Having solar panels is very different from getting power off the local grid. The advances in solar technology in recent decades and increased affordability mean that more homes are using solar than ever before, but homeowners with solar panels still have many questions regarding this. Whether you’ve already installed them, bought a home with them in place, or are thinking about putting them where you live, you might wonder whether or not they’ll work on cloudy days. Since you will rely on them to generate power to pay off, it’s a legitimate question. Whether or not solar panels work on cloudy days is very important in places that are known for overcast weather.

Do Solar Panels Do Anything in the Rain or Under Clouds?

Photovoltaic panels use sunlight to generate power. They’re at their most effective under direct sunlight. However, they can still work even if the light is partially blocked by overhead clouds or even reflected off of other things. Rainy days can actually help your panels because precipitation usually washes dirt or dust off the surfaces.

Daylight is more important than sunlight. Modern panels are highly sophisticated pieces of technology. They can work all year long in many kinds of weather. While they can still work while cloudy, you should know that they’re not going to be as effective. When there aren’t as many direct rays from the sun hitting the panels, there won’t be as much power generated. The less shadow there is over any solar panel, the better it’s going to perform for you.

One thing to watch out for on cloudy days is the “edge of cloud effect.” When that happens, you might see an energy spike in your panels. If the sun’s rays are actually magnified when breaking through the cloud cover, then you might actually get significantly higher electrical generation than you usually do. That might sound great at first, but it can result in extra problems. The sudden generation of high electricity might blow out your fuses. You might even see your inverter lifespan get a little bit shorter every time it happens.

How Much Effectiveness Do Solar Panels Lose in Cloudy Weather?

Ideally, your solar panels are positioned in places where they get sunlight all throughout the day. However, many homeowners can’t do this. Also, cloudy days still happen. Given that, your solar panels aren’t going to be as efficient on overcast days as on sunny ones. However, just how much efficiency are they going to lose? Overcast weather and cloudy days do seriously impact the efficiency of solar panels, and they might only generate a quarter of the energy that they would output under direct sunlight.

What About the Shade?

Solar panels can still produce electricity in the shade, but there will be a serious reduction in how much they can generate. Ideally, you won’t have any shade on your panels. Shade from buildings, gravel, leaves, or trees can all drop the overall power that your panels generate and weaken the system’s efficiency. If you’re relying on solar panels to pay for themselves in terms of power generation, any drop in efficiency is going to make it take longer. Some shade might be unavoidable because of how the sun moves over the course of the day, but anything you can do to keep them clear and in direct sunlight is going to help you make the most of your investment.

How About Snowy Days?

A slight dusting of snow doesn’t usually have any impact on solar panels. As long as they’re not directly coated on the panels, everything should continue working normally. An accumulation of snow might drop efficiency by more than 5%, however. Fortunately, you can counter this by using a bigger inclination angle. If snow is able to slide off the panels and not stick, then you’ll keep more of your prized efficiency. You might also mount the panels high enough to stick out of deep snow on the ground. While panels can absorb reflected solar energy, their angle usually doesn’t help them generate more power due to glare off of surrounding snow on the ground.

Can Solar Panels Work When It’s Night?

Solar panels have to have sunlight. There’s still at least low light on a cloudy day, but there’s nothing for panels to work with at night. Fortunately, you can have a battery system installed that saves your daytime power for nightly use. You might also have a setup where your daytime power is sold into the grid and you take power off the grid at night. That way, you’re still reducing your carbon footprint and saving money on power.

What Solar Panels Work Best on Cloudy Days?

Nearly any solar panel should work when it’s cloudy. However, some options do better than others. The three primary categories of solar panels currently on the market include polycrystalline PV, monocrystalline PV, and amorphous (also known as thin film). Each technology is different in how it’s made and how much silicon is used. They’re also different in terms of cost, total physical size, light sensitivity, and efficiency levels.

Monocrystalline PV is often the best choice for overcast weather; the cells in them use the highest-caliber silicon, as the crystals are formed from just one item. That means that the electrons generated can flow freely and farther, so there’s a higher electricity rate. These panels are also smaller in size and therefore work great in limited spaces. Also, they have higher resistance to fluctuations in heat, and they even last longer than many other solar panels.

They’re great choices for cloudy days for many reasons, but they’re also rather expensive. The higher-caliber materials contribute to the cost. Also, the manufacturing process is more sophisticated.

How Can You Improve Solar Panel Efficiency?

There are steps you can take to improve your solar panels and their efficiency on overcast days. The biggest factor is simply location. Put them somewhere that maximizes how much time they have in sunlight, especially as the sun arcs over the daily sky. Keep their angle in mind, too, which is going to be largely determined by your latitude or distance from the equator.

Remove anything blocking them that you can. You can’t move your neighbor’s house, but you can possibly trim down or cut down bushes and trees that keep the sun from hitting your panels directly. Also, make sure that your panels are always clean. Wind and rain might do some of that for you, but just a non-abrasive sponge and water are all you need to get most debris and dust off of them.

Our Professionals Can Help

Choosing solar panels makes two statements about your lifestyle. First, you want to free your budget of dependence on fossil fuels because you’re willing to invest in the limitless clean energy of the sun. Second, you want to reduce your personal environmental footprint. To get answers to your solar questions in the San Diego area, contact us at Friar's Heating and Air. We offer heating, cooling, indoor air quality, and solar services. Call us at your earliest convenience to see how Friar's Heating and Air can help your home.

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