We finally got our first really good snow-storm of winter! Five inches of thick, fluffy snow blanketed our driveway AND our photovoltaic solar panels. Should I clear the snow off the solar panels? How much more power will the panels produce? Is it worth it?
Waking up on a Saturday morning, the whole driveway was covered with snow. After clearing it, I started wondering about the solar panels. Checking the power-meter I have dedicated to the solar, I was surprised to see that even covered with snow, the panels still produced power. Only 40 watts, but hey, that’s SOMETHING!
The weather forcast for the following day predicted cold temperatures (High of 9℉, Low of -4℉) but also FULL SUN! So, should I clear the solar panels? I have a Snow-Joe brand roof rake. https://amzn.to/2RYU0dZ
It extends to 21 feet long and has a plastic blade for clearing snow from a roof.
I’m still recovering from a traffic collision last spring, and part of the injuries is a reduction in range of movement in my left shoulder. Frankly, it takes a lot of shoulder strength to use a roof rake. I was just about ready to decide NOT to clear the snow from the solar panels when my brother stopped by. I asked him, and he agreed to clear the snow from the panels.
While he did that, I set up the GoPro camera to record a time lapse.
Actually clearing the snow from the panels is a bit of work. It’s not terrible, but it’s a chore, in the same way that shoveling snow is. Normally, I’d welcome it in a “at least I’m getting some exercise in winter” kind of a way.
In the case of my particular solar setup, the 21 foot roof rake only just barely reaches the top-most row of solar panels. However, I’ve found that even clearing PART of the snow from that row allows the sunlight to get to the panel, start heating it up, and eventually cause the snow to melt enough to slide down.
This morning, the sun did come out! It was a glorious sunny day with blue skies. I took a few photos through the morning to see how much that remained of the snow would melt. The thin, icy layer left from scraping the snow quickly melted off. The big thick chunks of snow remained. As the panels heated up from the sunlight, they did eventually start sliding down, but only because most of the snow had already been removed.
By 1:00 PM, there wasn’t that much snow left. Even the snow from the top row of panels had slid down to about the middle. I pulled out the roof rake again and cleared the rest of the snow. A little while later, I checked the production of the solar panels and found that the output had more than TRIPLED just from clearing the rest of the snow!
Using micro-inverters also helps maximize production. Each panel is independent from the rest. If one panel is covered with snow, is doesn’t effect the uncovered panel next to it. In traditional serial string solar arrays, anything shading one panel brings down the production of the entire string. Usually, it’s a shadow, but the same applies to snow.
I checked my total energy production at the end of the day. We produced 13.3 kWh of energy for the day. Electricity in my area cost about 13 cents per kWh. So, multiplying the 13.3kWh times 13 cents gives us approximately $1.73! In other words, that’s the value, that’s what I got paid to clear the snow. On the other hand, if it was sunny tomorrow as well, it might DOUBLE that value. However, the weather report looks like it’s nothing but clouds and more snow for the next four days.
So, is it worth it? Was clearing the snow worth that $1.73?
I guess it depends. How bad do you want that power, and what does it take to get?
If I can stand on the ground and clear the snow and get a little exercise, that doesn’t seem like a bad deal. On the other hand, if I needed to climb onto the roof, or even stand on top of a ladder, those both offer risk of falling, maybe even a broken bone. I don’t want that for $1.73.
Probably the most motivated individual for clearing snow from a solar array might be somebody Off-Grid. In that case, it’s not the economic value of the electricity, but rather HAVING electricity or NOT! It’s also been my experience that many off-gridders use ground mount arrays, with the panels either steeply mounted, or adjustable to go to a steep tilt in the winter. Either way means more production from the low sun and LESS likelihood of snow accumulation.
What about you? Do you make it a practice to clear snow from you panels? Do you just let the sun melt it? Do you figure that production is at a minimum in the winter anyways and instead concentrate on maximizing summer energy production?
Let us know! We’d love to hear what you are doing with your solar panels in snowy winters!
Until next time, stay charged up!
-Ben Nelson
{ 2 comments… read them below or add one }
I’m a 66 year old strock survivor and an air force veteran. I’ve been ina wheelchair for ten years but next year I’m going tp baca raton,Fl for the cure.After I’m cured my 34 year old son and I areplanning tp travel together in a georgieboy pursuit class a rv and tour the country. It’s a ten ton bus that gets about 7 mpg I plan to put an electric motor in the middle of the drive shaft and make it a hybrid. I had already planned to make the housepart all electric, no propane by using24 lithium house batteries in one storage bay.I know that’s about15k but since I plan to have 2400 watts of solar on the 36 foot roof. I plan to use an aims 6000watt split phase inverter to power the house 6000w divided by 120v gives me 50amp service so I never have to plug into shore power, a cost savings. Plus with34000 watts of power I can use a residential refrigerator, induction cooktop, dishwasher, plus have a washer dryer combo and warmup electric radiant floor heat or run two 5000btu mini split air conditioners. might as well turn it into a parallel hybrid too. My question for you is how big abldc motor am I going to need for a twenty thousand lb vechicle.
You will need a specialty motor for a vehicle that big. There have been several bus companies that have had very large motors right in the driveshaft to built hybrid busses. I would investigate some of those and try to find the specs and similar motors.