Do Solar Panels Work on Cloudy Days?

Cubix Mark
Solar Panels with Overcast Clouds

As the world turns towards cleaner, more sustainable energy options, solar power has taken center stage, capturing the interest of homeowners and businesses alike. With a promise of renewable energy and lower electricity bills, solar panel installations are higher than ever. Although, despite the enthusiasm for this sun-powered technology, one question we often receive from potential customers is: “Do solar panels work on cloudy days?”

Understanding Solar Energy

To understand the effect cloudy days have on solar energy production, we first need to understand how it works. Solar energy is created by transforming the sun’s rays into electricity that can be used in our homes and businesses. This process involves a piece of technology known as a solar panel.

The Science Behind Solar Panels

Solar panels are made up of many small units called photovoltaic (PV) cells. A typical solar panel comprises many of these cells, which are essentially small, sandwich-like structures. Each ‘sandwich’ consists of two slices of semiconductor material, usually silicon, with a layer of conductive elements in between.

Photovoltaic Effect

When sunlight, composed of tiny energy particles called photons, strikes a solar cell, it penetrates the cell’s surface and reaches the semiconductor layer. Here, the photons transfer their energy to the atoms of the semiconductor. This energy is absorbed by electrons – the negatively charged particles orbiting an atom’s nucleus – causing them to break free from their atomic orbits.

This action sets the stage for the creation of an electric current. The solar cell is designed so that these freed electrons can only move in one direction, creating a flow of electric charges. This is essentially an electric current, which is then collected by thin metal fingers on the top of the cell and transferred to a wire. From here, the electricity can be used immediately or stored in a battery for later use.

Can You Power Your Home on a Cloudy Day?

So, what happens on a cloudy day? Will your solar panels stop working?

Effects of Overcast Conditions

Contrary to common perception, overcast or cloudy conditions do not spell a total halt in solar energy production. Yes, it’s true that solar panels thrive under clear, sunny skies, but they don’t entirely cease their operation when those skies turn grey.

Clouds certainly act as a barrier, scattering and diffusing the sun’s rays, but they do not completely block sunlight. In fact, diffused sunlight, which is sunlight that reaches the Earth’s surface indirectly after being scattered by atmospheric particles, can still fuel solar panels. Remember, it’s not the visible brightness of the sun but the ultraviolet (UV) rays that our panels need to produce electricity.

Efficiency During Cloud Cover

While it’s true that under a cloudy sky, the output of solar panels decreases, they don’t stop producing electricity altogether. Research suggests that, depending on the density of the clouds, solar panels can still generate between 10-25% of their maximum output. Think of it as a dimmer switch – the output dims under cloudy conditions, but the light doesn’t go out.

How to Use Solar Power on Overcast Days

While it’s true that solar panels themselves can’t generate electricity without sunlight, they don’t leave you powerless when the sun goes down or during those heavily overcast days. This is where the wonder of modern energy storage technology, specifically solar backup batteries, comes into play.

Solar backup batteries are an integral part of many solar power systems. They are designed to store excess electricity generated by the solar panels during the day, effectively saving it for a proverbial rainy day – or, in this case, a cloudy day or night-time.

How do Solar Batteries Help?

 When your solar panels are basking in the sun’s glory and producing more electricity than you’re consuming in real time, instead of letting this excess power go to waste, it gets sent to your solar battery for storage. This stored energy is then available for use whenever you need it, such as during the night when your panels are dormant or on those cloudy days when panel efficiency might be reduced.

This ability to store and use power as needed is one of the key advantages of having a solar battery as part of your solar energy system. It provides a level of energy independence, ensuring you have a reliable power source, even when conditions aren’t optimal for solar energy production.

Solar backup batteries come in various sizes and capacities, allowing you to choose one that best fits your energy needs. Larger systems can store enough power to run your home for a few days, which can be especially useful during power outages or periods of prolonged poor weather.

Getting the Most out of Your Solar Panels on Cloudy Days

First, make sure you are using a high-efficiency solar panel. Solar panel technology is constantly improving. Today’s panels are much more efficient than those from a decade ago, and they’re getting better at converting lower levels of sunlight into electricity.

Also, regular maintenance and optimal placement of your panels can help increase their efficiency. For instance, installing panels at an angle helps them capture more sunlight, and keeping them clean ensures they can absorb as much light as possible.

solar panels on house

The Future of Solar Power

Looking ahead, the future of solar power is bright, even on cloudy days.

Advancements in Solar Technology

Advancements in solar technology, such as the development of solar cells that can capture a broader spectrum of sunlight, will further enhance the efficiency of solar panels. Additionally, improvements in energy storage solutions will allow us to make the most of the solar power generated on sunny days.

The Impact of Solar Energy on the Environment

Solar energy can play a significant role in reducing our reliance on fossil fuels, leading to a decrease in greenhouse gas emissions. This makes it a key player in mitigating climate change and promoting environmental sustainability.


In conclusion, solar panels do work on cloudy days, albeit with reduced efficiency. However, thanks to constant technological advancements and proper system management, solar power remains a viable, sustainable, and increasingly efficient energy option for our homes and businesses, regardless of the weather. The good news is that Utah is the 9th sunniest state in the nation. This means that Utahns looking to add solar to their homes can rest assured that cloudy days won’t significantly impact their solar energy production. 

Frequently Asked Questions

Q: Do solar panels work in the rain?
A: Yes, solar panels can work in the rain. Rain can help cool down solar panels, improving their efficiency, and it also helps clean the panels, which can lead to better performance.

Q. Can solar panels work at night?
A: Solar panels can’t produce electricity at night, but many solar systems are equipped with battery storage systems that store excess power produced during the day, allowing you to use solar-generated electricity at night.

Q. How much energy can solar panels produce on a cloudy day?
A: On a cloudy day, solar panels might produce around 10-25% of their usual output. However, this can vary depending on factors like the density of the clouds and the type of solar panel.

Q. How can I improve the efficiency of my solar panels on cloudy days?
A: Regular maintenance, optimal placement, and choosing high-quality panels can improve efficiency. Also, technological advancements are leading to more efficient solar panels that can perform better under different light conditions.

Q. Is solar energy a good option for areas with many cloudy days?
A: Yes, solar energy can still be a good option for areas with many cloudy days. The key is to have a well-designed system that’s properly sized for your energy needs and possibly a battery storage system to store excess power for use when the panels aren’t producing as much.

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