Many are wondering why solar panels are able to generate electricity during the rainy season. It has been a stigma that solar panels are useless in the rainy or cloudy season of the year. Photovoltaic panels have dominated the market for solar powered systems. The science of generating electricity with solar panels boils down to the photovoltaic effect. The silicon photovoltaic solar cell absorbs solar radiation or the photons from the sunlight. When the sun’s rays interact with the silicon cell, electrons begin to move, creating a flow of electric current. Though these are more effective in direct sunlight, solar panels still work even when the light is reflected or partially blocked by clouds. There will always be visible light even during the harshest storms and it will penetrate through clouds and rain.
Rain is also beneficial to the solar panels. It helps to keep panels operating efficiently by washing away any dust or dirt.
Typically, solar panels produce 10 to 25% of rated capacity on a cloud or rainy season. The density of the clouds on that day varies its exact amount of produced energy. The amount of energy produced may vary depending on the kind of solar panel used. Monocrystalline solar panels perform slightly better performance in low light compared to polycrystalline.
The table below shows a brief overview of power generation of your solar panel generation during normal days versus heavy rainy days. This is just to give you a rough estimation on what kind of generation you can expect from your solar panels during the rainy season.
| SOLAR SYSTEM SIZE | DAILY SOLAR GENERATION IN SUNNY WEATHER | DAILY SOLAR GENERATION IN CLOUDY WEATHER (50%) | DAILY SOLAR GENERATION IN RAINY WEATHER (10%) |
| 1 kW | 4 kWh | 2 kWh | 0.5 kWh – 1.5 kWh |
| 3 kW | 12 kWh | 6 kWh | 1 kWh – 3 kWh |
| 5 kW | 20 kWh | 10 kWh | 2 kWh – 4 kWh |
| 8 kW | 32 kWh | 15 kWh | 3 kWh – 6 kWh |
| 10 kW | 38 kWh | 18 kWh | 4 kWh – 8 kWh |
You can still make the most out of your solar panels even when it is raining. While energy production might be somehow limited, this is not going to affect your vision of the bigger picture. What matters most is the amount of sunlight you gather all year-round.
Cloudy and rainy days are inevitable and always come and go, but for the most part, this will never affect the return on investment of your solar panel installation. Let us break the stigma that solar panels are useless during the rainy days.
