According to a popular post on social media, a thin layer of snow is "why solar doesn't work in Canada". Quite the claim but does it have any validity?
How does snow affect solar generation?
Should you clean the snow off your panels?
Does solar work in Canada?
We'll answer these questions and more below!
How does snow affect solar generation?
Snow has a hard impact on the instantaneous electricity generation of any solar panel. Most of our systems see 70% to 100% of electrical generation LOST during times of snow coverage. This is not all doom and gloom. Solar irradiance does indeed pass through snow. Our natural lakes in Canada rely on that light for plants to photosynthesize and fish to have food. However, it is not enough irradiance to generate any substantial amount of electricity. Does this mean that solar doesn't work in Canada?
Well, no. It does mean that you may have to clean off the panels on your temporary lighting trailer, but it has very little affect on your homes grid-tied solar power system. When we calculate generation, we are looking at your annual generation compared to your annual consumption of electricity. We aim to 100% offset your electrical consumption with renewable solar energy, but we do not expect this to happen in the winter months.
Here in Alberta, we do not project very much generation during the winter. When it snows you will see your generation drop to near 0 Watts. Don't fret my friends! After a day or two (or five) the snow will slide off the panel or melt and you will be back to generating electricity, but how much? Even in ideal situations, your generation will be far less in the winter than it is in the summer months. Typical sunlight hours is around 5hrs a day and the amount of energy to reach your array is less than the summer due to atmospheric effects. Likewise, during the summer you can expect very potent sunlight for 14 hours a day. This is when the generation really happens. Take a look below at anticipated solar generation by month(green) and consumption(grey) to see how the winter compares:
As you can see, December is producing less than 20% of the energy produced in July. This home is a full offset, producing an equal amount of energy as it consumes.
Should you clean the snow off your array?
The answer to this can vary depending how the array is being used. A solar array mounted on a temporary light trailer (like the popular social media post) will require occasional snow clearing. These trailers have battery storage that is sized to be recharged every day. If you don't clean the snow off, you won't charge the batteries and when night comes around you'll be in the dark.
How does this compare for a home grid-tie solar energy system? Vastly to say the least. Our systems are sized with no snow removal. When you see the economics on your solar proposal, these anticipate zero snow clearing or any other maintenance. Most people aren't going to get on their roof and sweep off their panels and it would be ridiculous for us to expect that. If you really want the slight additional power generation, feel free to clean the snow off, but as far as I am concerned - save your back, it's not worth the effort.
So, does solar work in Canada?
Solar works great in Canada if your goal is to generate carbon-free renewable electricity.
Solar works great in Canada if you want to save money on electricity.
Solar works great in Canada.
In summary, if anyone tells you solar doesn't work here in Canada - you can be assured that they are misinformed or ideologically driven. Solar works great here and we have the results to prove it.