High-temperature hydrothermal energy has been used for electric power generation since 1909, and is presently used in over 20 countries around the world.
Power generation requires a high-temperature geothermal resource, in the form of steam or hot water reservoirs with temperatures higher than 170 C. These types of geothermal resource are generally limited to recent volcanic terranes, such as those found near tectonic plate boundaries (west coast of North America, Iceland, New Zealand, Japan). Energy, in form of steam from high temperature geothermal reservoirs situated close to the surface (500m - 2,000m), is transformed into electricity by steam-driven turbines - similar to oil and gas generated power.
Although Canada does not currently have an operating geothermal energy power plant, there have been extensive studies at Mount Meager, along the Lillooet River, north of Whistler, B.C.. The BC Ministry of Energy and Mines map (see links) shows areas around BC that have varying degrees of geothermal energy potential. Low hydro-electric power and fossil fuel prices have reduced the economic incentive to develop the resource; however, there has been recent renewed interest in the Mount Meager Area.
- There are currently 9600 MW of geothermal energy produced globally
- Geothermal is commercially viable in 24 countries around the world
- US geothermal plants along the West coast produce 2800 MW of electricity
- The Philippines is the second largest producer of geothermal energy worldwide, with 1900 MW. According to the Philippine Department of Energy, an additional eight geothermal power plants will come on line by 2010, with a further 621 MW of capacity.
Whats Happening in BC?
British Columbia has better prospects for geothermal development than any other province in Canada. The many hot springs found around the province mark some of the geothermal deposits. Most have been used only for local or recreational purposes. Meager Creek, near Pemberton, has substantial amounts of hot water below ground, and may offer prospects for geothermal electrical power. Mount Cayley and Mount Garibaldi have also been explored.
In March 2004, the BC government started accepting bids from geothermal energy companies that want to develop the resource potential in the Meager Creek and Kinbasket Lake (near Valemount, BC) areas. Western GeoPower Corp. has as its mission statement: "To develop the Meager Creek Project as Canadas first commercial geothermal generating facility for electricity", so geothermal energy may soon become part of BCs commercial electricity portfolio.
In June 2004, the BC government granted drilling permits for two deep production wells to confirm the commercial viability. South Meager has been classified as a "high temperature" geothermal field with maximum temperatures to date up to 275 deg C . The site has a potential development capacity of 200 MW.
What Does it Cost?
Geothermal energy is considered to be one of the cheapest forms of large-scale grid-tied energy. The levelized cost of geothermal energy ranges from 3.3-3.9 US cents per kWh, compared to 5.0-6.4 US cents for wind energy and 7.3-8.7 US cents for biomass (US Department of Energy, Office of Utility Technologies). "Levelised cost" means the average cost of power production over the life of a power plant, taking into account all capital expenses and operating and maintenance costs, plus fuel costs for power plants that rely on external fuel sources.
For the Meager Creek Geothermal Project in B.C., the estimated long-run marginal cost of geothermal energy is 5.9 CDN cents per kWh, compared to BC Hydros current long-run marginal cost of 5.5 CDN cents.
Advances in technology have reduced geothermal electricity generation costs by over 25% in recent years. Generation costs are expected to drop a further 20% between 2000 and 2020, while operation and maintenance costs are expected to drop by 30% by 2020. (Western GeoPower Corp, 2003)
Geothermal energy production can have more or less environmental impact, depending on the siting of the generation facilities (the area of land required and amount of noise generated in construction and operation) and the extent to which water resources are re-circulated into the hot water reservoirs to prevent the land subsidence resulting from a decrease in reservoir pressure.
Geothermal fluids contain dissolved gases, mainly carbon dioxide (CO2) and hydrogen sulfide (H2S), small amounts of ammonia, hydrogen, nitrogen, methane and radon, and minor quantities of volatile species of boron, arsenic, and mercury. Geothermal power provides a significant environmental advantage over fossil fuel power sources in terms of air emissions because its production releases no nitrogen oxides (NOx) or sulfur dioxide (SO2), and much less CO2 than fossil-fuelled power. The reduction in nitrogen and sulfur emissions reduces acid rain, and the reduction in CO2 emissions reduces the contribution to global climate change. CO2 emissions can vary from plant to plant, depending on the characteristics of the reservoir fluid and the type of power plant. A typical 100 MW plant will reduce CO2 emissions by 600,000 tonnes/yr, and NOx and SO2 emissions by 120,000 tonnes/yr compared to a natural gas plant of equal size. (Western GeoPower Corp, 2003)
Geothermal plants are very efficient, operating at 95-98% availability on a consistent basis. Thus, geothermal power has a tremendous advantage over most other renewable resources, in that it produces "base load" electricity. Utility-scale geothermal power production employs three main technologies: dry steam, flash steam and binary cycle systems. The technology employed depends on the temperature and pressure of the geothermal reservoir. Unlike solar, wind, and hydro power, a geothermal power plant can operate independently of fluctuations in daily and seasonal weather.
Social, Economic & Political Matters
Geothermal energys three main advantages are its low price, its consistent supply, and the fact that it is a clean, renewable source of energy. Unlike natural gas, which will cost more in the future as supplies run short, geothermal energy will cost less in the future as industry efficiency increases. Price stability is very important for industry, so the more that geothermal and other sustainable energies can replace natural gas in the BC grid, the more stable the long term price becomes.
These are some policies which will promote the use of geothermal energy in BC:
- Placing an environmental tax on fossil fuels such as coal and natural gas, to account for the harm done by CO2 emissions, and local air pollution.
- Providing geothermal energy producers with a guaranteed price of 7 cents/kWh for the first 5,000 MW of geothermal energy until 2015.
Can I Do It at Home?
No. This section focuses on grid-tied geothermal generation. For a homeowner-friendly type of geothermal energy, see Groundsource Heat.
- BC Ministry of Energy and Mines Geothermal Rights
- Canadian Geothermal Association
- Geothermal Energy Association
- Geothermal Resources Council
- International Geothermal Association
- Renewable Energy Policy Project
- Renewable Northwest Project
- BC Hydro Gr.8-12 Geothermal Energy Module
- Western Geopower Corp. presentation on Meager Cr. Geothermal Project
Compiled by Jamie Cowan, for the BC Sustainable Energy Association, 2005.