What is Geothermal?
The Heat Beneath Our Feet
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Geothermal reservoirs are formed when hot brine (fluid) is trapped underground in permeable and porous rocks under a layer of impermeable rock
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Rain and groundwater can seep down faults and fractured rocks for kilometres and heat up at depth
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This hot or warm fluid can flow to the surface as steam or hot brine (fluid) through hydrostatic pressure
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Many geothermal areas have visible surface manifestations of the underground heat source, such as hot springs, fumaroles, and geysers
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The geothermal fluid can also be pumped to the surface with a geothermal well
Types of Geothermal Sources
Moderate-High Temperatures
P O W E R G E N
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High temperatures (over 150°C) are suitable for power generation
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Includes plate subduction zones (“Ring of Fire”), rift zones (East African Rift), and extensional environments such as mid-oceanic ridges (Iceland)
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Mature technology - over 100 years old
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Considered conventional geothermal
Low-Moderate Temperatures
D I R E C T U S E
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Moderate temperatures (90°C to 150°C) are suitable for power generation and/or direct heat use
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Can be shallow or deep
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Can be used for direct-use applications in a cascading system or stand-alone
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Can produce power through Organic Rankine Cycle (ORC) technology
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Considered conventional geothermal
Low Temperatures
G E O E X C H A N G E
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Low temperatures can be used for space conditioning (heating and cooling) and hot water
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Shallow, low-temperature source (the ground, lakes, etc.)
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Geoexchange systems relies on seasonal temperature differentials, treating the Earth as a thermal battery
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Should not be confused with conventional geothermal
Types of Geothermal Power Generation
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Dry Steam Power Plants: steam directly creates power
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Flash Steam Power Plants: hot brine (fluid) flashes to steam as pressure decreases
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Binary Power Plants: transfers heat from geothermal fluid to a working fluid with lower boiling point to produce vapour
Alberta No. 1 is a binary power plant.
How Geothermal Energy Works

Hot brine (fluid) can be pumped to the surface to create electricity and/or supply heat.
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If the brine is hot enough for the intended purpose, large diameter production wells will be drilled, along with adjacent injection wells.
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After the wells and facility infrastructure are established, brine heated by the Earth's thermal energy is pumped to the surface
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Thermal energy is extracted from the brine for useful work through an Organic Rankine Cycle (ORC) system.