This article was published by The Energy Mix on April 10, 2024.
By Gaye Taylor
The future of North America’s first solar heating community in Okotoks, Alberta, remains in question as its directors grapple with aging technology and cost concerns, pledging full transparency with concerned homeowners.
Launched in 2007, the Drake Landing Solar Community (DLSC), a 52-unit planned community about a 30-minute drive from Calgary, proved to be a knockout technical success. It showcased a large-scale seasonal solar+storage system that supplied over 90 per cent of the community’s space heating requirements, wrote CBC News in March. The low-emissions pilot project represented “the future of sustainable residential heating systems,” winning several building, environment, and sustainability awards—important for its mandate as a feasibility test for heating homes through a northern hemisphere winter.
“But now, the system is starting to fail, and it could be decommissioned,” CBC writes. “It’s one outcome the community faces.”
As a result, Drake Landing may have to switch to natural gas heating —but that should not be seen as a failure, Tim Corboy, a spokesperson for Drake Landing Company, which runs the community, told CBC.
“It’s important to note that we do not see this project as a failure at all,” he said. “At the time, this system was revolutionary and caught attention from around the world.”
And “much has been learned because of this community.”
But those words are cold comfort to resident Ryan Johnson, who bought one of the homes because of the project’s famed status as North America’s first-ever solar residential community.
“I think it’s ridiculous, honestly,” Johnson told Okotoks news outlet the Western Wheel.
“We bought this place because it’s solar-heated, and the fact that they just want to walk away from it, and what, we’re going to go back to natural gas?” he asked. “There’s no incentive for people to continue to live in these houses then.”
A Technological Triumph
Until recently, residents of Drake Landing stayed toasty during 17+ years of Alberta winter using little more than the warmth of the summer sun, thanks to high fraction borehole thermal energy storage (BTES), a technology that stores solar energy in the ground until it’s needed. The process begins by collecting 1.5 megawatts per day of thermal power from the community’s 800 solar thermal panels, mounted on garages. Those megawatts power heat a glycol solution running through an insulated loop of piping, which connects to a heat exchanger and short-term storage water tanks at the local energy centre.
In summer months, the heated water in the short-term storage tanks is distributed underground beneath the energy centre through pipes inside 144 boreholes. Hot water travels down through the pipework, heating the surrounding earth to 80°C by the end of each summer.
Come winter, the heat stored in the BTES is circulated to the 52 homes via a district heating loop system linked to individual stand-alone solar hot water heaters. Each home also came equipped with a backup gas furnace.
The success of Drake Landing also owes to building design. The 1,500- to 1,700-square-foot homes feature higher than typical insulation values, an airtight building envelope, and energy efficient windows.
Just five years after the project was switched on, its promise was being fully realized, project designer Doug McClenahan, a former research program manager for thermal heat and power at Natural Resources Canada (NRCan), told Green Building at the time.
“It’s designed to provide an average of approximately 92 per cent of the heat demand from solar,” he explained. “It takes a number of years to build up to that steady state performance— so now that we’re in year five, we’re just approaching that right now.” By 2015, the DLSC would more than exceed its target, covering 100 per cent of heating demand that winter, NRCan said in an emailed statement to The Energy Mix.
An Aging System
But 17 years after being launched, the Drake Landing BTES “has begun to reach end-of-life,” the Drake Landing Company, which runs the community in partnership with the ATCO utility company, said in a statement to The Mix.
The solar thermal panels, the air handler units that circulate heat to each home, and the “custom-made fittings that connect it all together” are showing their age, and it has been hard to find experts familiar with the decades-old technology. The company adds it has “worked hard over the last year and a half” to find reliable solutions to these issues.
With repair costs pegged at between C$1 and $2 million, external funding will be required, and has not yet been secured. That will mean striking a balance “between continued system operation and the mounting financial inputs required to keep it running safely and effectively,” the company said.
Doug McClenahan expressed surprise that the solar panels have worn out so soon.
“Thirty or 40 years would not seem out of the realm of possibility,” he told The Mix. “But of course they must be operated and maintained as designed and not allowed to stagnate at high temperatures on sunny days, for example, if a repair to a leak had to be made.”
The original manufacturer Enerworks no longer makes these panels, so “it is a bit more of a challenge to replace them,” he said. But “there are other products, primarily from Europe, that could be used.”
As for the air handlers, he said the “replacement of circuit boards and fans, typical of furnace maintenance, would not be unusual for such products, and at some point consideration would be given to replacement with a new product.” But “I expect such products would be available.”
Citing health and safety as its “top priority,” the Drake Landing Company has vowed to “see full resolution before next winter.”
A Failure to Engage
CBC writes that Drake Landing residents were first warned about system failures last fall. The news did not come soon enough for at least one resident who spoke anonymously with the Western Wheel.
“We moved here because of this,” they said. “We weren’t told that it was going to be dismantled. We found out shortly after we moved in.”
“It’s frustrating because that’s the main reason why we moved into this was for the green energy,” the resident added.
While the BTES was a rousing technological success, there were signs that the Drake Landing pilot had been less triumphant on the community engagement front. A 2019 lessons learned report produced [pdf] for an International Energy Agency solar heating and cooling conference highlighted the need for earlier, more frequent engagement with homeowners, having a project exit strategy for a smooth transition out of technology demonstration, designing a project with the technology/component life cycle in mind, and transferring knowledge for innovation and low maintenance costs.
Some community consultation did occur, McClenahan said. “I do recall a meeting in 2017 with the homeowners during which future scenarios and technologies were discussed,” he wrote. Now, the Drake Landing company is anxious not to repeat its past mistakes, the board continues to meet regularly, the company said, and residents will be informed about all new developments.
“While next steps at Drake Landing are still being determined, it is imperative—and the board’s intention—to communicate with homeowners first and foremost,” said ATCO media manager Doris Kaufmann Woodcock.
Landing’s End or a New Beginning?
Some residents have “already pulled the plug” on using the sun’s energy to heat their homes and have opted for gas furnaces, writes CBC. But the Drake Landing Company is still considering alternatives to decommissioning the entire system. Spokesperson Corboy said the options include a new communal energy system or individual ones, new solar technology, individual heat exchangers, or forced air gas furnaces.
For McClenahan, whose expertise and insight helped bring the community into being, the future of Drake Landing could still be very bright.
“In my view, this community would be an ideal candidate to quite easily transition to a net-zero community,” McClenahan said, adding that “there would be a good business case for this.”
A first step would be “replacing the solar thermal panels with solar photovoltaic panels using the existing garage roofs which are oriented optimally to maximize solar collection.”
Next steps would be “adding a heat pump system, either centrally in the Energy Centre, or individually in the homes, and replacing the current air handlers.”
Solar photovoltaics “have come down in price significantly since this project started and the heat pump industry has grown and products have become more efficient,” McClenahan added. “The electricity from the solar PV panels could be fed into the grid, and the existing borehole field can be utilized for the longer term.”
With those new features, Drake Landing could well become “a net-zero showcase”, he said. And “with the move toward electrification of heating loads in Canada and the increase in renewable energy into the grid, I can’t think of a better community set up to achieve this in a cost-efficient way.”
And “if there is one thing that could bring me out of retirement, it would be to lead a team of experts to study that option and make this transition happen!”
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