This picture is a scene I found
　　in a city a few years ago.

There is a solar cell in my house, but I could not imagine that animals were riding on it. When I sent this photo to my friends including foreigners, everyone was surprised.
Writing from now on is a general solar cell story and has nothing to do with goats.
I intend to write in an easy-to-understand manner, but there may be some technical logics. Please understand what I intend to do.
I am trying to write in the following items. Click on the section you want to read.