DLSC homes decrease GHGs by 5 tonnes each/yr

By: Jordana Levine

The first of its kind in North America, the Drake Landing Solar Community (DLSC) is heating its homes with solar energy and reducing five tonnes of greenhouse gases per year in every house.  The community, located in Okotoks, Alberta, has 52 homes heated by seasonal thermal energy storage; the solar heat is stored underground in the summer and used in the homes during the winter.

The project, which was first created by Natural Resources Canada (NRCan), began collecting solar energy in June of 2007 and, after five years, the community is expected to receive 90 percent of its heat from solar alone. The need for non-renewable fossil fuels will diminish and shift to a cleaner and more sustainable unlimited source of energy: the sun.

The DLSC project leader, Doug MeClenahan, says that there are almost no other projects like this one anywhere in the world.  “You could probably count them on two hands.”

The community’s space and water heating comes from solar energy, which is collected by 800 panels arranged on garage roofs around the community.  Each panel generates about 1.5 MW of thermal power on a summer’s day. There is a combination of seasonal and short-term thermal storage (STTS), with boreholes in the ground to store the seasonal energy.

When heat is transferred to the homes, there is an automatic valve in the basement of every house that shuts off the heat transfer when the temperature of the thermostat in the home is reached.  If the STTS doesn’t have enough heat to distribute to all the homes, there is a back-up gas boiler Energy Centre that will turn on to help out.

Energy in a community the size of the DLSC costs 14 to 17 cents per kWh.  “Fifty-two homes was a reasonable size, but it was still considered to small… to be cost effective today,” says McClenahan. He explains that the next step is an analysis of a larger-scale project using a computer simulation.  The analysis should be completed within a year.

“If you go to larger scale, you have much less surface area for heat loss… so the efficiency can go up considerably,” McClenahan explains.  “The bigger the project, the less cost it is per unit volume or per unit area.”  Drake Landing isn’t that effective now because it’s losing heat on the surface area of the land.

Still, McClenahan says, I know [the technology]’s promising enough that we should pursue it until we are able to do the analysis.”  However, beyond that, he says it’s incredibly difficult to tell exactly what the costs and savings could be in a larger community. “Until we do the analysis, I’d hate to guess.”

The community does more for the environment than just conserve energy, though. Homes are designed with low-impact landscaping and use locally manufactured materials.  The materials used include upgraded insulation, certified sustainable lumber, drywall made from recycled materials, and well-insulated windows, among other environmentally friendly products.

Also, the homes are all required to follow The Town of Okotoks’ water stewardship measures: low flush toilets, ultra low flow showerheads and faucets, and insulated water lines.  Larger homes require a recirculation pump and every home is supplied with a low water consumption dishwasher and clothes washer.  A rain barrel supplies water for gardening.

By the end of the community’s second year, McClenahan says it’s already receiving 67 percent of its space heating from the sun.  “We’re hoping that this will continue to increase” to over 90 percent.

“I would like to see, in the next 2 to 3 years, a [larger] follow-up project,” says McClenahan, hopefully with bigger cities in Canada like Toronto and Montreal.  “We don’t want to end up with just one demonstration and that’s it.”

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