Photovoltaic solar panels are designed to convert sunlight into energy, and their efficiency can vary depending on the amount of sunlight they receive. Solar panels are most efficient when they are exposed to direct, unobstructed sunlight.
According to the manufacturer’s manual, you get the best results when the weather conditions are close to the standard test conditions (the solar irradiation of one kilowatt (kW) per square meter and a temperature of 25 degrees Celsius or 77 degrees Fahrenheit) under which solar panels perform at their maximum.
However, as surprising as it may be, photovoltaic solar panels can still produce solar energy in low light conditions, such as on cloudy, rainy days, during the early morning or late afternoon hours when the sun is not directly overhead. How?
Keep on reading. We will explain with what efficiency solar panels work on cloudy and rainy days, as well as whether they can be used with artificial light or at night.
Do solar panels work when there is no sun?
Photovoltaic solar panels need direct sunlight to produce electricity. Each panel consists of solar cells. The energy of the sun knocks the electrons loose from the atoms in these cells, which makes them flow through the semiconductor material inside the panel and produce energy.
It is only natural to wonder whether your panels will work when the sun is not shining or when the conditions outside are not ideal. The good news is that while solar panels are less effective on cloudy or rainy days, they can still generate some percentage of electricity. In fact, solar panels can produce energy even when the sky is completely overcast. So, the answer is yes, but how much energy you get depends on a few factors.
The amount of energy that solar panels can generate on cloudy or rainy days will be lower than on sunny days. This is because the clouds reduce the amount of direct sunlight that reaches the panels, which limits their ability to generate electricity.
However, solar panels can and will still produce a significant amount of electricity, and the amount will vary depending on the type and thickness of the clouds, the duration of cloudy skies and at what time of the day the clouds roll in. Extreme temperatures can also impact the efficiency of solar panels. Very high or low temperatures can cause the panels to become less efficient.
Lastly, we cannot forget the importance of efficiency with which solar panels themselves convert incoming sunlight into energy. There are several factors that affect solar panel efficiency, including the type of solar cells used, the size and orientation of the panels.
One of the most important factors that determines solar panel efficiency by default is the type of solar cells used. There are two main types of solar cells: monocrystalline and polycrystalline.
Monocrystalline cells are made from a single, pure crystal of silicon and are generally more efficient than polycrystalline cells, which are made from multiple silicon crystals.
The average efficiency of solar panels has steadily increased over the years, with the most efficient panels currently able to convert over 25 percent of the solar energy they receive into electricity. As technology continues to improve, it is likely that solar panel efficiency will continue to increase, making solar energy an even more viable option in more variable climates.
Another factor that can affect the efficiency of solar panels in low light conditions is the angle at which the panels are tilted. Solar panels are typically mounted on a frame that allows them to be tilted at an angle, which is known as the “angle of incidence.”
The angle of incidence is important because it determines how much of the sun’s rays are absorbed by the solar panel. In general, solar panels that are tilted at a steeper angle will be more efficient at capturing sunlight and converting it into electricity.
Do solar panels generate enough power on cloudy rainy days?
As we discussed previously, solar panels do generate electricity on cloudy and rainy days, although the amount of electricity is lower and may differ each day due to the numerous factors mentioned in the previous section. But do not despair. Solar panels can still be an effective source of renewable energy in these conditions.
Some solar panels are specifically designed to be more efficient at generating electricity on cloudy days, and these panels may be a good choice for areas with less sunny days than for example California.
In addition, having solar panels on your house can also help to offset energy use during times when the sun is not shining. For example, if your home generates more energy than it needs during the perfect sunny days, the excess energy can be stored in a battery set or sent back to the grid (in a program called net metering*). This stored excess energy or energy credits from the grid can then be used to power the home at night or during times when the sun is not shining.
*Net metering eliminates the need to install batteries with the solar system and allows you to divert any excess power produced by your solar panels to the grid in return for credits on your utility bills.
Best solar panels for cloudy days
If you live in an area with frequent cloudy skies, you may want to consider purchasing solar panels that are specifically designed to be more efficient in less ideal conditions.
Here are some options to consider:
- Monocrystalline solar panels: High-quality monocrystalline solar panels are made from a single crystal of silicon and are known for their high efficiency and ability to produce energy in low light conditions.
- Thin-film solar panels: Thin-film solar panels are made from layers of photovoltaic material that are only a few micrometers thick. These panels are flexible and lightweight, and they can be more efficient at performing well enough even on cloudy days compared to traditional crystalline solar panels.
- Bifacial solar panels: Bifacial solar panels are solar panels that can generate electricity from both the front and back sides. These panels are particularly effective at producing electricity on cloudy and rainy days, as they can capture more light from the sky and reflecting from the ground.
- Hybrid solar panels: These panels combine the benefits of monocrystalline and thin-film technology and are able to generate electricity in a range of light conditions.
It’s important to note that all solar panels are affected by cloud cover to some degree, and the amount of electricity they generate will depend on the specific conditions. To maximize the effectiveness of solar panels in cloudy climates, it’s important to choose a high-quality panel with a good warranty and to consider factors such as panel orientation and angle of incidence.
When do solar panels stop working in less favorable weather conditions?
Solar panels are able to generate electricity even on cloudy days because they use photovoltaic cells to convert sunlight into electricity. These cells are made of semiconductor materials, such as silicon, that are able to absorb photons of direct or indirect sunlight (reflected light) and release electrons. When the electrons are released, they create a flow of electricity that can be used to power devices and appliances.
While energy generated by solar panels may be reduced on cloudy days, the solar cells are still able to absorb some light and produce smaller amounts of energy. This is because clouds are not completely opaque and still allow some light to pass through. Additionally, solar panels are often designed to be able to generate electricity in a range of light conditions, including low-light conditions such as those found on cloudy days or foggy fall mornings.
However, when the sun is not shining, such as at night, the solar panels are not able to generate electricity. This is because there are no photons to be absorbed by the photovoltaic cells. As a result, solar panels will stop working.
Additionally, some extreme weather conditions may obstruct the sunlight reaching solar panels. This happens, for example, when snow and ice remain on the panels and cover their whole surface area. In this case, rays of sun may not be able to get through the snow layer, obstructing the reach of the light. Similar effect could have a thick layer of dust.
While solar panels cannot generate electricity when the sun is not shining, there are other renewable energy sources that can be used to generate electricity during these times. For example, some homes use wind turbines or hydroelectric power to generate electricity at night or during times when the sun is not shining.
Do solar panels work with artificial light or at night?
Solar panels are not able to generate electricity using artificial light or at night. This is because solar panels rely on the energy from the sun’s photons to generate electricity, and artificial light does not have the same energy as sunlight. Solar panels are also not able to generate electricity at night.
Solar energy does work even in cloudy climates
Solar panels can be a good option for supplying energy for your home even in cloudy climates, but you need to take into consideration that their ability to generate energy will be reduced compared to sunny conditions. The amount of electricity that solar panels are able to produce is directly related to the amount of sunlight they receive.
In sunny conditions, solar panels are able to absorb a large amount of sunlight and work at their best potential. However, in cloudy conditions, the amount of sunlight that reaches the panels is reduced, which can result in lower energy production than expected.
However, the increasing popularity of solar technology for residential purposes brought one great advantage to homeowners considering solar like you. You can use the Global Solar Atlas, an online tool that features information about how much output from a photovoltaic solar system you can expect in your specific location. The tool also mentions average solar irradiance values, optimum tilt of solar panels and many other useful parameters. This means that you should have a pretty good idea about your annual solar panel output beforehand anyway.
In any case, it is good to remember that in order to maximize the effectiveness of solar panels in cloudy climates, it’s important to choose a high-quality panel with a good warranty and to consider factors such as panel orientation and angle of incidence. It’s also a good idea to consider energy storage options, such as battery systems, to store excess electricity for use during cloudy periods.