Written by Arjun Bedi
Edited by Emil Koch
Human society as we know it today functions on one fundamental concept: energy. From the electrical supplies in our house powering our technological gadgets to the heat we use for our stoves to the fabric we use for our clothes, all of these have been made possible by mass-scale energy production. But all power needs a source of fuel, right?
For far too long, the only fuel source to satisfy our incessant consumption and demand for electrical energy was fossil fuels: oil, coal, and natural gas. However, as mankind sets its eyes on the prospect of a better future for the generations to come, an increasing shift has been observed, with a societal focus placed on the idea of renewable energy sources. Three promising sources of such energy have been found: wind, solar, and hydro energy.
But what is renewable energy? Why do we even need it? And what makes fossil fuels so terrible that entire countries are attempting to move away from it?
How does electrical energy production work?
The fundamental concept of all electrical production remains the same: we must turn a turbine connected to an electrical generator, which causes the electrical generator to spin and produce electricity.
With non-renewable sources like fossil fuels, fuel is combusted, releasing a large amount of thermal energy. This thermal energy will heat a store of water and convert it to steam. This steam then drives a turbine and causes an electrical generator to spin and create electricity.
Why are fossil fuels harmful?
On the surface, fossil fuels may seem excellent fuel sources; they’re cheap, trivial to transport, and very reliable. Their usefulness was suitably demonstrated during the Industrial Revolution, and since then, fossil fuel use has significantly vamped up (data collected indicates fossil fuel use has increased eightfold since 1950 as global energy demands rise every year).
However, concerns over the use of fossil fuels were present as early as the 1800s due to the emission of carbon dioxide. As any student over the age of 12 could tell you, carbon dioxide is a greenhouse gas. It absorbs the infrared radiation (heat) that is directed at the Earth by the Sun and raises the Earth’s temperature. This would raise average surface temperatures, leading to rising sea levels, more extreme weather, flooding risks, droughts, and potential famines. While there is a carbon cycle present that removes and adds carbon dioxide in a balanced manner, the presence of humans and excessive use of fossil fuels means that the addition of carbon dioxide to the environment vastly outweighs the carbon dioxide removed during the photosynthesis of plants and other natural processes. This is the primary issue with the burning of fossil fuels, but hardly the only one.
The combustion (burning) of fossil fuels often leads to the release of many harmful pollutants. The burning of coal leads to the release of nitrogen oxides and sulfur dioxide into the atmosphere. Nitrogen oxides and sulfur dioxide react with various chemicals like water, oxygen, etc, to form sulfuric and nitric acid. These products then dissolve in rainwater and come down as acid rain. Acid rain is an extremely dangerous consequence of the use of fossil fuels due to its effect on the environment. Acid rain comes in contact with soil can cause it to dissolve nutrients and affect soil pH, and this can greatly degrade plant life in the area. The resultant disruption of plant life could collapse ecosystems and erode food chains.
The pollutants released by fossil fuels contribute to human health concerns. Already, in certain cities of China, air pollution has reached concerning levels, forcing children to wear gas masks just to safely reach school. Air pollution has been linked with health conditions like diabetes, Alzheimer’s, dementia, various cancers, respiratory failure or malfunction, obesity, and more.
Fossil fuels like oil and natural gas, which may be considered slightly safer than coal, are not exempt from their share of potential disaster. Oil spills are plausible, such as the 2010 oil drill explosion, which caused the largest oil spill in marine history and had a catastrophic impact on surrounding sea life, both animal and plant. Natural gas is extremely explosive, prone to leakage, difficult to store, and more.
Finally, fossil fuels are non-renewable. A non-renewable source refers to any source of energy that is not infinite or is replenished naturally at a rate greater than at which it is consumed. Fossil fuels are the result of dead plant or animal life under vast amounts of pressure and heat and are not replenished at a speed that makes the use of these fossil fuels sustainable. The scarcity of fossil fuels means that it is a temporary fuel source and impractical in the long run.
Renewable sources of energy:
So, solar, hydro, and wind energy are called renewable because they are infinite or are replenished naturally at a rate where their use is sustainable for an indefinite period.
Also, while not a strict criteria, renewable sources of energy tend to have little to no carbon footprint, so they do not contribute to air pollution, land pollution, health risks, etc.
Solar power:
As the name would suggest, solar energy uses energy from the Sun and converts it to electrical energy. There are two types of methods by which we can harvest electrical energy from the Sun, but both involve the use of solar panels: PV or thermal. Thermal solar panels store the thermal energy possessed by the Sun’s rays and use it to heat water store. On a domestic scale, households may use this to install solar panels on the roofs of their houses to heat the water they use for bathing and other purposes. On an industrial scale, the water store could be vapourised, and the resulting steam could be used to turn a turbine and generate electricity.
On the other hand, PV solar panels are slightly more complicated and take advantage of a phenomenon called the photovoltaic effect. Typical, PV solar panels are constructed of silicon, which is a semiconductor (simply put, a semiconductor may be thought of as a material that could very easily conduct electricity when energy is provided). The semiconductor is impacted by photons (particles of light) that energize the material and cause a direct current to be induced. This direct current is then converted to alternating current and used for the various purposes we desire. Typically, efficient use of solar energy requires the construction of solar farms. This involves a large area of land covered with interconnected solar panels that simultaneously harvest energy from the Sun. The subsequent large amount of electrical charge produced is directly fed into the national grid of the country and used to supply households and industries.
Solar energy is advantageous because:
It allows the reduction of carbon footprints and mitigating climate change. Once solar panels are installed, they have relatively low operating and maintenance costs. While the Sun’s lifespan is technically finite, the time taken for the Sun to die is about 10 billion years, a time scale so insurmountable that for all practical intents and purposes, the source is infinite and is thereby sustainable in this aspect. Solar energy can help reduce the strain on the grid, leading to a more reliable electricity supply. The solar industry has seen significant growth, leading to job creation. Solar installation, manufacturing, research, and development all contribute to employment opportunities in various regions. Solar energy systems can be adapted for large-scale industry use or small-scale personal use. From small residential installations to large utility-scale solar farms, solar power can adapt to suit various energy demands. Ongoing advancements in solar technology are improving efficiency and reducing costs. This makes solar energy increasingly accessible and competitive with other forms of electricity generation.
Having said that solar power also has certain drawbacks, such as:
The semiconductor material solar panels tend to be made of is expensive, and therefore, the construction of solar parks is financially demanding. High initial costs may put off many businesses able to invest in this industry due to a perceived lack of profits or diminishing returns, and this could cause stagnation of solar technology or reduce the positive impact of solar power. Solar technology is reliant on ideal weather conditions and is therefore susceptible to bouts of low electricity production. Furthermore, the batteries and solutions proposed to circumvent this issue are expensive and again discourage investment in this venture by the private sector. PV solar panels have a fixed efficiency of conversion from light energy to electrical, locked in at 15-20%. This indicates that a great supply of light energy is not converted to a useful product, which would mean that solar farms have to be larger, which is expensive, leaves a bigger carbon footprint to supply the manufacturing of the relevant materials, uses up more scarce materials, and may require more land to be cleared for the solar farm to be built.
Wind power:
Wind turbines use blades to harvest the wind’s kinetic energy. Wind flows over the blades creating lift, causing the blades to turn. The blades are connected to a shaft that turns an electric generator, which generates electricity. The primary benefit of this is the fact that wind is inexhaustible and infinite. The nature of the power source is such that it can be integrated easily into more rural areas with multi-purpose land and stronger winds. This allows a more efficient use of the wind turbines as opposed to placing them in areas where they are unlikely to generate much electricity.
Wind turbines also provide one of the most cost-effective, low-priced energy sources today. With its low prices, wind power may be a more viable investment for the private sector as a better opportunity for profit. In 2022, wind power generated 10% of the United State’s energy, and subsequent investments into the industry contributed 20 billion dollars to the economy. From this, we can see that the implementation of renewable energy sources can bolster economies as well. Private industries may also, therefore, have an incentive to invest in wind power in developing economies, creating job opportunities there as well as diversifying the electricity mix.
However, wind power also has a few disadvantages, such as the fact that wind turbine farms tend to be built in remote and rural areas, away from urban cities where there is more demand. The expansion of wind power to urban regions may be expensive or need the development of new transmission systems, which take up both time and money. Wind power is also reliant on weather conditions, so areas with less or mild wind may not benefit much from the electrical generation in this manner. Wind power on its own, therefore, cannot necessarily replace or sustain a large part of the electrical mix. Moreover, wind turbines have been observed to disrupt wildlife, and further research is required to fully understand and minimize the impact wind farms may have on surrounding animals.
Hydroelectric power:
A hydroelectric facility uses the kinetic energy of running water as fuel for its electrical generation, but without using up the water and instead recycling it. Due to using water as the main source, these facilities tend to be erected near water sources. The basic idea is that the primary water reservoir is at an elevated point high above. This water contains a high amount of gravitational potential energy due to being higher from the ground. The greater the elevation and the larger the volume of the water, the greater the electrical energy produced.
The water is dropped down to the plant via a pipe (called a penstock) and is driven towards a turbine. As the water falls, its gravitational potential energy is converted to kinetic energy. This water then turns the hydro turbine, which is connected to a generator. Currently, hydroelectric power is the largest source of renewable energy in the electrical sector.
The advantages of hydropower are, as seems to be common, that it uses water, a clean source of energy, so no carbon footprint. Hydropower is also more reliable than the other sources of energy, as it depends on no weather conditions. This also means that hydropower can supply a relatively consistent amount of energy, whereas it may vary with solar and wind power. Hydro plants are also adaptable to the demands of consumers and can rapidly increase or decrease electrical generation.
There are cons that hydropower has, though, which must be addressed. The main disadvantage is that the building of a dam or a reservoir can alter the surrounding environment to an alarming degree. This includes the destruction of habitats, displacement of animals and people, the risk of droughts for communities that rely on that body of water, and the alteration of river ecosystems.
Conclusion:
From what we've observed thus far, a realistic summary of the aggregated information and facts suggests that no single renewable source is sufficient to fully replace fossil fuels. Certain geographical locations do not allow solar and wind power to reach their full potential. It is clear that a combination of all three renewable sources, as well as other energy sources (biofuels, geothermal, nuclear), must be present in the global electrical mix. Additionally, time taken to research techniques by which the harvesting of electrical energy can be refined, as well as ways of reducing waste or harmful side-effects of renewable sources, would go a long way in forging a brighter and greener future for our future generations.
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