Generated by heat stored in the earth, geothermal power production involves drilling into permeable pockets of superheated water and steam found deep underground. Thermal energy is stored within the rock and fluid in the earth’s crust.
Some of this geothermal water travels through faults and cracks and reaches the surface of the earth as geysers or hot springs, but most stays below the surface, providing a geothermal reservoir. Once tapped, these reservoirs provide geothermal plants with water hot enough to generate electricity.
Potential Resources?
Geothermal resources are usually found along major plate boundaries where earthquakes and volcanoes are common. Much of the geothermal activity in the world occurs in the Ring of Fire, which encircles the Pacific Ocean.
British Columbia has potential geothermal resources in the coastal mountains and the interior, in northeast British Columbia and in the belt along the Rocky Mountains.
Geothermal Benefits:
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Provides long-term, continuous power generation;
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Relatively unaffected by changing weather conditions and work efficiently in colder temperatures;
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Once developed, geothermal production provides stable, long-term revenues;
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Provides a renewable, low emission energy source because water is replenished by rainfall and the heat is continuously produced inside the earth;
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Offers scalability: a large geothermal plant has the potential to power entire cities while smaller power plants can supply more remote sites;
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Has a comparably smaller environmental impact on the immediate surrounding area than other types of power plants.
Challenges:
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distance of site from grid;
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heat sources are located deep within the earth, making it difficult to tap.
Steam Method
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Geothermal steam goes directly to a turbine which drives a generator to produce electricity;
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The steam eliminates the need to burn fossil fuels to run the turbine, as well as the need to transport and store fuel;
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Geothermal steam only emits excess steam and very small amounts of gases.
Direct Energy
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Direct, high-temperature geothermal energy can be used directly by using the water from within the earth to heat buildings and entire districts through a heat exchanger;
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The famous British Columbia Radium Hotsprings use geothermal directly to heat its pools.
Geo-exchange
- Geo-Exchange systems are commonly known as ground or water source coupled heat pumps;
- Recognized as the most energy efficient means of heating and cooling a building and providing domestic hot water;
- Geo-exchange is an alternative to traditional oil, gas or coal-fired heating, ventilation and air conditioning systems
- Geo-exchange takes advantage of the sun's energy stored in the ground, where the earth's temperature remains consistent throughout the year. In the winter, heat pumps extract heat from the ground or ground water and transfer it into buildings for space or hot water heating. In the summer, the process is reversed, removing heat and cooling the building;
- Geo-exchange uses less electricity than conventional systems and has greater efficiency than most gas and oil furnaces.
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