Solar panels will be most efficient in direct sunlight, however they can also work at lower light intensities as well. Most large panels will be able to absorb energy on cloudy days, although they won’t be able to do so with maximum efficiency.
Solar cells won’t work at all during the night, so if your area experiences long, dark winters, then you will need to be prepared to use the main power grid during nighttime. This is one reason batteries are such an essential component of any renewable energy system.
Storage cells allow you to build up a bank of power during the day, so you can continue using it at night or during periods of very low sunlight.
If you live in an area with very little direct sunlight, then solar panels may still be a viable option if you can afford to buy bigger batteries for storing more energy.