I'm probably showing my age here, but when I was in grade school, I loved playing with my solar powered calculator. If I ...

A solar-powered calculator. Its solar cells are just above the buttons, on the right. These cells generate the energy needed to make the calculator work. (PaulPaladin / Alamy Stock Photo ...

Though costly to implement, solar energy offers a clean, renewable source of power. 3 min read Solar ... and handheld calculators. The cells are made of semiconductor materials like those found ...