Suppose you wake up one morning, and your house has no heat or electricity. When your parents go to fill up the car with gas, all the gas stations are closed. Permanently.
It may sound like a nightmare, but it could happen. There’s a limited supply of fossil fuels (coal, oil, and natural gas). What we use today is gone forever, so it’s important to develop other sources of energy. Also, burning fossil fuels releases harmful pollutants into the atmosphere.
That’s the bad news. The good news is that people have been experimenting with energy sources that aren’t fossil fuels. Some are as old as the Sun. Others are as young as the twenty-first century. Here are a few.