What is renewable energy

What is renewable energy

Renewable sources of energy are those natural sources which do not get depleted over time when we use them to generate usable energy and it is possible due to continuous natural replenishment. The main forms of renewable sources of energy include hydropower, wind power, geothermal energy, solar energy, biomass and biofuel. Generation of electricity that can power anything which runs on electricity is the primary purpose of the renewable sources. It is also possible to use renewable energy to fuel an automobile or heat water among other things. It should be noted that the renewable sources of energy are also called alternative sources of energy because these are not our primary sources today. The bulk of the world’s energy needs are still met by the non-renewable sources of energy, namely coal and petroleum. Actually, in most nations, the non-renewable sources provide power at a cheaper rate than the renewable sources, but the problem with coal and oil is that they do not replenish themselves as rapidly as the alternative sources; in fact, it takes millions of years for these fossil fuels to form under the earth. Therefore, the fossil fuels are limited and we will run out of these at one point of time, which of course leaves us with no option but to depend on alternative energy. Keeping the future in mind, governments in all developed countries are trying to promote research and use of the renewable sources of energy through rewarding systems and subsidies. Even if a significant portion of the power demand is met by the alternative sources of energy, we can make the fossil fuels last for much longer. Renewable energy sources are explained in detail below:

Hydropower — Energy is obtained from water with the help of a turbine even if the water flow is not very fast because it is denser than air, which means that it requires comparatively less effort and speed. Hydroelectricity is generated in dams like the Akosombo Dam and they are built on rivers all around the globe, fully equipped to harness the hydroelectric power. Even where there are no dams, micro hydroelectric power stations are often found to produce as much as 100kW of electricity. The difference between the cold temperature of the ocean’s deep water and the comparatively higher temperature of the water found near the surface of the ocean is also utilized for power generation and is known as Ocean Thermal Energy.

Wind power — Just as running water turns a turbine to generate electricity, the flow of the wind also is utilized to turn wind turbines which achieve the same result. Wind power plants are usually located near seashores or on high altitudes because these areas enjoy the benefit of a constant breeze necessary for a wind power plant to continue generating electricity. Industry standard wind turbines can generate as much as 3 MW of rated power, without polluting the air or contributing to the greenhouse effect.

Geothermal Energy — Geothermal energy is that form of energy which utilizes the heat from the core of the earth to harness electricity. The geothermal heat pumps which are used to achieve the goal are located especially in the locations around the globe where volcanic activity is present. Such a geothermal power station would need to dig kilometers into the ground until the mechanism reaches the source of power. Expensive as it is to get such a facility up and running, it is rewarding too, because there is hardly any maintenance cost once it is set up. Geothermal energy can be obtained through steam, flash or binary plants, depending on the availability and location of the geothermal power plant. Dry water vapor is pressurized out of the cracks on the surface of the earth, and then directed in such a way that it turns the turbine to activate the generator. A flash plant is required when it is not possible to obtain and release the steam directly over the turbine. Its main function is to separate the boiling water from the steam. A binary geothermal plant on the other hand, passes the hot water through heat exchangers. This starts boiling a fluid which is organic in nature and that is what turns the turbine for power generation in this case.

Solar Energy — The energy that we receive from the sun in the form of sunlight is converted and harnessed into usable energy with the help of photovoltaic cells made out of conductors like silicon or CIGS. Solar energy is a very promising source of renewable energy and apart from the active conversion of photons into current through solar panels; there are also passive ways to use solar energy. People all around the world, even before the advancement of technology, used the sun to their advantage by building in such a way that the structures receive enough sunlight and heat. Heating and drying are also small but passive uses of the sun’s rays.

Biomass — Biomass is an indirect solar energy resource actually, because it comes from burning plants which had earlier captured the sun’s energy through photosynthesis of course. The remains of crops, edible plants and other green plants are used as biomass, but certain plants are also grown with the sole purpose of using them as a renewable source of energy.

Biofuels – The two main forms of biofuel are biodiesel and bioethanol. The use of bioethanol is quite common in the States as a supplement to gasoline that improves performance, but it is possible to use this bio alcohol solely as a fuel to run an automobile. Bioethanol is obtained from sugarcane and other starch crops. Made mainly out of grease, biodiesel is also obtained from animal fats and vegetable oils. Again, like bioethanol, biodiesel is also used as a supplement with diesel to reduce emissions and improve performance, but it is also capable of powering a vehicle as a primary fuel.

As the years pass by us, scientists are putting in more and more effort to device new ways and invent technology to take advantage of the renewable sources of energy more effectively and less expensively. The more the population depends on renewable sources of energy; the better is the chance of the fossil fuels lasting longer.



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