Snow pauses panel output, and grid-tied solar shuts off in an outage. How a home battery keeps Carbondale and Basalt homes running through a winter storm.
Short answer: Snow on your panels stops most of their output until it slides off or melts, and on a sunny day after a storm that often happens on its own. A standard grid-tied solar system shuts off when the grid goes down, even on a clear day, so it can't keep your lights on during a winter outage. A home battery such as the Enphase IQ Battery 10C can. It runs the circuits you choose on stored power, and it recharges from your panels once they clear.
We've been putting solar on roofs from Carbondale to Glenwood Springs since 2003, and two winter questions come up a lot. My panels are buried, is something wrong? And, from a dark kitchen in Basalt during a storm: why isn't my solar doing anything?
Panels need light on the glass. A few inches of fresh powder blocks most of it, so production drops close to zero while the snow sits there. That's normal and it doesn't hurt the system.
Snow rarely stays long on a tilted array. Dark glass warms up as soon as the sun hits it, a thin layer melts underneath, and the rest slides off. On a bluebird morning after a storm in Snowmass you can watch it happen by lunchtime. Flat or low-pitch roofs hold snow longer, and so do arrays in the shadow of a ridge or tall spruce, which we factor in when we plan a system.
Short winter days are part of the yearly production estimate in your proposal, so a slow December is expected. A snowy week is a dip you can plan for.
Usually, no. Climbing onto an icy roof is a far bigger risk than a few days of lower output. Metal roof rakes and shovels can scratch the glass or catch the frames. If snow is stuck on your array for a long stretch, or ice is building up at the bottom edge, call us and we'll take a look.
Heavy, wet snow loads up trees, and trees come down on power lines. Out toward Marble and up the side valleys, a single downed line can leave a road of homes dark for hours.
A grid-tied system without a battery is designed to switch off when the grid fails. That protects line crews working to restore power, but it means your panels sit idle during the outage, sun or no sun.
With an Enphase IQ Battery 10C, your home separates from the grid and keeps going on stored power. You choose the backed-up circuits ahead of time. Common picks are the furnace fan, the fridge, the well pump, some lights and the internet router. Once the panels shed their snow, solar starts refilling the battery during the day.
Plan for the worst version of this: a storm that buries the panels and takes down the line at the same time. In that case the battery is working only on what it stored before the storm. That's why we size backup around the loads you really need, not the whole house. The Enphase IQ Battery 10C is 10 kWh per unit, and we install it in sizes of 10, 20, 30 or 40 kWh.
Enphase's data sheet lists an ambient operating range of -4°F to 122°F while charging. Cold nights in Eagle and El Jebel can drop below -4°F, so placement matters. We look for a spot that stays inside the rated range.
If Xcel sends your bill, its residential on-peak window runs from 5 to 9 p.m. on non-holiday weekdays, all year. In Rifle in December, it's dark before that window opens, so your panels aren't helping by then. A battery that charged during the day can carry the house through those hours. Read Xcel time-of-use rates in Colorado for how the rate works.
Summer can bring a different kind of outage: utility power shutoffs during high fire danger. The battery does the same job in both seasons, but the timing and warning are different. Our post on fire safety outages and power shutoffs covers summer. For the hardware and backup options, see batteries and backup. Price ranges are in what solar costs in the Roaring Fork Valley.
Barely. Snow blocks the light, so output drops close to zero until it melts or slides off. On a tilted array in the sun, that often happens within a day.
Not by itself. A grid-tied system without a battery shuts off when the grid goes down. With a home battery like the Enphase IQ Battery 10C, your chosen circuits stay on.
Enphase rates it to charge from -4°F to 122°F ambient. We pick an install spot that keeps it inside that range through a valley winter.
No. The fall risk isn't worth a few days of output, and metal tools can damage the glass. Call us if snow or ice stays stuck for a long time.
It depends on which circuits you want running and for how long. We size it from your actual loads, using 10 kWh units in systems of 10 to 40 kWh.
We're an Enphase Gold Installer based in Carbondale. Tell us which circuits you can't do without and we'll design backup around them. Get a free quote, or call us at (970) 963-1060.
%2520(1)-min.jpeg)