Well we received quite a bit of snow over the last five days which makes collecting solar energy kind of difficult. What I really had not thought entirely through when deciding where to position our solar panels was the reduction in solar output due to snow covering the panels. As the solar panels are located on the roof of our two-story house its difficult to remove the snow. We had hoped the snow either would not stick (nope) or would quickly melt away. Of course this is Minnesota and December-February temperatures will often remain below 32 degrees for weeks on end. For example we were predicted to make approximately 775 kWH of energy in January, but we ended up making only 340 kWH as the panels were obscured with snow.
To add insult to injury, Peoples Cooperative (our electricity provider) tacks on an additional charge for users who have Grid-Tied solar panels. Here is our January bill.
We received 1142 kWH in January from the grid. Our solar panels generated 340 kWH of electricity (not shown), of which the house directly used 105 kWH as it was being generated (not shown), and sent back 235 kWH that was in excess of use during solar generation hours. However, that credit for those excess electrons was almost entirely soaked up by the extra Solar grid fee of $24.31 that is charged by Peoples Coop. Peoples Coops point of view on this is that the monthly service charge does not entirely cover grid maintenance with the remaining grid maintenance $$$ being baked into the 11.1 cents per kWH. Since they presume we will net out out to zero at the end of the year, grid tied solar users end up not paying their fair share of the grid maintenance. So to not be penalized any particular month by the Solar Grid Fee, we have to generate and send back to the grid approximately 225 kWH to cancel that fee.
Because of snow cover we have only generated 49 kWH of solar in the first 12 days of February, which means we wont even cover the Solar Grid Fee! Here is our solar panels covered with snow and the lack of output on a full sun morning on Feb 13th.
Solar Connection, our solar installer, indicated that if you get just some of the panels uncovered they warm up quickly and will melt the snow. A google search of getting snow off solar panels yielded some interesting possibilities. Some people chuck tennis balls or nerf balls at their panels to try and uncover a small area, some people spray warm water from a hose, through that one sounds dodgy. Based on the long term forecast for several days of putative sunny weather, I pulled out a roof rake (actually a broom) and our long extension ladder and had a go at it.
The reach of the roof broom allows quick cleaning of the entire bottom row of panels, but only 1/3 of the upper row. Hopefully, having a bit of the upper row uncovered will allow the sun to do the rest. Here are the panels one hour later after being uncovered and allowing the sun to do its work. It was only 15 degrees that morning, but this still seemed to work.
Almost immediately after doing the first pass and heading inside I could hear and see large avalanches of snow coming down as the panels warmed up and the snow slid off. The solar panels jumped to their full February output of > 7000 watts and we were able to generate 18 kWH that day (Did not stay 100% sunny that day).