Introduction to renewable energy

What is renewable energy?

Renewable energy is energy which can be obtained from natural resources that can be constantly replenished.

Any energy resource that is naturally regenerated over a short time scale and derived directly from the sun (such as thermal, photo-chemical, and photoelectric), indirectly from the sun (such as wind, hydro-power, and photosynthetic energy stored in biomass), or from other natural movements and mechanisms of the environment (such as geothermal and tidal energy). Renewable energy does not include energy resources derived from fossil fuels, waste products from fossil sources, or waste products from inorganic sources.

Types of renewable energy:

Solar energy is energy which is created from sunlight, or heat from the sun. The solar power is captured when energy from the sun is converted into electricity or used to heat air, water, or other fluids.

Wind energy is generated by converting wind currents into other forms of energy using wind turbines.  Winds are generated by complex mechanisms involving the rotation of the Earth, the heat capacity of the sun, the cooling effect of the oceans and polar ice caps, temperature gradients between land and sea, and the physical effects of mountains and other obstacles.

Hydropower is a renewable source of energy which uses the force or energy of moving water to generate power.

This power, or ‘hydroelectricity’, is generated when falling water is channeled through water turbines. The pressure of the flowing water on turbine blades rotates a shaft and drives an electrical generator, converting the motion into electrical energy.

Bioenergy is a form of renewable energy derived from biomass to generate electricity and heat or to produce liquid fuels for transport. Biomass is any organic matter of recently living plant or animal origin. It is available in many forms such as agricultural products, forestry products, and municipal and other waste.

Geothermal energy is the energy stored as heat in the earth.

Ocean energy is a term used to describe all forms of renewable energy derived from the sea.