Do Solar Panel Work in rain?

Solar panels generate the most electricity on clear days with abundant sunshine, but do solar panels work in cloudy weather as well?

As anyone who has received a sunburn on an overcast day can tell you, much of the sun’s light still gets through to the Earth even if there are clouds in the sky.  It’s that same light that is responsible for creating energy in solar panels.

So, the answer is not surprisingly “Yes”. Solar panels work as long as they receive light, how faint or dim the light may be.

On a cloudy day, the average solar panel will produce in between 10-25% of their rated capacity. The exact amount will vary depending on the density of the clouds, and also by the type of solar panel. Different panels can be designed to catch more or less of the spectrum emitted by the sun. The broader the spectrum the better the panel will be at capturing light, and generate electricity.

Sundaya’s solar panels have been designed to capture as much of the incoming spectrum as possible, capturing blue and red wavelengths that normally may be omitted. This allows our panels to operate both in cloudy as well as rainy days, though be it with limited capacity.

When measuring with which speed a solar panel will recharge a battery, you usually measure in energy yield per full day. However since days turn into night, and some days may be partially cloudy, you need to find a equalized measurement that accommodates for the changes in incoming light. One proven method to solve this is to count backwards, and just say how many hours of direct sunlight a panel needs to fully recharge a battery. At Sundaya we display all of this information on the back of our panels.

If you want to recharge a 30 kJ battery for instance, you would need to receive 3 hours of direct sunlight for a full charge.  Now if its heavily cloudy and raining, and the efficiency drops to 25% it would take 12 hours for a full charge. The battery would still recharge it would just take longer.

Since all our Sundaya products are waterproof as well, you can with no concern leave your panel out in the rain. It will recharge you batteries perfectly fine, it may just take a bit longer.