The Solar Cell is of kind a energy, not like a battery. That solar cell changes energy from the sun into electricity. If you face the solar cell to the sun it will work faster. It is made of the sand. Look at the picture and find the space station. See the 2 gold rectangles on the side of the space station? They are Solar Cells. Astronauts use it because you can't go back to space station and change the battery. They can have energy from the sun and they can work by themselves. If you break the solar cell, it still can work.