For centuries, humans have fulfilled their energy requirements by depending on fossil fuels like coal, oil and natural gas. But the major problem with harnessing energy from these resources is that they can deplete in the future. Why? Because they take a very long time to replenish i.e., millions of years. These energy sources that can be diminished are called non-renewable energy sources. However, what we are going to talk about is the opposite of non-renewable energy and is called renewable energy or green energy. This article will give you complete guidance on what is renewable energy and 5 major types of renewable energy sources.
In the past few decades, research and development have exploded in the fields of renewable energy thus ensuring a large number of new promising technologies that can reduce our reliance on coal, oil, and natural gas. Before going through the types of renewable energy, let’s talk about renewable energy itself and how does it benefit humans and the environment.
What is renewable energy?
Renewable energy or clean energy, often referred to as green energy, is defined as the energy derived from those natural sources that are constantly replenished by nature and are not depleted, for example, sunlight and wind. Sunlight keeps on shining and wind keeps on blowing even though their availability rests on factors such as time and weather.
Why should we go for renewable energy?
Renewable energy guarantees the following:
An abundant supply of energy
Unlike non-renewable energy sources, renewable energy sources are inexhaustible as they replenish quickly by nature. Renewable energy sources such as sunlight, geothermal heat, wind, etc. are capable of supplying a surplus amount of energy for an entire country.
Reduced global warming
Global warming is a major climate issue at present and is caused by the release of greenhouse gases (GHGs) in the atmosphere (Read more about 7 Most causes of Global Warming). However, most of the renewable energy sources emit little to no GHGs. It has now become possible to reduce global warming by replacing GHG-emitting energy sources (fossil fuels) with clean energy sources like solar energy, thermal energy and so on.
Minimal public health issues
Coal and natural gas plants emit air and water pollutants that can cause cancer, breathing issues, heart problems, neurological dysfunctions, or even premature deaths. But with the renewable energy approach, there are relatively fewer harmful emissions in the surrounding environment and minimal cases of public health issues.
More jobs and economic benefits
Fossil fuel technologies are usually capital and mechanized intensive whereas renewable energy is labour-intensive. Wind farms need technicians for regular maintenance and solar panels are installed with the help of labour. Therefore, new vacancies in the renewable energy sector create a ripple effect and benefit not only the individuals but the country’s economy as well.
You might be interested in 6 Top Countries Leading in Renewable Energy.
Cheapest energy source
Renewable energy offers an affordable and stable electricity supply than traditional fossil fuels. Moreover, due to the huge demand for clean energy, its prices are falling at such a rapid rate that it is likely to become the cheapest source of energy in the future.
Reliability and stability
Renewable energy is derived from a variety of sources. All of them are replenished naturally which means more potential to harvest energy across the globe. Furthermore, renewable energy systems are distributed and modular (comprises of multiple equipment units) which is why there is little probability of large-scale failures.
5 types of renewable energy
Since research in the renewable energy sector is advancing at such a rapid rate, it has become difficult to keep track of all kinds of renewable energy sources that are currently under development. Here are some of the major types of renewable energy:
Sun produces a superabundant amount of heat energy via nuclear fusion reactions. In a fusion reaction, two smaller atoms fuse, using heat and pressure, to form a heavier atom thus emitting a large amount of energy. This energy reaches the earth in the form of solar radiation which is then consumed for various purposes.
Humans have been utilizing solar radiation for thousands of years to stay warm, dry foods, and grow crops. Recently, solar energy has become one of the major sources of renewable energy. China, Japan, and the U.S are the leading countries with solar energy production.
- Solar energy is mostly harvested through the use of solar panels. Solar panels have photovoltaic cells and when sunlight falls on these cells, an electric current is produced through the photovoltaic effect.
- Solar energy is also harvested by concentrating solar power (CSP) plants that use mirrors to concentrate solar radiation.
If you would like to learn more about Solar Energy I recommend listening to this Audiobook, Taming the Sun: Innovations to Harness Solar Energy and Power the Planet.
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Wind energy is another source of renewable energy that is powered by the sun. This is because wind formation results from irregular heating of the atmosphere. The atmosphere is heated unevenly because of the earth’s orbit, rotation, and tropology. Further changes in winds are due to the surface (land or water) they are flowing over.
Wind energy is harnessed through the use of wind turbines that are mostly installed on higher altitudes or offshore areas with stronger winds. A wind turbine consists of rotor blades, a shaft, and a generator. The wind rotates the rotor blades that are connected with the main shaft which then moves and spins the generator to produce electric power. The most commonly-used wind turbine is a three-blade turbine. Winds powerful enough to push rotor blades produce electricity. Hence, stronger winds produce more energy.
Though the winds seem strong enough to generate electricity, expensive wind farms must be installed to produce enough electricity that can make a difference. Even though some people may complain about how wind turbines appear or sound, they are becoming a valuable source of energy with a continuous decline in prices.
Hydroelectric energy, also known as hydropower, has been a way of harnessing energy from flowing water for centuries. It is the largest source of renewable energy in the world so far and China, U.S, Canada, Russia, and Brazil are the leading producers of hydroelectric energy.
- To harvest energy, water is usually stored in a reservoir or dam. When water is selectively released through a narrow path, the gravitational potential energy stored in the water adds an incredible speed to its flow. This flow spins the turbine which rotates the generator to produce electricity.
- Other than dams or reservoirs, there are tidal and wave energy projects operational around the globe to produce energy from the ocean’s natural rhythms.
Geothermal, as the name indicates, is the heat energy found under the earth’s crust. This heat energy comes from both the original formation of the earth and the radioactive decaying of minerals. For millennia, humans have been using geothermal energy in the form of hot springs for bathing. But now with advanced research and technology, it is utilized to generate electricity or for heating and cooling buildings. Geothermal energy is utilized at both large and small scales.
- On a large scale, wells are dug deep into the earth’s surface with underground reservoirs of hot water and steam. These wells trap steam and hot water to generate electricity.
- On a small scale, buildings are often equipped with geothermal heat pumps or ground source heat pumps for heating and cooling. Through these pumps, earth serves as a heat source in winters and heat sink in summers.
Moreover, geothermal energy is always available unlike solar or wind energy that is dependent on weather conditions and timings.
Biomass energy is a sustainable and renewable energy source used to generate electricity or other forms of energy from organic wastes such as scrap lumber, certain crops, forest wood, logging residues, organic municipal waste, chicken litter, etc. Organic waste has stored energy often in the form of sugar or cellulose derived from the process called photosynthesis. Biomass energy is a substantial waste management strategy (Read more about What Is Solid Waste Management?).
Instead of open burning or dumping waste in landfills, a sustainable approach is to convert them in fuels with far fewer GHG emissions than fossil fuel energy.Tweet
The following are the different possibilities to harness multiple forms of energy from organic waste.
- Burning of biomass to generate heat or run steam turbines for electricity production (combined heat and power).
- Landfilling or anaerobic digestion of biomass to produce biogas.
- Conversion of biomass to other biofuels such as ethanol and biodiesel.
Conclusion on types of renewable energy
Renewable energy is an innovative and sustainable approach to fulfill the global energy demand. Furthermore, it has a greater potential to harness the energy and save money on your energy bills.
The list doesn’t end here. Unlike petroleum-based fuels that emit tons of pollutants in the surroundings, it is relatively an environment-friendly option. With the increasing energy demands across the globe, renewable energy is providing a sustainable solution to the power grid.
It has now become quite clear to us that renewable energy is a far better option, with plenty of benefits than non-renewable energy sources. There must be continuous research and development in renewable energy to look for even more advanced, cleaner, and sustainable energy productions than we already have.
There are other ways to a sustainable future as well. Check out 10 ways to make 2020 your most sustainable year yet.