What is renewable energy?

Coal, petrol, and natural gas are still mainly used in many countries for energy. These sources which are called fossil fuels are not renewable. There are limited amounts of fossil fuels, which means they can end one day, and as the reservoirs declines they will become more expensive. The environment will get harmed more with their production. Whereas renewable resources do not come to an end since they renew themselves continuously. Most of the renewable energies originate directly or indirectly from the sun. Solar light or solar energy are used directly for heating and lighting at homes and other buildings, and indirectly to produce energy, heat or cool water, and for various commercial or industrial purposes. Due to the differences in the heating of sun, the wind forms. The energy of the wind is caught by means of wind turbines. Water mass in oceans and streams evaporates as the sun heats. When this water vapour makes it to the rivers or streams again as rain or snow, the hydraulic energy is caught by the hydroelectric power plants. Solar heat and light helps plants grow with the help of rain and snow. Organic substances which form the plants are known as biomass. Biomass can be used to produce energy. Biomass energy is gained by using biomass. Hydrogen is found in many organic compounds just like water. It is the most common element found in earth. However, it is not found naturally in gas form, but always combined with other elements such as oxygen to form water. When it’s decomposed from other elements, hydrogen energy can be used as a fuel or turned into electricity. Not all renewable energies source in the sun. Tidal energy in oceans is caused by the gravitation of sun and moon towards each other. In fact ocean energy originates from many sources. Besides tidal energy, ocean waves, and winds form ocean energy with tides. As the sun warms the surface of oceans more than its depths, it causes a temperature difference which can be used as a source of energy. All types of ocean energy counted above can be used to produce energy.