Do Solar Panels Work In The Rain?

Updated on November 22, 2022
Do Solar Panels Work In The Rain?

Do solar panels work in rainy weather?

Solar panels do work in the rain but with much reduced output. Power output may be between 5% to 10% of the solar system rating in full sunshine. Output watts depends on the effective irradiance i.e. sunlight level. Light rain will block less sunlight and heavy rain, which tends to fall from darker rain-clouds.

Video – Do Solar Panels Work On Rainy Days?

How efficient are solar panels work on rainy days?

Research studies have found that the impact of rain falling onto solar panels has an even worse than dark cloudy days on panel output.

This is because rain drops out of clouds, so there are two things blocking sunlight – rain droplets and clouds. If the rain is heavy, then it stands to reason that more light will be blocked.

How is solar energy generation affected by rain?

Solar panels only produce about 10% of their fully rated power in the rain. Yes, in fact they will work in rainy weather, but with a very low efficiency.

Why does rain reduce solar panel output?

Solar panel output watts depends on several factors and any solar system system has losses.

However, by far the biggest factor affecting solar output is called irradiance, which is a measure of the strength of the sun’s energy when  it falls on a solar panel’s surface.

Irradiance is measured in kilowatt-hours per square meter per day (or year) (kWh/m2/day). For convenience sake when sizing solar panels, this is also known as peak-sun-hours.

The sun’s strength changes by location, for example, Las Vegas, Nevada has a higher irradiance level than Anchora, Alaska.

The sun’s energy can also be reduced by putting something in the way of the sun’s rays and the solar panel, such as a tree (shading), clouds or rain.

Why does rain reduce solar panel output?

Does rain damage solar panels?

It depends. Rain is water, and water does come from the sky, but rain isn’t always what or how much you’re expecting.

Rain in the form of a light mist might not do any damage at all. In fact, a light coat of rain could even work as a protective barrier that helps to keep other harmful elements like dust and dirt off your panels.

A heavy downpour, however, might cause your solar panels to be damaged. In general, the heavier the rainfall levels are, the higher your risk of damage.

If it’s raining that hard or for an extended amount of time you should expect some damage. Heavy rain could break apart modules and rip the wiring connections on your solar panels.

High winds and hail are other weather conditions that can work against you as well. Hail can break apart solar panel modules and crack glass.

Can hail-stones damage solar panels?

Hail is very dangerous for solar panels. Although you can decrease your risk, hail storms are among the most common causes of power outages in the US.

According to data released by the North Central Power Coordinating Council, there were over 20,000 reported “disturbances of service” in the US due to hail and lightning damage during 2014.

Areas with a high density of solar panels often report service interruptions caused by hailstorms. Recently, hail storms damaged solar farms in West Virginia, causing power outages.

Even if the damage isn’t severe enough to cause a power outage, hail can cause serious issues with your solar system.

If you’re using an inverter, it could become damaged by water or ice that was left on the surface of the panel after the hail storm.

This is because sudden temperature changes can fry your appliances and damage wiring.

Can hail-stones damage solar panels?

Solar panels are much less efficient on rainy days – Image source:

Do solar panels work in the snow?

Yes. A few inches of snow or a light dusting of frost won’t hurt your solar system. Solar panels work from the sunlight that reaches them, and snow can actually help to reflect that sunlight.

It’s also important to remember that solar panels are often installed in some of the most inhospitable places on earth—places where they’ll see plenty of snow.

Solar panels are designed to be able to stand up against all kinds of weather and temperatures—even snow and ice storms.

Solar panels get warm in use and are mostly installed on an angle so snow will just slide off them and won’t stick. Solar panels are also designed to withstand heavy snowfall.

How well do solar panels work on cloudy days?

Clouds do reduce how much energy a solar system can capture. You’ll get the least amount of sunlight available on a cloudy day, and it’s not uncommon for some regions to be cloudy for most of the day.

If you’re in an area where you’ll only see partial sun for most of the day, you might want to consider installing more solar panels than you would if your area saw plenty of sunny days.

Do solar panels work in winter?

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Yes. Solar panels work even in the winter. Snow is actually a good reflector of sunlight, so it won’t block your solar panels from producing energy.

However, snow and ice will still be melted off your panels when you’re using them. This melting can cause damage to your inverter and other components in your system.

You should plan for regular maintenance to check for any damage from the snow and ice that’s been melted off the surface of your solar panels.

Do solar panels work at night?

No. Solar panels depend on direct sunlight, so they’ll stop working when the daylight is blocked. That said, you could still use solar energy at night if you’re using an off-grid solution.

You’d have to stockpile the energy you produce during the day in batteries. In this way, your off-grid solar system could store up and save as much energy as possible so that you can use it at night.

Do solar panels work in the moonlight?

Not at all. The moon’s energy is much too weak to charge your solar panels. They’ll only work when there’s plenty of direct sunlight available to convert.

Can a solar panel work in fog?

It depends on how thick the fog is. Even if it’s thick enough to cut down visibility, thin fog should still allow enough sunlight through for your solar panels to function correctly.

Resource: Solar panel output in the rain

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