Geothermal heat pumps are one of the cheapest and most reliable ways to heat and cool most buildings. Also known as geoexchange, earth energy, or ground source heat pumps, geothermal heat pumps should not be confused with geothermal energy, which is harvested by large power plants to generate electricity.
The upper three metres of the Earth's surface remains a nearly constant temperature of between 10 and 16°C. In winter, geothermal heat pumps draw this heat energy from the earth, using a series of underground pipes, and transfer it to buildings, warming them. In summer, the heat pumps work in reverse, taking excess heat from inside and discharging it into the cooler earth. Because the earth itself supplies the renewable thermal energy, the only requirement is a small amount of electricity to run the pump. As a result, the systems run with almost no pollution or greenhouse gas emissions.
According to Manitoba Hydro, installing 1,000 geothermal heat pumps in homes generates $15 million in construction-related activity. The energy savings achieved by installing a geothermal heat pump are considerable. Annual heating costs in Manitoba average $400, markedly lower compared to $1,000 for electric furnace or electric baseboards, $1,250 for a gas furnace or $1,600 for a conventional oil furnace.
The David Suzuki Foundation's head office in Vancouver is located in a building that is heated and cooled by geothermal heat pumps, reducing energy use and greenhouse gases, and also saving the Foundation money.