This piece is an adaptation from an article written by Emily Chung on June 22, 2023, as part of What on Earth’s, CBC News initiative entitled "Our Changing Planet".
Heating and cooling your home with a ground-source heat pump is climate-friendly and very efficient. But it can require expensive digging or drilling. Waterfront home or cottage owners have a cheaper shortcut: pond or lake geothermal (or geoexchange) heating and cooling. (Submitted by John Wypich)
John Wypich of Port Severn, Ont., has heated his home with a lake geothermal system for 29 years.
"There are many cottages along lake shores that can make use of these simple sources of heat," Wypich says.
Wypich lives in a waterfront home on a peninsula that juts into a lake called Gloucester Pool — one of hundreds of lakes splashed across Ontario's Muskoka region. When he first moved in 50 years ago, his home was heated with oil. But when the oil tanks leaked, he started looking for alternatives.
The area didn't have natural gas access; some of his neighbours heated their homes with propane.
"But I wanted to have an environmentally friendly device," Wypich recalled.
His research turned up geothermal (or geoexchange) heating, which uses an electrically powered heat pump to move heat into a home in the winter and out in the summer.
Normally, heat is exchanged with the ground far below the surface, which has a relatively constant temperature throughout the year — even when air temperatures are very cold. That's why it's very efficient.
However, digging or drilling to lay the underground heating loop (a closed loop of pipe or tubing containing the liquid that transfers the heat) can be expensive or impractical for many homeowners.
But waterfront properties have another option: the loop can simply be sunk to the bottom of a nearby lake or pond — no digging required — as long as it's deep enough so it won't freeze in winter.
So Wypich hired a local contractor to do just that.
"It was straightforward," he said. The system also has an electric backup heater.
(Submitted by John Wypich)
Jeff Hunter, founder of Evolved Thermal Energy and president of the Ontario Geothermal Association, said the water typically needs to be at least three metres deep. In Wypich's case, the heating loop is about six metres down.
Hunter estimated that where the pond or lake option is available, it can be as little as a quarter of the cost of a vertical ground loop (which requires deep drilling) and 60 to 80 per cent of the cost of a horizontal ground loop (which requires a lot of land).
In some cases, there may be a permit required — typically, similar to one required to modify the shoreline for a dock, Hunter said. But "overall, it's generally accepted."
He noted that the heating loop is closed, and no water is taken from the lake. Wypich doesn't recall requiring a permit.
He did experience a glitch about 15 years ago when the system started leaking. He suspects someone may have dropped an anchor that punctured the heating loop, and it had to be replaced.
But generally, over 30 years, he said, "we've had good service from it."
Hunter said more people should look into the option of lake or pond geothermal.
"I would say absolutely investigate that first if you have ready access to a water source."