EARTH ENERGY TECHNOLOGY

There are two types of energy that can be obtained from the earth: earth energy and geothermal energy. Geothermal energy uses steam or hot water in the earth's crust to power turbines or to heat buildings or water. It is used in locations where there is volcanic activity or hot springs near the earth's crust (Iceland, Philippines, Italy, Indonesia, Mexico, New Zealand, Japan and China). Earth energy uses temperatures found in the earth or underground water to cool or heat air and water for buildings.

A conventional way to tap earth energy is by using heat pumps. Also called ground-source heat pumps, they take advantage of the constant year-round temperature of the earth. Either air or an antifreeze liquid is pumped through underground pipes then recirculated into the building. The liquid or air moves heat from the ground to the building, providing pre-warmed air to the building's heating system.

Major drawbacks to using earth energy in the backcountry are the difficulty in bringing in drilling equipment and the shallow soil cover at elevation.

Precedent

Drake Landing Solar Community, Okotoks, AB

Best Practices Report

Natural Resources Canada

There are more than 30,000 earth energy installations in Canada that are used for residential, commercial, institutional and industrial applications. Earth energy is used widely in northern Europe, especially in the Scandinavian countries, which have adopted the technology quickly. Earth energy is becoming more common in the southern United States where it's used to cool buildings.

A 30°C fluctuation between day and night is reduced to a fluctuation of less than 1°C at a depth of 57 centimetres below the surface. Likewise, a fluctuation throughout the year of 30°C is reduced to 1°C at a depth of 11 metres. In the Bow Valley at an elevation of 1480 metres, the subsurface temperature is 4.5°C throughout the year, close to the mean annual surface temperature. In Canada, earth energy is used as a pre-heat source in winter: it takes less energy to heat air at 4.5°C to room temperature than to heat outside air that is at -20°C.