How Does Snow Affect Solar Panel Efficiency?

Question

I live in an area which experiences heavy snowfall. How does this affect the efficiency of the solar panels which are on my roof?

Answer 1

Snowscapes can significantly alter the design of solar panels and some roof systems. Some of the solar systems are designed in such a way that their surface remains slightly above freezing point making it possible for light snow to not accumulate because it immediately melts after contact. However, those systems are rendered less effective when heavy wet snows are falling where some amount of snow is bound to lie on the roof. But when there is snow on the roof after it elicits some thermal energy from the substrate, in most cases only the bottom portion, which may include water, gets warm and enables the whole snow sheet covering the roof to detach and slide down. This result in a loss on solar efficiency but it is only short lived as the snow has not been cleared and the system already has mechanisms to remove snow and circumvent any functional limitations.

Comments

So glad you live up North, which really demonstrates how impacted these systems are in the winter. Not only is the orientation of the sun lower to the horizon, but your power needed to maintain the system is almost net neutral.

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This was EASILY the most relevant solar power review I've seen.  You literally hit every concern I've had about going solar.  Snow, bi-directional charging, practical information for the Northeast...  Very comprehensive.  Thank you!

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Hey, I live with an off grid system, biggest downfall besides the price is that in the winter the panels get covered with snow and mine are three stories high.  I have a JLG crawler but its such a hassle to wake up boot up the machine, clean them, then wait for the batteries to charge. I would recommend keeping your panels accessible if you're in an area with hard winters.

Also the biggest upside is you can build anywhere, I built a huge log cabin that was getting denied by the city, so we just didn't tell anybody and built it anyway off-grid.

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You can fix the snow falling in front of the door with snow guards. They can be use to divert the snow to either side. They also are used to help break large sheets into strips so you don’t have huge masses of snow that could cause death by slamming down on someone.

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One thing you didn't mention: how's the maintenance of the roof? It's cool that maintenance during snow isn't a big deal but how often do you have to clean them to keep them in optimal condition? Perhaps an update on the maintenance (or the lack thereof) in the next vid about it.

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That 55 MWh yearly energy consumption is just insane since that doesn't even include heating! In the arctic circle in northern Europe, with winters where you have typically 1 meter (or ~3 feet) of snow and temperatures hitting below 0 °F during the winter for 2-3 months,  a basic family home with electric heating uses around 25 MWh in a year for EVERYTHING!

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Fun fact as to why your solar roof performs better in the spring: Just like batteries, solar panels also have a preferred temperature they operate at. The efficiency of solar panels is highest at 25 degrees Celsius (77F). When the Sun shines on the panels they might warm up beyond the ambient temperature, and in the summer this means that the performance and thus the yield is reduced. Whereas in spring the more moderate temperatures and sunny days mean that your panels at working at peak efficiency!