Making a street reconstruction a geothermal experiment

TORONTO, ONTARIO - When Douglas Worts learned that the City of Toronto was going to fix the pavement on his street, he knew what he had to do: he called his councillor to get it stopped.

Worts has nothing against good roads. But he looks at his street – Laurier Ave. in the Parliament-Wellesley area – as more than a roadway.

He thinks it has the potential to heat and cool his house and others, by providing the footings for a geothermal heating system.

Now the city is interested in the idea, and has given $25,000 to Worts and his neighbours, through the Don Vale Cabbagetown Residents Association, to carry out a feasibility study.

Worts had never thought much about geothermal heating and cooling until he happened to hear that it was being considered for the University of Ontario Institute of Technology in Oshawa.

He talked up the idea at the Laurier street party in 2007, and some neighbours expressed interest.

He explained that down past the frost line, the Earth keeps a temperature that's warmer than winter air and cooler than summer air.

Geothermal systems take advantage of that by pumping fluid through underground pipes to carry the seasonal warmth or coolness to the surface.

Worts is keen on geothermal because the Laurier Ave. homes, built in 1888, are not energy-efficient by today's standards.

Worts thought tapping a green energy source like geothermal made a lot of sense.

One obstacle to geothermal at Laurier Ave. is geographic: There just isn't much surface area along the narrow street, where houses lack front yards or driveways.

Worts figured the roadway itself would be far more accessible for drilling rigs.

And the project would set an example of how geothermal could also have application in dense urban neighbourhoods.

"This is a perfect size street to be doing this kind of experiment," says Worts.

Staff at the energy efficiency office at city hall have been helpful, Worts said, and are willing to give residents a permit to drill on the street.

The holes will have to be very deep – about 175 metres or 575 feet, Worts says – because there's no room to run buried pipe sideways.

Each home will need its own system, because setting up a single system with common ownership proved legally complex, and not everyone on the street wants to convert to geothermal.

Worts says 16 of the 22 residents have shown serious interest.

Their councillor, Pam McConnell, supports the project.

"I think it's fabulous," she said in an interview. "It's a small street, but it could have major implications in quite a large circumference around Cabbagetown.

McConnell strongly approves of using the city street for the drill holes, because the project is in keeping with city policy on curbing carbon emissions.

"If we need to give up a little space in our right of way, that's fine with me," she said.

"I don't think it impacts the use of the street or the sidewalk. It doesn't impact the public realm, and has very important public benefits."

But money remains an obstacle – even doing a detailed feasibility study is expensive, and the Laurier Ave. residents were hobbled by lacking a formal organization.

A solution to that problem appeared one day when Sameer Dhargalkar, a Laurier resident and co-backer of the geothermal project with Worts, was walking his dog.

In Wellesley Park, he struck up a conversation with another dog owner, Lee Garrison, who heads the Don Vale Cabbagetown Residents Association.

"We just started talking out of the blue," Garrison recalls.

When the geothermal project came up, "I said: 'Let's talk some more, because I'm head of the residents' association and we've been wanting for a while to find some flagship projects to kick-start a green initiative in Cabbagetown.'"

The residents' association is now a partner in the project and provides the funding link with the city.

However, money is still an issue.

A consultant has estimated the cost of a geothermal unit at $27,000 per household.

Worts figures that with grant incentives, and with the savings from drilling many holes at once, the cost would fall to $17,000 or less.

Worts hopes the city or some other sponsor can be persuaded to loan this upfront money to owners.

He says a house spending $2,000 a year on heating and cooling might slice that to $800 with geothermal.