Why Do Solar Panels Work Better In Cold Temperatures?
Solar panels produce electric power from solar radiation. They are made of photovoltaic cells or PV cells. PV cells generate electricity regardless of the temperature of the surroundings. As long as sunlight hits the photovoltaic modules, i.e., solar panels, they can produce DC power. But when you are asked to imagine the best possible weather for your solar system, you’ll think of a bright sunny day! Right? It’s because we know from the fundamental concept that the more sunlight hits the solar panels, the more electricity is produced. That’s right! We need adequate sunlight falling on our panels to generate enough electricity.
The efficiency of the solar panel, or better to say, the generation of electricity, depends mostly on solar irradiance. High temperature does not contribute to higher efficiency. You will be surprised to know that heat reduces the output efficiency of your solar panels. Cold weather is actually good for solar panel efficiency! Your panels can produce electricity even below the freezing temperature.
Stick to this article to find out what is the relation of your panels with temperature and how cold temperatures help solar panels to work better.
Let’s begin with simple questions.
What is the effect of temperature on solar panels?
We all know solar panels produce electricity from the sunlight. We might be living with a misconception that the hotter climate suits solar power generation best.
But that’s not the truth. Cold weather has a direct impact on solar panel efficiency. It’s not only a bright summer day when your panels produce decent electricity.
Although solar panels are sensitive to temperature change, in reality, the temperature doesn’t play an enormous role in the panel’s efficiency.
Your panels produce optimal amounts of power when exposed to direct sunlight. And during winter or in cold areas, the sky stays mostly clear. The amount of solar irradiance is perfect for better output results.
Do solar panels work best in cold temperatures?
A Michigan Technological University study says that solar panels are worth investing in if you live in an area with a cold climate. The weather outside your home can be harsh, extremely cold, and uncomfortable for you, but your solar panels can generate a delightful amount of electricity.
To your surprise, photovoltaic panels become more efficient in cold weather as the electrical conductivity improves with low temperatures. Solar panels are actually another electronic gadget you have, just like your household appliances, computer, etc.
Almost every electrical device functions better in cold temperatures. Heat can reduce solar panel efficiency by 10-25% as the weather becomes hotter. But in cold weather, solar panels do a great job.
Technically, the electrons are at rest in the PV cells. When sunlight or a stream of photons full of energy hits them, a huge potential difference (voltage difference) is developed in the panels. That creates more electricity. This is why solar panels work more efficiently in the cold.
Solar panel efficiency
Well, since we agree on the part that cold climates are optimal for solar panel efficiency, let’s talk about it in detail.
The optimal weather conditions to get the best solar panel efficiency are:
- Temperature below 25°C
- No shade upon solar panels
- No blocking in the path of sunlight
- No snowfall or light snow that goes away quickly
- Minimal cloud coverage
But in winter or in colder regions, all of these conditions are not always fulfilled. In fact, the solar panel output is lower in winter months than in summer, and a 5kW system produces almost 13kWh a day in winter but 20kWh in summer.
But if we ask the question if solar panels are efficient in cold temperatures, the answer is yes!
Although the output is lower in cold climates, it has a lesser impact compared to overheating.
The graph below shows the temperature relation with the efficiency of two different panels with different trap densities.
As temperature rises, the panels also become less efficient as they generate low voltage. The temperature coefficient of a solar panel tells us how much power a panel will lose for each °C rise in temperature.
Suppose the temperature coefficient is -0.25% per °C means the solar panel’s power output will decrease by 0.25% for each degree rise in temperature. Also, that means if the temperature falls down by 1°C, the efficiency increases.
This happens to a specific temperature gradient. The efficiency at first increases with a lowering in temperature, but then it decreases. Extreme cold climates reduce solar panel efficiency, just like a hotter climate.
So, in short, you will have a seasonal variation in solar power output which seems to provide the best values in colder weather.
Power generation (Summer vs. Winter)
From the quantitative analysis of the data we have, it’s clear that the power generation is lower in winter than in summer.
But there can be exceptions. On some days in the winter, when the climate is cold, you can generate a lot of electricity. The average power generation on a cold day is 40% of a summer day, and you’ll definitely have peak power generation on summer days.
Actually, this whole thing depends on your geographical location. Some places receive direct sunlight during winter, which helps to produce better in that time.
Although, in general, power production on hotter days of summer is higher than in winter, solar panels work more efficiently in cold climates.
Cold weather keeps your panel cool and allows the electricity to flow to the home more efficiently.
Advantages of cold weather
- Enhanced efficiency: Daily energy production increases with cold temperatures. Hence, the efficiency of your solar panels is enhanced in colder weather.
- Albedo effect: Bifacial modules of your panels show a hike in efficiency after a snowstorm. Due to the albedo effect, the amount of sunlight trapped by the panels gets increases, notably causing higher energy production. Solar panels seem to work optimally in areas with regular snow or cold regions.
- Dark silicone cells: If your panels are covered in mild snow, sunlight still passes through them and reaches the panels. Due to the dark silicone cells of the panels, heat gets trapped, and the panel temperature tends to rise to a standard 20~25°C. This temperature is much more than the surroundings, which helps to melt the ice. This leads to a clear and decent surface of the panels.
- Government incentives: Many places with moderate to extremely cold climates offer thoughtful solar panel installation incentive programs.
- Cold winds: Cold breezes in these specific areas provide an ambient temperature. Cold wind removes the heat from the surroundings and helps the panel to work better. Also, the chances of clouds hovering over your panels in the windy atmosphere get reduced. That’ll definitely help solar panels to generate more power.
Disadvantages of cold weather
- Decrease in energy output: Sunlight can penetrate a light layer of snow on the panels, and the production is not much hampered. But the energy output will drastically fall if the panels get overall covered by snow. Also, if only one panel in the array has excessive snow on it, the whole system’s efficiency gets reduced.
- Expensive panels: As in colder areas, we always encounter a chance of snowfall, so we have to install durable solar panels with no frames to help the snow slide off. Also, the panels must be strong enough to take the weight of the snow sometimes.
- Maintenance: You need experts to clean up your panels if they are fully covered in heavy snow. You cannot clean your panels on your own because there is a chance of damaging them. Extra care and the cost of maintenance are required in cold areas.
- The angle of the panels: To get the maximum sunlight on winter days, we need to adjust our panels’ angle, which may negatively impact snow build-up on your panels.
- Fewer sunlight hours: You cannot entirely depend on the electricity produced in the wintertime as the sunlight hours are much lesser than in summer. On some days, the panels may get sunlight for a very short span, and the power output can be low. Electricity produced in summer is more dependable.
Can solar panels work in the snow?
Solar panels can produce electricity by absorbing the energy of the sun’s rays, not from the heat. We have learned that solar panels can generate DC power even below freezing temperatures. So, yes! Solar panels can work in the snow.
Even if your solar panels get covered in snow, they’ll still get sunlight through the snow. Yeah, the productivity is low when panels are covered in snow, but even then, you don’t need to clear the snow from the panels. You can damage them by doing so. A layer of snow can indeed result in a production blackout for a while.
But the snow sheds off quickly because of the titled arrangement of the panels. You can change the angle at which your panels are installed by seasonal tracking. A stepper angle can make it hard for snow to gather.
And also, the special glass of the panels accelerates snow melt. The dark silicone cells in the solar panels absorb heat by trapping the sunlight. Generally, solar panels have a temperature around 20°C, much warmer than the surroundings. So, the snow melts easily and doesn’t affect the production so much.
Nevertheless, the snow on the ground sometimes reflects extra sunlight to your panels, and snow acts like a mirror. Because of the albedo effect, panels covered in snow can absorb as much as twice the amount of sunlight, increasing the energy output!
How does the output energy change with cold temperatures?
Solar panels generate lower electricity when exposed to high temperatures compared to when they are in cooler areas. Believe it or not, your solar systems can often generate more electricity on a cool, windy day than on a hotter day when the sun is blazing.
Graphically the power output changes like the below curve with respect to temperature.
Rising temperature means an increase in resistance which reduces the current through the panels. The optimal temperature is 25°C for the panels for best energy production. Above the temperature of 35°C, the energy production comes to 3.6% lower than general.
For example, silicon crystalline solar system modules experience a temperature coefficient between -0.30% to -0.45% per degree rise in temperature above 35°C. An increase in temperature reduces the bandgap in semiconductor materials, and this affects most of the semiconductor properties of the PV cells, which leads us to disrupted power generation.
In cold weather, the solar efficiency is not only better, but up to a threshold limit, the energy production increases with a decrease in temperature.
How to maintain your solar panels in a cold climate?
You don’t need to worry about many factors. If you want your solar panels to work without any obstacles, you need to take care of the angle of your solar panels and snow!
Adjust the angle such that your panels get the maximum sunlight during winter. In cold regions, you need to determine the angle at which your panels will receive most of the sunlight. Your panels need adequate sunlight to produce electricity. Also, the angle of the panels helps to slide off the snow. Panels at a steeper angle will have less snow build-up.
The next thing to keep in mind is that even if your panels are covered in snow, don’t try to clean them. Wait till the snow sheds off. It’ll not take much time, and the energy production will not get much hampered.
Solar panels work better in cold climates. All the above discussions only conclude with this result. The popular belief that summer is best for solar power generation is false. Power output is obviously high in the month of May or June when the bright sunny days are the longest, but solar panels work more efficiently in cold temperatures.
Power output doesn’t say it all. Cold weather helps the panels produce more electricity on some days of winter compared to summer days. We must consider some factors to get the best energy production in colder climates and look after our solar system cautiously.
Based on market research, even in icy areas like Alaska or Antarctica, solar energy is a convenient option.