A free online tool released by the City of Calgary has helped the city see a spike in rooftop solar installations.
The Residential Solar Calculator, launched in early 2022, assesses the energy potential for households planning to install solar panels on their properties. It calculates the environmental impact and estimated costs, information that helps people decide whether it’s worthwhile to invest in new technology.
After residents select a location on the map and enter their monthly electricity consumption or home size, solar potential is determined by how much sunlight the property receives and the available roof area for the panels. Factors such as obstructions, shading, roof shape and orientation can also influence the final calculations.
According to figures provided by the City of Calgary, panels producing 16 megawatts of energy were installed at the end of 2022, the year the calculator went online. That number rose to 32 megawatts the following year, and nearly doubled again in 2024, with a total of 62 megawatts by the end of the year.
Lewis Percy, Calgary’s corporate environmental specialist, said the city is the only municipality in Canada that has developed an in-house solution service like the solar calculator.
“We know that obviously installing solar panels on roofs is an increasing trend for people, and Calgary has fantastic sunshine hours. We are the sunniest city in Canada. So it's an education tool, and it helps people to understand this solar value a little bit better,” he said.
The fact that the calculator was created by city staff might also attract the interest of other cities and small communities east of Calgary, like Banff, Percy suggested.
“We've offered our code base for this and our methodologies to those cities,” Percy said. “As of yet, though, we don't know any city that has actually run the exact same process as us, but we have certainly had discussions with those cities about how they could do this if they wanted to.”
The solar calculator has one major limitation: the financial modelling it uses is difficult to apply for buildings other than houses because energy costs are not fixed for buildings like schools, hospitals, and businesses, “and that directly impacts the payback,” Percy said. “That's one of the key components that we look at. We can assume that in the residential setting because of the regulated rate option that we have for electricity in Alberta, but we can't do that on the commercial side because often different commercial portfolios have agreed rates of utilities.”
He said Google inspired the development of the Residential Solar Calculator. Google’s Project Rooftop uses Google Earth imagery to scan roof shapes and analyze local weather patterns to provide personalized solar energy plans. It is exclusively available in the U.S.
The Residential Solar Calculator earned the City of Calgary the Bloomberg Philanthropies What Works Cities certification in February, a recognition launched in 2017 to establish exceptional data management that informs city policies and enhances public services for citizens. It is open to cities in the Americas with a population of 30,000 or more. Besides Calgary, Edmonton, Hamilton, and Winnipeg qualified for the certification, which was the first time Canada was qualified for the recognition. Calgary is the only Canadian city to have received a Gold certification.
Herman Cardoso, Calgary’s manager of data and analytics, highlighted the collective efforts of 20 different business units in the city in collecting, processing and validating all the data for the project. “Data analytics is no longer a shiny word for decision-making. Now, corporations are understanding, and this is an example of how Calgary managed it,” he said. “Being data-driven and well-run local government are also opportunities for residents to see the data as a factor in decision-making. It includes trust and transparency in city operations.”
Comments
This is a great step. But don't be surprised if Danielle Smith goes after this policy and kills it, only because she's the premier who has Alberta's cities under her thumb, and because she lives in fear of her oil and gas benefactors who in turn live in fear of the sheer economic advantage renewables have over fossil fuels. One little whispered comment in Smith's ear at an O&G dinner at Calgary's Petroleum Club and it's gone the next day.
But residents and businesses needn't despair. Solar is still cheap to install and will save thousands over its lifespan only because Alberta's gas-fired power companies have a monopoly and have therein jacked electricity rates to the sky, giving the public ammunition to jump to rooftop solar, which is especially effective with batteries. Medicine Hat is completing a huge solar farm of its own, so there you go, a town-scale exercise in energy independence in the most conservative part of an oil-saturated province.
Solar panels and windmills both use petro-chemicals in their construction, petro-chemicals which release GWGs in their production. I'd be surprised if heat pumps don't too.
Is Medicine Hat's installation intended to provide energy to its residences, or is it to power a huge new data centre installation so it can call itself a "green" or "net-zero" project?
Do does that computer or phone we both type on. This means I should not get solar?
Great point.
Solar panels are 100% recyclable. There is an industry forming that does just that, and this also applies to wind turbines and batteries. The level of recycling and the amount of power drawn from a grid are matters of government regulation. Vote accordingly.
Regarding emissions from individual components of clean energy, the UK has miraculously cut its national emissions in half in a single generation by replacing coal, oil and gas combustion tech with wind and solar tech.
Bring it on.