Solutions > Home construction > Alternative energy
Geothermal
Geothermal systems have been generating plenty of buzz in Manitoba in recent years for their ability to provide reliable, environmentally friendly heating and cooling for homes. And they do this while using a readily available resource – energy from the earth below us.
Manitoba has become a national leader in geothermal technology with more than a quarter of all installations in Canada happening in Manitoba. (1)
A geothermal heat pump is often more expensive to install than other heating and cooling systems. To help pay for the installation of a geothermal system, Manitoba Hydro offers Residential Earth Power Loans.
Geothermal systems are also known as earth energy systems. Very simply, the temperature in the ground below the frost line is fairly constant – cooler than outside air in summer and warmer in winter. Geothermal systems draw this heat or cold from the earth using a series of pipes placed underground. In winter, geothermal systems distribute the heat through the house, while in summer they work in reverse, circulating cooler air from the earth through the house, and returning the heat to the ground. They may also provide water heating.
Geothermal systems have three components:
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Ground Loop
The ground loop extracts the energy from the earth. The loop may either be closed or open. A closed loop circulates a fluid mixture through the underground pipes. An open loop circulates well or surface water. The loops may be laid horizontally or vertically. They may even be installed at the bottom of lakes or ponds.
Horizontal loops require more space, while a vertical loop system is more appropriate for smaller city lots. For instance, four boreholes drilled into an area of 96 sq ft may be sufficient for a 1600 sq ft house. (2)
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Heat Pump
Inside the house, the heat pump transfers heat between the distribution system and the ground or ground-water loops.
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Distribution System
The air is then distributed through the house’s ductwork (in a forced air system) or via a hydronic (hot water space heating system) system.
Using geothermal heating and cooling could reduce annual heating costs by 50-70 percent.
- The average single family residence would see heating costs of approximately $449/year with geothermal, compared to $991/year for a high efficiency gas furnace or $1455 for a conventional gas furnace. (3)
- Other than the electricity to power the system, it requires no other energy source.
- For the average house this could mean a five tonne per year cut in greenhouse gas emissions. (4)
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New Home
Installing a geothermal system in a new home makes more sense than retrofitting it later.
- The installation cost could become part of the overall financing for the house.
- The savings on the heating bills would start immediately.
- Access to the lot should be easier, with fewer concerns about harming landscaping, while other requirements (electrical service etc) could be built in immediately with less fuss.
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Existing Home
There are a number of challenges to installing a geothermal system in an existing home.
- Access to the site with heavy equipment needed for digging may be difficult or impossible, although some contractors do specialize in small lot installation with minimal disturbance to the yard.
- Your home’s electrical service may need to be upgraded, especially if you’re replacing a fossil fuel furnace.
- Because more air needs to be moved through the house, ductwork may also need to be upgraded.
- Landscaping will be disturbed, and it will take time for the earth to settle.
- Existing heating and cooling equipment will need to be removed carefully and services cancelled. (5)
Manitoba Hydro suggests installing a geothermal system in an existing home may only be economically feasible if the current heating system is at or near its end.
