By Jake Brooks
If someone stood up in a crowded room and said that Canada has access to thousands of megawatts of reasonably-priced, dependable, carbon-free power generation that remains entirely undeveloped, he or she would likely face a fair bit of skepticism. This must be unproven technology, many would think. It must use a lot of land or water resources. There must be a problem with it or someone would have built it here, skeptics would mutter. However in this case, the doubters may be all wrong. The technology is mature, with operating installations all over the world, using minimal amounts of land and producing virtually zero atmospheric emissions.
In fact, there’s a strong case that geothermal is the most under-developed source of energy in Canada. According to its proponents, the barriers to its development are not economic or technical. The primary reason that geothermal energy remains under-developed is that it has often been overlooked in energy policy processes. While wind, solar, waterpower and bio-energy qualify for a range of renewable energy programs at the provincial level, geothermal has been inexplicably excluded from most. While the same renewable sources enjoy special treatment at the federal level, geothermal is again largely left out. It does not benefit from the full range of policies supporting conventional fossil fuels nor from most of the special programs available for renewables and energy efficiency.
The Canadian Geothermal Energy Association (CanGEA) proposes a national target: Installing 5000 MW of geothermal power capacity in Canada by 2025. Likely comparable with the cost of many existing programs for renewable energy and energy efficiency, a program of this nature could bring Canada in line with other countries that are developing significant geothermal energy resources. Such an initiative could be a major contributor to meeting national climate change targets, and produce a remarkable variety of specific benefits. For example, CanGEA estimates that it would:
• Eliminate 25 million tonnes/year of CO2 emissions (12.5% of Alberta’s 2050 GHG reduction commitment)
• Create 20,000 construction jobs related to power generation investments
• Create 8,500 operation & maintenance jobs related to power generation investments
• Create several times these numbers of jobs in the non-power part of the investments (i.e., in thermal infrastructure construction and maintenance)
• Produce $4.4 billion/year in power sales
• Deploy more than $25 billion in capital spending
• Produce $82.5 billion economic output in supplier industries over 30 years
• Provide at least 15,000 MW of power plant by-product heat for direct uses
• Solve high energy costs in many northern, First Nation and remote communities
• Contribute to Canada’s northern sovereignty
• Present power export opportunities to the U.S.
Alison Thompson, Chair and Co-Founder of CanGEA, notes that attractive geothermal resources are readily available in all regions of Canada and many are located in areas that are in need of economic development.
Geothermal energy systems rely on extracting heat from below the surface of the earth. The same advances in drilling technology that have recently extended the underground reach of the oil and gas industry can also be used to extract heat, which can drive generation turbines or be put to other uses. The heat energy is continuous, year-round, and does not produce greenhouse gases. The amount of heat available just a few miles below the earth’s surface, although theoretically exhaustible, is far more than humanity is likely to need for centuries, if not millennia. (The centre of the earth is hotter than the surface of the sun.) Incidentally, geothermal energy extraction is sometimes confused with ground source heat pumps, essentially thermal transfer systems. These heat pump systems, although they are becoming popular in some regions for space heating and cooling, are actually earth-based storage devices, not sources of energy. Vendors will sometimes use the term “geothermal” when marketing ground source heat pumps, creating confusion for those trying to build awareness of geothermal energy.
From an engineering perspective, geothermal energy sites vary greatly depending on the temperatures available, the nature of the drilling required to access the heat, and the other materials that would co-exist with the hot water. In many cases oil and gas fields already in production also contain geothermal resources that can enhance the value of the overall extraction project. There are two primary types of geothermal resources in Canada:
• Hydrothermal: Where heat and hot water are extracted from subsurface materials
• Hot Sedimentary Aquifers (HSAs): Underground pools harboring both petroleum and geothermal resources.
HSAs are particularly interesting in Canada. These are geological areas where oil and gas resources co-exist with thermal resources. While significant capital is often invested to extract the oil and gas in HSAs, typically large amounts of hot water are extracted at the same time, and discarded essentially unused. The heat is usually overlooked, generally considered incidental to the petroleum production. Yet, with oil and gas extraction going deeper than ever before, wells are encountering more high temperature resources than ever before. For a relatively modest additional capital investment the operators can harvest thermal energy and what are known as “Co-produced fluids” from these HSAs at the same time as extracting oil and gas.
Geothermal energy can be used in different ways including the following:
• Directly, usually in the form of hot water (think of spas and district heating systems for example)
• As “Co-produced fluids” at an oil and gas extraction facility (micro-electricity)
• Unconventional Geothermal (Hot Sedimentary Aquifer) Systems (small power plants that can be repeated across a large system)
• Conventional hydro-thermal systems where utility scale power can be achieved
• Enhanced Geothermal Systems: (Still experimental and where special systems are used to enhance the geothermal resource).
Typically when producing electricity from geothermal resources, the heat is used to drive Organic Rankine Cycle or Stirling engines located at the top of the well. The technology for these kinds of engines is mature, having been in use for decades. Alison Thompson points out that the flow rate of fluids in these installations is typically pretty high – fast enough to ensure that very little heat energy is lost as the hot water moves up the well.
“Efficient dual purposing of existing infrastructure” is how she describes the opportunity. And although it has been technically possible to extract thermal resources this way for many years, the geothermal opportunity is expanding greatly as recent advances in drilling techniques have opened up access to deeper underground resources, where temperatures are higher. Well operators have to extract the water, cool the water, and dispose the water in any case, Thompson notes. Grid operators and system planners will likely see value as they come to realize that geothermal power is dependable as baseload generation, can provide ancillary services like black start operation, and can be designed to adjust its output on short notice.
CanGEA points out that, “because the exploration and development of geothermal reservoirs use techniques and technologies nearly identical to the petroleum and mining industries, geothermal is the best way to redeploy existing Canadian subsurface geoscience expertise and associated services toward a sustainable energy future. In particular, the development of geothermal provides Oil & Gas workers with a social license to use their skills and services toward a sustainable economy.” Tellingly, Chevron is the world’s largest geothermal power developer.
At the largest Geo-Park in Iceland, 650 jobs have been created in a range of geothermal-related industries. In Germany in 2015, over 150 jobs were created in a geo-greenhouse operation. In Moose Jaw, Saskatchewan, at the Temple Gardens Mineral Spa, 200 jobs have already been created.
CanGEA recommends that the Federal government explicitly include renewable heat, from geothermal and other renewable energies in the Canada Infrastructure Bank, Green Bond, and Low Carbon Economy Trust programs. In a submission to the federal government on the 2016 budget, CanGEA recommended the establishment of a renewable heat incentive program to complement existing renewable energy programs. CanGEA suggests that the $36 million Eco-Energy for Heat Incentive program be expanded to include renewable heat sources that have been so far excluded, such as geothermal and other renewables. Only passive solar heating was allowed to claim the 25% capital rebate, up to $400,000/project. It has also tabled other recommendations to "Adjust the tax code to enable geothermal to reach parity with other natural resources funding."
Worldwide, more than 13,200 MW of power generation is driven by geothermal energy, and this amount is growing quickly. 3600 MW are located in the US and more than 900 MW are in Mexico. This amount pales in comparison to the 28 GW of geothermal heating installations in use for district heating, space heating, spas, industrial processes, desalination and agricultural applications as of 2010. Although the emissions of greenhouse gases from Canadian geothermal resources are likely to be zero, there are a few geothermal sites in other countries where affected rocks can react with brine from geothermal processes releasing small amounts of carbon dioxide. However these releases are miniscule compared to the GHG releases related to fossil fuel usage, and that type of rock is not expected to be present at Canadian geothermal sites.
Considering that current geothermal power generation capacity in Canada is zero, CanGEA anticipates a fairly significant growth curve. The organization encourages interested parties to “help make geothermal project development a reality in Canada” by accessing policy information on its website and raising concerns with all levels of government. The organization is running training events on tax planning for geothermal developers in the coming weeks.
It seems entirely possible that the skeptics will be proven dramatically wrong as the rate of growth in geothermal energy in Canada moves forward at a dramatic pace in the next few years.
For more information, readers may wish to visit: http://www.cangea.ca/. The organization recently released its pre-budget submission to the federal government, also described as the “Definitive guide to why the geothermal energy industry has not kept pace with wind and solar in Canada”. Copies are available here: http://www.cangea.ca/uploads/3/0/9/7/30973335/cangea_pre-budget_2016_finance_subcommittee_submission.pdf
See also the related articles, “Geothermal to grow worldwide,” elsewhere in this issue and "Global geothermal alliance formed," IPPSO FACTO, February 2016.