Drake Landing: A ray of sunshine for solar thermal energy

Okotoks in southern Albertais one of the sunniest places in the country makingit a perfect location for Natural Resources Canada tolaunch a groundbreaking demonstration project.

Some residents of the town located just south of Calgary arenow reaping the benefits.

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"We wanted to show that it is possible in a cold Canadian climate to provide essentially all of the residential space heating needs for a community using solar energy," saidmanagerDoug McClenahan.

"On average, 60 per centof the energy used in Canadian homes is for space heating, and approximately two-thirdsof this is provided by fossil fuels."

With the help of governmental and private partners, NR Canada completedDrake Landingin 2007.

Consisting of 52 houses, it's the first large-scale solar community in North America to use borehole thermal energy storage to heat homes.

Storing heat underground

"The simple fact that we can store heat underground and utilize the energy that was captured from three or four, five months ago, is awesome," saidKeith Paget from Sterling Homes.

His company developed the neighbourhood and built the houses to R-2000 standards, ensuring maximum energy efficiency.

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The project has exceeded expectations. Since its inception, the solar system has been providing well above 90 per centof the space heating requirements. The last few years saw efficiencies of up to 98 per cent, requiring only a two per centtop-up from natural gas.

Homeowners pay a monthly fixed rate, about $70 to maintain the infrastructure. The community is revenue neutral.
The real benefit comes from the reduced greenhouse gas emissions. The space heating system cuts about four to fivetonnes of greenhouse gas, per household, every year.

Drake Landing homeowners monitor theenergy centre in real time, with the help of an app.

How it works

"I was drawn to the technology, looking for a way to reduce the carbon footprint for our family," saidhomeownerKlymBolechowsky. "In terms of costs, I think it's relatively comparable to a conventional home, I think there's a bit of ethics in it."

The heating process starts behind the houses, on the roofs of the detached garages where 800 solar-thermal panels are mounted to the roofs to collect the heat from the sun.

The array can generate as much as 1.5 megawatts ofheat during a sunny, summer day.A non-toxic glycol solution is heated by the system and pumped to the community's energy centre, where the heat is extracted and diverted into a web of 144 boreholes,drilled 37 metres into the earth.

The heat is transferred to the surrounding soil and rock. By the end of summer, the ground's ambient temperature can reach 80C.

During winter months, this heat store feeds the homes through a central district heating system.ATCO Gasmanages and runs the project.

Energy-saving frontier

"It's environmentally friendly, it's innovative.... We're looking down the road, we want to be an energy provider, not just a natural gas provider," saidsenior managerKelly McCann.

The other energy-saving frontierin Canadian homes is hot water tanks. In Drake Landing, solar thermal energy helps with that too.

Each house has dedicated solar thermal panels to pre-heat the water before it's brought up to thefinal temperature, using natural gas. This process saves each household another tonne of greenhouse gas per year.

Borehole thermal energy storage has proved its worth, but to apply it wholesale would require abigger scope.

"This is a demonstration project of just 52 homes.... In a large-scale project of 1,000homes or more, the economics are much more feasible," saidPaget with Sterling Homes.

Meanwhile, Natural Resources Canada islooking to build on the success of Drake Landing. They've started a study for another project in Okotoks. The next goal is to move towards a 100 per centrenewable net-zero energy community.

It will use very high-efficiency housing and buildings to maximize the solar thermal energy, and will include photo voltaic technology, heat pumps and bio-energy.