With rapid economic growth and material prosperity, the world is entering a period of energy crisis. To many countries this situation is the result of the increased demand for energy and severe shortages of traditional energy sources which cannot be continuously replenished and will finally be used up. In the near future, the problems of traditional energy sources could be solved by the development of renewable energy sources such as wind power, solar power and biomass. The aim of this essay is to examine the current energy crisis related to the use of traditional energy sources. It will outline possible solutions and evaluate the viability of these renewable energy sources as serious alternatives. The evaluation will look at the advantages and disadvantages of each solution in terms of its technology, cost and environmental impacts.
Nowadays, the demand for energy sources especially oil has dramatically increased due to the rapid rate of economic growth in developed countries and the process of industrialization and urbanization in the developing world. We are using up our conventional fossil fuel resources, also called non-renewable energy sources such as coal, oil and natural gases, which took millions of years to create and cannot be continuously replenished. Many countries which heavily depend on oil and other non-renewable sources may be under conditions of low oil supplies and high oil prices before they find suitable alternatives. Therefore, it is quite possible that we will face the challenge of an energy crisis.
Energy crisis may be defined as a situation in which low energy supplies and increasingly high energy prices negatively influence economic growth and national security. (Williams 2003) The imbalance of energy demand and supply may cause high inflation, low economic growth and high unemployment in industrial nations. For developing countries with large population such as China, the high energy prices may force them into debt and they will be poorer and poorer. Furthermore, there are also environmental problems for these countries with abundant fossil fuels. Carbon dioxide, as the largest contributor to global warming, is mostly released by burning fossil fuels. According to Seitz (2002, p. 127), the CO2 level is expected to double before 2100. Various solutions have been adopted to deal with the current energy crisis, among which using renewable energy sources as alternatives appears to be a wise choice.
Renewable energy is so called because it comes from sources such as wind, sunlight and biomass, which can naturally replenish themselves and never run out. (Elliott 1997, p. 85) Now, many renewable energy technologies are developing quickly, among which solar power has yet to be fully developed, while wind power has been used almost all over the world.
Wind power has been used for centuries as a source of energy. More recently it is increasingly used as a renewable energy source to generate electricity since it has many excellent features. First of all, the cost of wind-generated ...
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Renewable energy is so called because it comes from sources such as wind, sunlight and biomass, which can naturally replenish themselves and never run out. (Elliott 1997, p. 85) Now, many renewable energy technologies are developing quickly, among which solar power has yet to be fully developed, while wind power has been used almost all over the world.
Wind power has been used for centuries as a source of energy. More recently it is increasingly used as a renewable energy source to generate electricity since it has many excellent features. First of all, the cost of wind-generated electricity is declining very quickly because of the advances in wind turbine technology, thus wind power is competitive in price with the power produced from fossil fuels. Moreover, wind power is a clean energy for it produces no air or water pollution, nor does it release toxic or hazardous substances. In addition, wind turbines can be easily and quickly erected in a few months. (Wind of change 1999) Besides inland wind, offshore wind blows more constantly and the construction of offshore wind farms causes less controversy about land use.
In other settings, wind power may cause deforestation if wind turbines are built in forested areas. The main problem with wind is that it is not steady, and there is no easy or inexpensive way to store it. Another problem is that the wind turbines are noisy and the visual effects are regarded as unpleasing. As Brower argued (1992), some endangered birds are killed if they collide with spinning wind turbines, which has become a problem in many wind farms. Lastly, as stated by Heinberg (2005, p. 153), there is a technical problem of low conversion efficiency that only about 20% of actual wind energy could be converted to electricity, but it might be solved in the near future.
Solar energy, the power from the sun, has greater potential than wind power to become a major energy in the future, though it has not been fully developed. Direct sunlight has been used by humans for heating and drying for millennia. Nowadays, it can be directly used in solar thermal systems which collect sunlight through mirrors to heat a fluid in order to generate electricity. Several distinct types of solar thermal systems have been developed in many countries. The biggest breakthrough of sunlight use in twentieth century is photovoltaic (PV), which turns sunlight directly into electricity. PV has been used in space satellites and could be developed more for private use. Solar power is similar to wind power in that they both produce no harmful emissions and both are widely available. People can fix mirrors on the roofs of houses to collect sunlight for house and water heating, thus no additional spaces are required for installation. (Brower 1992) However, if much energy is needed, huge installations which occupy large amount of lands are required.
Similarly to wind power, solar power also has the problem of storage due to its intermittent availability. In addition, the production of PV is so complex that it has not been mass-produced. So the PV is still expensive. Unlike wind power, PV cannot be considered as a clean energy. Brower (1992) indicated that some materials used in PV are usually exotic and hazardous to people who will contact with them. The energy conversion efficiency of PV is only about 15%, even lower than that of wind power. (Youngquist 2000) Since a lot of people living in areas without electricity to produce heat, the more invest on solar power has been on the agenda of renewable energy development.
Biomass is a modern term used today for what is, in fact, our old fuel source -- crops. Now, other forms of biomass such as animal and human wastes, seaweed and garbage have been commonly used. Biomass is distinguished from other renewable sources by its versatility of being converted to many forms such as liquid (like ethanol), gaseous fuels (like methane), electricity, and heat. (Biomass: versatile source of energy 2000) What is more, it is cheap and widely available all the year round so that any location can be chosen for setting up biomass conversion systems. Unlike wind power and solar power, biomass does not have the problem of storage since it is easy and inexpensive to store and transport. The major benefit of using biomass as a fuel is that it greatly reduces emissions of greenhouse gases, especially contributes a lot to the reduction of carbon dioxide which is the key factor of global warming. (Chinese Academy of Science Staff 2000, p. 53) Biomass also brings good news to farmers. Energy crops such as sugar cane they grow could provide extra income to them, and more chances of employment are created. Meanwhile, energy crops could stabilize the soil and prevent it from eroding which helps the restoration of environment.
However, the negative aspects of biomass use cannot be neglected. Firstly, although biomass contributes a lot to greenhouse gas reduction, as mentioned by Brower (1992), the combustion of biomass produces air pollutants including carbon monoxide, nitrogen oxides, and particulates such as soot and ash. Secondly, the municipal wastes burned often generate harmful emissions and foul odors. Thirdly, there remains a controversy about land use. It is argued that poor countries will face worse situation of starvation if they focus on growing energy crops instead of food crops. Finally, Heinberg (2005, p. 173) claimed that the energy needed for biomass conversion is more than the biomass-derived fuels release when burning. In other words, the net energy of biomass conversion could be considered zero.
In conclusion there is an urgent problem of how to deal with the current energy crisis caused by increasing demand of energy (e.g. oil) and lack of energy supplies. Now, the renewable energy seems the best choice. Three main renewable energy sources were evaluated. Both wind power and solar power are widely available and produce no harmful emissions to air and water. However, they both have the problem of storage due to their intermittent availability. In addition, wind power is associated with noise, unpleasant visual effect and bird death, whereas, PV is linked to high price, radioactive materials and low energy conversion efficiency. Biomass is a more versatile source and easier to store. It also could indirectly benefit farmers and soil. Although it involves problems of air pollution and land use, biomass, compared to wind power and solar power, might be the simplest and cheapest source to produce energy. In the near future, other forms of renewable energy could be developed more. In a short term renewable energy is not a serious alternative of the traditional energy such as coal and oil; nevertheless, it is a long-term strategy for an energy crisis. Non-renewable energy could be eventually replaced by new forms of renewable energy which are more secure and sustainable.
List of References
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http://www.ucsusa.org/clean_energy/renewable_energy_basics/environmental-impacts-of-renewable-energy-technologies.html
Chinese Academy of Science Staff 2000, Cooperation in the Energy Futures of China and the United States, National Academies Press, Washington, p. 53. Retrieved December 6, 2005, from Ebrary: http://site.ebrary.com/lib/uon/
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