Classy Caps Mfg. Inc. Evansville, Ontario, Canada / www.fencecaps.com How your solar Powered Deck and Wall light works -The solar panel converts sunlight energy into electricity during the day. The photocell automatically turns the light on at night with the electricity stored in the batteries. It requires no wiring, because it runs off the sunlight energy to recharge the batteries so there is a0 cost to run the solar cap. The number of houses the light stays on depends on.