In an open field near the centre of the Blatchford redevelopment sits a small round building with mirrored cladding reflecting the bright blue sky and the words “Energy Centre One” displayed prominently on one wall. Inside is an enormous heat pump, a machine that efficiently converts energy from one state to another through a loop of pumps, compressors, valves and refrigerant.
“It’s 10 times more efficient than any furnace,” says Christian Felske, a professional engineer and the City of Edmonton’s Director of Renewable Energy Systems. “The way mechanical engineers describe efficiency is the COP value, the coefficient of performance. This one can achieve 10, which is massive.”
The 536-acre Blatchford redevelopment is one of the City of Edmonton’s signature environmental initiatives. In partnership with private developers, the City is turning the former city-centre airport into a carbon-neutral community for 30,000 Edmontonians. The City committed to powering Blatchford with a utility driven entirely by renewable energy. This heat pump – together with the ones to follow – is the key to making that happen.
Next to Energy Centre One is a large stormwater pond that will ultimately be in the middle of Blatchford’s central park. Underneath the pond is a geo-exchange field consisting of 570 bore-holes of about 150 metres each. At that depth, the ground is a consistent eight degrees Celsius, summer or winter, no matter the weather, because the ground acts as a giant solar battery, absorbing and storing heat. A mix of water and refrigerant is passed through the pipes in the boreholes, drawing the energy from the ground. The heat pump then circulates that fluid through a network of underground pipes to the homes that have been built at Blatchford, where small heat pumps draw heat from or insert heat into the system, depending on need. It means there are no natural gas furnaces or hot water heaters at Blatchford. As buildings get both their heating and cooling services from the same system, there is also no need for separate air conditioning. As Felske says, you can find renewable energy in many places, including the sun, the wind and the water. But it’s also hidden underground. “Maybe that’s less sexy and it’s sometimes forgotten, but it’s efficient,” he says.
He explains that the system is a geoexchange, not the more well-known geothermal energy system which uses kilometres-deep wells to extract very hot water to generate electricity and heat. It is not an experimental technology, he explains. It’s fourth or fifth generation, with much of the research and development having happened in Europe. He says he now has two years of data from the heat pump, which is rated at one megawatt, and that it is working well. “People are getting heat in minus-40 and cooling at plus-30,” he says.
Blatchford includes many smart planning ideas, including laneway housing to increase density, high-efficiency buildings, separate bike lanes and trees on every street. But with the majority of a building’s energy consumption being attributable to heating and cooling, the heat pumps are crucial to meeting the development’s environmental goals.
At this point, the utility is generating far more energy than can be used by the few homes that are connected to it. To be fully efficient, the system will need many more buildings attached, and a mix of residential and commercial. “Commercial needs more cooling so offices shed heat into the system,” Felske says. “That heat can be picked up for residential use.” As the community fills up, two more heat pumps will be installed in Energy Centre One, and other similar buildings will be built as necessary.
Countries around the world are mandating a move away from burning fossil fuels for heating and cooling, and heat pumps are the pieces everyone talks about. They’re more expensive to install initially, but long-term they are both more environmentally friendly and more cost effective than fossil fuel systems. Felske hopes Blatchford will become an example for the world. “The initial reasons for building heat pumps were around energy supply and cost,” Felske says. “Now, these systems have become attractive to decarbonize cities, and that’s the idea in Blatchford. Hopefully, it will be used as a showcase for other systems in Edmonton and beyond.”
This article appears in the October 2022 issue of Edify
