Fossil fuel, like coal, natural gas and, of course, oil are mostly depended upon in many countries as energy sources. There are many problems using fossil fuel sources, first: it’s a finite source that will end someday. Secondly, they are major sources for environmental pollution, either air, water or soil and cause the global warming.
Recently many countries started using the renewable and alternative energy sources that cause much less, if not null, pollution and the emission of gases that cause the greenhouse effect, that causes global warming, and the following article discussing 7 of the most used sources of renewable energy.
The energy generated from sunrays is the greatest energy source. It has many uses, like generating electricity, heating water, warming buildings, and lighting and in many industrial processes. The technology for collecting solar energy is currently in development and is subjected to many improvements, but the current ones are the Photo-Voltaic solar cell, water-heating pipes and mirror arrays.
Wind energy has been used since ages in the movement of ships by sails and in windmills to grind grains. Recently it has been used for electricity generating by using wind turbines to capture its movement and convert it to the required energy.
Water is considered one of the most renewable element in the world as they the water cycle caused by evaporation and precipitation maintain the amount of water in the world. When water falls through dams, this movement is used by turbines to generate electricity. And even small turbines can be used to generate electricity in individual houses in some places in the world.
This kind of energy has been used for so long since humans started to burn wood for warmth and for cooking. The wood is still one of the main sources for biomass energy, but it is not considered a renewable or alternative energy source. Otherwise, food and crops waste are now used to produce this kind of energy, along with the methane gas produced by human and animal waste is used to produce energy for transports and for industrial factories that use fossil fuel otherwise.
In nature hydrogen always found in combination with other elements like in water it is combines with oxygen, and is the most common element on Earth. It has a great potential to become a great alternative energy source in the future, as once it is liberated from its combination with the elements it can be used to produce a massive amount of energy like in motorizing cars, like the ones produced in 2015 in both Japan and the United States.
Mostly used as an alternative source for heating in Houses and commercial buildings. The earth produce heat that can evaporate water deep under surface and cause the emission of vapor that is used also for generating electricity and other sources of energy.
Compared to other renewable energies, it is not cost-effective currently, but may be with the development of technologies the cost can be cut-down. But generally it has many sources of energy as the tidal waves movement is used to generate electricity. Add to that the thermal energy stored in the ocean can also be used in electricity generation also.