Canada gets most of its energy from hydropower, coal and nuclear. But scientists say that geothermal power could meet the country’s energy needs one million times over.
The statement is taken from a federal report on geothermal energy. The document was compiled by a team of 12 scientists led by Stephen Grasby at the federal Geological Survey of Canada and made public on the eve of a conference in Toronto earlier this month.
One of the main advantages of geothermal is that it is available 24 hours, unlike wind and solar, which face intermittency issues.
British Columbia, Alberta, the Yukon and Northwest Territories are the areas where the heat exists closer to the surface, but there are geothermal energy opportunities all over Canada. The researchers estimate that 100 projects would meet the country’s energy needs.
The biggest drawback for geothermal implementation is that upfront costs are very high. The logistics involved are quite daunting: wells must be drilled miles into the earth to bring heat to the surface. And then plants need to be built to turn the heat into electricity. All of this comes with its share of environmental impact, but much less aggressive than the impact caused by fossil fuels.
The report highlights a technique called ‘enhanced geothermal’ as one with great potential. Water or CO2 is injected into the wells so that it can migrate through the cracked rocks to capture heat. The heated water or CO2 is brought back to the surface to produce electricity. Europe and Australia are currently testing this type of hydropower technology.
What do you think? Is geothermal a truly sustainable alternative, and economically viable one as well?
Article by Antonio Pasolini, a Brazilian writer and video art curator based in London, UK. He holds a BA in journalism and an MA in film and television.
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I have been advocating geothermal power development for some years and I am surprised that development has been so slow!!
A Canadian company has completed a successful project in the state of Nevada recently but all the other projects under consideration are on hold, primarily for reasons of permitting and the expected high capital cost.
The governments and the investors should take into consideration a very important factor: “the Capital cost of a properly esigned ad constructed project that will continue operating at full capacity for many years will fade into insignificance after amortisation is completed”.
The equipment required for Wind and solar power, besides not being availalbe 24 hours per day, has a far sorter life span than a properly constructed geothermal installation.
Government support of wind and solar power projects is much more available than for geothermal; this should be reversed for the simple reason that geothermal power development is far less damaging to the environment and the footprint of a typical geothermal plant is the size of a city block!!
The fears that geothermal plants cause earthquakes is greatly exagerated;the intensity is in the order of Richter 0.2 that is similar to a big loaded truck speeding over a bridge!! I am presently living in an area where temors of Richter 1 or 2 are almost a daily occurrance and these do not cause any damage.
Polution of the groundwater can be avoided by injecting only distilled water for recirculation. It can be condensed from the steam from the cooling towers of a geothermal facility. There is no excuse for using water that contains dissolved solids; hard water will eventually reduce the life of a geothermal well by plugging the joint structure in the rock at depth.
A modern geothermal facility uses distilled water to transfer the heat from depths of about 3000 to 5000 metres to a heat exchanger at the surface.
The heat is transferred to a low boiling point liquid that flashes into vapour and turns the turbine to produce electricity. After the low boiling point liquid passes through the turbine, it is condensed and returned to the heat exchanger in a closed circuit.
Cold air and/or any local water supply is commonly used to cool the low boiling point liquid so that it condenses. If there is a large body of water nearby, such as a river, lake or ocean, direct cooling of the low boiling point liquid can be carried out in submerged tubes.
The amount of make-up distilled water required depends on the losses in the deep wells; this amount can usually be prepared by a separate circuit at the exhaust of the turbine before the vapour proceeds to the main condensor circuit.
The process of extracting heat from great depths is relative straight forward but the risk of drilling a hole into impermeable rock is quite high; better geological testing with advanced technology applied at the surface is required to reduce this risk. This is where government assistance could reduce the risks substantially.
Paul V. Preminger, P.Eng. (R)
Further to my comments above; the whole world could obtain all the power for all requirements from geothermal wells.
am living in Chile where the possibilities of obtaining geothermal power are far greater than in most otherlocations in the world. However the local politicians and the investors need to be educated in respect of the subject.
The recent drilling that took place at 4300 metres above sea level at El Tatio was doomed to failure…the area has many scatterred steam vents that should have indicated to everyone the simple fact that the ground consisted of broken rock with many channels for the steam to escape to the atmosphere and it was extremely difficult to isolate any steam to power a turbine.
As a result of the El Tatio “blowout”, the revised government regulations have essentially stopped all progress in the development of geothermal power in Chile.
There are many sites in Chile that meet the minimum requirements for the developmet of geothermal power.
The minimum requirement for the development of modern “dry rock” geothermal power is that there must be Solid rock near to the surface and all the way down to where sufficient heat is available to be captured and brought to the surface.
Starting a geothermal well at an elevation of 4300 metres above sealevel means that that location has a “penalty” of 4 kms of drilling just to reach the top of a well collared at 300 metres above sea level.
Just because the first operating geothermal plants in Italy and California are operating in an area where the steam is captured from natural vents does not mean that is the only way to go; in fact in the long term these are the worst way to go!!
The heat in the earth is generated in the magma by two factors; radioactive decay of certain elements and “tidal” action within the magma caused by the varying gravitational forces of the moon and sun. This heat is always present and is always being replaced as it makes its way to the surface of the earth because the forces producing it are also always present.
Drilling near a volcano is not the answer; volcanos have a habit of causing caos followed by a dormant period that may extend for centuries. Getting close to the magma with the bottom of the well assures that the heat will be available constantly.
All wells in solid rock will reach a point where sufficient heat is available to produce power; the key is not to have to drill many kms!!
Have a nice day!!
Paul V. Preminger
Geothermal electric generation systems are used successfully in some Western parts of the U.S. and some foreign countries. They can also make a good base load system however, their size is limited at the moment to usually less than about 100 megawatts between adjacent geothermal sites. What we need for geothermal to really take off is an economical method of drilling wells since many wells are required for each geothermal site.
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