The heat of the sun is now being used to warm the bones of students at the College of New Caledonia as a result of the provincial government's push to make public buildings more energy efficient and reduce greenhouse gas emissions.
A system of flat-plate solar collectors installed on the roof of the residence is now being used to supply 60 per cent of the energy the 44-room student residence at CNC uses to heat water.
Sunlight heats a solution of propylene gycol/water in a closed loop that goes to the roof and leads to a heat exchanger, which then warms city water as it flows through a separate system. That heated water is further warmed to 54 C by natural gas hot water tanks in the residence. Water to the solar panels is pumped only during daylight hours. On days when the temperature dips below 0 C, the glycol keeps the solution from freezing.
The system is expected to save about 197 gigajoules of natural gas and shave $2,600 off the estimated $8,000 annual natural gas bill the college pays for hot water in the residence.
"It's the main thing we're doing this year as part of our energy-management strategy and greenhouse gas reductions plan," said CNC energy manager George Friedrich.
"It is a project that the provincial government started last year through the Public Sector Energy Conservation Agreement [PSECA] funding plan to demonstrate the technology is viable in the North."
PSECA, through its partnership with Solar BC, which is funded by BC Hydro, fully covered the $136,400 cost of the project. Swiss Solar Tech of Summerland was awarded the contract to build the system and construction began in July. The system has been operational since late August.
Low-flow shower heads have been installed in showers and reduced-flow tap aerators are now in the sinks at the student residence to help conserve hot and cold water. Washing machines pipe in cold water only and a smart meter has been installed to more accurately track electricity usage. In the residence, only the common areas are heated with natural gas. Student rooms rely on a combination of heat pumps and baseboard electrical heat.
As of 2010, all public-sector organizations in B.C. were required to start operating with carbon-neutrality. The amount of natural gas, electricity, fuel for fleet vehicles and paper consumption is tallied and each organization must pay $25 for every tonne of greenhouse gas emissions. CNC's solar project will save 9.9 tonnes of CO2 per year or the equivalent of what two cars produce in a year, resulting in a cost savings of $250.
"It's really good that we have a government that's committed to GHG emissions reduction and they can help us out to improve the business case for putting these things in, even though our energy costs are low," said Friedrich. "We don't always have the best business case because of that, so with the incentives we're able to do things that make good sense for the environment.
"We're very fortunate to be in a province where we have a public utility. It's not driven by profits. Now, the big mandate it to avoid building generating capacity to meet our demands, so there's a huge push on conservation."
CNC uses more than $250,000 per year in electricity, which means it qualifies for the province's energy management program. The college spent $694,000 last year for electricity and natural gas at its Prince George campus.
"Energy is not always the most expensive part of running an operation, but it's something a lot of businesses don't really consider as a manageable expense," Friedrich said. "BC Hydro has recognized that one of the biggest hurdles to get over is the human resources to dedicate to look at how a business uses energy and identify the opportunities and then follow through to get projects implemented."
