Low-Temperature Geothermal Power

Low temperature geothermal systems are a cost effective and carbon-free way to heat homes and in some circumstances to generate utility scale power.

Image Source: International Energy Agency

Low Temperature Geothermal

By the Numbers

149°C

Maximum temperature for resources to be considered low temperature

1.3 million

Geoexchange systems installed globally

36,000

Homes and buildings with geoexchange systems in Canada

$6,250

Approximate cost to install a geoexchange system

25 years

The Canadian government has not funded research into geothermal power plants

Last Updated: May 2012

Charlotte Helston

In the past, the term geothermal energy was used to describe high temperature resources extracted from deep, subterranean reservoirs. The definition has since been broadened to encompass low temperature geothermal resources as well. Low-Temperature Geothermal (Low-T) refers to energy resources derived from the earth's shallow subsurface, i.e., at temperatures below 149°C (300°F). High temperature geothermal resources exhibit temperatures above 149°C, and are typically found in areas of high tectonic activity, like volcanic belts. The word geothermal simply means earth-derived heat. Temperature increases with depth within the earth's crust due to the heat generated from both primordial heat (generated when the earth was created) and radioactive decay; this is referred to as the geothermal gradient (on average about 2.5-3°C/100m). Low-T offers a range of low-intensity applications including use in spas, direct space heating and cooling systems, in aquaculture, agricultural drying, snow melting (particularly in Iceland), and low wattage power generation. Geothermal resources have been identified in over 90 countries and there are records of geothermal utilization in over 72 of them.

Data from Natural Resources Canada and the U.S. Department of Energy and the Environmental Protection Agency, show that if just 100,000 homes swapped conventional heating and cooling systems for geoexchange, Canada could reduce its CO2 emissions by 400,000 tonnes – the equivalent of planting more than 90 million trees.

Lately, new technologies have expanded Low-T's traditional services of household heating and cooling. Use of Low-temperature geothermal for power generation has gained popularity in recent years as the geothermal family's more accessible sibling, residing closer to the surface than high-temperature reservoirs, and tappable almost anywhere underfoot because it relies on the natural geothermal gradient. Low-T power comes at a significant downside however, with equipment costing more and overall efficiency providing a smaller profit compared to high-temperature powered generation.

Canadians use low-T to maintain comfortable temperatures indoors year-round with Geoexchange systems. As for power generation? Like high-temperature geothermal, low-temperature is not used for power generation anywhere in Canada, though the potential is there should the country decide to move toward it.

Low-Temperature Geothermal, Low-T Power, Groundsource, Geoexchange, Heat Pump, Heat Exchanger - What's what in Low-temperature Geothermal?

The above terms are often used interchangeably, which has created much confusion. Though a few of the terms are synonymous, most are not. Misunderstanding of these terms must be addressed prior to a discussion of the resource. Thus, briefly, an explanation of Low-T geothermal vocabulary:

  • Low-temperature Geothermal: Low-temperature geothermal projects are defined as projects that use water temperatures of up to 149°C (300°F) to provide heating and cooling, or to produce power in output capacities of just a few megawatts.

  • Groundsource and GeoExchange Systems: Geoexchange and Groundsource mean the same thing. They both refer to a central heating and cooling system that pumps heat to or from the ground. This is a type of low-temperature geothermal project.

  • Heat Pump: Groundsource and Geoexchange systems use a heat pump to force the transfer of heat above and below ground.

  • Heat Exchanger: These are used in high-temperature and low-temperature applications to transfer heat from one medium to another. In Low-T Geoexchange systems, they are built into the Heat Pump.

  • Low-Temperature Geothermal Power: The use of geothermal resources below 149°C (300 °F) to generate electricity, usually through the use of a secondary fluid.

  1. Canadian Geothermal Energy Association (CanGEA). ‘What is Geothermal?’ CanGEA. Accessed May 30, 2012. http://www.cangea.ca/what-is-geothermal/.
  2. Axelsson, Gudni., Jonasson, Thorgils., Olafsson, Magnus., Egilson, Thorsteinn., Ragnarson, Arni. ‘Successful Utilization of Low-Temperature Geothermal Resources in Iceland for District Heating for 80 Years.’ (2010). Proceedings World Geothermal Congress 2010. Accessed May 30, 2012. http://b-dig.iie.org.mx/BibDig/P10-0464/pdf/0517.pdf
  3. Oldmeadow, E., Marinova, D., Birks, D., Whittall, S., Brown, S. ‘Low Temperature Geothermal Applications as Enablers of Sustainable Development: Practical Case Studies from Australia and UK.’ Water Resource Management. Vol. 25 (2011) 3053-3071. Accessed May 30, 2012. http://www.springerlink.com/content/9w0tu7g3h14u1318/
  4. Clean Energy Association of British Columbia. ‘Geothermal Fact sheet.’ Accessed May 30, 2012. (http://www.cleanenergybc.org//media/CEBC_FS-Geothermal_web.pdf)
  5. Dickson, Mary and Mario Fanelli. 2004. ‘What is Geothermal Energy?’ Prepared February 2004 for the International Geothermal Association. Accessed May 30, 2012. http://www.geothermal-energy.org/314,what_is_geothermal_energy.html
  6. Bertani, Ruggero. ‘Geothermal power generation in the world 2005-2010 update report.’ Proceedings World Geothermal Congress. Bali, Indonesia. International Geothermal Association. (2010). Accessed May 30, 2012. http://geothermie.nl/fileadmin/user_upload/documents/bestanden/IGA/Geothermal_electricity_in_the_world_2010_report_Ruggero_Bertani.pdf

Geoexchange Systems

How Geoexchange works

Diagram of a home geoexchange system.
Artist's depiction of a home geoexchange system.

Groundsource or geoexchange systems use stored solar heat and/or the earth’s heat as it is stored in the ground and in bodies of water like oceans, lakes and ponds.  These systems account for around half of all geothermal use. Generally, the earth’s surface under the frost line maintains a nearly constant temperature between 10 and 16°C. Temperatures below and above ground shift back and forth with the seasons. In winter, ground temperatures are warmer than the air above them, while in summer, temperatures are cooler under rather than over. These temperature differences are the key to geoexchange systems.

In geoexchange systems, a heat pump is used to transfer heat stored in the earth to buildings in the winter, and out of them during the summer. In this way, the earth acts as a heat source in the winter, and a heat sink in the summer.

The system is made up of three main components:

  • Pipes buried in the ground
  • A heat exchanger
  • Ductwork to distribute heat in the building

The series of pipes form a "loop" that circulates fluid (either water, or a mixture of water and antifreeze) that absorbs heat from or releases heat to the ground.

Pipes being buried
Pipes are buried beneath the ground where warm temperatures are of use in the winter, and cool ones in the summer.

The loop is constructed of polyethylene piping buried in the ground, or alternatively submerged in a nearby lake or pond (lake loop/ pond loop). The heat transfer liquid is circulated along the loop. The liquid absorbs heat as it circulates through the ground, and delivers it to the heat pump, which extracts that warmth and disperses it throughout the home. The cooled liquid is then recirculated around the loop over and over again. This is often described as a closed loop system.

A different way to run a geoexchange system, is to directly pump ground or well water through the heat pump. This eliminates the need for a heat transfer liquid, relying instead on an existing water supply. This is often described as an open loop system, as new water is being used, even though used liquid is returned to the ground. These systems can be problematic if the well water has a high mineral content, resulting in potential scale build-up and rusting over time.

Both systems extract heat from the liquid that gets circulated through the piping, but what then?

The heat can be distributed throughout the building using air or water. Forced-Air Systems are the most widely used in Canada, but hot-water or hydronic systems can be found as well.

Forced-Air Systems

In a Forced-Air System, heat from the piped liquid is transferred to air that is blown over it. This heat transfer is accomplished with the use of heat exchangers that move heat from one medium to another. The warmed air is then guided through ducts to all areas of the house (the same way Forced-Air fossil fuel or electric furnaces would operate).

Hydronic, or Hot-Water, Heating Systems

In Hydronic systems, the heat exchanger transfers heat from the piped liquid to liquid contained in a hot water distribution system. Some types of equipment that can be used to disperse heat within this system include hot water baseboard radiators and radiant floors. The former are the most used, however, radiant floors are emerging as a popular choice for their comfort and efficiency.

Liquidtowater
A liquid to water heat pump.

The problem of "recharging" geoexchange systems:

To help explain the concept of “recharging”, the Canadian Geoexchange Coalition suggests thinking of the geoexchange earth loop as a rechargeable battery, permanently connected to a battery charger (heat energy contained in the ground). If the loop is repeatedly drawn upon at a rate quicker than it can recharge (reheat) itself, then the system will be unable to run properly. Unfortunately, there is no simple way to recharge it quickly. The larger the loop, the less of an issue recharging becomes. Thus, it is important to closely predict a building’s energy demand, and install an appropriately sized loop.

Where can Geoexchange be used?

Geoexchange is viable almost everywhere. A series of pipes are buried underground near the building they are heating/cooling. This may require the removal of trees and shrubs to properly install the system. Usually, where space allows, pipes are buried horizontally in trenches four to six feet underground. If space is limited, pipes can be implanted vertically into the ground by drilling to a maximum of about 300ft. If the ground is quite rocky, this method may not be an option. Once the pipes are buried, the surface can be reclaimed as before.

pond loop
Here is an assembly of Geoexchange tubes, ready to be sunk to the bottom of a pond where warm temperatures are of use in the winter, and cool ones in the summer.

Geoexchange systems range from small backyard systems, to large systems for businesses and institutions. The West Vancouver Community Centre, for instance, relies largely on a geoexchange heating and cooling system to regulate the air within its facilities, as well as the water in its aquatic centre. Geoexchange is also becoming popular in schools across the province.

Bodies of water including ponds and lakes also offer the potential for a GeoExchange system that naturally provides the fluid needed to provide the heat differential. If a body of water is being incorporated into the system, the pipes are submerged in the water body.

Pond loops being sunk
Here's the same geoexchange system being sunk to the bottom of a pond.

Geoexchange Around the World

Global interest in geoexchange technology is gradually increasing, with the majority of recent growth in the United States, Japan, and Europe. The total number of geoexchange systems installed throughout the world stood at 1.3 million in 2005, which represents almost double the number of units installed in 2000.

Iceland, the country to put geothermal on the map, has utilized low-temperature geothermal hot water since the 1930s. At present, about 90% of their space heating is provided by a combination of high and low geothermal sources. In most cases, district heating systems, or networks, transfer heat through a network of pipes, rather than installing independent systems for every household.

Other countries, including Japan, New Zealand, Hungary, and the United States also draw on the heating and cooling applications of Low-T. Presently, solar hot water and solar space heating provide cheaper systems for those considering renewable heating technologies without such a large installment cost. However, geothermal offers a more reliable and constant source of energy. Sunlight varies, while geothermal temperatures are always locked underground. In some cases, as in Canada's north where daylight hours are limited during the winter months, geothermal could present a better fit than solar.

Geoexchange in Canada

The geoexchange industry in Canada appears to be at the cusp of a massive growth cycle. About 30,000 residential homes and 6,000 commercial and institutional buildings are heated and cooled with geoexchange systems in Canada.

Geoexchange in BC

At present, over 70 known ground source systems are installed or in construction in businesses in BC. Individual homes with geoexchange systems are estimated to exceed that number, though no data could be found.

Politics of geoexchange development

Development of low-temperature geothermal resources differs greatly from that of high-temperature geothermal resources, as they do not require tenure through the Geothermal Resources Act.

As of 2011, the BC government was allotting tax-free grants for new geothermal heat pumps when homeowners upgraded their heating equipment in the amount of up to $1,250-$2,500 as part of the LiveSmartBC efficiency incentives program. Federal ecoEnergy grants are also available for the installation of geoexchange systems in the amount of up to $5,000 dollars. Despite this incentive, the remaining uncovered costs of ground source installation remain substantial — a certain barrier to the spread of this energy source.

Heating costs can be reduced by 50 to 70% in winter, and cooling costs by 20 to 40% in summer. With the minimized heating and cooling bills, payback on the initial investment takes five to 12 years.

The BC Sustainable Energy Association, suggests policy changes here to accelerate the use of geoexchange systems.

Economics and costs of Geoexchange Systems

Groundsource systems offer the security of fixed installation and constant operational costs. Unlike other energies whose costs fluctuate according to the laws of supply and demand, ground source heat remains very resilient against such changes. In a world where fuel prices are becoming more and more unpredictable, the value of ground source is gaining attention.

To heat an average, 2,000 sq. ft. house with a geoexchange system would cost an installation fee of approximately $20,000 to $30,000 dollars.  Additional costs may include modifications to the interior ductwork, water hookup and lawn restoration. Heating costs can be reduced by 50 to 70% in winter, and cooling costs by 20 to 40% in summer. With the minimized heating and cooling bills, payback on the initial investment takes five to 12 years. These statistics vary depending on location; colder regions may require larger, and more expensive, systems.

Environmental Impact of Geoexchange Systems

With 70% of residential and commercial energy use focused on space and water heating, direct, Low-T geothermal offers the ability to compensate for all, or almost all, of that energy, minus the emissions. On a household, business or institutional level (many schools have converted to geothermal heating), Low-T can transform buildings on site from net energy consumers to energy producers. Pollution is minimized and the only consumables required are water (sometimes water and antifreeze) and electricity to operate the heat-pump. Geoexchange systems produce no emissions if used in conjunction with a green source of electricity to run the heat pump (e.g. solar).

An important consideration is the use of water for geoexchange. For closed loop systems, this is often not an issue because the extracted water is reinjected (granted at a different temperature) and recycled continuously. Open loop systems are more intensely regulated because there is a net transport of water. Although geoexchange systems, even closed loop, are not directly interacting with the environment, they are changing the temperature of the ground. This concept is known as "thermal contamination" and may have effects on soil/ground dwelling organisms. This effect increases with magnitude of the temperature change and the volume of ground affected. In addition, care must be taken in properly sealing the boreholes and ground loops to prevent groundwater contamination.

The results of a 2010 Canadian GeoExchange Coalition study demonstrate the advantages in greenhouse gas emissions when converting from conventional heating systems to geoexchange systems. They found that if as little as 2% of Canadian single-family homes installed geoexchange systems, a potential country-wide reduction in emissions of 376 000 tons of CO2 would be possible. That's the equivalent of taking nearly 112,000 cars off Canadian roads.

  1. Tomarov, G.V., and A.A. Shipkov. ‘The World Geothermal Congress WGC-2010.’ Thermal Engineering. Vol: 57 (2010) 989-992.
  2. BC Hydro- Regeneration. ‘Geoexchange systems.’ Last modified April 19, 2012. Accessed May 30, 2012. http://www.bchydro.com/powersmart/technology_tips/geoexchange_systems.html
  3. Canadian GeoExchange Coalition. ‘Comparative analysis of greenhouse gas emissions of various residential heating systems in the Canadian provinces.’ (2010). Accessed May 30, 2012. http://www.geo-exchange.ca/en/UserAttachments/article63_GES_Final_EN.pdf.
  4. Canadian GeoExchange Coalition. ‘Comparative analysis of greenhouse gas emissions of various residential heating systems in the Canadian provinces.’ (2010). Accessed May 30, 2012. http://www.geo-exchange.ca/en/UserAttachments/article63_GES_Final_EN.pdf.
  5. Canadian GeoExchange Coalition. ‘Comparative analysis of greenhouse gas emissions of various residential heating systems in the Canadian provinces.’ (2010). Accessed May 30, 2012. http://www.geo-exchange.ca/en/UserAttachments/article63_GES_Final_EN.pdf.
  6. The NEED Project. ‘Geothermal.’(2011) Accessed May 30, 2012. http://www.need.org/needpdf/infobook_activities/SecInfo/GeothermalS.pdf
  7. Canadian Geothermal Energy Association. ‘Geothermal Projects in Canada.’ (2011) Accessed May 30, 2012. http://www.cangea.ca/projects/archive/
  8. Gunnlaugsson, Einar., Ragnarsson, Arni., Stefansson, Valgarour. ‘Geothermal Energy in Iceland.’ International Symposium in Izmir, Turkey (2001). Accessed May 30, 2012. http://www.or.is/media/files/country.pdf
  9. Axelsson, Gudni., Jonasson, Thorgils., Olafsson, Magnus., Egilson, Thorsteinn., Ragnarson, Arni. ‘Successful Utilization of Low-Temperature Geothermal Resources in Iceland for District Heating for 80 Years.’ (2010). Proceedings World Geothermal Congress 2010. Accessed May 30, 2012. http://b-dig.iie.org.mx/BibDig/P10-0464/pdf/0517.pdf
  10. Salvador, Amos. ‘Energy: A historical perspective and 21st century forecast.’ American Association of Petroleum Geologists. Tulsa, Oklahoma (2005).
  11. Arellano, R., and M. Schriver. ‘Understanding geoexchange: heat pump technology.’ North American Clean Energy. Vol: July/August (2011). Accessed May 30, 2012. http://www.nacleanenergy.com/?action=article&id=11368
  12. BC Hydro- Regeneration. ‘Geoexchange systems.’ Last modified April 19, 2012. Accessed May 30, 2012. http://www.bchydro.com/powersmart/technology_tips/geoexchange_systems.html
  13. The BC Sustainable Energy Association, suggests policy changes here (http://www.bcsea.org/learn/get-the-facts/renewable-energy-technologies/groundsource-heat
  14. Canmet. ‘Renewables.’ Natural Resources Canada. (2010). Accessed May 19, 2011. http://canmetenergy-canmetenergie.nrcan-rncan.gc.ca/eng/renewables/solar_thermal.html
  15. Johnston, I.W., Narsilio, G.A., Colls, S. ‘Emerging Geothermal Energy Technologies.’ Journal of Civil Engineering, v. 15 (2011) 643-653.
  16. Johnston, I.W., Narsilio, G.A., Colls, S. ‘Emerging Geothermal Energy Technologies.’ Journal of Civil Engineering, v. 15 (2011) 643-653.
  17. Johnston, I.W., Narsilio, G.A., Colls, S. ‘Emerging Geothermal Energy Technologies.’ Journal of Civil Engineering, v. 15 (2011) 643-653.
  18. Canadian GeoExchange Coalition. ‘Comparative analysis of greenhouse gas emissions of various residential heating systems in the Canadian provinces.’ (2010). Accessed May 30, 2012. http://www.geo-exchange.ca/en/UserAttachments/article63_GES_Final_EN.pdf.

Low-Temperature Geothermal Power Plants

Low-T Geothermal's potential to generate power has seen heightened interest in recent years due to a political interest in reducing emissions and the consumption of non-renewable resources. Unlike high-temperature geothermal resources, which occur deeper underground and typically in areas of high tectonic activity, Low-T can be harnessed just about anywhere.

How It Works

High-Temperature Geothermal power uses water-based steam to drive turbines which then generate electricity. Low-temperature geothermal power production also powers turbines to the same end-result; however, it uses an intermediary fluid.

Power generation from geothermal resources is usually accomplished through the use of a conventional steam turbine or a binary plant. Conventional steam turbines require fluids in excess of 150⁰C. This hot, highly pressurized fluid is then 'flashed' to produce steam, which drives the turbines to create electricity. The high temperatures required for this type of power production restrict it to use with high-temperature geothermal resources. Because water drawn from a Low-T geothermal resource is not at or near the boiling point of water, it is not possible to 'flash' these fluids to produce steam. Instead, the heat energy held within the water is transferred to a secondary fluid (thermal oil or silicone based oil), which has a much lower boiling point, and it is then this fluid which is 'flashed' to produce steam to drive a turbine. This process has been termed the Organic Rankine Cycle (ORC) and enables power production from fluids with a temperature as low as 75⁰C. This type of power production occurs in a binary power plant and enables electricity production from the more widely distributed and accessible Low-T resource.

Organic Rankine Cycle of Binary Power Plant

Countries using low-temperature geothermal

Low-temperature geothermal is still a new technology, compared to its sister resource High-T geothermal. Most power plants are moderate to high in the temperature category. Many companies have proposed development plans for Low-T areas, though few have actually begun drilling. It seems that most of the countries currently harnessing high-temperature geothermal (the U.S., Iceland, and the Philippines to name a few) are currently exploring Low-T resources as well.

At the time of writing, Alaska was home to the world's lowest temperature geothermal plant to date. The Chena Hot Springs power plant uses fluid as cool as 75°C to generate electricity. Installed in 2006 by United Technologies Corp., the systems replaced expensive and polluting diesel generation systems. The Chena plant is often referenced in studies and company proposals, acting as the benchmark by which future Low-T geothermal power developments are measured.

Low-Temp Geothermal's potential in Canada

Canada produces no power through geothermal activities, either high-temperature or low. The country's highest potential site for geothermal is Mount Meager, an area 70 km northwest of Pemberton, BC, and within the Upper Lillooet Provincial Park. Mount Meager is classified as a high-temperature resource area, with maximum temperatures up to 275°C.

$10 - 20 million in funding has been granted to the ADK/Borealis project. Through the use of Low-T thermal resources this project will provide enough electrical power for the community (~750 people) and enough heating capacity to serve the local greenhouse for food production.

No other major low-temperature power plant sites have been announced for exploration or development in Canada that we know of. A central reason for this is the financial risk faced by developers. Companies must bid for land leases before they even know what kind of resources occur below the surface. Costly exploration may reveal unusable resources, resulting in a situation of money spent and nothing gained. Without governmental support to aid these companies, power from geothermal sources, either low or high, are unlikely to take off.

Politics of Low-Temp Geothermal in Canada

It is uncommon for renewable energy markets to be able to grow and compete with conventional markets without the support of government funding and other incentives. For almost 25 years, geothermal science has not been funded by the Canadian Federal Government, states the Canadian Geothermal Association. This is a likely reason why Canada has fallen behind other countries around the Pacific Rim in geothermal energy development. Germany, the Philippines, and Mexico, among others, have implemented policies that encourage the use of geothermal resources.

The BC Sustainable Energy Association lists several current policies (such as a 7 cent/kWh price guarantee for the first 5000 MW of geothermal power until 2015) as well as suggested policies to promote the use of geothermal energy in BC here.

Economics of Low-Temp Geothermal Plants

Low-temperature geothermal resources are more difficult to extract power from, as the highest temperature in the power generation cycle has a direct link to the overall efficiency. The Chena Power Plant in Alaska puts out electricity at 6 cents per kWh. The 2006 installment replaced the existing diesel generator, which produced power at 30 cents per kWh. The Geysers, a high-temperature geothermal power plant , sell power at 3-3.5 cents per kWh.

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Geothermal developers can share the infrastructure of oil and gas fields to generate electricity from otherwise wasted hot water.

Possibly the most economical fashion to employ the use of Low-T resources is to "piggy-back" on the oil and gas industry. In the U.S, nearly 3,000 litres of hot water are produced from oil and gas wells. The hot water is largely seen as an inconvenience that requires expensive disposal. "Co-produced fluid" technologies eliminate waste while providing electricity to be used on-site, or sold to the grid. Collecting "waste" fluid, and passing it through an Organic Rankine System, can offer energy savings and diminished greenhouse gas emissions. With the high up front costs of developing a geothermal power plant, sharing the existing infrastructure of oil and gas fields eliminates the need for hydraulic fracturing and drilling. In addition, there is potential to use the infrastructure from old oil and gas fields which are no longer in production to harness geothermal resources to produce electricity.

The first successful generation of electricity from co-production (funded by the U.S. DOE) occurred in 2008 at the Rocky Mountain Oilfield Testing Center in the U.S. The binary geothermal power generation system used low-temperatures to generate 150-250 gross kilowatts of power.

Environmental impact of low-temperature geothermal

Low-temperature and high-temperature geothermal power plants swap fuel for either thermal oils or water-based steam, thus cutting back emission levels to only about 1% of the CO2 released by comparable fossil fuel plants. Likewise, only 1-3% of the sulphur compounds (which contribute to acid rain) produced and emitted by coal and oil-fired power plants, are released. The avoidance of emissions from transporting fuels to the plant further alleviates the CO2 emission levels. Land impacts are minimal; only a few acres are required for the plant's buildings. While geothermal wells and pipelines may extend over a considerable area, surface uses may carry on as before. Farming, wildlife grazing, and recreational activities have not been shown to suffer any negative effects from geothermal power plant operations. Of course, as with any human activity, some noise pollution and habitat displacement does occur, though it is markedly less than that of conventional energy production plants.

  1. Frick, S., Kaltschmitt, M., Schroder, G. ‘Life cycle assessment of geothermal binary power plants using enhanced low-temperature reservoirs.’ Energy, v. 35 (2010) 2281-2294.
  2. Crowe, Robert. 2011. Capturing waste heat with rankine cycle systems. Renewable Energy World.com. Retrieved at: http://www.renewableenergyworld.com/rea/news/article/2011/01/capturing-waste-heat-with-organic-rankine-cycle-systems
  3. Hansen, T., 2008, Low-temperature Geothermal Technology Expands Clean Energy Reach. Electric Light and Power.
  4. Blodgett, Leslie. ‘Taking a look at the low-temperature geothermal developments and prospects in Mexico, Canada, and the U.S.’ Geothermal Energy Association. (2010). Accessed May 30, 2012. http://www.renewableenergyworld.com/rea/news/article/2010/09/low-temperature-geothermal-energy-expanding-market-opportunities
  5. Canadian GeoExchange Coalition. ‘Comparative analysis of greenhouse gas emissions of various residential heating systems in the Canadian provinces.’ (2010). Accessed May 30, 2012. http://www.geo-exchange.ca/en/UserAttachments/article63_GES_Final_EN.pdf.
  6. Chena Geothermal Power Plant. Fact sheet. Retrieved from: http://www.yourownpower.com/Power/.
  7. Reinhardt, Tim. 2010. Low Temperature and Coproduced Resources Team Lead. Geothermal Technologies Program. U.S. Department of Energy. Retrieved at: http://www1.eere.energy.gov/geothermal/pdfs/webinar_20101118_aapg_low_temp.pdf.
  8. Davis, A.P., Michaelides, E.E., 2009, Geothermal Power Production from Abandoned oil wells. Energy, v.34, p. 866-872
  9. Reinhardt, Tim. 2010. Low Temperature and Coproduced Resources Team Lead. Geothermal Technologies Program. U.S. Department of Energy. Retrieved at: http://www1.eere.energy.gov/geothermal/pdfs/webinar_20101118_aapg_low_temp.pdf.
  10. Clean Energy. 2011. Why Geoexchange? Residential Section. Retrieved at: http://www.cleanenergydevelopments.com/residential/why-geoexchange.
  11. Clean Energy. 2011. Why Geoexchange? Residential Section. Retrieved at: http://www.cleanenergydevelopments.com/residential/why-geoexchange.

Bibliography


To ensure continuity of material, all of the external web pages referenced here were cached in May 2012.

Readers are recommended to explore the current links for any changes.

Arellano, R., and M. Schriver. ‘Understanding geoexchange: heat pump technology.’ North American Clean Energy. Vol: July/August (2011). Accessed May 30, 2012.

Axelsson, Gudni., Jonasson, Thorgils., Olafsson, Magnus., Egilson, Thorsteinn., Ragnarson, Arni. ‘Successful Utilization of Low-Temperature Geothermal Resources in Iceland for District Heating for 80 Years.’ (2010). Proceedings World Geothermal Congress 2010.

BC Hydro- Regeneration. Geoexchange systems. Last modified April 19, 2012. Accessed May 30, 2012.

BC Sustainable Energy Association, suggests policy changes here.

Bertani, Ruggero. ‘Geothermal power generation in the world 2005-2010 update report.’ Proceedings World Geothermal Congress. Bali, Indonesia. International Geothermal Association. (2010). Accessed May 30, 2012.

Blodgett, Leslie. ‘Taking a look at the low-temperature geothermal developments and prospects in Mexico, Canada, and the U.S.’ Geothermal Energy Association. (2010). Accessed May 30, 2012.

Borealis Geopower. 'ADK/Borealis Geothermal Demonstration Project selected for Clean Energy Fund.' For NRCan Press Release. 2011. Accessed May 30, 2012.

Canadian GeoExchange Coalition. 'Comparative analysis of greenhouse gas emissions of various residential heating systems in the Canadian provinces.' (2010). Accessed May 30, 2012.

Canadian Geothermal Energy Association. ‘Geothermal Projects in Canada.’ (2011) Accessed May 30, 2012.

Canadian Geothermal Energy Association (CanGEA). 'What is Geothermal?' 2012. Accessed May 30, 2012.

Canmet. 'Renewables.' Natural Resources Canada. (2010). Accessed May 19, 2011.

Chena Geothermal Power Plant. 'Fact sheet.' 2012. Accessed May 30, 2012.

Clean Energy. 2011. 'Why Geoexchange? Residential Section.'

Clean Energy Association of British Columbia. 'Geothermal Fact sheet.' Accessed May 30, 2012.

Crowe, Robert. 2011. 'Capturing waste heat with rankine cycle systems.' Renewable Energy World.com.

Davis, A.P., Michaelides, E.E. ‘Geothermal Power Production from Abandoned oil wells.’ Energy, v.34 (2009) 866-872. Accessed May 30, 2012.

Dickson, Mary and Mario Fanelli. 2004. ‘What is Geothermal Energy?’ Prepared February 2004 for the International Geothermal Association. Accessed May 30, 2012.

Frick, S., Kaltschmitt, M., Schroder, G. ‘Life cycle assessment of geothermal binary power plants using enhanced low-temperature reservoirs.’ Energy, v. 35 (2010) 2281-2294.

Gunnlaugsson, Einar., Ragnarsson, Arni., Stefansson, Valgarour. ‘Geothermal Energy in Iceland.’ International Symposium in Izmir, Turkey (2001). Accessed May 30, 2012.

Hansen, T. ‘Low-temperature Geothermal Technology Expands Clean Energy Reach.’ PennEnergy. (2008). Accessed May 30, 2012.

Johnston, I.W., Narsilio, G.A., Colls, S. ‘Emerging Geothermal Energy Technologies.’ Journal of Civil Engineering, v. 15 (2011) 643-653.

The NEED Project. ‘Geothermal.’(2011) Accessed May 30, 2012.

Oldmeadow, E., Marinova, D., Birks, D., Whittall, S., Brown, S. ‘Low Temperature Geothermal Applications as Enablers of Sustainable Development: Practical Case Studies from Australia and UK.’ Water Resource Management. Vol. 25 (2011) 3053-3071. Accessed May 30, 2012.

Reinhardt, Tim. ‘Low Temperature and Coproduced Resources Team Lead.’ Geothermal Technologies Program. U.S. Department of Energy. (2010). Accessed May 30, 2012.

Salvador, Amos. ‘Energy: A historical perspective and 21st century forecast.’ American Association of Petroleum Geologists. Tulsa, Oklahoma (2005).

Tomarov, G.V., and A.A. Shipkov. ‘The World Geothermal Congress WGC-2010.’ Thermal Engineering. Vol: 57 (2010) 989-992.

When no treaty was signed between the government, and no war was fought over the land, first nations groups in Canada are entitled to the land on which they have historically lived and still inhabit.
In solar thermal energy collectors, the Absorber Area refers to the area absorbing the radiation
A technique where acidic solutions are pumped into a well, melting away debris about the bottom of the well and allowing the gas to flow more freely.
An electrical current that reverses its direction at regularly recurring intervals. Abbreviated to AC.
A series of processes in which microorganisms break down biodegradable material in the absence of oxygen. Used for industrial and/or domestic purposes to manage waste and/or release energy.
A device used for measuring wind speed.
The average speed (and direction) of the wind over the course of a year.
Asia-Pacific Economic Cooperation (APEC): A 21-nation group of Pacific-Rim nations that seeks to promote free trade, raise living standards, education levels and sustainable economic policies. Canada is a member.
The artificially increased discharge of water during the operation of hydroelectric turbines during periods of peak demand.
Small particles released into the atmosphere as part of the flue gases from a coal plant. Fly ash is dangerous for human health but most power plants use electrostatic precipitators to capture it before release.
The waters off the Atlantic provinces that has been producing oil and gas since the 1990s, and continues to have considerable untapped oil and gas potential. The region has similar geology to the oil-rich North Sea.
'The ionizing radiation which we are all inescapably exposed to every day. It comes from radon gas in the ground, the sun, distant supernovas, and even elements inside our own bodies. The average exposure is around 361 mrem per year for a person in Washington state (it varies by region).
Base-load power is that provided continuously, virtually year-round to satisfy a regions minimum electricity needs. Hydro and nuclear power are well-suited for base-load grid needs.
A renewable fuel in which soy or canola oil is refined through a special process and blended with standard diesel oil. Biodiesel does not contain ethanol, but research is underway to develop diesel blends with ethanol.
Renewable energy made available from materials derived from biological sources.
Natural gas, or methane, that is created by microbes consuming organic matter. Usually found near the Earths surface and is usually immediately released into the atmosphere.
Biological material from living, or recently living organisms such as trees, grasses, and agricultural crops. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel.
A facility that integrates biomass conversion processes and equipment to produce fuels, power, and chemicals from biomass. The biorefinery concept is analogous to petroleum refineries, which produce multiple fuels and products from petroleum.
Bitumen is "petroleum that exists in the semi-solid or solid phase in natural deposits. Bitumen is a thick, sticky form of crude oil, so heavy and viscous (thick) that it will not flow unless heated or diluted with lighter hydrocarbons. At room temperature, it is much like cold molasses."
Bottom Ash: Bottom ash are small particles that result from coal combustion, but unlike fly ash they are too heavy to be released into the atmosphere and must be stored.
Canadian Environmental Protection Act: Passed in 1999, CEPA is "An Act respecting pollution prevention and the protection of the environment and human health in order to contribute to sustainable development."
Cap and Trade: A system where the government sets a limit on how much of a pollutant may be emitted. It then sells the rights to emit that pollutant to companies, known as carbon credits, and allows them to trade the credits with other companies. The EU has implemented a cap and trade program for carbon dioxide.
Carbon Footprint: A calculation based on the set of greenhouse gas (GHG) emissions caused by an organization, event, product, or person.
Carbon Sink: A carbon sink is a natural or artificial reservoir that accumulates and stores carbon-containing chemical compounds for an indefinite period.
Carbon Monoxide: A deadly gas produced from the tailpipe of cars that burn gasoline.
Capacity Factor: The ratio of the actual output of a power plant over a period of time and its potential to output if it had operated at full nameplate capacity the entire time.
Cellulose: An organic compound consisting of several hundred to over ten thousand linked glucose units. Cellulose comprises the structural component of the cell wall in plants, many green algae. It is the most common organic compound on Earth comprising about 33% of plant matter.
Cellulosic Biomass: Fuel produced from wood, grasses, or the non-edible parts of plants that is mainly comprised of cellulose.
Cellulosic Feedstock: The inedible cellulose which comprises most plants and trees. Yields are much higher as any part of the plant can be used and because they do not compete with food, therefore, cellulosic feedstock is an ideal candidate for large scale sustainable biofuel production.
Cetane Rating: Also known as cetane number (CN), this is a measurement of the combustion quality of diesel fuel during compression ignition. It is a significant expression of diesel fuel quality.
Clean Power Call: A request sent out by B.C. Hydro to private power utilities for new electricity-generating projects totalling 5,000 GWh/year. B.C. Hydro will help fund the successful projects and then buy power from them once completed.
How efficiently a turbine converts the energy in wind into electricity. Just divide the electrical power output by the wind energy input.
Using the energy left over from one primary energy conversion to fuel another. The most prominent example of this are natural gas co-generation plants which first feed fuel into a gas turbine. The residual heat from that reaction then heats water to spin a steam turbine.
Collector Area: In solar thermal energy collectors, the Collector Area refers to the area that intercepts the solar radiation.
A mixture of hydrocarbons present in natural gas. When gas is lowered below the hydrocarbon dew point, a condensate, that is, a liquid, forms. These can be used for combustion just like oil and gas. These are also known as natural gas liquids.
Generation of electricity using fossil fuels.
Gas reserves that form beneath porous layers of sandstone. Until recently this has been the only kind of gas commercially extracted.
When bituminous coal is baked at high temperatures it fuses together ash and carbon, creating coke. Coke can then be used to reduce the oxygen content of iron, strengthening it and creating steel.
A force generated by to the earths rotation which deflects a body of fluid or gas moving relative to the earths surface to the right in the northern hemisphere and to the left in the southern hemisphere. It is at its maximum at the poles and zero at the equator.
Decentralized Electricity Generation: Decentralizated electricity generation is a concept used to describe a large number of dispersed energy generators, often closely integrated with the people that use the electricity. Wind turbines and solar panels are good examples: they can be put within communities, be owned by members of the community and generate electricity for it. Alternatively centralized energy generation, far more common in North America, is where a small number of large plants owned by utility companies (hydro-electric, nuclear or fossil fuel) generate large quantities of electricity.
The portion of the oil business that involves refining the crude oil, bringing it to market and selling it. Gasoline service stations are the most lucrative part of downstream operations.
Effluents: Gases or liquids released by a human-made structure, in this case flue gases from a coal-fired power plant.
Electrolyte: Usually a solution of acids, bases, or salts, electrolytes are substances with free ions which make them effective electrical conductors.
Electrolysis: A simple technique for splitting water atoms to obtain hydrogen, driven by an electrical current.
Requirements that set specific limits to the amount of pollutants that can be released into the environment by automobiles and other powered vehicles, as well as emissions generated by industry, power plants, and small equipment.
Transforming one form of energy into another. Most energy conversions that run our economy are conversions from a primary source to electricity (wind or nuclear) or movement (oil).
Energy Currency: Energy that is usable for practical purposes. These include electricity and petroleum which power appliances and vehicles.
A measurement of the amount of energy stored in a given volume.
Energy Return On Investment (EROI): This is the ratio of usable energy obtained over the amount of energy required to get it. The oil sands has a low EROI because instead of being sucked out of the ground in liquid form the oil must be painstakingly mined and heavily refined, a process that requires large quantities of energy itself.
An energy source is the means by which energy is generated. The energy profiles each deal with a different source of energy, and most are simply means to attain the energy currency we all use: electricity.
Enhanced Geothermal System: A new technology, EGS does not require natural convective geothermal resources, but instead can draw power from the ground through extremely dry and impermeable rock.
The provincial Environmental Assessment Office is a politically neutral agency tasked with reviewing major construction projects in B.C. Their purview includes assessing the environmental, economic, social, heritage and health effects over the lifecycle of projects.
A blend of ethanol and diesel fuel. plus other additives, designed to reduce air pollution from heavy equipment, city buses and other vehicles that operate on diesel engines.
A policy device that encourages investment in renewable energies, usually by guaranteeing power producers that their energy will be bought.
In food processing, fermentation is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria or a combination thereof, under anaerobic conditions. In simple terms, fermentation is the chemical conversion of sugars to ethanol.
A finite, or non-renewable resource, is one where a limited amount exists. Once the existing stocks of that resource are exhausted there will be no more, at least in any reasonable human time scale. Only so much fossil fuels and uranium exist on earth, making these finite, non-renewableresources. The wind, sun and tides are renewable resources since it is impossible to run out of them.
First Generation Renewable: Well established renewable technologies that emerged early on in the Industrial Revolution. These include hydropower, biomass combustion and early geothermal power.
Fission is a nuclear reaction where a heavy atom is hit by a neutron, causing it to split into lighter atoms, release more neutrons, and huge amounts of energy.
Flat-plate collectors are a type of non-concentrating solar energy collector, typically used when temperatures are below 200 degrees F. They are often used for heating buildings.
Flex-Fuel Vehicle: Also known as a dual-fuel vehicle, this is an alternative fuel vehicle with an internal combustion engine designed to run on more than one fuel, usually gasoline blended with either ethanol or methanol fuel.
Flue gases are the gases that are released into the atmosphere by a flue, or pipe, from the steam boiler.
Many biofuel feedstocks such as corn, sugarcane, and soybeans are also key sources of food for millions of people. Production of crops for bioenergy may displace other food-related crops, increasing the cost and decreasing the availability of food. The central question is one of ethics: Should we use our limited land resources to grow biofuels when the same land could be producing food for people?
Fracking: Hydraulic fracturing is the process of injecting high pressure fluids into deep, geologic formations, in order to fracture the rock and render it more permeable.
Fuel Crops: Crops grown specifically for their value as fuel to make biofuels or for their energy content.
Fumaroles: Openings in the Earths crust that emit steam and gases.
Gasohol: Otherwise known as fuel ethanol, gasohol has been distilled and dehydrated to create a high-octane, water free alcohol. All water must be removed because a water-alcohol mixture cannot dissolve in gasoline. Fuel ethanol is made unfit for drinking by adding a small amount of a noxious substance such as gasoline.
Geothermal Gradient: The rate at which temperature increases deeper into the earth, towards the earth's molten core.
Geothermal Task Force Team is a government program that aims to: develop policies, in collaboration with affected agencies, related to tenure issuance, examine the regulation of the use of geothermal resources not currently covered by legislation, build a royalty and resource rent model for geothermal resources, and develop a science based review of the known geothermal resources in the province.
Geyser: Springs characterized by intermittent discharge of water ejected turbulently and accompanied by steam.
Giromill Turbine: Uses lift forces generated by vertical aerofoils to convert wind energy into rotational mechanical energy. They are powered by two or three vertical aerofoils attached to a central mast by horizontal supports.
Glut: A situation where the market has been flooded with goods and there is more supply than there is demand causing the price of goods to drop.
Gravity Survey: A technique of measuring minute changes in the Earths gravity field. This allows geologists to map lighter and denser rocks underground.
Green Energy and Green Economy Act of 2009: Legislation by the province of B.C. to boost the investment in renewable energy projects and increase conservation, create green jobs and economic growth in Ontario. Part of Ontario's plan to become a leading green economy in North America.
Head: The term head refers to the change in elevation of the water.
Head Differential: The difference in pressure due to the difference in height of water level.
Heat Exchangers: These are used in High-Temperature and Low-Temperature applications to transfer heat from one medium to another. In Low-Temperature Geoexchange systems they are built into the heat pump.
Horizontal Axis Wind Turbine (HAWT): Horizontal Axis Wind Turbine. These are the most common types of wind turbines and look like aircraft propellers mounted atop towers.
Hydrocarbons: A compound of almost entirely hydrogen and carbon. This covers oil and natural gas. Coal, the third fossil fuel, contains so many impurities it is usually disqualified from this title.
Hydrostatic Head: The distance a volume of water has to fall in order to generate power.
Intermittent Energy Source: Any source of energy that is not continuously available due to a factor that is outside of direct control (ex. Wind speed or sunshine).
An internal combustion engine operates by burning its fuel inside the engine, rather than outside of it, as an external, or steam engine does. The most common internal combustion engine type is gasoline powered, followed by diesel, hydrogen, methane, and propane. Engines typically require adaptations (like adjusting the air/fuel ratio) to run on a different kind of fuel than they were designed for. Four-stroke internal combustion engines (each stroke marks a step in the combustion cycle) dominate the automotive and industrial realm today.
Kinetic Energy: The ability of water falling from a dam to do work, that is, to generate electricity. Water stored above a dam has potential energy which turns to kinetic energy once it begins to fall.
Levelized Cost of Electricity: The cost of generating electricity (capital, operation and maintenance costs). Measured in units of currency per unit of electricity (ex. kWh).
Magnetic Survey: A technique for measuring the intensity of magnetic fields from several stations.
Manhattan Project: The massive Anglo-American-Canadian scientific undertaking which produced the atomic bombs that helped end the Second World War. It marked the birth of the nuclear age and scientists were immediately aware of the potential to use use nuclear power for civilian use.
Market Penetration: The share of the total energy market a specific energy source has in relation to its competitors. So the market penetration of wind power would be measured by its share of the electricity market, while ethanol would be compared to other vehicle fuels, not to total primary energy use.
Matrix: In geology, this is the finer mass of tiny sediments in which larger sediments are embedded.
Methanol: Methanol is produced naturally in the anaerobic metabolism of many types of bacteria, and is ubiquitous in the environment. Methanol is toxic in humans if ingested or contacted on the skin. For its toxic properties and close boiling point with ethanol, that it is used as a denaturant for ethanol.
Miscanthus: A low maintenance perennial grass which is thought to be twice as productive as switch grass as it has a longer growing season, greater leaf area, and higher carbon storage per unit of leaf area.
MMBtu: A unit of measurement which means a million Btus (British thermal units). A Btu is roughly the amount of energy it takes to heat a half kilogram of water from 3.8 to 4.4 °C. MBtu is used for a thousand Btus.
Moderator: A moderator is used to slow down neutrons, which enables them to react with the atoms in the nuclear fuel. If enough atoms react then the reactor can sustain a nuclear chain reaction.
M Mount St. Helens is an active volcano located in Washington state. It is most famous for its catastrophic eruption on May 18, 1980 where fifty-seven people were killed, 250 homes, 47 bridges, 24 km of railways, and 298 km of highway were destroyed.
Mud-Pools: Pools of bubbling mud. Also known as "paint-pots" when the slurry of usually grey mud is streaked with red or pink spots from iron compounds.
Nacelle: The housing atop a wind turbine that holds the gearbox, generator, drive train and brakes, as well as the rotors.
Name-Plate Capacity: The intended full-load sustained output of a power plant. For example an average wind turbine's name-plate capacity is 2 Megawatts. The capacity factor is the actual output, so for that 2 MW wind turbine with an efficiency of around 30-35% (average) then it has a more realistic capacity of around 0.7 MW. Most power stations are listed in terms of their nameplate capacity.
National Energy Board: A regulatory agency established by the federal government in 1959 that is primarily tasked with regulating oil and gas pipelines that cross provincial and national borders.
National Energy Program: A set of policies enacted in 1980 that sought to make Canada energy independent. Petro-Canada was created and oil prices were kept artificially low to protect consumers. Shares of oil revenue were diverted to the federal government who used them mostly in the eastern provinces to offset a decline in manufacturing. The program was extremely unpopular in western Canada and was discontinued shortly thereafter.
Nuclear Renaissance: A term used by politicians and the media for the renewed interest in nuclear energy in the past decade. Many countries are now expanding their civilian nuclear programs.
Octane: The octane rating of a fuel is indicated on the pump – using numbers such as 87, 90, 91 etc. The higher the number, the greater the octane rating of the gasoline.
Oil in Place: The total hydrocarbon (oil and gas) content of a reservoir. Sometimes called STOOIP or Stock Tank Original Oil In Place.
Oil Patch: A term for the Canadian oil industry. This specifically means the upstream operations that find and extract oil and gas, mostly in Alberta but also B.C., the other prairie provinces, Newfoundland and Labrador.
Oil Window: The range of temperature at which oil forms. Below a certain temperature and kerogen will never progress to the form of oil. Too high and natural gas is formed instead.
OECD: The Organization for Economic Co-operation and Development is a 34 country organization dedicated to advocating democracy and the market economy. Membership is largely limited to Western Europe, North America, Australia and Japan, what are often considered the world's developed nations. Sometimes referred to in the media as the "rich countries' club".
Passive Seismic Survey: A way to detect oil and gas by measuring the Earths natural low frequency movements.
Peak Power Demand: Power demand varies over minutes, hours, days and months. Peak power demand are the times when the most people are using the most power. To meet this demand extra sources of power must be switched on. Some forms of electricity generation, such as natural gas turbines, can be turned on quickly to meet peak power demand and are better suited for this purpose than others, such as nuclear, which are better as sources of baseload power.
Permeability: A measure of the ability of a porous rock to allow fluids to pass through it. High permeability in the surrounding rocks is needed for the formation of gas reserves.
Photovoltaic Cell: A non-mechanical device typically fabricated from silicon alloys that generates electricity from direct sunlight.
Pickens Plan: Investment of $1 trillion into wind power in the U.S.A., named for an American oil tycoon. The plan aims to reduce the amount of foreign oil imported to the U.S.A. while providing economic and environmental benefits.
Pondage: The main difference between small and large hydro projects is the existence of stored power in the form of water which is held back by dams at large hydro stations. Some small hydro projects have pondage, however, which are small ponds behind the weir of a dam which can store water for up to a week.
Potential Energy: The energy stored in a body or a system.
Porosity: Closely related to permeability, this is a measure of the amount of "voids," or empty space in a rock where gas or oil can pass through to collect in a reservoir.
Possible Reserves: Possible reserves are a class of unproven reserves that geologists use for oil that they are only 10% sure is present in the ground.
Purchasing Power Agreement: A contract between two parties, one who generates power for sale, and another who is looking to purchase it. B.C. Hydro buys power from companies that build their own power generating stations.
Primary Battery: A primary battery is one that is non-rechargable because the electrochemical reaction goes only one way. It gives out energy and cannot be reversed.
Primary Gas: The degeneration of decayed organic matter directly into gas through a process called "thermal cracking." This is opposed to secondary gas which is formed from decayed oil that has already formed.
Probable Reserves: Probable reserves are a class of unproven reserves that geologists use for oil or gas that they are at least 50% sure is actually present.
Proven Reserves: An amount of a resource any resource to be dug out of the ground (oil, coal, natural gas or uranium in energy terms) that geologists have a 90% or higher certainty can be extracted for a commercial gain with the technology available at the time."
Recompleted: The process, by which an old oil well is redrilled, fractured, or has some other technology applied to improve the amount of oil recovered.
Reforming: In oil refining, reforming is using heat to break down, or crack, hydrocarbon atoms and increase their octane level. This technique creates some left-over hydrogen which can be collected and used.
Renewable Portfolio Standard (RPS): Law that requires electric utilities to produce some portion of their power from renewable sources like wind, solar, geothermal or biomass. RPSs are necessary to keep renewables competitive in an era of cheap natural gas electricity.
Rent-Seeking: The practice of using resources to compete for existing wealth rather than to create new wealth, often to the detriment of those who seek to reform societies or institutions. Economies that fail to diversify away from oil are often pre-dominated by a rent-seeking mind-set where people become more pre-occupied with securing the windfall resouce profits for themselves, usually oil, rather than seeking to develop new industries.
Reserves: The fraction of the oil in place that can be considered extractable. This depends not only on the geology, but the economics (is oil expensive enough to make extracting it profitable?) and technology.
Reserve Growth: When an oil or gas field is first discovered, reserve estimates tend to be low. The estimates of the size of the field are expected to grow over time and this is called reserves growth.
Ring of Fire: The Pacific Ring of Fire is a region of high volcanic and seismic activity that surrounds the majority of the Pacific Ocean. This region is essentially a horseshoe of geologic activity, characterized by volcanoes, earthquakes, deep sea trenches, and major fault zones.
Riparian: The term riparian refers to the wetland area surrounding rivers or streams. A riparian ecosystem refers to the biological community supported by an area around a river.
Savonius Turbine: Uses drag generated by the wind hitting the cup, like aerofoils, to create rotation.
Second Generation Wind Turbine: Technology that is only now beginning to enter the market as a result of research, development and demonstration. These are: solar, wind, tidal, advanced geothermal and modern bioenergy. Much hope has been placed upon these technologies but they still provide only a fraction of our energy.
Secondary Battery: Rechargable batteries are sometimes known as secondary batteries because their electro-chemical reactions can be reversed.
Secondary Gas: When oil is subjected to so much heat and pressure it degenerates into gas. The process through which this happens called "thermal cracking."
Secondary Recovery Schemes: When so much oil has been sucked out of an oil reservoir it will lose pressure and the oil will no longer flow out of the reservoir from natural pressure. When this happens secondary recovery schemes can be employed. This means that fluids or gases are pumped into the well to increase pressure and push the remaining oil up out of the well.
Shale: A type of sedimentary rock with low permeability, which was once thought to prevent any commercial extraction of the gas inside. Fracking allows gas developers to access it.
Sound Navigation and Ranging (SONAR): Initially devised as a technique for detecting submarines. An emitter sends off pulses of sound. The pulses bounce off objects and return to a receiver which interprets their size and distance.
Spot Market: A market where commodities are traded for immediate delivery. A future market on the other hand is one where delivery is expected later on. Because of the dependence of gas users on those who are at the other end of the gas pipeline, the natural gas market is mostly a futures market.
Steam Coal: Steam coal is coal used for power generation in thermal power plants. This is typically coal that ranges in quality from sub-bituminous to bituminous.
Straight Vegetable Oil (SVO): Vegetable oil fuel. Most diesel engine vehicles can run on it so long as the viscosity of the oil is lowered enough for complete combustion. Failure to do this can damage the engine. SVO is also known as pure plant oil or PPO.
Strategic Petroleum Reserve: An emergency store of oil maintained by some governments and corporations. The U.S. Department of Energy holds 727 million barrels of oil.
Subcritical Power Plant: A coal-fired power plant that operates at less than 550ËšC. Because the temperatures and pressures are than other plants, these plants operate at a low efficiency, around 33-35%. These plants are still the most common in the world and many are under construction
Supercritical Power Plant: Supercritical plants are coal powered power plants that can sustain temperatures of 550ËšC to 590ËšC and transfer up to 40% of the coals energy into power. This technology has only come into use in recent years. Most new coal-fired power plants built in the West are supercritical.
Switchgrass: One of the dominant native species of the North American prairies, tallgrass is being researched as a renewable bioenergy crop. It is a a native perennial warm season grass with the ability to produce moderate to high yields on marginal farmlands.
Thermal Power Plant: A thermal power plant is any that is powered by a steam turbine. The steam is created by heating water which in turn spins the turbine. Most coal and gas power stations operate in this way, as do all nuclear plants. Coal powered and gas plants are often just called thermal plants.
Total Carbon Cost: The amount of carbon dioxide emitted during an action or a process. One exmaple is building a natural gas plant. The total carbon cost would include everything from the carbon emitted to get the materials to build the plant, to the carbon emitted in the building of the plant, and the carbon emitted during the operation of the plant.
Unconventional Gas: Unconventional gas reserves come in many different geological formations, and include tight gas, shale gas, coalbed methane and methane hydrates. Extraction of these sources has only just begun and has hugely extended the lives of many gas fields and unlocking many new ones. The unlocking of unconventional gas reserves in the last five years has revolutionized the global energy system.
Ultracritical Power Plant: These are coal thermal power plants that operate above 590ËšC and can attain efficiencies above 40%. These plants are just coming into service.
Undiscovered Reserves: The amount of oil and gas estimated to exist in unexplored areas. Much of B.C. has not been thoroughly explored for fossil fuel potential and many of the estimates of B.C. fossil fuel resources rely on the concept of undiscovered resources
United States Geological Survey (USGS): The United States Geological Survey. The department responsible for estimating American fossil fuel reserves. They also conduct many studies that span the globe.
Unproven Reserves: Oil reserves in the ground that petroleum geologists are less certain are there, but have strong reason to believe is present. Unproven reserves can be broken down into probable reserves and possible reserves. These numbers are used within oil companies but not usually published.
The portion of the oil business that involves finding oil and extracting it.
Uranium is a heavy metal that is naturally radioactive. An isotope, U-235 can be enriched to support a nuclear chain reaction. Uranium is used in many nuclear power plants.
A 2,730 MW dam built in north-eastern British Columbia along the Peace River during the 1960s.
Any activity where humans bore down into the Earth to access reserves of oil or gas trapped in underground geological formations.
These are produced from wood residue (like sawdust) collected from sawmills and wood product manufacturers. Heat and pressure are used to transform wood residue into pellets without chemical additives, binders or glue. The pellets can be used in stoves and boilers.
A remote mountain in Western Nevada where the U.S. Department of Energy has planned on storing all of the country's spent nuclear fuel underground since the 1990s. The proposal met stiff opposition from local residents and in 2009 the project was cancelled.
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