During the day, even if it’s overcast, the radiation from the sun warms the Earth. A solar panel harnesses this energy and converts it into electricity (direct current). Electricity cables and a solar inverter are then needed to convert this energy into electricity (known as Alternating current) that can be used in your home or office.
You don’t need direct sunlight to produce electricity from a solar panel, it will produce electricity even if it is overcast.
LIGHT is all you need to produce electricity!
Most solar panels on homes and offices are connected to the national grid. Being connected to the grid means you can import electricity if you are not producing as much electricity as you require at that time.