Fuel sources are materials that can be used to generate energy. These sources include peats, oilwells, peatbogs, and energybars. Peats are organic materials such as plant matter that can be burned for fuel. Oilwells are wells drilled into the ground to extract petroleum, which is a type of fuel. Peatbogs are wetlands where peat is formed from decaying plant matter. Energybars are snacks made from ingredients such as nuts, grains, and dried fruits that provide energy.