Daniel Kunz of U.S. Geothermal, Inc.
Image: U.S. Geothermal, Inc.
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Editor's note: This Q&A is a part of a survey conducted by Scientific American of executives at companies engaged in developing and implementing non–fossil fuel energy technologies.
What technical obstacles currently most curtail the growth of geothermal energy? What are the prospects for overcoming them in the near future and the longer-term?
Currently the biggest obstacle to geothermal development is the lack of sufficient direct economic incentives for the drilling of geothermal resources. There are no significant technical obstacles that are curtailing current growth and development. Like the oil and gas industry, the geothermal industry would benefit from a strong, specific and appropriate tax incentive tied directly to expenditures made for production and injection well drilling. The prospects look good now for some stimulus of the renewable energy sector with the Obama administration's recognition of the long-term strategic imperative to develop domestic, renewable and clean energy sources to secure the future of our country.
Are there obstacles to scaling up geothermal to serve a national or global customer base?
There are significant obstacles today to scaling up geothermal to serve a global customer base because most of the current investment in geothermal is going toward localized development of shallow and known geothermal resource areas that tend to be limited in size. The reality is that geothermal development has a great potential to scale significantly based on the engineered geothermal systems (EGS) outlined in the Massachusetts Institute of Technology's 2006 report on the future of geothermal energy. In EGS development there is no risk of failure for the discovery of the energy. It exists in vast quantities some seven to 10 kilometers below the surface in the heat of the Earth's volcanic system. The challenge is in developing systems that can extract that heat and transport it to the surface to make electricity.
Deep drilling already occurs in oil and gas discovery, but EGS requires special attention due to the increased size of the required well diameter. The concept requires that we construct a "teapot" at those depths by selecting the right subsurface rock conditions and then fracturing the rock in place. Once the "teapot" has been fractured so it can be used to boil water, a pair of wells will operate in unison with one well used to inject water (or even carbon dioxide) into the teapot and the second well used to allow the steam or gas to escape to the surface, where it will turn conventional turbine and generator equipment. The promise is that these systems will be very large power stations, built closer to the load centers to eliminate transmission issues, and will be a clean and renewable source of power. The concept needs a serious push by the federal government much like the big hydroelectric dams that were developed in the 1930s and later. Given the size and scale of the current economic crisis bailout being funded by the U.S. taxpayers, a modest $1 billion expenditure for an EGS demonstration site would be a very wise investment in the future of energy development.
Can the existing energy infrastructure handle growth in geothermal energy? Or does that, too, need further modification?
The advantage of the current geothermal development is that the projects start out relatively small, say 20 to 50 megawatts, and these facilities can be added to the existing transmission system without too many major issues. The medium to longer-term development of larger and more geothermal plants will require ongoing upgrades and improvements to our transmission systems so that geothermal projects can be built in more remote areas, new generation capacity can be added without overloading already loaded transmission systems and the grids can be smarter about optimizing the peaks and valleys of electricity supply and demand.
Given the current economic crisis, can your industry get the necessary capital (from public or private sources) to adequately finance its growth?
Yes, if the projects have good geothermal resource and reservoir data. Renewable energy projects can still attract investors and funding. Geothermal energy is base-load power that can be more reliable than intermittent sources like wind and so is more desirable to a utility. The primary financing problem goes back to the cost of initial geothermal reservoir discovery and development drilling. This type of capital is higher-risk and harder to find in the difficult financial environment that Wall Street and Washington has placed upon us.
From a strategic standpoint, which is the bigger competitor for geothermal: incumbent coal, oil and gas technologies or other alternative energy technologies?
It is the incremental power generation choice that a utility has. For example, a number of utilities have been using natural gas generation as a source of power for peaking requirements. Others look to coal in the longer term and try to find alternate sources for the more near term. Utilities that are located in renewable portfolio standard states will require increasing sources of renewable, and geothermal energy competes with wind and biomass and solar in those cases.
Is there a cost target that you and others in your industry are aiming to achieve in, say, five years?
The cost target for the geothermal industry is to try and remain competitive with conventional energy sources. This requires an increased number of competitors for the supply of generation equipment and plant construction services as well as lower costs for basic material and supplies which have increased dramatically over the past few years. To remain competitive, the geothermal industry also needs low-cost capital because the up-front development is relatively capital-intensive. This can be achieved through more tailored and specific federal tax incentives that are appropriate for this industry. Once the front-end capital costs are repaid, geothermal power generation offers very low ongoing costs for a base-load source because it does not require annual purchases of a market-driven fuel component like gas or coal or uranium.
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13 Comments
Add CommentIt sounds really good to me; so why don't the government give one hundred billion for the construction of two geothermal power plants in each state. Each state can put in 500,000,000 and that should produce enough geothermal power plants to generate enough electricity for the US, Canada, and Mexico. Of course, we would sell it to Canada and Mexico for the same price we sell it to each other. If Alaska can have a working geothermal power plant, every state in the US can have a geothermal power plant. Each state could use their 500,000,000 to upgrade their grid. Let's get started on it tomorrow and work the kinks out as we go...like Microsoft does with its software.
Reply | Report Abuse | Link to thisI love geothermal - it's nuclear power without the nuclear waste (the Earth is hot mostly because of the decay of the radioactive material it contains).
Reply | Report Abuse | Link to thisBut:
Natural gas plants: cheap to set up, expensive to operate
Geothermal power plants: expensive to set up, cheap to operate
Guess which one is more compatible with a business culture that's focused on the next quarter, not 10 years out?
I work in the geothermal industry as a geoscientist. Geothermal investment amounts to paying for your energy up-front. This is the opposite to coal, oil and gas generation where fuel costs happen after the plant is built. Actually, there are likely to be hidden costs associated with coal, gas and oil that only appear much later: war, sea level rise, loss of biodiversity etc.
Reply | Report Abuse | Link to thisMost of the up front costs in geothermal are imposed by interest payments to privately owned banks. For example, in the first five years of a geothermal development there will be many wells drilled, and a power plant to build. Revenue will not flow back to the investors until the plant is finished. During this time of zero revenue, money is borrowed for drilling and building the plant, and interest payments to banks compound heavily.
Those that complain that geothermal is too expensive, or requires subsidies should consider that tax payers in the industrialized world are currently subsidizing (bailing out) banks to the tune of trillions of dollars. This is the same banking system that is constraining growth in geothermal! A small fraction of these dollars would be better spent providing emerging geothermal technologies with the funding they need to move forward.
Just a couple of questions which will help answer an inconvenient problem...
Reply | Report Abuse | Link to this(1) What is the specific heat of the rock formations you intend to use?
(2) What is the thermal conductivity of those rock formations?
Those two questions define the problem, which is as follows: How much heat can you pump out of the rock formations before they have been cooled off enough that you can no longer get usable amounts of hear from them. Rocks can get very hot, indeed, but they also cool off rather rapidly. And they are rather poor conductors of heat, which means that they won't warm up again very fast.
Which means your rather expensive low-pressure turbine system becomes about as useful as a car with an empty gas tank.
A typical lifespan for a conventional geothermal plant is ~30 years. Conventional reservoirs associated wih recent magmatism can be exploited for generations. For example Wairakei is a 150MW geothermal plant in New Zealand that has been in continuous operation for over 50 years.
Reply | Report Abuse | Link to thisThe basin and range geologic zone in Nevada currently host 18 geothermal power plants. These are generating power from deeply circulating groundwater that is heated by rocks at temperatures that are typical for the western USA; these power plants are not reliant on nearby active volcanism.
Geothermal capacity in Nevada is forecast to increase 30% this year so I would guess the economics of these plants must be quite sound. It follows that the lifespan of these plants must be quite good..
Interesting... I went to the site of the Geothermal Energy Association (www.geo-energy.org) and looked at the numbers for California. The site says >>In 2007, 4.5 % of California’s electric energy generation came from geothermal power plants, amounting to a net-total of 13,439 GWh<<
Reply | Report Abuse | Link to thisThere are 365.25 days in a year and 24 hours in a day, making 8766 hours in a year...
13.439 GWh/8766 = 1.533 GW average per hour for the uear...
I don't have numbers for California cities: all I've got is numbers for New York City: ConEd (our local power company) has reported our maximum draw - own generation plus draw from the Grid - at almost 14,000 Gigawatts on a hot July day... NYC alone would need over 9,100 times the entire installed capacity of the State of California.
I don't know how much acreage these plants (44 of them?) require, but 9,100 of them is a bit much...
I get the sneaky feeling that the people advocating Geo-Thermal aren't power system engineers.
As far as >>Geothermal capacity in Nevada is forecast to increase 30% this year so I would guess the economics of these plants must be quite sound. It follows that the lifespan of these plants must be quite good..<< No, it doesn't. Not in the least. I could also mean that various coal-burner power companies, in order to be able to say that they are "investing in alternative energy" are building these toys (for "research" purposes) just so they can point to something for PR purposes. This has already been done with a "64Megawatt" solar "power plant" in the California desert. It has been passed around from company to company for a few years now, and apparently operates ONLY when the press or visiting dignitaries are around.
Can we get real now, folks????
In spite of academic resistance to our work during the last runup of oilprices 1979 ,we made scores of reverse refridgeration installations then,heating &cooling homes ,utilizing 40-45 0F ground water @ 6-10 Ga.Imp.per min.These saved a min of 40% over current space heating N.Gas costs,There are over 100,000 oil and gas wells with the Quaternary sediments cased in Sask. alone .The future is enormous for replacing combustion with heat exchange (cool water to hot air or water)in most locations in central Canada & the U.S.A.A deeper 7200ft. well on Uof Regina campus while confirming the heat gradient to 120F plus 35000 bbls perday, the professors shut with no attempt to even heat the campus!
Reply | Report Abuse | Link to thisYou have a greater challenge!, Power generation at the Yellowstone Volcano!The Chinese took our N.Am.SubGradeGeoth.concepts and experience and ordered 2 million units this year from Trane and other supplliers.We have to push to recapture the lead we had 30 years ago.Dont leave it to new researchers ! Individual & Corp. enterprise has even provide the interface for "Burning Water"without Co2 orCh4.I hope Boone Pickens takes note.
Yours Truly, D.L.Surjik,Geoph.Emeritus,Regina Sask.Can.
>>I don't have numbers for California cities: all I've got is numbers for New York City: ConEd (our local power company) has reported our maximum draw - own generation plus draw from the Grid - at almost 14,000 Gigawatts on a hot July day...>>
Reply | Report Abuse | Link to thisYou have your units very wrong. Total nameplate capacity for NY State in 2007 = 43 Gigawatts. For the entire USA the capacity in 2007 was 995 Gigawatts. Q: How could the draw-down for NY city exceed the capacity of the entire USA? A: It can’t and you are out by a factor of 1000 (http://www.eia.doe.gov/cneaf/electricity/epa/epates.html).
I can’t believe you are suggesting geothermal plants in Nevada are “toys” used for greenwashing publicity by coal generators. I suggest you do your homework. You could start by checking out Ormat Technologies based in Nevada. ORMAT are a genuine, successful geothermal company. I doubt they require funding from the coal industry.
As the ball players say, "Good Eye!" wharfbanger@gmail.com. I like how you noticed that if it is not oil, coal, or nuclear, the GOP rounds up their cronies and throw in a lot of distorted numbers and worthless letters to try to confuse and scare people. Their 1+1 never equals 2 when the democrats are in office. The democrats are in heavy favor of geothermal, so the republicans would be heavily out of favor for it. Anyone who reads ScAm know that one geothermal power plant with twenty turbines will produce enough clean electricity for 170,000,000 homes and businesses for the nest million years or so. As long as you keep the plant and the turbines in good repair you will have all the electricity you will need for the rest of your time. The GOP is scared to death that they are going to loose their dirty money. Everyone of the GOP in Texas has a oil well in their back yard, so guess what they don't want to get rid of.
Reply | Report Abuse | Link to thisWhat you missed is the production of hydrogen vis magma chemistry. The science of this process has been demonstrated by Sandia Lab many years ago. Now Ormat at their Hawaiian site is including the hydrogen production dimension in their DOE EGS proposal. It will be interesting to see the quantities of hydrogen produced -- trillions of cubic feet for Hawaii to use for transportation if they can be ready in time. See <www.magma-power.com>
Reply | Report Abuse | Link to thisThis is why one must drill into circulating magma See www.magma-power.com
Reply | Report Abuse | Link to this'
Professor KEzar
Monty says geothermal takes up too much land and can be dangerous. Also the equipment is prohibitively expensive. How wrong is he?
Reply | Report Abuse | Link to thisAlso they say geothermal can power everything in CA north of the golden gate.
Australia has a lot going on in the Hot Rock Energy / Geothermal space. Our govt. is actively supporting the research and development with grants. Australia also has the distinct advantage of having the shallowest hot rocks with temps at 250 degrees centigarde at 4kms. You can read about Australia's Hot Rockers at www.HotRockEnergy.com
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