It's a big question, especially here in the UK: do solar panels work on cloudy days? You'll still be able to reap the rewards of having a solar photovoltaic (PV) system when it's overcast, it just won't be as effective. While a cloudy day might see your solar panels lose some of their effectiveness, a partially cloudy day could actually see you solar PV system get a little boost from time to time. Known a. A bit of rain can actually be really good for your solar panels as it helps to clear them of any dirt that c. While the rain helps to clean the solar panels, being on the roof all year round could see the solar system face some adverse conditions. For this reason, solar panels are made. As the name suggests, solar panels will be generating the most energy during a clear day when the sun is shining. You can help to make your solar panels more effective by: 1. Ensuring th.