: Sunlight can be used for passive heating or active systems (like photovoltaic cells). Energy Conservation

Fossil fuels, including coal, oil, and natural gas, have been the primary energy source for centuries. These non-renewable resources are formed from the remains of ancient plants and animals. While fossil fuels are widely available and have a high energy density, their use has significant environmental drawbacks, including air pollution and climate change.

Most worksheets for this section ask you to identify the parts of a wind turbine or a hydroelectric dam. Remember that turbines always convert kinetic energy into rotational energy for a generator .