September 01, 2008
Cool runnings: A geothermal primer
Geothermal technology takes the heat off wallets and energy providers
It is cool to be kind to the environment and it is cool to own your own home, but did you know that cool is really just the absence of heat?
With the popularity of geothermal energy taking off as awareness of our environmental impact rises, condo buyers have the eco option to not only appear cool, but also to live in the definition of cool. In a nutshell, geothermal technology basically draws heat from the homes it serves to heat and stores it in the ground to be used later.
“We are essentially using the same technology as what is used in your refrigeration,” says Larry Peters of REACT Energy in Calgary. Refrigerators remove the heat from the air inside of the box and dispose of it through coils located at the back of the fridge. “We are doing the same thing except on a massive scale,” Peters explains.
Geothermal heating takes the heat out of a home in the summer and transfers it into an antifreeze-like fluid that is circulated in pipes located in the ground. Because the ground is cooler than the fluid, the heat is sucked out of the fluid and stored in the surrounding dirt and rocks. In some cases the pipes are run in a horizontal trench or they can be inserted into deep boreholes dug in the earth.
Geothermal systems get rid of the heat in the summer to create air-conditioning, Peters explains. Conversely, when things cool down and the thermostats get turned back on for heating, the cycle changes direction and heat energy from the earth is sent back to the condo building. A heat exchanger transfers the warmth to a heating distribution system, such as the ducting in your home and this heat is then circulated within the building.
But geothermal technology isn’t new. REACT Energy has been in business since 1999 and Peters acknowledges the business of geothermal hasn’t changed much over the years—but instead, it is the interest in the medium that has taken off.
“In 1999 we practically had to buy our way into appointments to get people to hear what we had to say,” he says. “Now it is the opposite.”
People are now talking about the environment and individuals are looking at how to reduce their carbon imprint, he explains. “There has been a huge shift in the market awareness and education level and people’s desire for the technology.”
In fact, business is booming. Peters said the company is expecting a 320 per cent growth in sales this year. REACT is currently working on a geothermal system for a car dealership in Okotoks and has a condo project slated to start later this summer in Osoyoos, B.C.
Here in Calgary, REACT could be working on the biggest geothermal project in the city if a proposed system goes ahead in the northwest neighbourhood Sage Hill Crossing. The development is a proposed 120-acre mixed-use development that is currently before the City for approval. The overall area of Sage Hill Crossing is expected to include 7.5 million square-feet of commercial, residential and multi-family units.
A feasibility study was wrapped up in April, at which time REACT recommended environmental measures for the site including a geothermal heating system for the recreation centre. So far no decisions have been made on what from the study will be implemented, and until the developer has permits and approvals from the city it is unknown if geothermal will be heating and cooling system of choice, Peters says.
The difference between geothermal heat and other heating systems is an absence of waste. In typical heating scenarios waste heat from the inefficiencies of fossil fuel-burning devices simply escapes up the chimney. But geothermal technology is unique in its ability to capture the heat to use for another day when it’s needed.
At Resiance Corporation they are not letting the heat escape at the Gateway South Centre condo project in Lake Bonavista. According to Barry Chow, executive vice-president of Resiance, using a geothermal system in an apartment-style condominium is just the icing on the environmental cake. “A single-family home is just a heat generating cube,” Chow says. “And that heat just radiates into space.”
A condo is the perfect fit for the technology as neighbours already share heat through the walls and floor, says Chow. “From a fossil fuel standpoint it is always more efficient to live in a multi-family building.”
At Gateway South Centre residents don’t only share heat, they also share heat rarely produced using fossil fuels. Five hundred boreholes that run 300 feet deep are the catalyst for heat to be exchanged into the ground until it is needed again. Occasionally natural gas is needed to run the condo’s boiler system, but the majority of the building’s heat is garnered through the geothermal system and solar panels on the roof.
“We knew supplemental heat would be needed because we are a generally cold climate,” Chow says. “We went the extra mile and put in solar panels.”
The geothermal system also heats the water for residential use in Gateway South Centre.
Cutting down dramatically the amount of natural gas used to heat water and space is a boon to both the environment and the pocketbook, Chow says, adding, “The real contribution of this system is every year those units save three-quarters of a tonne of carbon dioxide emissions.”
Taking into account the project’s 500 units, this adds up to 375 tonnes of carbon dioxide emissions Calgarians are no longer breathing in every year.
What’s more, with the costs of fossil fuels growing to new heights, those living at Gateway South Centre are putting back some of their green back into their wallets by avoiding high utility costs. Buyers saw the value in the project from the beginning, apparent in the fact that Gateway South Centre sold out last year, and is now almost fully occupied.
As the project nears completion, Chow is confident the company’s taking a chance on geothermal has paid off. “When we started reducing carbon emissions was not as big a priority as it is now. We were pioneers in reducing emissions. I am very proud of this project.”