Fossil fuels
(coal, oil and natural gas)
Energy from the sun's used by plants in photosynthesis and stored as chemical energy. Plants are eaten by animals. Dead plants and animals gradually rot and, over millions of years, are compressed to make fossil fuels. Fossil fuels are burned, creating heat and light energy plus emissions.
Biomass in the form of wood
(biomass is the total quantity or weight of organisms in a given area and volume)
Energy from the sun is used by trees and plants in photosynthesis and stored as chemical energy. Wood from trees can be burned to release heat and light energy.
Biomass in the form of dung
(biomass is the total quantity or weight of organisms in a given area and volume)
Energy from the sun is used by plants in photosynthesis. The plants are either eaten by humans, or they are eaten by animals and dung is produced. Dung can be burned to release heat and some light energy.
Wind power
Energy from the sun heats the atmosphere, causing winds. The wind turns turbines, which generate electricity.
Wave energy
Energy from the sun heats the atmosphere, causing winds and therefore waves. The waves drive turbines, which generate electricity.
Solar power
Energy from the sun is collected and stored in photovoltaic (relating to the production of the electric current at the junction of two substances exposed to light) cells to be used as electricity. Alternately, flat-plate solar thermal collectors can be used to store the sun's heat energy, which can be used directly, or to heat water to make steam to drive a turbine to generate electricity.
