Do Solar Panels Work in the Winter and Snow? 

Winter is officially upon us and a common question we receive is whether our solar panels work in the winter and snow. When EmPower Solar designs rooftop systems, the engineering team accounts for seasonal differences in solar production and savings so that clients receive the most accurate forecasts possible. We’ve been based here in New York for over 15 years, and are all too familiar with the unpredictable winter weather. Solar panels are installed in every climate across the world, so there are many answers to these common concerns, but today we address winter weather for solar panels when it comes to Long Island and New York City.

Solar Panels Work Fine in the Snow

There are many misconceptions about solar panels in the winter. Many believe that panels don’t work in the winter, but cooler weather actually allows for a more even flow of electricity from your system’s photovoltaic (PV) cells into your home. Cooler temperatures enhance solar energy production efficiency, increasing the daily amount of electricity produced. The bigger factor that affects system production in winter is that we have fewer daylight hours, and the sun is lower in the sky, so more shade is created at different times of day from nearby trees, which can reduce the amount of direct sunlight hitting the panels. It is important to remember that panels create electricity from the sun’s light, not the sun’s heat.

WHAT HAPPENS TO MY SOLAR PANELS WHEN IT SNOWS?

During a light snowfall, sunlight can still get to the solar panels and produce energy. In a heavy blanket of snow, solar panels will not receive enough sunlight to operate, and the system is not likely to turn on or produce any energy on those days. However, snow typically melts off of solar panels quicker than it melts off of an asphalt roof. This is possible because our engineers make sure your panels are in the best position to get the maximum amount of sunlight possible, and panels are usually installed facing the south, west or southwest. Unlike rough roof shingles, the solar arrays are smooth, so the snow typically melts or slides away quickly and easily on its own. We also install ‘snow guards’ over decks, doorways, and windows that prevent snow from coming down in large chunks during melts.

SHOULD I CLEAR SNOW OFF MY SOLAR PANELS?

There are times during heavier snowfall and blizzards when the snow may pile up on your roof and solar panels. Panels won’t work at this time, but it’s only temporary. If you are, however, concerned with squeezing out every last kWh of your system, you can call our service team at 516 837 3459 (x153) to schedule a snow clearing. The cost to do so is not usually offset by production you will gain at this time of year, so we don’t always recommend it, but it is available. We also don’t recommend climbing on your roof in the snow, or using any brushes, scrapers, or other tools to clean the snow off of your panels. The solar panels are coated in a unique anti-reflective coating that can be seriously affected by foreign objects. Product warranties do not cover damage accidentally caused by cleaning your panels.

SOLAR POWER GENERATION IN THE SUMMER VS. WINTER

When solar panels are installed on a home, the home still remains tied to the electric grid and has access to net metering. That way, the utility company can both buy excess energy and provide electricity if the solar panels can’t receive adequate sunlight. This applies to business and commercial scale installations too.

From spring through autumn, solar panels operate at their maximum capacity, and often produce more energy than a home needs in a given month. That excess energy is sent back to the grid, and the homeowner earns solar credits on their monthly utility statement. In the winter, when solar panels are not producing as much energy, homeowners can use their built-up solar credits and pull energy from the grid without necessarily having to pay for those credits. Keep in mind that this occurs mostly in systems designed to produce 100% or more of a home’s annual energy needs. Sometimes systems can only produce a portion of annual energy needs, so some energy will need to be purchased from the grid when there are no credits available.

Keep in mind, if your panels are installed right before the winter, you won’t have that summer energy bank to draw from. Once you’ve made it through the high production months and build up your credit bank, you will be able to take advantage of your energy credits next winter.

Be Mindful of Your Energy Consumption/Monitor Your System

Since the days are shorter and your panels have less access to sunlight, we recommend keeping an eye on your energy consumption. If you already monitor your system closely and want to keep production and consumption even, here are a few tips for you:

• Everyone loves a good holiday light display, but those shows can be energy hogs. Blow-up decorations use a lot of energy with the fan motor constantly running, so make sure to use a timer to prevent your displays from using all of your produced energy.
• It may be tempting to turn on that electric space heater if you’re working in the garage or the basement, but remember that they pull an enormous amount of energy and operate extremely inefficiently. Use portable electric space heaters sparingly and only when necessary.
• Unplug idle electronics, such as coffee makers, microwaves, chargers, printers, and even your computer. It feels good to power down for the day!
• Replace your traditional light bulbs with LED bulbs. LED bulbs are the most efficient lighting option, and use 75% less electricity than incandescent bulbs. When you’re not using those new lights, be sure to switch them off!
• Consider turning down your thermostat by a few degrees, especially during the hours you’re tucked away in bed or at the office. The U.S. Department of Energy suggests saving energy in the winter by setting your thermostat to 68°F while you’re awake and setting it lower while you’re asleep or away from home

It’s critical that you consistently check your system to ensure that it is producing energy as expected. We recommend that you login and verify system operation at least once a week. You’ll also have access to full reports on your energy data. Note: if there is snow on top of your panels, you may get errors. This will go away when the snow melts in a few days!

There’s snow reason not to go solar in the North East!

For more information on monitoring your system, solar net metering, as well as a comprehensive list of FAQs, please visit the Client Corner.