Does Solar Power Work In Cloudy Weather?
Solar panels do generate electricity in cloudy weather although their output is diminished. In general, the output varies linearly down to about 10% of the normal full sun intensity. Since flat plate solar panels respond to a 180-degree window, they do not need direct sun and can even generate 50-70% of their rated output under a bright overcast. A dark overcast might correspond to only 5-10% of full sun intensity, so output could be diminished proportionately. Indoor light levels, even in a bright office are dramatically lower than outdoor light levels, typically by a factor of several hundred or more. Solar panels designed for outdoor use will generally not produce useful power at these light levels since they are optimized for much higher intensities. On the other hand, solar panels designed for lower light levels like the cells found on calculators are optimized for those conditions and perform poorly in full sunlight.