How a shared geothermal loop serves a neighbourhood
A community geothermal district system connects many buildings to a shared source of ground heat, usually a field of boreholes and a pipe network that distributes low-temperature fluid to heat pumps in each building. It spreads the cost of drilling and operation across users, but it needs an owner, a metering plan and a regulatory route.
What is a community geothermal district system?
In a normal ground-source installation, each house has its own loop. In a community system, a central borehole field or other ground source is connected by a shared pipe network. Two designs are common. In one, the pipes carry fluid near ground temperature and each building has its own heat pump that lifts that heat to a usable level. In the other, a central plant raises the temperature and sends hotter water to the buildings, as in a classic district heating network.
The first type is often called an ambient or shared loop. It lets some buildings heat while others cool, with heat moving between them through the loop. For the wider concept of district systems, see district heating in Canada.
How is it different from individual geothermal loops?
Shared systems trade independence for scale. A single large borehole field can be designed once, drilled efficiently and maintained by professionals instead of by each owner. Buildings with different loads can balance each other, because a home needing heat in January can draw from fluid warmed by a building that is cooling. Costs and risks that fall on one homeowner in a single-house system become collective ones.
The compromises are real. Everyone depends on one owner and one plant, so governance matters. Fair billing needs meters. A system that grows in stages needs a loop designed for expansion. See district energy versus individual heating for a broader comparison, and ground loop types for the building blocks.
What did Drake Landing show about shared ground systems?
Drake Landing Solar Community in Okotoks, Alberta, is a close cousin. It served 52 homes through a district loop supplied from an Energy Centre. The heat came from solar collectors on the garages, and the surplus of summer was stored in 144 boreholes about 35 m deep. Monitoring reported that solar supplied 97% of space heating by 2012 and 100% in the 2015-16 heating season.
It differed from an ambient loop in one important way: the district loop typically ran at 40 to 50 C, hotter than shared ground loops, and the borehole field was charged with heat rather than only drawing it. Read the district heating page and the borehole storage page for the details. The guide on borehole thermal energy storage explains why storing heat in the ground differs from just drawing it. The project also wound down from about 2020 and decommissioning began in 2024, which is a useful reminder that long-lived infrastructure needs a long-term owner.
Who owns and operates a community system?
Models vary. A municipality, a utility, a non-profit, a developer or a cooperative could own the loop. Each has different access to financing and different regulatory obligations. In some provinces, thermal energy services sold to customers may fall under utility regulation, and the rules differ, so ask the provincial energy regulator and your municipality. Agreements need to cover who pays for repairs, how heat is metered and billed, what happens if the owner exits, and what service customers can expect.
Ask also about long-term operating arrangements, since a shared field is only as good as its maintenance. The lesson from whether Drake Landing could be replicated today is that technical performance and ownership planning both have to hold up for decades.
What should a community check before starting?
- Heat demand. Density and building type decide whether a network is worthwhile; low-density rural homes may suit individual loops better.
- Ground conditions. Drilling tests and thermal response tests tell you what the ground can do.
- Land and rights. Where the borehole field goes, and who has access, must be settled early.
- Business model. Capital cost, rates, and who carries risk.
- Incentives. Funding for community energy projects changes; check the Government of Canada energy pages and your province.
For another take on shared solar-assisted energy, compare community solar heating and rooftop solar.
Quick answers
What is a shared geothermal loop?
It is a network of buried pipes connecting several buildings to a common ground source. Each building typically has a heat pump that draws from or returns heat to the loop.
Is community geothermal the same as district heating?
It is a form of it. Some community systems send hot water from a central plant, while others circulate near-ground-temperature fluid to heat pumps in each building.
Who pays for a community geothermal system?
That depends on the ownership model. Costs may be covered by a utility, municipality, developer or cooperative and recovered through connection fees and heat charges.
Did Drake Landing use a geothermal heat pump?
Not as its main source. It stored solar heat in a borehole field and distributed it through a district loop. The ground acted as a heat store.