an adventure in geothermal heating/cooling systems
In Toronto at the beginning of the 21st century, citizens rely largely on oil and natural gas for heating homes and water, as well as for cooking food. But this is also a time of climate change – which science has directly linked to the use of hydrocarbons (including oil and gas). If climate change is to be addressed effectively, it is essential that society’s current reliance on hydrocarbons as fuels be massively reduced. The implication is that current societal needs for energy in our buildings be shifted to renewable energy sources. One of the best options in this regard involves geothermal (or more accurately geo-exchange) systems, which use the earth as a continuous source for both heating and cooling. By drilling deep holes into the ground, it is possible to circulate water slowly. In winter, the system draws heat from the ground, increases its intensity through a heat-exchange technology and then circulates warmth through the house. In summer, using a similar process to that of a refrigerator, the system extracts heat from the house and deposits it in the ground – resulting in coolness being circulated in the house. Essentially, geothermal systems move heat around, rather than generating it – and this takes far less energy than burning fuels. In fact, geothermal systems deliver 4 units of heat/cool energy for every 1 unity of energy input (i.e. the electricity to circulate the liquid, drive the heat-exchange unit and power the circulating fan).
In 2007, I was living on a cul-de-sac in the downtown Toronto neighbourhood of Cabbagetown. Our Victorian row-house was one of 22 heritage houses on Laurier Avenue. At that time, the Government of Canada was offering eco-energy efficiency grants to homeowners who upgraded their homes to achieve measurable gains in energy performance. I hatched an idea that Laurier Avenue would be a perfect site for a demonstration project using geothermal systems. Simultaneously, the City of Toronto was offering “Live Green Toronto” grants to projects that would push the boundaries on addressing environmental problems. The image of a cluster of heritage homes being retrofitted with geothermal heating/cooling systems was a powerful one. The question was, it is possible to transform heritage architecture from being energy inefficient to being very efficient? If so, then this strategy could help Toronto to preserve its distinctive neighbourhoods – built in many architectural styles that evolved over the decades – while achieving a critical shift in both both energy efficiency and greenhouse gas (GHG) reduction.
After talking with my neighbours, it was clear that many were interested in knowing more. So I arranged for a geothermal energy contractor to visit Laurier Avenue and talk with us about our options, the potential benefits and the challenges. Interest grew, but there was at least one big challenge. There was insufficient space on private property for the bore holes required for the system. We wondered if it was possible to locate the bore-field under the road? It became clear that we needed to answer this and many other questions. This then became the basis for our application for a Live Green Toronto grant – to conduct a feasibility study that would determine the viability of using geothermal systems to retrofit heritage homes. My neighbour Sameer Dhargalkar, a specialist in ‘clean-tech’, worked with me to develop the application. We joined forces with the Cabbagetown Residents Association, so that our proposal was coming from an incorporated non-profit, rooted in the neighbourhood.
Many meetings were held to confirm our application. In short, we were successful! In the Fall of 2008, we were awarded a grant by the Mayor of Toronto, David Miller. The Mayor expressed clearly his enthusiasm for the project. Pam McConnell, the city Councillor for our area, was also a huge supporter of the initiative and her staff were critical as we tried to move this innovation forward.
Over the coming months, neighbours created a Request for Proposals that was sent out to potential engineering firms that could conduct the feasibility study. We hired RESCo Energy Inc to work closely with us in conducting the research and answering the critical questions that arose in the process. Mark Henschel, a Laurier Ave resident, joined me in carrying the main load associated with this project.
The long and short of the story is that the study was conducted successfully. It demonstrated clearly that geothermal systems were head and shoulders better than traditional heating/cooling systems in terms of efficiency, operating costs and reduction of GHG emissions. Capital costs are high, since the technology commands a relatively small portion of the heating/cooling sector, and because drilling of boreholes is expensive. A copy of the final report, sent to the City in September 2010, is available here DVCRA Geothermal Study Final Report – Sept-2010. Mark Henschel and I presented on the project to the Toronto Environmental Executives – a summary document of that presentation is available here Geothermal Presentation TEE 22-11-10 slides2.
Part of what we found through our study was that part of the City of Toronto encouraged citizen-based innovation, while other parts of the City became serious obstacles to moving these ideas forward. The silos that are a reality within the municipal government structure meant that meaningful change has a hard time being realized. Accordingly we approached the Toronto Environment Office, which initiated the Live Green Toronto grant program and is an incredibly important force in creating meaningful change within the City. We were direct in saying that we wanted to move from feasibility to action – and that we had many neighbours willing to pay a premium to realize the vision of being a demonstration project on geothermal heating/cooling in Toronto. Recognizing that the obstacles at City Hall are real, a staff member was assigned to help us move our project (for which there were no good systems for moving it through approvals) through the bureaucracy. It made a huge difference!
Ultimately, we ran into obstacles that simply ground us down. The fact that any project that was requesting support through the federal eco-energy grant program had to be completed and inspected by a certain date – which was coming up fast. Given the late changes in what was being required by the Transportation Department, related to installing bore-holes under the street, residents became nervous about the prospect of getting part way through the process, having it stall and watching the grant deadline pass. The result would be having to pay an extra $10,000 per house – for the privilege of already spending a premium on the installation of these systems. So, we admitted defeat.
Part of the learning for us was that the eco-energy grant program was actually focused in the wrong way. Rather than trying to address the challenge of GHG emissions from buildings on a one-building-at-time basis is not the best way to proceed. Instead, the benefits of creating district energy systems expands the benefits enormously – and, in fact, is the only viable way to actually transform the urban infrastructure of buildings that are both energy inefficient and reliant on the burning of fossil fuels.
One of the legacy pieces of this process was that Toronto Community Council approved the concept for this project – thereby signalling the City’s embrace of the need for change in how we power buildings, and the approach of using geothermal systems as part of the solution. Also, in response to our experience, the City of Toronto has moved to create a simplified, integrated process for people who want to install a geothermal system in their home.
I remain hopeful that the City of Toronto, which has such a great track-record for addressing environmental issues, will continue to make progress towards transforming the energy systems of existing buildings. Green Laurier is a small part of that process.