As the world’s population continues to escalate, the demand for domestic and industrial energy also continues to increase. We need more sufficient and efficient energy in order to develop the world economy. Over the years, we have discovered and utilized different sources of energy in an effort to make our work easier and our lives simpler. These sources have been broadly categorized into three: fossil energy, nuclear energy and renewable energy.
Fossil energy is generated through the burning of fossil remains. Currently, fossil energy is the predominant source of energy in the world. It is estimated that 86% of the world's energy today is supplied from fossil energy. The three forms of fossil energy are coal (which is solid), petroleum (which is liquid) and natural gas (which is gaseous). Coal was mainly used to provide energy during the industrial revolution in the 18th and 19th centuries. Then as the 20th century commenced, petroleum took center stage as the dominant source.
Petroleum still is a major source of energy today as it is used to propel automobiles, airplanes and many other machines. However, when it became apparent that the supply of petroleum was dwindling, there was increased need to harness natural gas to produce electricity. Although fossil energy is common and readily available, it unfortunately has very damaging effects on the environment. Coal, petroleum and natural gas are environmentally unfriendly (Howe, 2004).
Burning of fossil remains releases excessive carbon dioxide and other toxic materials into the earth's atmosphere and biosphere, thereby, disrupting the earth's carbon cycle tremendously. “This causes greenhouse effect resulting into global warming and consequently, climate change. Besides, fossil energy is getting depleted since it has been overused, and it is not renewable. This means that once coal, petroleum or natural gas is used, it is well and truly gone for good. This is rather wasteful and unfriendly to the environment since whatever is taken from the environment ought to be replenished in one way or another.
Nuclear power is a more recent source of energy. It is generated in two different ways: nuclear fusion and nuclear fission. Nuclear fusion is whereby the nuclei of atoms are fused under extremely high temperatures to produce energy. The sun for example, naturally generates heat and light through nuclear fusion. Nuclear fission on the other hand, is man made. It is whereby the large nuclei of uranium atoms are split under carefully-controlled reactions. Nuclear fission produces a great amount of heat which is used to heat up water to create steam.
This steam drives turbines thereby producing electricity. Currently, it is estimated that nuclear power (or atomic energy as it is also called) meets about 6% of the world’s total energy needs and 15% of the world's electricity needs. Many cities in the developed world now use electricity generated from nuclear reactors. Compared with fossil energy, nuclear energy is considered more environmentally friendly since it is much cleaner. It can also generate more energy using less fuel. A ton of uranium produces more energy than is produced by millions of tons of coal or millions of barrels of petroleum.
That having been said, nuclear power is still not the most environmentally friendly source of energy. For one, generating nuclear energy produces extremely hazardous high-level radioactive waste. This waste is very difficult to dispose off safely and must be buried deep underground in huge concrete dumps or stored and managed within the nuclear plant for thousands of years. And as the recent nuclear disaster in Fukushima, Japan proved, exposure to nuclear radiations can cause devastating effects on the surrounding population and the environment. Secondly, nuclear power is not renewable. One of these days, the world is going to run out of uranium supply and consequently, out of nuclear energy.
The third source of energy as earlier mentioned is renewable energy (also called alternative energy). “Renewable energy basically refers to the energy harnessed from such natural sources as sunlight, water, geothermal heat and wind” (Boyle, 2003). This source of energy can be replenished constantly and naturally, and is therefore considered quite environmentally friendly and a better option to the non-renewable energy sources discussed above. Currently, “it is estimated that renewable energy accounts for approximately 16% of the world’s final energy consumption” (Breeze, 2005).
One major form of renewable energy is hydropower. Hydropower is produced by using generators to convert the energy of falling water into electricity. The use of water to generate power is nothing new. It began hundreds of years ago, though it gained predominance in the mid-20th century. Today, hydropower accounts for roughly 20 percent of the global electricity output. The United States alone has over 2,000 hydropower plants, making hydropower America’s largest renewable energy source. Hydropower is considered to be very friendly to the environment since there are no chemicals involved in its generation and therefore no wastes. However, establishing a hydroelectric power plant may necessitate deforestation and even the diversion the natural course of a river, displacement of fauna from their natural habitat, and disruption of human settlements.
Another major form of renewable energy is solar power. Solar power as the name suggests, simply refers to energy derived from the sun. Since time immemorial, humans have used solar power to meet the most basic of their energy needs, for example water heating, drying of clothes and crops, and even cooking. In modern technology, solar power is produced by gathering radiation from the sun and converting it into electrical energy. This is done by using solar panels.
Solar panels are large flat panels made up of many individual solar cells. Many homes, especially in the developing world now use solar power to meet various domestic power needs like in cooking, heating water and lighting. Solar power is quite cheap since it is inexhaustible and free for all who can harness it. It is also deemed environmentally friendly since it involves no pollution of air or water. However, manufacturing solar panels and building solar power stations tremendously interferes with the environment. Solar power technology also contributes to environmental pollution in that it promotes the use of lead batteries which in turn contribute to the increase in lead emissions.
A third major form of renewable energy is geothermal energy. Geothermal energy refers to energy obtained from the heat present underneath the earth. It is harnessed in regions where there is volcanic activity. Volcanic activities make rocks under the ground hot. These hot rocks in turn heat up underground water producing steam. This steam is channeled to the earth’s surface through holes that are drilled deep into the earth. The steam is then purified and used to turn turbines, which power electric generators. Geothermal power stations are quite expensive to build and there are still not many of them in the world.
However, once built, they are generally very cost effective. There is growing debate though, on whether geothermal energy is truly renewable and whether it can really be depended upon to meet the energy needs of the future. Some pundits also argue that geothermal sites will sooner or later run out of steam, rendering all the geothermal energy plants useless. Geothermal energy is considered environmentally friendly since it produces no harmful by-products. But there is always the risk that improper drilling into the earth can release dangerous gases and minerals. Besides, the construction of geothermal power plants does have a negative effect on the natural landscape.
Biomass energy or “bio energy” is another form of renewable energy. This is energy produced from the organic matter that makes up plants. The most common source of biomass energy today is wood. For thousands of years, people have used wood to cook food and keep themselves warm. Wood has also been burnt on a larger scale to make steam for power stations. Other sources of biomass energy that have been put into similar use include food crops like sugar cane and fast-growing trees like poplar and willow, which have been harvested and used to produce energy. Wastes such as animal manure, seaweed, forest residues, lumber and paper mill wastes, crop wastes, garbage and even the organic component of municipal and industrial wastes have also been used to generate heat, electricity and transportation fuels. The use of biomass energy is considered advantageous to the environment because it does not release excess carbon dioxide into the atmosphere. Whatever carbon dioxide is produced by biomass energy is taken in by existing plants.
Biomass has also helped preserve the environment by reducing the need for fossil fuels. Moreover, the use of biomass energy promotes agriculture in that there are plants like sugar cane and corn, which are grown specifically for the purpose of energy production. However, the use of biomass energy is not entirely environmentally friendly. Though the burning of biomass does not produce as much greenhouse gases as the burning of fossil fuels does, the fact is that it still produces greenhouse gases. Biomass energy may also encourage deforestation in an effort to give space for the planting of “power crops” (that is, crops that can be used to generate energy). In addition, the harvesting and manipulation of biomass energy ironically involves the use of fossil fuels. The chain saws used to fell trees and the trucks used to transport them use petroleum!
There is yet another important form of renewable energy – wind power. This is energy generated from wind. For thousands of years, wind power has been harnessed to pump water for irrigation, grind grain, sail boats, drive machinery and produce electricity. The energy in wind is captured through windmills. A windmill is a machine made up of a high tower (usually over 20 meters tall) with a set of large rotor blades at the top (Gipe, 2004). When the wind blows, the rotors revolve and the blades spin, thereby generating energy.
Having reviewed all major sources of energy, it easy to conclude that, wind power is the most viable source of energy. This is because like other alternative energy sources, it is clean, cost-effective and renewable. But wind power is a cut above all the rest in that it is the friendliest to the environment. Unlike fossil fuels, windmills do not release any greenhouse gases. Indeed, windmills do not interfere with the atmosphere in any way whatsoever and therefore are not contributors to the problem of climate change as a result of global warming. And unlike nuclear plants, windmills do not involve any chemical processes in producing energy; therefore there are no harmful by-products to be disposed and no risk of any radioactive materials or other harmful substances and gases being leaked.
Windmills hardly pose any danger to human or animal life. Furthermore, unlike hydropower and geothermal power plants which take up huge chunks of land, windmill farms take up very little land space. Being towers, windmills only occupy a few square meters for the base. This allows the land beneath windmills to still be used for farming, grazing and any other purposes (Chiras, 2009). Hardly any forests are cleared, or wildlife displaced, or populations resettled, or rivers diverted, or the ecosystem disrupted in any other way to erect windmills. Further still; unlike solar panels which encourage the use of lead batteries which are harmful to the environment, windmills generate power without the involvement of lead batteries.
Again, unlike the case of biomass energy, the harvesting of wind power does not involve the use of non-environmentally friendly products like petroleum. In harvesting wind power, there is hardly anything to be cut down and transported. Contrary to the widespread claims by the “Not In My Back Yard” (NIMBY) advocates, that windmills are an unfriendly sight to behold, many ordinary citizens actually admit that they are often fascinated whenever they see windmills and that they always find it interesting to watch the windmill blades spinning slowly and effortlessly. If anything, the billowing of black smoke from oil fields, or the sight of millions of liters of water trapped behind a dam, or even the sheer massiveness of a nuclear or geothermal power plant are more unpleasant, if not scary to the eye.
In conclusion, it is encouraging to note that in an effort to meet their ever growing energy need, while at the same time conserving the environment; many countries are now turning to wind power to produce energy. “Thousands of windmills are under construction in energy-hungry countries, like the United States, India, Denmark, Iceland, Spain, France, Portugal, Ireland, The Netherlands, Germany, China and Brazil” (Chiras, 2009). In some of these countries, the government is even offering unprecedented tax incentives to spur the development of wind energy. Over the past ten years, the use of wind power has increased at more than 25 percent annually. It is predicted that should this trend continue, energy from windmills will account for one third of the global energy output by 2050. Evidently, it is finally time for the wind to blow.