Top 6 Renewable Energy Sources
1. Solar Energy
Experts view energy from the radiation, light, and heat of the sun as the most dominant renewable energy resource in the future. Solar energy is clean and available in abundance. We receive 12,000 times more energy from the sun than the total amount we produce from conventional energy sources. Solar engines and photovoltaic cells are used to harness solar energy for electricity generation. Solar ponds, solar architecture, and high-powered solar thermal collectors ensure industrial use of solar energy. Its commercial and household use is growing due to development in harnessing technologies, cost-effectiveness, and government subsidies on solar equipment. In many countries, both public and private sectors have set up huge photovoltaic power plants to harness solar energy.
Related: Solar Energy: Source of Future Energy
2. Wind Energy
Wind is a renewable resource of cheap and clean energy. Wind mills use the strong pace of airflow to rotate turbines and produce electricity. Wind farms in coastal and high altitude areas harness up to 5-MW power from each turbine, thanks to strong and constant wind flow. According to estimates, the potential of wind energy that we can harness is forty times higher than the present global electricity demand. At present, wind energy constitutes 2 percent of the total energy produced in the world, and it is growing fast. More than 80 countries in the world have large wind farms dedicated to commercial production of wind energy. In Denmark, one-fifth of the nation's electricity comes from wind mills. The production of wind energy in the United States has seen a six-fold increase in the past five years.
Related: How is Wind Power Generated?
Water is the most used and oldest known renewable energy resource at our disposal. Two-thirds of the total area of earth is water. We can produce abundant electricity from it by converting its potential energy to kinetic energy through regulated flow from a height and operate turbines to generate electricity. Huge dams such as Hoover Dam and Three Gorges Dam produce large amounts of electricity. There are also numerous check dams, run-of-the-river projects, and pumped-storage facilities engaged in producing small- to medium-scale electricity.
Modern techniques have made it possible to harness hydropower from the ocean. Undersea currents, such as the Gulf Stream, have kinetic energy that can be used to operate turbines. Ocean thermal energy can be produced from temperature differences in the seas. Power generation from tides through controlling dams is already underway in India and many other countries. The European Union is leading the successful technology development for producing energy from sea waves.
4. Biomass Energy
In many countries, energy is generated from biodegradable wastes. Plants capture solar energy during the photosynthesis process. We can resurrect this energy from forest residue and use it for electricity generation. Energy can also be extracted from other biomass sources, such as household waste and bovine dung. Urban waste and other biodegradable wastes are full of methane and other gases, which can be used for cooking and heating purposes. Recent research has resulted in viable technological options to convert biomass to energy, in the form of heat, electricity, or biogas. Thermal conversion produces heat from biomass that can be used to create steam and operate turbines. Chemical and biochemical conversion produce fuel from biomass by breaking down the molecules.
Related: Biomass as Energy Source
5. Geothermal Energy
Geothermal energy is produced from the heat of the earth’s core. Hot underground steams emanating from natural springs can effectively operate turbines. Similarly, hot water from geothermal springs is used to recreate steam and run turbines and produce electricity. Technological development has led to the use of geothermal heat pumps and establishment of binary plants to augment geothermal energy production. In countries such as Australia, holes are drilled deep into the earth’s crust to put cool water in and pump hot water out. This hot water is used to produce steam for turbines. In the binary method, the hot water heats organic fluids that in turn spin the turbine. Iceland provides 8,000 mw energy from geothermal sources.
Related: Uses of Geothermal Energy
Biofuel is produced by fermenting certain plants such as sugar cane, jatropha, and vegetables. Around 2 percent of total vehicles in the world run on biodiesel. It is a blend of ethanol produced from sugar plants and regular fuel. It increases octane and improves emission by reducing carbon monoxide. The success of biodiesel has resulted in cultivation of sugarcane and jatropha plants specifically for biofuel purpose. Tests are going on to use biodiesel as the sole fuel for vehicles. In many European countries, vegetable oils and fats are used through the transesterification process to produce biofuel.
Related: Biofuel: Sustainable Energy Solution