Even on cloudy or rainy days, solar panels can work.
Although the power generation efficiency of solar panels will be restricted to a certain extent under overcast conditions, the overall photovoltaic power generation will be less than that on sunny days.
Wavelength and energy are inversely proportional, according to Planck’s law. Short-wavelength radiation occupies the purple end of the spectrum, including ultraviolet radiation and gamma rays.
In contrast, long-wavelength radiation dominates the red end, including infrared, microwave, and radio waves.
So solar panels can still work on cloudy days.
However, due to current technical reasons, solar energy is still very low, resulting in lower power generation efficiency on cloudy days than on sunny days.
PVMars’ remote monitoring APP collects the power generation conditions of solar sites, and you can intuitively see the power generation capacity of solar panels under different conditions.
Solar panel performance on cloudy days
Solar station location: Mexico
Power station type: household users
Solar panel area: 33㎡
Solar panel capacity: 6.6kWp
From the above picture, we can see that the rainfall on May 13 was very heavy, but the solar panels can still work continuously.
Its power generation is still 4.3 kWh, which is enough for a 2000w air conditioner to work for about 3 hours.
In cloudy or overcast conditions, the power generation capacity of solar panels will be reduced because clouds will block sunlight from reaching the photovoltaic panels.
Although the power generated will be reduced, it will not stop generating electricity.
Modern solar panels usually have a certain degree of scattering and low-light working ability, so they can still generate some electricity.
We cannot control weather factors. So is there any way to maximize the power generation of solar panels?
Solar panel power-up methods
We can increase its power generation by cleaning the debris around the photovoltaic components, dissipating heat reasonably, and cleaning regularly.
1- Daily dust removal
If the photovoltaic panel is found to be dusty, just use a dry broom, rag, or mop to sweep away the attachments on the surface of the solar panel components.
So if rains, it can help you brush off the dust layer attached to the solar panel for free. Save time and money by reducing manual cleaning.
2-Foreign matter attachment
For photovoltaic panels that have been running for a long time, there are often foreign objects such as dirt and bird droppings on the glass.
At this time, you can use a slightly harder scraper or gauze to scrape it, but to prevent damage to the glass surface, do not use hard materials to scrape it.
3-Super stains
If there are objects on the surface of the photovoltaic panel that cannot be wiped or scraped off.
You can remove them with clean water and a flexible brush. In case of oily dirt, use detergent or soapy water to clean it.
Warm reminder: The glass cover of the solar panel assembly is easy to break after exposure to the sun.
Try to choose to clean it in the early morning, evening, night, or rainy days, and clean it at least once every 3 months.
Solar panels working at night
At night, solar panels cannot directly obtain energy from the sun, so they do not generate electricity. This is because the sun has set below the horizon and there is no sunlight to absorb.
To provide continuous power supply on cloudy days or at night, solar panels usually need to be equipped with battery energy storage systems.
The battery system stores excess electricity during the day and then releases the stored electricity on cloudy days or at night to meet power needs.
This enables solar panels to achieve an all-weather power supply, not only relying on direct sunlight.
In addition, some solar systems also use other supplementary power generation technologies, such as wind power or backup generators to cope with weather changes and nighttime power needs.
Our advice
To ensure the continuity of power supply, solar panels are often used in conjunction with other power sources to make up for the lack of power at night or on cloudy days.
1- Energy storage system: By installing a battery energy storage system, the excess power generated during the day is stored and then used at night or on cloudy days. This ensures a continuous power supply.
2- Diesel generator sets: Diesel generator sets are used to provide power when needed. This backup generator is usually powered by oil or other fuels and can provide power when needed.
3- Connecting to the public utility grid: Grid-connected solar systems are usually connected to the national grid, allowing excess power to be sold back to the grid.
Power is obtained from the city grid to make up for the lack of power. This is called an “on-grid” operation.
Although solar panels need sunlight, it is not as much as you think. The factors that determine photovoltaic power generation are the intensity of sunlight and the duration of sunlight.
As long as there is light, electricity will be generated. There is light on rainy days, but the light intensity is weak and the duration of light is short, so less electricity is generated.
Although there will be a certain impact, the average annual power generation can be achieved!
