Earth is in the perfect position to harness the sun’s energy. It’s in what is known as the Habitable or “Goldilocks” Zone of the solar system. Other planets like Venus are too close, in which case they are scorching hot. Or they are too far, like Pluto, in which case they are freezing cold.
The sun is a giant nuclear fusion reactor that produces 35,000 times more power than the planet needs. It dwarfs all other energy sources combined. But what happens when the sun isn’t shining? Can solar panels produce solar energy on a cloudy day?
Solar panels work even on overcast days. That means even on a cloudy day in winter, or even on a rain-soaked day in summer, your solar panels will still produce electricity. This article explores how your solar panels work even when it is cloudy.
How Do Solar Panels Work?
Solar panels work through the process of a photovoltaic effect. In this process, sunlight is converted by a solar panel into an electric current you can use to power your appliances. To understand how solar panels work in cloudy conditions you first have to understand a little about the photovoltaic effect.
On a side note! If you’re in need of a reliable and high-performance portable solar panel, We strongly recommend the Jackery SolarSaga 100W Portable Solar Panel (Amazon Link).
With a high conversion efficiency and foldable design, this solar panel is easy to transport and set up, making it perfect for outdoor activities like camping, hiking, and RV trips.
The US solar cell technology used in this panel ensures that you get the most efficient and reliable solar charging possible.
There is also a 60W option that is more affordable (Amazon Link)
The photovoltaic or PV effect is a simple process to understand. Light contains particles of energy or electromagnetic radiation. Solar panels are composed of solar cells. The solar cells are made of two semiconductors namely the p-type and the n-type.
Joining these layers creates an electrical field at the p-n junction where the layers are joined together. When photons hit a solar panel, electrons which are in both layers are charged or excited. This causes them to move to create a flow of electric current. (Source)
What Happens to Solar Panels when It Is Cloudy?
Solar panels still produce energy even on cloudy days. On overcast days solar panels produce between 10 to 25% of their maximum output. The decrease in output is due to there being less available light for the solar panels to absorb and convert to energy.
Solar panels can convert almost any form of light into electricity. They absorb a broad spectrum of light which consists of visible light, infrared and ultraviolet light. Most of what is absorbed and turned into electricity is visible light or the light you can see. Less than 50% of infrared is converted to electricity. It is even less for ultraviolet.
The sun produces light energy at the highest intensity. On a clear day, up to 1,300 watts of energy strike the Earth. Artificial lighting like LEDs or halogen lights produces only a fraction of that.
The ideal conditions for a solar panel are therefore found in direct sunlight. This is why it is important to install solar panels away from shade and why the output is diminished on rainy days. There is just not enough light from the sun.
Does rain damage solar panels?
Solar panels cannot be damaged by rain as they are waterproof. A good quality solar panel should be able to withstand the effect of rain, high temperature, and even hail storms without suffering any damage.
If there is any leakage into the solar panel as a result of rain then it is most likely you have a defective solar panel. In this case, the manufacturer should replace the solar panel. Most solar manufacturers guarantee their solar panels against material defects.
Also, find out If Solar Panels Work Underwater?
Will your solar panels work in the rain?
Solar panels generate an electric current in the rain so you will still have electricity. The only caveat is they will not produce as much as they would on a sunny day. The lower irradiance on a rainy day means there is less light for your solar panels to generate an electric current from.
For more on this, check out our post Do Solar Panels Work on Rainy Days? How To Protect Them!
Do solar panels work in the snow?
Solar panels will work in snowy conditions. Light snow has a lesser effect on the power generation of a solar panel. Heavier snowfall will greatly reduce the solar panel’s output as the module is shaded and cannot effectively absorb sunlight. (Source)
What Solar Panels Are Best for Cloudy Days?
Monocrystalline solar panels are the best solar panels for cloudy days. This is because monocrystalline solar panels have the highest light-to-energy conversion efficiency of all commercially available solar panels.
Solar panels fall into two main categories. We have crystalline silicon-based solar panels which consist of monocrystalline and polycrystalline. Then we have thin-film solar panels of which we have Cadmium Telluride, Amorphous Silicon, Copper Indium Diselenide, and Gallium Arsenide.
Crystalline solar panels have higher efficiencies than thin-film solar panels. Monocrystalline and polycrystalline differ in terms of their efficiency and how they are made.
Monocrystalline has a higher efficiency than polycrystalline. Monocrystalline solar cells are “purer” than polycrystalline because they are made from a single silicon crystal. Polycrystalline is made from numerous pieces of crystal. It is this difference in how they are made that results in the difference in efficiency.
| Solar panel | Average efficiency |
| Monocrystalline | 18-21% |
| Polycrystalline | 15-18% |
| Thin-film | 12-15% |
On a cloudy day, monocrystalline solar panels will produce more energy because they have higher efficiency. Higher efficiency means they can convert more of the light they absorb into electricity.
Monocrystalline solar panels outperform both polycrystalline and thin-film solar cells on clear days as well. Although they tend to be more expensive, monocrystalline solar panels produce more energy which typically means you have to buy fewer panels compared to the other two solar cell types.
Low Light Solar Panel Research
Solar cell technology is still relatively young. The first modern solar cell was made in 1954 and had an efficiency of less than 2%. Solar panel technology continues to improve and today we have solar panels reaching conversion efficiencies of over 20%. (Source)
As the industry grows and more research is funded, you can expect solar cell technology to improve to reduce and maybe even eliminate weaknesses like low energy output in low light conditions.
This could mean solar panels that produce just as much energy in cloudy conditions or even at night as they do in direct sunlight.