how does a solar panel lights up a bulb or a tube or various other electrical appliances during night when no solar radiations are present
Answers
solar lights work because of the photo voltaic effect. The most important part of a solar light is the photo voltaic or solar cell. The solar cell is the part that converts sunlight into direct electrical current. You can clearly see the solar cell as a dark panel at the top of a solar light.
A solar cell consists of multiple layers of crystalline silicone and chemicals that create layers of negatively-charged electrons and positively-charged spaces. As sunlight passes through the solar cell, it excites the negatively-charged electrons and pushes them into the positively-charged spaces.
The positively-charged spaces then transfer the electron stream as a direct current of electricity through wires embedded into the solar cell to a battery where the electricity is stored until it's needed. The battery charges throughout the day as sunlight continues to be converted to electricity.
When evening approaches, the solar cell stops converting sunlight as it weakens and eventually disappears. A photo receptor on the light detects when it's dark and turns on the light, which is usually made up of several light-emitting diodes (LEDs). The battery then supplies electricity to the light throughout the night.
This process repeats on a daily cycle. During the day, sunlight is converted to electricity and stored in the battery. At night, the battery supplies the electricity to the light until it is all used up or the photo receptor shuts off the light as daylight reappears.
Store in battery as the output is obtained is dc and this store electrical energy in battery can be used to light up bulb during night. That's how the solar panel lights up a bulb during night also. Hope it helps you......