Understanding Renewable Energy
Renewable, or clean energy comes from natural sources or processes that are constantly replenished on a human timescale. Solar wind power, geothermal power, hydropower and biomass are all sources of clean energy. Non-renewable energy sources include coal, crude oil and natural gas. These resources have been created over millions of years through natural processes.
The pertinent differences between renewable and non-renewable sources of energy are:
- Renewable sources are usually non-polluting whereas non-renewable sources pollute the environment and contribute to global warming.
- Renewable sources are constantly getting replenished and won’t reduce in quantity as we use them, whereas non-renewable sources take millions of years to replenish.
- Non-renewable sources are generally more energy-dense compared to renewable sources, which is a big issue since non-renewable sources then are more convenient to use.
Even though the sources of renewable energy have always been around, it is only now that our scientists have invented economically viable ways to harness energy from renewable sources. In the past, it was much cheaper to use non-renewable sources but now, it is the same cos or cheaper to use renewable sources. For example, today, almost no one is constructing thermal coal power plants, which burns coal to produce heat which is converted into electricity that powers a generator.
Here are some of the major types of renewable energy:
Solar Energy: Solar Panels – There are two types of solar energy, photovoltaic solar energy and solar thermal energy. Photovoltaic solar energy converts light into energy using technology that uses the photoelectric effect to its advantage. The other type is solar thermal energy, which refers to utilising heat energy. To make this process more effective, you can use concentrated solar energy, which takes a lot of sunlight and concentrates it using lenses and mirrors and that produces even more heat than regular thermal energy and therefore, it produces more energy.
Wind Energy: Windmills – Wind turbines use blades to collect the wind’s kinetic energy. The wind makes the blades turn and produce lift, which is similar to an airplane’s wings, and the blades are connected to a drive shaft, which rotates and in turn, rotates an electric generator which produces energy.
Geothermal Energy – Geothermal energy converts heat from the earth into energy, instead of burning fossil fuels to produce the heat for energy.
Nuclear Energy: Nuclear Reactors – This is a more complex source of energy. In nuclear reactors, an atomic nucleus is broken into two, but there is some mass left over, which is converted into energy. An enormous amount of energy is produced this way. However, the reason I call this complicated is because it is neither renewable nor non-renewable. Why? Even though a nuclear reactor can continue breaking apart nuclei, this process is only possible with unstable nuclei. These unstable nuclei are only found in specific elements like uranium and plutonium which are rare in nature.
Hydropower: Dams – A man-made lake, or reservoir, has a dam built stopping the majority of the flow of water, but through a pipe-like structure built inside the dam from the reservoir to a turbine, water flows at high speeds due to the pressure difference and spins the turbine which is connected to a generator which produces energy when the process takes place.
Importance of Renewable Energy Today:
Firstly, coal is used every day everywhere and soon, when it inevitably runs out, we will be in an enormous amount of trouble with 40% of the world’s energy literally vanishing into thin air in the form of pollution. However, that’s only coal, 80% of the world’s energy today is produced from fossil fuels, and research predicts fossil fuels running out this century. Meanwhile, renewable energy, such as solar energy, can go on for billions of years, and most probably, humans will be extinct by then.
Secondly, this burning of fossil fuels, which is how most of our energy is generated, produces large amounts of air pollution in the form of CO2 and other gases, which are really harmful for the environment and our lungs.
Thus, renewable energy is an extremely important subject that governments and even regular citizens need to understand and investigate more. It defines the future of humanity.
Samarth Meattle, 6A