How Solar Lighting Works

Solar lighting uses solar cells to produce illumination.

The energy emanating from the sun seems boundless and abundant. Solar energy is clean, readily available and free. Converting that solar energy to electricity and solar lighting is a little more difficult and expensive.

The Basics

Solar lighting generates light through solar cells. Solar cells convert sunlight into electricity, which is stored in nickel cadmium batteries. At night, the stored energy in the batteries provides power to run small bulbs inside the solar lights.

Description

Solar cells consist of silicon crystals or less expensive crystals constructed of copper-indium-gallium-selenide. Silicon is more expensive because larger crystals are not easily grown. Crystals made from the other materials are more flexible and cheaper but are not as efficient as silicon in converting solar light into electricity.

The Process

When the crystals absorb sunlight, the electrons between the atoms become excited and shake. This motion produces an electric current. The batteries inside the solar lights absorb and store this electricity during daylight hours. When the light sensor detects darkness, the lights use the stored energy from the batteries to power the light bulbs.

References

• Scientific American: How Does Solar Power Work?
• Energy Savers: Outdoor Solar Lighting