What are the main sources of renewable energy?

renewable energy

Renewable sources provide an alternative source of energy compared to fossil fuels. Renewable sources of energy contribute to 14 % of the world’s total energy and provide an effective substitute to use of fossil fuels, which causes air pollution and produce greenhouse gases that contribute to global warming.

These alternative sources of energy are among the most environmental friendly and helps save energy, combat climate change and reduce extraction of raw materials. The sources of renewable energy include solar energy, wind energy, thermal power, biomass and tidal power.

Solar energy

renewable energy solar

This is the use of sunlight to generate electricity. The sun can produce more energy than what a nuclear plan can produce in a year.  Solar energy provides a very reliable source of renewable energy and is available in both direct and indirect forms. It can be used in households for cooking, water heating and drying crops. It also used in industries and businesses.

Generation of solar energy

A photovoltaic system, made up of silicon solar cells, are used to capture solar power by exciting electrons in the silicon cells using light photons from the sun. The systems contain an inverter which converts the solar power from direct current (d. c) to alternative current (a. c). The energy can then be safely used.

Wind energy

renewable energy wind

Wind is ranked second in the most reliable renewable sources of energy. Asia is the world’s known continent for extensively utilizing wind energy.

How is wind energy produced?

  • Wind energy is harvested using wind turbines.
  • The turbines convert kinetic energy produced by wind to generate mechanical power.
  • These turbines are then connected to a generator to produce electricity.
  • The electricity produced goes through a transformer to increase its voltage and make it easier to transfer to long distances.
  • Power stations then receive the current and convert it to a lower voltage that can that can safely be used for industrial and commercial purposes.

Thermal power

Thermal power is a more cost effective source of renewable energy compared to the use of fossil fuels. This is the energy contained within a system due to its high temperatures. The energy can be produced by converting heat to electricity. It can be obtained from the sun, when burning coal or wood, and in hot springs. Energy produced by thermal power is used for industrial, domestic and commercial purposes.

Geothermal power

renewable energy images

This type of thermal energy is produced by heat from the earth surface (geothermal). The heat warms water contained in the underground reservoirs. This heated water can have variety of uses depending on their temperature. The high temperature energy reservoirs are used to generate electricity. Geothermal power can be harvested by a dry spring’s plant, flash stream plant and binary cycle.

Dry stream plants

These thermal plants use underground streams to rotate a turbine. The turbine then activates a generator to produce electricity.

Flash stream plants

Flash steam plants use water very hot water of up to 360°F temperature. The water is pumped from underground reservoirs. While the water comes up, its temperature decreases forcing it to evaporate and change to steam form. The steam is then used to power a generator.

Binary cycle

The binary cycle plants use heat from low temperature reservoirs that is between 250-300°F. The water is used to boil a fluid which then powers a generator.


Biomass is used to generate biomass power-carbon neutral electricity obtained from organic wastes. Materials that make up biomass include crap lumber, certain crop residues, manure, animal wastes and forest debris

Biomass is among the most effective sources of renewable energy. Apart from energy production, it also helps clean up the environment (by recycling waste products and reducing deforestation).Biomass energy can be generated through heat, fermentation or decomposition

Generation of biomass energy through heating

Biomass plants burn wood and other organic wastes products to heat water. The heated water produces steam which runs a turbine to generate electricity. This electricity is used in homes and industries. The whole process includes;

  • Energy from plants is transferred and stored in plants
  • When plants are cut or die the plant matters are delivered to a large trough (bunker).
  • This residue is then burnt to heat water in a boiler to release heat energy in form of steam.
  • Power from the steam is then directed to turbines through pipes
  • The steam turns blade in the turbines which are made up of coils and magnets.
  • The charged magnetic fields produce electricity that is sent to homes through cable.

Tidal energy

With 70% of the world’s surface covered with water, tidal waves make a good alternative source of renewable energy. Production of tidal energy is done by the aid of energy power generators. The larger the waves are the more power it generates.

Tidal energy is determined by the speed, height and density of water. The waves are stronger on the surface and its power reduces by the water depth. Turbines are placed in areas where there are high tidal movements to capture the kinetic energy on tidal waves to produce electricity. The energy can be used to generate electricity and pump water in to reservoirs.