First winter with solar, what should I prepare for？
Posted by Heamora@reddit | preppers | View on Reddit | 33 comments
Hey folks, I've been putting together my first solar setup lately. Since winter's coming and snow can really mess with efficiency, I've already got renogy shadowflux panels.They're supposed to work even with some snow covering them. That's one of the reasons I bought them. But with winter coming, the real issue isn't the snow, it's the weak sunlight and shorter days. I'm a bit worried about keeping my batteries topped off when there's barely any sun for days.
For those who've been through a few winters with solar, how do you usually deal with this? Do you adjust the tilt angle, use any tricks to keep panels clear, or just rely on backup sources like a generator? I want to make sure I have enough power all winter.
Internal_Raccoon_370@reddit
Um, no, they are not going to work with snow covering them no matter what you may have been told.
Depending on how far north you live, your days are going to get shorter which means fewer hours of usable sunlight. Plus the sun is going to be lower on the horizon meaning the sunlight has to travel through far more atmosphere reducing its intensity. Changing the angle of the panels will help. A bit. But nothing makes up for the fact there is going to be far fewer hours of usable sunlight. Plus there is the weather to consider. Where I live I can get cloudy weather that lasts for days, even weeks where I get virtually no solar production at all.
You're going to need some kind of backup system, either powering your place directly from a generator or using the generator to recharge the batteries.
TheAspiringFarmer@reddit
This is the most important point. And similar here. Long stretches of grey, cloudy days. Gloomy and dark. Not going to generate much solar energy in that environment.
Internal_Raccoon_370@reddit
Exactly. I have whole house solar but I still have a grid connection. If I didn't, last winter I would have had to run my gas generator about 4 - 5 hours every two days or so to recharge my batteries for a lot of December, and most of January and February.
Solar is absolutely great but you're entirely dependent on the weather.
wihaw44@reddit
Most of your solar output is dictated by where you live, it depends on your latitude. So it’s definitely worth having a backup power source for cloudy days or long winter nights.
Ezio367@reddit
I’m using the shadowflux panels too. They worked pretty solid during the summer, and I’m planning to tilt them steeper for winter. Kinda looking forward to seeing how they do.
Upper-Glass-9585@reddit
I adjust my panels twice a year on the equinoxes. I'm at the 44th parallel so I go up to 59ish degrees for the 6 months of winter and down to 29ish degrees in the 6 months of summer. The winter angle also helps shed snow.
Creepy-Cantaloupe951@reddit
Oh... you're about to fall into the "trap" of buying more batteries. Then, buying more panels. Then, buying more batteries :)
nanneryeeter@reddit
Winter where?
Alaska?
Colorado high elevation?
South Texas?
Florida?
I mean, fuck. Location, elevation, microclimates all matter. Do you really believe that "winter" is a useful descriptor at all?
suncalc.org might be a useful tool.
Heamora@reddit (OP)
Fair point. I'm in northern California, up in the foothills. I just moved in here not very long ago. So I'm not sure what's the winter whether will be like. I've heard that it can get a bit snowy and cloudy tho.
ohyeahwell@reddit
Foothills get some snow, not too bad. Usually starts the third week of November around Downieville, Grass Valley, Sierra City etc.
gonyere@reddit
Im in eastern Ohio. I pay significant electric bills for Jan, and Feb. Small ones for Dec and March.
TheSensiblePrepper@reddit
This was my question.
OP, we need to know your general area to give any real suggestions that will work for you.
I am in the Upper Midwest/Great Lakes area with solar and have to do certain things for snow but those might not apply to you at all.
ohyeahwell@reddit
I was surprised that my solar generator/80qt portable fridge combo ran indefinitely in winter sun.
smsff2@reddit
No, I don’t adjust the angle. Winters weren’t as bad as I expected. Even the shorter winter days provide enough electricity for my limited needs.
We use a 30-watt LED light during dinner, for about 30 minutes a day. The 50-inch TV uses between 20 and 80 watts, depending on the brightness of the picture. We can watch a movie for about two hours. The 40-watt furnace runs through the night, around 10 hours. That adds up to roughly 515 watt-hours per day.
I used to keep a generator handy in case the batteries ran out of power, but that hasn’t happened in two years. I’ve put the generator in storage.
HajjiBalls@reddit
Please name the TV. My 52 inch pulls 215 watts.
smsff2@reddit
Did you actually measure the power consumption, or is that what the label on the back of the TV says? I remember my TV’s specifications on the back label are somewhat similar. The 20 to 80 watts figure is what I read on the screen of my 12V-to-110V inverter.
I’ll need to visit my bug-out location to check the model and manufacturer of the TV. I don’t have that information readily available. It’s an old, non-smart TV. We usually connect it to a Chromebook using an HDMI cable. I’m not sure if that makes a big difference in power consumption.
party_peacock@reddit
What kind of furnace is that? 40W is tiny, I would imagine it'd be about the equivalent of one of those cigarette lighter plugged space heater fans for a small car
smsff2@reddit
It's Chinese diesel heater
Cute-Consequence-184@reddit
Diesel heater or propane heater with fans running.
I live tiny and don't need to run fans so mine is without fans completely.
alocksrq@reddit
Yeah, 40W seems really low for a furnace. Most electric heaters are way more powerful, so you're probably right about it being gas or diesel. If they're just using that wattage for the fan, that's a pretty clever setup!
lexmozli@reddit
It's probably gas or diesel operated (ie: not using electricity to heat). The 40w are just for a fan, circuit board or auto shut-off safeties.
shikkonin@reddit
Maybe just the blowers of a tiny diesel heater.
driverdan@reddit
The solution is to add more panels until you have enough to keep them topped off.
ruat_caelum@reddit
Just like driving (slower acceleration / letting foot off brake and slowing down without brake) using cruise control etc. The Driver's BEHAVIOR often leads to better fuel efficiency than any mechanical changed.
For power you want to google "Parasitic power" in short, just unplug stuff you aren't using. That TV pulls a bunch of power even when it's not on. Internet and router. charging bricks for phones and computers etc.
Turn lights and fans off in rooms you aren't in, etc.
The power strips with a switch on them will just cut power off.
A long extension pole with a floor broom head to wipe off snow won't hurt either so long as you aren't scratching the PV panels.
I suggest you "live normally" and see what happens. Document your daily power data, either in a notebook or dumping logs from charger etc.
Cute-Consequence-184@reddit
Most solar panels these days work great in the winter
joshak3@reddit
To clear snow off the solar panels, I use a 24-foot telescoping pole with a wide, soft brush attachment marketed as a "window scrubber." The attachment has soft material like a dust mop, not bristles as the word "scrubber" would imply. I bought both the pole and attachment in the window-cleaning section of a big box store.
I notice a huge difference in power production before and after removing snow. It may not matter for a dusting, but if you get even a few inches of snow, you'd want to clear them.
jazzbiscuit@reddit
On the plus side - I had panels kicking out about 125% of their rated wattage last winter because of snow reflecting sunlight onto them.... I'm in Ohio & the panels were just leaned up against the house to test things out, so too steep an angle for snow to build up usually. When it did, I'd just go brush them off. I ran them for a couple months that way before deciding to mount them on a mobile cart type setup.
JRHLowdown3@reddit
You will see a slight difference when temps drop low if your battery bank is not in a heated area. I've never noticed a significant drop, but always seems like some. But we are in an area that only gets snow once every 6-7 years. A few weeks of freezing temps, but rarely any snow.
A lot also depends on the size of your array(s). People freak out about cleaning their panels every 3.5 seconds thinking a little dust or a few leaves is going to tank their battery bank... It's not really like that except on very small arrays.
Ryan_e3p@reddit
Adjust the angle as needed for your panels to get direct sunlight, and even though the panels may say they work with some snow on them, best to keep them cleared.
And even with that, having a generator backup is a good idea.
One more thing to consider: Panels often produce higher voltages when they are really cold. Hopefully this was taken into consideration for your build. If you have a 500V inverter, and your string of panels comes out to 490V, that might play well with the inverter. It could trip a failsafe, burn out components, etc. Best to check the manual.
Here's a datasheet giving some stats showing anywhere from a 10% up to a 25% increase: Adjusting Panel Voc for temperature.pdf
makeitrayne850@reddit
get a generator for backup, because the sun takes a vacation in winter too
Eredani@reddit
Winter = shorter days and lower sun angle.
The solution is to over-engineer everything. Whatever your expected power load is, double it. Whatever your expected battery capacity is, cut it in half. Finally, cut your solar watts and sunlight hours each in half. Then re-engineer your system... Basically add a lot more solar or have a plan to make do with less.
A dual fuel inverter generator is a good idea to top off your batteries as needed.
shikkonin@reddit
Nothing?
AlphaDisconnect@reddit
Cleaning snow off the panels. Or suffer the decrease in power.