Can the use of geothermal energy thin the lake ice? Is there an environmentally friendly, cost-effective way to heat and cool a cottage with lake water?
Taking the energy stored in your lake and transferring it to your cottage will not harm the water or make any significant difference to ice thickness. You’d have to try something strange—like, say, heating a huge, leaky castle with energy from your swimming pool—to have any real impact on water temperature.
There are two types of geothermal water pump systems. In an open-loop system, pipes below the surface pull water out of the lake and the warmth from the water is used to heat the cottage. The water is then discharged back into the lake. In a closed-loop system, fluid circulating through underwater pipes absorbs the water’s heat but no water is actually removed from the lake.
There are currently many loop systems—open and closed—operating in cottage country without problems, and preliminary studies show they have a negligible impact on the lakes. Plus, there’s an enviro benefit: They don’t burn fossil fuels for heat, and they don’t release any pollutants.
There are cost advantages too, although the systems are not cost-effective for every cottager. Installation is expensive and factors such as the size of your cottage and how often you use it will dictate whether tapping the lake’s energy actually saves you money. Hire a CGC-accredited professional to install your system and get three quotations before you go ahead.