Solar energy production decreases in winter but that’s no reason to panic

winter solar energy

Yes, your solar energy system will produce energy in the winter.

Yes, solar energy production will drop in October but don’t panic; your panels collect energy year-round and will catch up next spring.

If you have solar panels on the roof of your home or office, you’ve probably enjoyed a productive summer. In an average year in Northern Illinois, we enjoy nearly 200 days of sunny or partly sunny days. Your solar panels eat it up. But, a higher percentage of those days are in the summer months.

In the winter, on average, 46 percent of the time between sunrise and sunset will have clear skies. That means that, out of 91 days of winter, we can expect 42 days with clear skies. When it comes to collecting solar energy, the solar panels on the roof don’t care if it’s 28-degrees below zero or 110-degrees outdoors. Sun is sun and sunlight creates solar energy.

The scenario above presumes that 42 of the daylight hours this coming winter will offer optimal sunlight for creating solar energy. That doesn’t mean the solar panels will sit passively on the roof the rest of the time.

Even without a clear sky, solar panels work. On a cloudy day, the solar panels will still collect energy they simply won’t do so as effectively. Depending on how thick the cloud cover is, the solar panels may only produce 25 percent of the solar energy they would on a clear day.

Winter is generally cloudier than summer. This, as Weatherman Tom Skilling has explained, warm weather tends to build taller cumulus clouds that grow vertically. In the winter, with colder weather, “condensation and cloudiness tend to be horizontally stratified, resulting in widespread and long-lasting overcasts.”

So, yes, your solar energy production will fall in the winter as a natural byproduct of more consistent cloud cover. But, your solar panels will continue to work and will catch up again next Spring.

If you’re concerned about it, you can try reducing your electrical usage in the winter. Unplug unused electronics. Check the refrigerator and adjust the temperature if it’s unnecessarily set too cold. Use LED holiday decorations. Insulate your electric water heater. If you have electric heat, you can seal your windows and doors, lower the thermostat and wear a sweater.

No matter what you do, don’t worry. Weather will warm again. The sunny days will increase next Spring and Summer.