A flammable material made from organic material buried under layers of sediment found near oil deposits

Energy that is made from the power of moving water

Energy that is made from heat inside Earth

Fuels such as coal, oil, and natural gas that were formed over millions of years from decayed plants and animals. This process requires time, pressure, and heat.

Working in the best way with little wasted time or effort

To use wisely to prevent waste; save

Fossil fuel that comes from energy stored by plants that lived hundreds of millions of years ago.

Plant materials or animal waste used as fuel

Resources that provide energy as an alternative to fossil fuels