It wasn't too long ago that seeing solar panels on your neighbor's roof would have surprised you, but more and more people are turning to renewable energy sources, like solar, to help power their homes. A recent study showed that solar usage had increased annually by 33% in the past decade. This growth is largely due to federal tax credits and the positive environmental impact, helping make the benefits of using solar more enticing than nonrenewable energies like coal and gas.
Still, if you're considering installing solar panels, you might be concerned about how much electricity your home will receive during less optimal conditions. You may wonder if solar panels work on cloudy days and if solar panels work at night.
While today's solar panels don't work at night, you still may be able to use excess electricity produced during the day, depending on the system you have installed. On cloudy days, your solar panels can still generate 75% to 90% of their expected output.
Read on to learn how much solar electricity production you can expect on cloudy days and how solar panels can be a reliable power source during nighttime or with limited sunlight.
Do Solar Panels Work on Cloudy Days?
The short answer is that solar panels work on cloudy days but may not generate as much energy as on a bright, sunny day. Typically, during non-optimal conditions, like cloudy or rainy days, you'll get around 75% to 90% of your average energy output. If there is substantial cloud coverage, like during a severe thunderstorm, your solar panels may not produce much energy at all.
However, this doesn't mean that solar panels aren't worth installing if you live in a region with a lot of overcast days. Many top U.S. cities where solar is popular are not particularly sunny. And depending on where you live, Texas solar incentives make it possible to enjoy energy bill savings and a quick break-even point on the cost of a solar installation or lease.
A rainy day here and there isn't the worst thing for your solar panels. A heavy rainstorm can help wash away dirt and debris from your home's solar panels, allowing them to absorb sunlight more efficiently. In many cases, your solar panels will generate less energy, but in certain conditions, cloud coverage or rain can actually help your solar panels be even more efficient.
Do Solar Panels Work At Night?
While your home's solar panels can work during cloudy days and sometimes even more efficiently, they will not produce any energy at night. How solar panels work is by using the photovoltaic (PV) effect—a process by which PV cells convert the absorbed sunlight energy into electricity.
The PV effect occurs when light energy strikes a solar cell, knocking electrons loose from the atoms in the semiconductor material. The solar panel cells form an electrical circuit generating electricity. For all this to happen, you need a constant light source, and the light produced by the sun is the most efficient. If there is not enough sunlight, such as at night, your panels won't make any electricity.
Scientists are working on solar panels that work at night or in the absence of light, such as in space. However, night solar panel technology is far from ready and reasonably priced for commercial use.
Since solar panels can only make power during the day, you may ask, "How do solar panels work at night?" While your solar panels won't generate electricity at night, the energy they produce can be stored for use when there is inefficient light or none at all.
Two solar energy plans help to resolve this issue. Net metering and solar-plus-storage technologies allow solar panel systems to access banked electricity overnight. Both utilize connections to the electric grid or a solar storage battery installed at your home. As a result, solar panels can be a sustainable 24-hour energy solution. You'll need to check with your energy provider to see if these options are available where you live to decide whether it's worth making the switch to solar.
What Factors Can Affect Solar Energy Output?
We've discussed how solar panel output can be affected by substantial cloud cover and nighttime, but other factors can prevent your solar panels from operating efficiently.
Dirt and Debris
If your solar panels are covered by a thick layer of dirt or debris, this may cause them to be less efficient. Dirty panels can affect output by up to 25%, the same as during a very cloudy day, so it's always a good idea to ensure your solar panels are free of excess dirt and debris.
Smog can also significantly reduce your solar panel output. One study showed that this is especially true in large cities or areas close to urban centers. Smog-like conditions can block the amount of direct sunlight, causing solar panels not to generate as much electricity. If you live near a major urban area, you may have to increase the number of solar panels on your home to help offset the effects of air pollution.
During the winter, you may be concerned if snow on solar panels will decrease output. A dusting of snow has little impact on solar panels because the wind usually blows it off before it becomes an issue. However, heavy snowfall that covers your panels will decrease the output, but usually not for too long. Since solar panels are typically installed at a steep angle and exposed to direct sunlight, heavy snow naturally tends to melt and slide off the panels, meaning that solar panels in snowy conditions will start producing electricity as usual in no time. Plus, as the snow melts, it may help increase output by cleaning dust and debris off your panels.
To maximize your energy output, solar panels need to point in a direction that captures the most sunlight. The best output occurs when your home's solar panels are perpendicular to the sun's rays. If you start to notice a continual decrease in your output, it could be that your panels need to be realigned.
Should I Make the Switch to Solar?
While the first practical solar cell was invented in 1954 by Bell Labs, it's only recently that this technology has become a popular energy alternative for both homes and businesses. During sunny days, the energy produced by solar panels can significantly reduce your energy costs. Still, solar panels aren't as effective under sub-optimal conditions, like during cloudy days or at night.
In Texas, Gexa Energy has helped thousands of homes switch to solar. Gexa can help you decide if solar panels are worth it and determine if they are the best alternative energy source for you, based on where you live and how much electricity your home typically consumes.