How do solar panels work in low-light conditions?

Answer: 
According to Mel Maniego of Prosolar International, solar power is still a viable option for typhoon-prone areas like the Philippines and locations with cool, cloudy climates. There are at least five continuous hours of sunlight per day on average, and this is enough to provide significant returns in energy expense, especially if your house is equipped with a battery.
Question: 
How do solar panels work in low-light conditions?