Ontario’s next power plant should be solar
Ontario needs to decarbonize its grid. We’ve known about climate change for decades and know how replacing emitting power sources like coal and gas with clean alternatives like nuclear, wind, and solar can help fight it.
Ontario also needs to grow its grid. We’re going to need more power as we grow in population, switch from gasoline cars to EVs, and replace our home heating systems with heat pumps (which use electricity to efficiently move heat indoors instead of burning gas to create heat).
So what kind of power plant should we build next? You may have looked into renewables like wind and solar and been disappointed by their drawbacks. Solar requires lots of sun and Ontario doesn’t get much sun compared to warmer, sunnier places in the world. It also produces no power at night.
But, when you carefully examine our options for implementing solar power and the current state of the grid it would be added to, it’s a great option for Ontario. In fact, it’s the best technology for our next power plant. Here’s why.
Solar is cheap and fast to build
The advisory firm Lazard produces the LCOE+ (Levelized Cost of Energy+) report annually which tells us the cost of producing electricity from different sources. You can access the latest 2025 edition for free. On page 8, you can see the cost of various power generation options.
Page 8 of the 2025 Lazard LCOE+ report, showing the cost of the most common power generation options.
It shows that the cost of solar is $38-78/MWh and how this cost is lower than every other energy source in the report. Note that this cost doesn’t include the cost of energy storage to address solar power’s intermittency. However, that doesn’t matter for Ontario right now. I will explain why later in this article.
The cost has been plummeting in recent years. Page 14 of the LCOE+ report shows how the price of utility scale solar now is about one sixth what it was in 2009. We have no reason to believe that the cost of solar won’t continue to decrease or at least remain as low as it is now.
This decrease in price has made it economical to create solar power plants in Canada. For example, the largest solar plant in Canada right now is the Travers Solar Project in Alberta, completed in 2022. It cost $700M for 465 MW in peak generation.
In addition to being cheap to build, solar power plants are also fast to build because we’ve figured out how to mass produce solar panels. We have a steady stream of solar panels coming from factories that we can fit into all sorts of shapes. It doesn’t take long to install solar panels once you have the land chosen for the new power plant. The Travers Solar Project mentioned above took only two years (2021-2022) to build.
Ontario isn’t too far north for solar
You might think Ontario’s northern latitude would get in the way of solar panels operating effectively, but you’d be surprised.
The Global Solar Atlas website shows the solar energy availability in different parts of the world. The map shows us where the best places are for deploying solar power. Here’s what a map of parts of Canada, the USA, and Mexico look like.
Screenshot of part of North America from the Global Solar Atlas map, showing solar energy available in different areas.
This map uses warm colours like red for areas where there is more solar energy available throughout the year and cool colours like blue for areas where there is less solar energy available.
Let’s compare Ontario to an area of North America typically associated with great solar energy potential - California. It’s clear that California has much more solar energy available than Ontario. It’s orange-red and Ontario is green-yellow. But, it’s not a big difference. If you click on each area, you can see the specific numbers. Toronto is measured at about 3.7 and San Jose about 4.9. The units don’t matter here because we’re just comparing one area to another.
This means Ontario is only slightly worse than California for solar and that the economics often work out well for solar, even in Ontario.
Solar puts land to good use
Building a solar plant requires land upon which to install the panels, but that land doesn’t have to be unused. We don’t always need to seek out unused fields to play out solar panels. Instead, we can smartly re-use land for its original purpose and for generating solar power at the same time. Examples relevant to Ontario include agrivoltaics and parking lots.
Agrivoltaics means placing solar panels on farmland when the panels wouldn’t negatively impact crop yields. Some crops, like tomatoes, even do better when shaded by solar panels. Agrivoltaics is showing success around the world and we’re testing it in Ontario right now.
Agrivoltaics system - gardening under photovoltaic panels. Image from Wikimedia Commons.
Parking lots can host solar panels above parked vehicles. It can be more expensive to build them this way because more structure must be built to raise the panels up compared to deploying them just on the ground. On the other hand, some costs are lower because the panels being closer to where the power is needed means we don’t have to build as many transmission lines.
Ontario Clean Air Alliance’s 2024 report on Parking Lot Solar found that if we put solar panels on top of every large parking lot in Toronto alone, it would output more than 2x as much energy as the Portlands gas power plant. Talk about solutions being close to home!
We don’t need energy storage yet, we can simply burn less gas
This is where we get into some of the technical details that often stop renewables from being viable solutions for us. The sun is great, but it doesn’t always shine. Solar panels aren’t producing power for us at night. This aspect of power generation is called intermittency.
So, if we wanted to run society on just solar, or any other form of intermittent renewable, we would need to build more peak capacity than we need and store excess energy generated during the day to use overnight. This makes things more expensive. It makes some of the numbers shared above irrelevant. Solar isn’t the cheapest option anymore if we need to produce massive amounts of it during the day and store the excess to use overnight.
But here in Ontario, this doesn’t matter yet, because there’s no need to store the energy from our next solar power plant. Here’s why.
The following chart from Electricity Maps is a snapshot of the energy Ontario produced between Sep 15th and Sep 18th. You can see this information yourself using this link. Note that it will be the most recent 72 hours whenever you visit the website.
Screenshot of Ontario data from Electricity Maps website showing sources of power generated in Ontario between Sep 15th and Sep 18th.
Notice how during the day, we are producing a lot of our power using gas. In fact, if we scroll over the peak period for solar on Sep 17th, which is 1pm (we were generating 356 MW of solar then), we’ll see that we were also generating 5.9 GW by burning gas at that time.
Screenshot of aforementioned Ontario data from Electricity Maps website, highlighting high gas usage at 1pm on Sep 17th.
This means that if we were to generate more solar power around 1pm, we wouldn’t need to store it. There would be nothing left to store because we could simply use it right away. And we would then need to burn less gas because solar would be pulling its weight more. And because we would have burned less gas, our emissions would have been lower.
This makes the economics work because this would all have happened without the cost of storing solar energy. No pumped hydro, no batteries… nothing!
This wouldn’t be true forever. Once we run out of gas generation to replace, we’d have to start storing the energy. Then the economics will change and we’d need to have a fresh look at what to build later.
Build solar now
Make Ontario’s next power plant solar.
It’s cheap and quick to build.
It’s effective despite Ontario’s relatively cooler climate. There’s still plenty of solar energy hitting Ontario compared to warmer climates that we think of as getting more sun.
We don’t need to find new land. We could use our existing farmland and parking lots more effectively by combining them with solar panels.
No new energy storage is needed yet. Just burn less gas.
It’s September 21st, 2025, and the world is celebrating Sun Day. What better day to push Ontario to clean up its power grid and fight climate change by building more solar?
Our elected officials need guidance from us. Point them in the right direction.
Political parties like the Green Party of Ontario understand the potential of solar power. It’s right there in the party’s policy, which focuses on adding wind, solar and energy storage to our grid. But, even if your MPP isn’t Green, you should get in touch with them and tell them you want Ontario’s next power plant to be solar.
