Cumberland, British Columbia plans heat from an old coal mine

Local authority buildings rarely arrive with an underground heat source already in place. A civic centre is normally built where the ground is level and the planning rules make it possible.

In Cumberland, British Columbia, that ordinary process left the village office, council chambers and recreation centre sitting directly above the former No. 6 coal mine.

For roughly 60 years the main workings have been slowly flooding - and the water down there stays at much the same temperature in every season. The village now intends to put that consistency to work.

Heat from an old coal mine

Cumberland is underpinned by close to 80 years of coal extraction. Between 1888 and the late 1960s, around 17.5 million tonnes of high-grade coal were taken from the area and shipped abroad to power steamships and feed smelters.

Once the pits shut, jobs vanished and the tunnels began to fill with water that had no clear purpose. That is changing.

The village is working with researchers at the University of Victoria (UVic) on a proposal to draw usable energy from the abandoned mine system.

Zachary Gould, a community energy planner with UVic’s Accelerating Community Energy Transformation initiative and the Cumberland project lead, says the idea is to treat the impounded water as the asset - not any remaining coal.

How it works

The mine water held in Cumberland’s underground passages sits within a tight temperature band all year: cooler than the surface in summer and warmer in winter. Heat pumps capture that difference - supplying warmth to buildings in cold months or rejecting heat to provide cooling in warmer weather.

Cooling in July, heating in January, and an expected near-zero carbon output. Engineers characterise it as a large ground-source heat exchanger - except that, in Cumberland’s case, the “excavation” was effectively done decades ago.

Similar, smaller-scale systems have been used for decades across several communities in Atlantic Canada to heat homes, commercial premises and community colleges.

Mayor’s pitch for coal mine heat

Cumberland is a small community - roughly 4,800 residents - and it does not have an in-house engineering team. The project gathered momentum after Mayor Vickey Brown watched an online webinar hosted by the Accelerating Community Energy Transformation initiative.

Brown was already thinking along these lines. Two municipal blocks above the No. 6 coal mine were earmarked for redevelopment, and she had been asking whether the workings below could supply heat to whatever is constructed on the surface.

Her priorities include affordable housing as well as industrial space. Brown is particularly keen on tenants such as greenhouses or food processors - operations that benefit when heat is both inexpensive and reliable.

Mapping the labyrinth

The push did not begin inside a council office. It grew out of regular meet-ups among local geologists, who share observations about what still emerges from the old mine openings.

Cory MacNeill, a geologist based in Cumberland, remembers the group comparing notes about methane that continues to seep from historic workings. From there, the conversation shifted to what other value the shafts might still hold.

“It’s about reimagining these old resources and relics of industry,” said MacNeill. Rather than focusing only on what was removed, the question became what the mine system might now return.

To establish what was actually underground, the team worked with the Victoria-based Cascade Institute to map the mine network, tracing the extensive, multi-layered maze that runs beneath much of the village.

Lessons from elsewhere

Cumberland is not attempting this without precedents. In Springhill, Nova Scotia, geothermal energy from a flooded coal mine has heated businesses and a community college since the 1980s, with mine water sitting at about 18°C (roughly 64°F).

In Heerlen in the Netherlands, the same concept was developed into a district-scale network, turning an abandoned coal mine into a town-wide system that heats and cools hundreds of buildings. A recent scientific paper sets out how that system has expanded.

Emily Smejkal, a research fellow at the Cascade Institute who specialises in geothermal energy, has been closely involved with the Cumberland work. Because the coal mine workings extend under most of the village, she says the same heat source could, in time, be shared across the community.

Heat from coal mine ruins

The story beneath this plan is not a neat one. For generations, Cumberland’s mines underwrote the local economy, but the labour was hazardous. People died young. Companies profited from a fuel burned in ways we now recognise as contributing to climate change.

Dawn Copeman, a historian with the Cumberland Museum and Archives, says producing clean energy from those same shafts does not erase the past - it makes use of it.

In 2011, a proposal for a new coal mine in the area prompted strong opposition. A plan to extract warmth from abandoned workings has been received in a markedly different way.

Before the pilot

The emissions numbers being discussed - including a projected 90% reduction in heating emissions for the civic precinct - are based on early-stage computer modelling rather than an installed, operating system.

The pilot has not yet been built. Real-world results will depend on how the underground mine responds once pumping starts, along with water quality and how the costs of required infrastructure play out.

What changes now

If the system performs as the modelling suggests, linking the civic precinct alone could avoid burning the equivalent of about 13,600 kg of coal (around 30,000 pounds) each year.

Brown would like to expand the network to an industrial area near Comox Lake, where heat-hungry firms could support new local employment and strengthen the tax base.

Until this work began, Cumberland’s mine network was chiefly recorded as a risk - methane requiring venting and the potential for subsidence. The proposal reframes it as usable infrastructure: a thermal asset created by one century and put to work by the next.

Other former coal communities, each with their own flooded underground labyrinths, are paying close attention.

Information from a press release in UVic News.