Many proponents would like to see more solar power in Ontario. I am supportive of this but solar power can only work in Ontario if it is part of a larger solution.
When most people think of the challenge with solar power they are referring to its intermittency. Solar generation can be significantly reduced if it is cloudy and, of course, there is no generation at night. This is definitely an issue but it is one for which there is a solution and that is energy storage. Energy storage in this context could be any sort of storage such as batteries, hydrogen or hydraulic. By combining solar generation with energy storage you can create electricity generation that more closely resembles base load generation. The issue then is no longer technical but one of cost. Energy storage is still very expensive and the combination of solar and storage is not yet competitive, at least not in Ontario. It may be in the future but we do not know when.
There is, however, a bigger issue with solar generation. The intermittency challenge with solar power is not just with regards to cloudy days and nighttime; it is also with the seasons. Solar power does not generate enough electricity in the winter in Ontario to be of use. And while energy storage can smooth electricity supply variations during the course of a day or over a few days, it cannot smooth it between seasons. The amount of storage that would be required is just not viable.
To illustrate, I have provided the solar production from 2.675 MW of solar generation in Niagara-on-the-Lake (NOTL) below. As you can see, lots of power is generated in the spring, summer and fall. However, in winter production drops to very little. The sun is too low on the horizon to have any strength and we can go for weeks without even seeing the sun. This is in NOTL which is one of the most southern points in Ontario. As you get further north the winter solar performance will be even worse.
The peak summer monthly usage in NOTL is around 25 GWh a month. To generate this in the height of summer solely with solar power we would need around 170 MW of solar generation. That is a very large amount but it would be feasible. 10 kW on every residence would provide around 90 MW and the rest would need to be on commercial establishments and utility scale installations. However, in December, even using a lower winter peak monthly usage of around 20 GWh, around 750 MW of solar installations would be needed. That is just not feasible.
As mentioned at the start, I am still a fan of solar power as part of a larger solution. One of the biggest advantages of solar power is that it can be installed in small increments. It does not need to be a multi-million-dollar investment like hydro, gas or even wind. Individual consumers can install their own solar to meet their needs. The advantage of this is that the consumer is paying the capital cost; not the government or the electricity industry.
Consumers can install their own solar generation on their own premises with a net metering agreement with their local electricity distributor. However, if you are in a condo, an apartment or your house is not suitable for solar panels then there is no other option. What is needed is community net metering. Under community net metering, a large solar installation would be created in which individual customers could own a share of the output. They would then have this output applied to their account as net metering. There are two benefits with community net metering, the first is that any electricity consumer could participate, not just those with the ability to have a solar installation attached to their residence. The second benefit is that building a large solar installation is much more cost effective on a kW basis. This would be more economically efficient than the equivalent amount of individual net metering installations on multiple residents. Unfortunately, community net metering is not currently allowed in Ontario.