The City of Mississauga is testing the waters with solar panels as a supplemental heat source for its busiest — and highest utility-consuming — outdoor pool this summer. If data-tracking confirms staff’s forecast for energy savings, the pilot will plunge the annual gas use of the Lions Club Credit Valley Outdoor Pool by around 5,650 cubic metres and its annual greenhouse gas emissions by around 10.7 tonnes.
In addition to its potential to lower the utility bill for the facility, the trial run was attractive to the municipality as an opportunity to demonstrate leadership in sustainability, said Daniela Paraschiv, manager of energy management, City of Mississauga. She said renewable energy is an area of particular interest at the municipality, and there was a stronger business case to be made for solar power than for some of the other options that are available.
“Although the cost-effectiveness might not be there yet, we need to be prepared and make sure our decisions are based on our experience and knowledge,” said Paraschiv. “As part of our strategic plan, under the green pillar, our goals are to lead and encourage environmentally responsible approaches and also promote a green culture, so we also want to educate our citizens on using alternative sources of energy so they can consider them for their homes.”
Educational materials will be publicized alongside the installation at Lions Club Credit Valley Outdoor Pool, which consists of 28 rooftop-mounted solar panels that measure four feet by 12 feet apiece. Paraschiv clarified that, technically, the “panels” are unglazed collectors, as the lighter-weight plastic units differ from the solar photovoltaic systems that are commonly associated with the renewable energy source.
“There are some small water tubes inside the collectors, and the pool water is circulated through those collectors, which are heated by the solar energy, and this is how the water gets heated,” she explained. “Not the whole pool water is sent to the collectors, just a portion of it.”
The forecast for energy savings and greenhouse gas emission reductions is based on the assumption that the panels will absorb a maximum of 40 per cent of the water-heating load, reducing reliance on the gas-powered boiler system.
The pilot will run from the opening of Lions Club Credit Valley Outdoor Pool, in late June, until the end of the season, the timing of which will be weather-dependent. If all goes well, the City of Mississauga will look into using unglazed collectors as a supplemental heat source at its other outdoor pools, of which it has seven. However, the pilot won’t simply be rolled out across its facilities.
“We need to investigate case by case because the business cases are so different from pool to pool,” said Paraschiv. “They depend on factors such as consumption, usage, state of the pool, orientation.”
Paraschiv added that low gas prices are a strike against the business case, which can be further diminished by additional costs that may arise, such as reinforcing the roof to support the weight of the system.
Once the required construction permits were in place, installing the system at Lions Club Credit Valley Outdoor Pool was straightforward, said Paraschiv. Upkeep will require little more than yearly inspections.
The installation included a building automation system (BAS), which staff will use to track a series of metrics. Data on boiler operations, outdoor air and water temperatures, and water flow will be compiled and crunched to determine how much pool heating the unglazed collectors provide.
Paraschiv said tracking data is critical to be able to show how the actual results stack up against the anticipated results. She urged other municipalities considering similar pilots to include control systems in order to be able to bear out their business cases.
Testing the waters now, with pilots such as the solar water-heating one, will help prepare the City of Mississauga, and others, for a future in which the business case for renewable energy strengthens.
“It’s good to explore the alternative sources of energy as much as we can, even [if], as I said, the cost-effectiveness isn’t there yet,” said Paraschiv. “It will come, I’m sure about that.”
Michelle Ervin is the editor of Canadian Facility Management & Design.