Introduction
Energy supply refers to the total quantity of usable energy that mankind can utilize. The main sources of energy are Fossil Fuels, Water Power, Wind Power, Nuclear Power, Tidal Power, Biomass Power, Solar Power, and Geothermal Power.
Fossil fuels
Fossil Fuels come from decaying plants and animals for hundreds of years. The 3 types of fossil fuels: coal, petroleum, and natural gas, serve most of the world’s energy needs. Energy from fossil fuels is generated by the process of combustion. Power stations heat water into steam which then rotates a turbine to generate electricity. Global coal production was 2235 MT in 1973, which increased to 4973 MT in 2005. Crude Oil production rose from 2867 MT in 1973 to 3923 MT in 2005. Natural Gas production rose from 1226 Bcm in 1973 to 2572 Bcm in 2005.
The advantage of coal is that it is not expensive the extraction process is easy. Oil and gas are good as space heating energy sources and are backed by a good distribution system. The disadvantages are they are non-renewable resources, they contribute heavily to air pollution, global warming, and acid rain by emitting poisonous carbon dioxide, sulfur dioxide, and mercury into the atmosphere; there are large price swings associated with supply and demand, which pose security risks for dependent countries; and the extraction process of coal regular involves accidents like cave-ins and development of lung disease by miners.
Hydroelectric Power
Hydroelectric Power is produced by harnessing water power by building a dam in mountainous areas where it flows from a height to a lower area. The harnessed water pressure and flow are used to turn huge water wheels to generate electricity. Hydroelectric power production was 1282 TWh in 1973, which rose to 2808 TWh in 2004. The top producers in 2004 were China (354 TWh), Canada (341 TWh), Brazil (321 Twh), and U.S. (271 Twh).
The advantage of hydroelectric power is that water is a renewable source of energy; there is an only one-time large investment while building the dam; it is particularly useful in mountainous areas where water flows from a height (for example, the U.S. has a network of many dams in the Western part of the country); unlike fossil fuels, it does not cause pollution. The disadvantages are the scarcity of suitable areas where water elevation exists; no future expansion prospects as dams already exist and cannot be enhanced; construction of dams negatively affect fish patterns (like salmon runs); the collapse of dams can lead to loss of life and heavy environmental damage in flooded areas.
Wind Power
Wind Power is used to generate electricity. Wind farms use the huge blades of wind turbines contained in wind towers to be rotated by wind power and generate electricity.
The advantage of wind power is that wind is a renewable source of energy; unlike fossil fuels, it does not cause pollution; it is well suited for use in rural areas not only to generate electricity but also to periodically pump water as used in the early 1900s; energy generation and maintenance costs are less. Its disadvantages are the scarcity of wind-friendly areas; there is a danger of heavy winds damaging energy-generating equipment; there is the constant danger that the huge turbine blades will maim or kill birds.
Nuclear Power
Nuclear Power generates electricity by splitting atoms of uranium and other elements by the fission process. Global production of Nuclear Power was only 203 TWh in 1973, with the Organization for Economic Co-operation and Development (OECD) countries share being 92.8%, followed by USSR at 5.9% and Asia at 1.3%. The production shot up to as large as 2738 TWh in 2004 with the OECD countries contributing 84.7%, USSR 9.1%, Asia 2.2% and other countries 4%.
The advantages are that it does not have a dangerous greenhouse or acid rain effect; nuclear fuel is not expensive, and a small amount of fuel can generate a huge amount of electricity; energy generation is the most concentrated source, and it is easy to transport as a new source. The disadvantages are its fuel (uranium) is a non-renewable source of energy; massive investment is involved to cover not only construction of nuclear power plants, but also providing emergency, containment, radioactive waste and storage systems, and for the cost of decommissioning of the plant at the end of its short life; nuclear proliferation is becoming an increasing global menace, for example, recent activities by Iran and North Korea, and the great danger of errors leading to disastrous results (as experienced in Chernobyl).
Tidal Power
Tidal Power uses tides to generate energy. Every coastal area normally experiences two high tides as well as two low tides every day. Tidal power generation needs the difference between the high and low tides to be at least 5 meters or more than 16 feet. A dam or barrage is constructed across estuaries to force water into tidal turbines which rotate and generate electricity.
The advantages are the existence of only a one-time investment; tides are renewable sources of energy; there is no danger of pollution. The disadvantages are the scarcity of areas where the exact tidal range magnitude occurs (there are only 40 areas present in the world), and the dams negatively affect sea life migration and local ecosystems.
Biomass Power
Biomass Power is energy drawn from organic matter such as forest and mill waste products, municipal and industrial wastes, crops and wastes, animal wastes, wood and wood wastes, trees, and aquatic plants.
Its advantages are that it uses waste material, thereby solving their disposal problems; and there is no shortage of biomass. The disadvantages are it is still in the initial, small-scale stage of development; and it contributes to pollution by emitting poisonous substances into the atmosphere.
Solar Power
Solar Power uses solar cells are used to generate electricity from sunlight and solar panels and solar mirrors to heat water.
The advantages of Solar Power are that the sun is a renewable source of energy; it does not cause pollution; like wind power, it is ideal for rural areas; and besides electricity, it can be used to provide heat. Its disadvantages are the scarcity of sunny areas (like those in the south U.S.A) in the world, where demand can be the most (like winter solar heating) when supply is least available; and materials used in the construction of solar panels and solar mirrors can negatively affect the environment.
Geothermal Power
Geothermal Power mines heat from hot rocks present in the earth’s crust. Wells are drilled to pump the hot water or steam to the surface where it is used to rotate turbines and generate electricity.
Its advantages are that it does not cause pollution; like tidal power, it requires a one-time investment; it is an attractive source of energy not dependent on scarce fuels that countries having favorable locations are exploiting (according to the U.S. Geothermal Energy Association, 61 projects are presently underway in the country which would enhance total energy availability to 5,000 megawatts). Its disadvantages are there are few areas in the world where tectonic plates collide, and it faces environmental hurdles common to new fossil fuel projects.
Local and international problems
There are several local and international problems associated with various sources of energy.
Petroleum has the dubious distinction of being the most problematic source of energy. It has been the cause of political and economic conflicts. Since most of the world’s oil reserves are found in the Middle East and North Africa, these countries have dictated terms on supplies to dependent countries. Although the U.S was ranked third in oil production in 2005, it also was the biggest oil importer in 2004 with 577 Mt, followed by Japan (206 Mt). Several International problems have been caused, such as the 1973 oil embargo when Middle East countries stopped supplies to the West in retaliation for their support to Israel. Petroleum has also caused local problems within the OPEC, where member nations are constantly bickering with each other to get the highest possible quotas.
Gas is another fuel that has caused international problems. In 2005, Iran deliberately slowed negotiations, hinting at backing out of a deal to supply 5 million tons of LNG to India for 25 years starting from 2009, because India voted against Iran in the U.N sponsored resolution to impose sanctions on Iran for its suspicious nuclear program.
Cost-Benefit analysis of various sources of energy brings to light interesting information.
In 2004, the Rocky Mountains Research Institute calculated the cost of generating electricity per kilowatt-hour: coal 4 cents, wind power 4.2 cents, gas 6.8 cents, oil 9.1 cents, and nuclear power 10 cents.
Although fossil fuels provide most of the world’s needs (86% in 1973 and 80.3% in 2004,15 they are scarce and being consumed at a rate far exceeding their slow formation process. Secondly, the main fossil fuel, petroleum, which catered to 45% of world needs in 1973 and 34.3% in 2004, is very costly due to the price manipulations of the exporting nations. April 2007 delivery light sweet crude oil was quoted at $ 61.28 per barrel at New York Mercantile Exchange, while Brent crude oil was quoted at $ 62.18 at London ICE Futures Exchange. The high price hits hard at oil importers such as China and Japan, the second and third largest oil consumers in the world, who consumed 6,391,000 and 5,578,000 barrels per day respectively in 2004. Although the U.S. was the third-largest oil producer in 2005 with 307 Mt, it was the world’s largest consumer in 2004, consuming 20,030,000 barrels per day. Thirdly, the pollution emissions of fossil fuels are tremendous. In 1973, global fossil fuel emission of Carbon Dioxide (CO2) was 15,661 Mt (oil 50.7%, Coal 34.9%, Gas 14.4%), which rose to 26,583 Mt in 2004 (oil 39.9%, coal 40%, gas 19.8%, others 0.3%). In 2005, the Union of Concerned Scientists in the U.S.A (UCSUSA) estimated that a typical coal plant yearly emits 3,700,000 tons of CO2, 10,000 tons of SO2, 10,200 tons of Nitrogen Oxide (NOx), 720 tons of Carbon Monoxide (MO), 220 Tons of Volatile Organic Compounds (VOC), 225 pounds of Arsenic, 170 pounds of Mercury and 114 pounds of Lead.
Biomass, Tidal, and Geothermal power are too small to consider fulfilling the requirements of the world. The latter two, like hydroelectric power, are limited to only certain areas of the world. Biomass power generation is still in its infancy period. Tidal power plants involve massive construction expenses and long payback periods, making power.
Solar power is hampered by the usage of large areas of land for small amounts of energy generation. Scientists propagating solar power have been charged with keeping 3 dangerous facts hidden from the public: first, since solar energy is generated by nuclear fusion within the core of the sun, it is very volatile; second, the source of solar energy is hydrogen, an extremely explosive gas with great destruction potential that can also cause hazardous fallout; third, the scientists do not yet fully understand how the sun works.
Conclusion
In my opinion, the best options are Wind Power and Nuclear Power, the first on an immediate basis, and the second in the long term.
Wind energy is set to become the best source of energy for the U.S. as well as the world. In 1991, the U.S. Department of Energy made a remarkable announcement: just 3 of the country’s States (North Dakota, Kansas, and Texas) were so wind-rich that potential wind energy harnessed could be sufficient for the entire country’s needs. In 2003, a Stanford group of engineers confirmed this astounding fact, adding that the wind energy potential was much greater than the 1991 estimate. The European Wind Energy Association and Greenpeace jointly conducted Wind Force 12 assessment which found that global wind energy potential was so great, that it would be double the global electricity demand in the year 2020; moreover, this only covered global land area – if the offshore potential is added, wind power can satisfy not only global electricity needs but also total global energy needs. These discoveries, added to its environment-friendly image, make wind power the most attractive proposition to the world at present.
The usage of nuclear power is steadily increasing. In 2004, the U.S was the largest nuclear power producer in the world (813 Twh) followed by France (448 Twh) and Japan (282 Twh). Still, it is hampered by problems related to the limited supply of uranium and the radioactive wastes of power stations. Scientists are increasingly excited at the prospect of developing nuclear fusion reactors that would use hydrogen and tritium for fuel. It produces higher energy output per unit mass per unit than the present nuclear fission process, and the level of radiation is very low than the fission process. This new form of nuclear power generation, which will take time to develop (after 40 years of expensive research, commercially available nuclear plants are expected only after 35 years from now), is an ideal prospect for the world in the future.
References
Brown, Lester R. Wind Power Set to Become World’s Leading Energy Source. Online. Earthpolicy.org, 2004. Web.
Chea, Terence. Rising Fossil Fuel Costs Boost Renewable Energy. Online. Deseretnews.com, 2004. Web.
Eere.energy.gov. Ocean Tidal Power. Online. Eere.energy.gov, 2005. Web.
Ewall, Mike. The Burning Issues with BioMass. Online. Energyjustice.net, 2000. Web.
Iea.org. Key World Statistics. Online. Iea.org, 2006. Web.
Iran-daily.com. India Assured 25-Year LNG Supply. Online. Iran-daily.com, 2005. Web.
Nationmasters.com. Energy Statistics: Oil Consumption by Country. Online. Nationmasters.com, 2005. Web.
Offshore-technology.com. Oil Price Fall Ahead of OPEC Meeting. Online. Offshore-technology.com, 2007. Web.
Simanek, Donald E. The Hazards of Solar Energy. Online. Lhup.edu, 1994. 2007. Web.
Szep, Jason. U.S urged to Ramp up Geothermal Power. Online. Commondreams.org, 2007. Web.
Ucusa.org. Environmental Impacts of Coal Power: Air Pollution. Online. Ucsusa.org, 2005. Web.
The Virtual Nuclear Tourist. Comparison of Various Energy Sources. Online. The Virtual Nuclear Tourist, 2005. Web.