The short answer is Yes. Solar Powered Street Lights do work in the winter. In fact, solar PV panels work better in cold temperatures than in hot temperatures (which we will explain later why).
If you are wondering how well they work during cold seasons, we’re here to answer that. In this article, we’re going to unravel your unsolved myths and questions about solar lights installed in cold climate countries. Read on!
Do Solar Lights Work in Cold Weather?
PV panels work by absorbing direct sunlight. It doesn’t matter if you’re experiencing cold or hot ambient temperature, as long as UV rays hit the PV panels.
To picture this, let’s first demonstrate how PV cells work through the Photovoltaic Effect.
When the rays hit the panel, the electrons within it will be disturbed by the incoming photons from the sun. Because the electrons are displaced from immobility, they will now be in motion. The electrons will now flow into a stream of electrical current.
There’s no heat involved in the process so when generating electricity, you don’t necessarily need a warm climate. You just need enough sunlight to directly hit your solar panels for 6 to 8 hours before it gets fully charged. This can be used for 4 to 7 days autonomy.
So to answer that question: Yes, solar street lighting system can work in cold weather.
Do Solar Panels Work Better in Cold Climates?
Solar panels in solar street lights can not only work great during winter, but they generate electricity better.
For one, winter snow is white and reflective. In fact, snow is the most reflective natural blanket of Earth. And thus, this renders solar panels free sunlight projection services.
This means that snow acts as a mirror projecting sun rays toward the solar panels for better PV performance. This not only intensifies the rays that hit the solar panel, but also allows more UV rays to be harnessed.
Another thing is that the cooler temperature can also help improve the output of the PV panel. Many people’s common notion is when it’s cold, the solar panel cannot optimize conversion. This is wrong. Photovoltaic cells can actually function better in colder climates than hot climates.
How Does Temperature Relate to How PV Cells in Solar Lights Work?
You might be wondering how solar PV cells work more efficiently in cold weather.
As mentioned earlier, solar panels work with electrons bumping and moving within it. When the system experiences cold temperature, the electrons won’t budge that much.
So when sunlight hits the panel during cold weather, there’s no excessive electron movements. This will naturally incur a huge voltage difference. And with a big voltage difference comes more energy produced.
In contrast, when the temperature is extremely hot, such as in deserts, the electrons have more input activity than the output energy. This is because excessive heat can lower the electron’s efficiency in converting the sun’s energy to current. In fact, solar panel efficiency may decrease above 77 °Fahrenheit (25 °Celsius).
And you know how excessive input versus a smaller output can lower a system’s efficiency, right? As a result, hot temperatures can actually lower your energy production. So the best scenario for solar lights is when the temperature is cold and there’s still a gleam of sunshine.
That also explains why one of the most efficient solar light systems in North America is in Canada, during its cold, sunny days.
But don’t conclude here just yet. There are reasons why some naysayers don’t agree with solar street light installations in winter. The next chapter explains why.
Can Solar Panels Withstand Snow?
Um…it depends. Because if it’s snow covering the face of your solar panel, it’s another story.
When snow accumulates on the surface, it can block the sun’s rays from reaching your panels. Thus, there will be a decrease in electricity produced.
That’s why manufacturers recommend installing PV panels in a tilted manner so that it would get off any particles and snow for an optimized energy conversion.
The great thing about solar panels is its sleek design. You see, they are designed with a smooth and tempered glass finish so as not to magnetize or attract any matter. When snow does accumulate on top, its sheeny surface can easily slide off the snow when it melts a little.
But don’t get us wrong. A pile of snow can reduce energy production. If a blizzard hits your town, snow can heavily accumulate on the panel’s surface, making it harder for it to receive sunlight.
In fact, a study reveals that solar panel production can be reduced by 0.85% to 5.31% when snow entirely covers the surface like shown in the picture.
Of course the most logical thing to do is to clean it. But be careful not to damage the glass with your snow rake.
Sometimes, hosing it down can do the trick of getting rid of snow. But if you can’t do the cleaning alone, better call the people offering solar panel cleaning.
Can You Leave Solar Lights Out All Winter?
This depends if we are talking about small solar garden lights, solar lanterns or solar street lights. It also depends where you live.
If you live anywhere on the sunbelt (shown below), it’s safe to leave your solar lights outside all winter.
For example in America, the safest places are Arizona, Oregon, California, New York, Nevada and other southern states in the US. In the Middle East, Iran, Turkey and other countries experiencing snow can leave their solar lights outside all year round.
If, however, you live in an area where it heavily snows and rains during winter seasons, you might need to store your solar lights. This is because moisture can build up inside some solar garden lights or solar yard lights.
It also depends which type of solar light you are using. Most solar street lights are built for areas experiencing heavy snow storms. Their batteries are enclosed and buried underground.
They also have stronger poles to withstand strong winds. For these types of lights, you wouldn’t need to lock them away during winter seasons. But for smaller solar lighting units, you might want to store them away during winter.
How to Charge Solar Lights in the Winter
Contrary to the belief that solar lights cannot produce electricity during the winter, it definitely can, but in reduced amounts. In the winter months, you have to make the most out of the lesser daylight you’re experiencing.
Here are a few things you can do to optimize solar energy production:
1. Face Them Toward the South
In the winter, daytime is shorter than nighttime. This means the solar panels experience more shadows. Hence, you should position them toward the south so they can collect more light. This also helps the snow to reflect light into the panels.
2. Angle Them at 60°
Solar panels work best when you place them directly perpendicular to the sun’s rays. Most manufacturers recommend a 30° permanent position for solar panels. If you have tiltable solar panels that can be adjusted through a remote control, it’s best to reposition them at 60° during the winter. This way, you can get the most out of the sunshine. Then get them back at the default angle once spring arrives.
3. Keep Them Away From Shadows
During the winter, remove anything that might cast a shadow on your solar panels. You may also want to relocate them if possible.
4. Keep Them Clean
As mentioned earlier, clear your panels from piles of snow.
In this article, we answered your question if solar lights work in winter months. Since you now know that they do, there’s no need to be afraid when you buy a set in the winter. In fact, it can be the best time to buy solar lights as prices are usually lower.
We also pointed out that cold climates don’t place much of a problem for solar street lights. This is on the condition that they receive ample sunlight for 3 to 5 hours a day.
In order to get the most energy production in your solar lights, you should consider adjusting them at the proper angle and tilt to avoid shadows during the winter. You must also clean them from excessive snow.
At HeiSolar, we offer solar street lights which can be best fitted for any extreme weather conditions. We can design, manufacture and supply specific solar street lights that could best fit your country’s/area’s weather patterns and conditions. Our greatest benefit is we assemble and manufacture everything in our own factory, so you can expect lesser prices than the market.
Plus, our in-house, self-developed battery for solar lights are designed with a high temperature and low temperature protection technology. This helps our solar street lights perform well in extreme weather such as winter seasons.