06. Geothermal 101
Blog: Geothermal: Learn how a reverse refrigerator heats over 100,000 buildings in Canada
Of all of the sources of green energy, geothermal is probably the least sexy. Solar panels glint in the sunshine and wind turbines spin majestically but there are few evocative descriptors for the humble ground source heat pump.
Once it’s installed there is little visible evidence of its presence in the home except for a few pipes coming out of the basement floor into a furnace-like appliance.
Yet what it lacks in sex appeal it more than makes up for in effectiveness. With over 100,000 ground source heat pumps installed in Canada it’s a proven way to heat and cool homes and buildings.
Geothermal energy is the classic example of an energy supply that is out of sight, out of mind. When student Preetpau Atwal started taking the Alternative Energy Program at NAIT she found that studying geothermal was the most interesting part of her studies.
“It just blew my mind how effective it is – you take energy just sitting there in the ground and you can use it for cooling and heating – it amazes my mind,” says Atwal.
Energy is more than just electricity. Heating a typical single family home in Canada takes up 60 per cent of that family’s total energy consumption. We prefer an ambient temperature of around 20 degrees Celsius. The inside of a natural gas-fired furnace reaches 1,200 degrees Celsius, a ground source heat pump reaches 65 degrees. Which one sounds like the safer, more human scale heating solution?
How six degrees becomes 65 degrees
If you’ve ever dug an outhouse or a foundation you’re probably familiar with the concept of the frost line. Below the frost line the ground doesn’t freeze. If it doesn’t freeze, then by definition, there is heat there.
In fact 46 per cent of the energy that comes from the giant power plant in the sky is stored as heat in the top 150 metres of the Earth as geothermal energy. So from two meters down to 150 meters you have stored, latent energy just waiting to be tapped by an enterprising home or building owner.
So if the heat is there how do we access it?
The answer is a ground source heat pump. A heat pump isn’t exactly the most exotic piece of technology. Everybody already has a heat pump in their home – your fridge. More…
Podcast: How to free yourself from your natural gas bill
The inside of a natural gas furnace is around 1200 degrees Celsius. The inside of a geothermal heating system? 65 degrees celsius. The preferred interior temperature for humans? 21 degrees Celsius.
Both geothermal and nautral gas heat your house but only a geothermal heating system means a lifetime free from riders, fees and bills from your natural gas retailer. Geothermal heating uses electricity to pump heat out of the ground.
Podcast: Geothermal Heating: An underground act about to hit the top of the charts
Geothermal heating isn't as complex as you would think. You drill some holes, sink some pipe and circulate water through the ground below the frost line which is a constant six degrees Celsius. That water goes through a ground source heat pump which is really just a larger, fancier version of the heat pump in your fridge.
It strips three degrees off of that water, compresses it, raises the temperature to 65 degrees celsius and provides hot water and space heating like a regular furnace.
These resources relate to this episode. They may be helpful in many ways, but we list them only for your information. This is not an endorsement of any of these programs, services or organizations and we make no guarantees about the products or services these companies or organizations may offer.
A Buyer's Guide for Residential Ground Source Heat Pump Systems
This buyer's guide exists to help readers with the decision to purchase and install a ground source heat pump (or geoexchange) system. This document is not meant to be a “do-it-yourself” guide.
Prospective buyers should seek out qualified advice and assistance to supplement the information provided here. The Canadian GeoExchange Coalition, as part of its market transformation initiative, has trained and accredited thousands of industry professionals since early 2007 and a list of qualified companies is available on its website. GO >
Comparative analysis of greenhouse gas emissions of various residential heating systems in the Canadian provinces
Curious to see how geothermal heating stacks up against natural gas? Learn it in this report GO >
The state of the Canadian geothermal heat pump industry
A report from the Canadian GeoExchange Coalition as it gives an honest accounting of the latest news in this space GO >
Geothermal Payback Calculator
Estimate the profitabliity of your yet-to-be installed geothermal system with this handy calculator GO >
Find an accredited geothermal installer
Search an accredited professional or qualified company at the official Canadian GeoExchange Coalition website GO >
Animated explanation of geothermal heating and cooling - Youtube
Video of a ground source heat pump borehole installation - Youtube
Time lapse video of a geothermal borehole being drilled - Youtube
While not discussed in this episode, deep geothermal as a possible source of energy in Canada was written about very eloquently by Melissa Shin - Corporate Knights
The Canadian GeoExchange Coalition's official website - CGEC