines what it estimates are the cost of different technologies based upon “levelized cost” which includes both capital and fuel costs. Their study places geothermal energy at a lower levelized cost ($/MWh) than many other types of merchant owned power plants including: Natural Gas Combined-Cycle, Wind, Biomass Combustion, Nuclear, Solar Thermal, and Photovoltaic. (11)

Many industry experts agree that geothermal is one of only a few alternative technologies that will compete economically with polluting technologies in the near term—even without considering the additional benefits of geothermal production

In a comparative analysis between wind and geothermal, geothermal came out on top, given a virtual operational lifespan of 50+ years and I don't think the authors included the additional costs that most renewables ential in regards to energy storage (batteries, molten salt, etc.)

According to statistics maintained by the National Wind Coordinating Committee (NWCC), the average cost of new installed wind generation is $1 million per MW. The operating efficiency is 28%, per the NWCC, simply because atmospheric conditions aren't always favourable. Annual average production is 2,453 MW hours per MW of capacity. The average capital cost component of one-kilowatt hour of windpower is 2.04 cents after 20 cumulative years of production. The cost falls to 1.63 cents after 25 years and 1.36 cents after 30 years.

Geothermal varies between $1.7 million and $2.1 million depending on plant scale. Based on an operating efficiency of 97%, annual production is 8,497 MW hours per MW of capacity. Assuming $1.9 million per MW, the average capital cost component of one-kilowatt hour of geothermal is 1.12 cents after 20 cumulative years of production. The cost falls to 0.89 cents after 25 years and 0.75 cents after 30 years. Operating costs for both sources of electricity is almost identical and average 1 cent per kilowatt-hour.

Geothermal sources are often not in locations where people live, so transmission systems are necessary, same as for nuclear plants that are often built away from metropolitan areas.

Simply digging deep is not necessarily the answer

If location is really that much of an issue, then digging deeper is the only answer. Furthermore, geothermal can recoup the costs of digging deeper via such applications as heating, sewage treatment, and offsetting transmission costs. What's more, you could theoretically retrofit a coal plant's elements into a geothermal setup.

< Mentor Note -- Post has been edited to remove insults >

 

[n01]

https://en.wikipedia.org/wiki/Cost_...ted_LCOE_in_the_U.S._by_2020_(as_of_2015).png

https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#United_States

 

[Miky]

Hi n01,
Iceland is/was creating a financial model project to sell electricity to Europe using their significant geothermal resources.
Not sure what happened to project... BUT, looking into that will tell you a lot more about current realistic geothermal practices.
Chk it out. And post what you find back here!
Miky

 

[ivanogre]

Why not use the thermal vents in the ocean? Put some type of hood over the vent to catch the heat to boil water and run a turbine.

 

[Astronuc]

Why not use the thermal vents in the ocean? Put some type of hood over the vent to catch the heat to boil water and run a turbine.

The vents are at such pressure, due to the depth of the ocean, that steam does not form. Rather, the hot water is either subcooled or supercritical liquid.

https://en.wikipedia.org/wiki/Hydrothermal_vent#Physical_properties

A turbine would require housing in a lower pressure casing (pressure vessel) to prevent collapse, while maintaining a lower pressure than the surrounding water. Assuming the power conversion was accomplished at the vent sites, then several hundreds or thousands of km of undersea conductors would be needed to get the electrical power to populated areas. Not very economical in most cases.

http://www.mesa.edu.au/deep_sea/hydrothermal_vents.asp (map).

 

[oldcatlover]

I'd like to thank those knowledgeable individuals above for increasing my understanding on the subject and only say in reference to, "the simple issue of drilling holes as deep as possible and extracting energy via heat":
As explained, there is simply nothing simple about it.

 

[Tish62]

If digging deep is really that much of a problem, then why not utilize places like Yellowstone where the magma chamber there is 8 km underground.

There might be some extremely undesirable side effects of pumping large quantities of water deep into the Yellowstone caldera. Like causing a super-volcano eruption that could depopulate a significant chunk of North America and push the planet into a mini-ice age.
There has been quite a bit of research on this topic.

 

[jkn]

There is a project to drill two 7 km holes in an area where crust is about 45 km thick. Temperature is expected to be enough for heating, but not for electricity generation.

http://www.st1.eu/news/st1-begins-the-drilling-of-geothermal-deep-rock-wells-in-otaniemi-espoo

Of course after rock around cracks connected to the holes has cooled, heating stops. So everything depends on cracks.

 

[jkn]

There might be some extremely undesirable side effects of pumping large quantities of water deep into the Yellowstone caldera. Like causing a super-volcano eruption that could depopulate a significant chunk of North America and push the planet into a mini-ice age.
There has been quite a bit of research on this topic.

Yes, that must be studied. But, could cooling magma and releasing pressure prevent an eruption?

 

[davenn]

Yes, that must be studied. But, could cooling magma and releasing pressure prevent an eruption?

that's like saying lots of little earthquakes stop the big one from happening
just doesn't work that way because of the huge amounts of stored energy in the stress fields

will never be cooled enough, considering the extent of the magma chambers under the Yellowstone area

 

[jkn]

If drilling under volcano causes an eruption, then eruption will came sooner than naturally. So it will be smaller. Yellowstone should not be first place to test this.

 

[davenn]

If drilling under volcano causes an eruption,

I doubt that that would occur

then eruption will came sooner than naturally. So it will be smaller.

bad assumption as you have no idea when the natural eruption will occur. Your drilling may only be weeks or months before the natural eruption

 

[n01]

This will be my last post in the thread. I appreciate the moderators allowing me to post here despite my recent emotional posts on the matter.

First I would like to explain the idea of LCOE;

The levelized cost of electricity (LCOE), also known as Levelized Energy Cost (LEC), is the net present value of the unit-cost of electricity over the lifetime of a generating asset. It is often taken as a proxy for the average price that the generating asset must receive in a market to break even over its lifetime. It is a first-order economic assessment of the cost competitiveness of an electricity-generating system that incorporates all costs over its lifetime: initial investment, operations and maintenance, cost of fuel, cost of capital.

The levelized cost is that value for which an equal-valued fixed revenue delivered over the life of the asset's generating profile would cause the project to break even. This can be roughly calculated as the net present value of all costs over the lifetime of the asset divided by the total electrical energy output of the asset.[4]

In very basic terms LCOE is the sum of the initial cost + yearly operating cost" over the life of the plant. Please also keep in mind that geothermal power plants can operate practically indefinitely until the temperature underground is exhausted, which is quite hard to do to my limited knowledge.

Now, with that understanding of the importance of levelized cost one can look at the graph of the cost of energy production per MWh:

https://en.wikipedia.org/wiki/Cost_...ted_LCOE_in_the_U.S._by_2020_(as_of_2015).png

As you can see, the assumption that cost is the limiting factor in construction of geothermal energy production is factually wrong, as per the information provided above. But, that is not a good source of information and quite insufficient in presenting the case for geothermal energy, hence I will refer the interested reader to a much better study on the comparative competitiveness of geothermal to all other sources of power production.

Levelized Cost and Levelized Avoided Cost of New Generation Resources in the Annual Energy Outlook 2016

Here is the take home message on page 6, table 1, in that report:

Now, some people may say that these are only projections of costs for a few idealized regions. However, there is research showing that these regions are not few and sparse.

See:

Everything I have mentioned may be insufficient to convince anyone that geothermal is really worth it. So, I refer to the document provided above titled, ' Levelized Cost and Levelized Avoided Cost of New Generation Resources in the Annual Energy Outlook 2016 '. This is a comprehensive document with many more details than what has been provided here.

Thank you for your time.

 

[Astronuc]

U.S. Geothermal Power Update
http://geo-energy.org/events/2014 Annual US & Global Geothermal Power Production Report Final.pdf

There is development in geothermal. One of the reasons that it hasn't taken off, is that there are already established utilities with existing power plants, and a natural gas industry providing relatively inexpensive fuel for gas turbine, combined-cycle plants. In addition, wind and solar are heavily subsidized.

Market Summary


The geothermal power industry reached about 3,442 MW at the end of 2013 (shown in Figure 5). New or refurbished power plants became operational in Utah, Nevada, California, and New Mexico. In total the U.S. industry added about 85 MW of new capacity additions. This number is about 40% lower than the capacity additions (148 MW) of 2012 and reflective of the difficulty in building a new power plant in the U.S. right now due to a number of policy barriers, inadequate transmission infrastructure, low natural gas prices and weak demand for new renewable geothermal power projects. Simply put, the U.S. geothermal industry is trending opposite of the international market which is growing at a steady 4% to 5% per year. In different circumstances the U.S. has one of the best potentials for geo power of any nation due to strong government support, the technical knowhow, experienced developers, and vast geothermal reserves. In addition, the U.S. market is struggling to advance projects because of political gridlock and an uncertain policy environment at the federal level.

However, . . . The Imperial Irrigation District (IID) has announced plans to promote development of up to 1,700 MW of new geothermal generation in the Imperial Valley as part of Salton Sea Restoration Initiative. Also, the California Public Utility Commission released a rulemaking authorizing Southern California Edison Company (SCE) to procure 400MW and may procure up to 700MW and San Diego Gas & Electric Company (SDG&E) to procure 200MW and may procure up to 800MW of preferred resources by 2022 to replace the retiring San Onofre Nuclear Generation Station.

See figure 7 and 8 in the report.

This is a comprehensive document with many more details than what has been provided here.

However, there is no basis for the geothermal plants. There is no information on the depth to which the plant must drill. If it's 1 km, or less, or more. The depth will affect the cost. Also, there is no information on the cost of replacing the piping due to corrosion, for example.

From http://www.nrel.gov/gis/geothermal.html, one finds:

http://www.nrel.gov/gis/images/geothermal/National%20Geothermal%20Developing%20Plants-01.jpg
http://www.nrel.gov/gis/images/geothermal/National%20Geothermal%20Operating%20Plants-01.jpg

The operating plants are < 90 MW, which is small compared to 1 GW plants. Under developing plants, there are some in the range of 200 to 300 MW.

 

[n01]

Having said that my previous post would be the last one, I feel compelled to just add that technology has made possible utilizing CO2 as the medium of the heat exchange that could potentially increase the efficiency of said geothermal hotspots by at least 10 times. This seems to overcome the rather low energy output from geothermal wells utilizing water as the medium for heat exchange problem, and hence more facilities needed for larger power output.

Furthermore, the CO2 can be permanently stored (sequestered) in those wells to a large degree (15 million tons per year).

However, there are some ambiguities in the link provided below as to the diameter of the outer ring (10 miles??). However, the depth would "only" be around 3 miles below the surface. Personally, I think everyone wins given such a possible state of affairs.

https://www.llnl.gov/news/turning-unwanted-carbon-dioxide-electricity

However, given our dependence on oil and natural gas, it is unlikely to take off as a policy or national priority, along with the rather obsession (?) with solar and wind.

 

[jkn]

I doubt that that would occur
bad assumption as you have no idea when the natural eruption will occur. Your drilling may only be weeks or months before the natural eruption

I agree: it would be very unlikely that drilling under volcano causes an eruption. Drill hole is so narrow that magma cool and block it.
But, It should be studied before drilling.If natural eruption would come soon anyway drilling has insignificant effect on timing and size of eruption. It might change direction of eruption. This might have large effect.

Assumption (In unlikely case that drilling causes an eruption then eruption will came sooner than naturally. So it will be smaller.) is valid anyway.

 

[jkn]

In very basic terms LCOE is the sum of the initial cost + yearly operating cost" over the life of the plant. Please also keep in mind that geothermal power plants can operate practically indefinitely until the temperature underground is exhausted, which is quite hard to do to my limited knowledge.

This is true if there are cracks that allow some fluid to transport heat. If there are no cracks, then heat storage will be exhausted. 100 m of solid rock is very good insulator. Cooling rock could cause more cracks, so this might not be a problem.

 

[Gary Feierbach]

My understanding is that Yellowstone has enough geothermal resources to supply the entire US with power for the foreseeable future. Why wouldn't tapping that resource also draw off sufficient heat to prevent that super volcanic site from blowing up thus saving hundreds of thousands of lives?

 

[davenn]

Why wouldn't tapping that resource also draw off sufficient heat to prevent that super volcanic site from blowing up thus saving hundreds of thousands of lives?

because a few small wells tapping a bit of steam doesn't do anything to reduce the huge amounts of magma that is slowly expanding the magna chamber as it enters into the chamber from the mantle below

 

[n01]

Yes, but either way, something HAS to be done about a potential Yellowstone eruption... It's literally an existential threat to the US.