Wednesday, November 7, 2012

Alternative Sources of Energy


Alternative Sources of Energy

As the population of the world increases, so does the need for energy. At the moment we are using fossil fuels as the main source of energy. According to sciencedaily.com Fossil fuels are hydrocarbons formed from the remains of dead plants and animals.

A fossil fuel is any naturally occurring carbon or hydrocarbon fuel formed by the decomposition of prehistoric organisms. Fossil Fuels were formed as a result of geologic processes acting on the remains of plants and animals that lived and died hundreds of millions of years ago. These dead plant and animal matter sank to the bottom of swamps and oceans and was covered by sand and rock (greenstudentu.com).  Ecokids.ca claims that the process of fossil fuels formation involved the exposure of these biological remains to extreme pressure and heat, and also took hundreds of millions of years. When these fuels are burned, they release energy. The main types of fossil fuels are coal, oil and gas. (www.thesolarspark.co.uk)

The earth has a limited supply of fossil fuels, they are burnt and finished that is why they are called non- renewable resources. According to Wikipedia “A non-renewable resource is a natural resource which cannot be produced, grown, generated, or used on a scale which can sustain its consumption rate, once depleted there is no more available for future needs.” This means we are using Fossil fuels much faster than the nature can create them for us. It takes millions of years for the earth to transform dead organic material into these fossil fuels. This is different from renewable materials, like wood, that can be planted again, so the supply can be renewed. When the last barrel of oil has been pumped out of the ground there is no more. Due to the extreme conditions and the time frame of the formation process, recreating it by humans is practically impossible. Hence the fossil fuels are considered the non-renewable ones.

According to greenenergychoice.com “Fossil fuels are the largest greenhouse gas emitters in the world, contributing 3/4 of all carbon, methane and other greenhouse gas emissions”. In other words fossil fuels are harmful for the environment because they release carbon dioxide, which is a greenhouse gas. Greenhouse gases cause the greenhouse effect, which according to news.bbc.co.uk is “the natural process by which the atmosphere traps some of the Sun's energy, warming the Earth enough to support life”. Simply put Carbon dioxide helps warm up the earth but the problem is that there is too much of these greenhouse gases, which is causing the earth to heat up more than it should. Greenhouse effect is a major contribution to global warming and if this continues then ice caps will melt, Sea levels will rise and Islands may drown.
Fossil fuels are not the only source of energy; there are alternative sources of energy, which are called renewable resources.audioenglish.net states that a renewable resource is “any natural resource that can be replenished naturally with the passage of time” this basically means that renewable resources are sustainable. There are several different types of renewable resources including tidal energy, solar energy, hydroelectricity, wind energy, geothermal energy, biomass, natural gas and nuclear power.


 
A very significant economic advantage of tidal energy is that it is predictable, and A Tidal Barrage has a very long life of around 100 years, which is much longer than that of even Nuclear Power Plants. On the other hand Tidal Barrages require massive investment to construct a Barrage or Dam across a river estuary.
No fuel is required in solar energy like it is in wind energy and the costs of operation and maintenance is extremely low. However, Solar energy can’t be utilized in cold countries, as there is barely any sun there. (greenworldinvestor.com).
Hydroelectricity is extremely reliable and consisting, but hydroelectricity needs a large reservoir and consisting it is a major challenge in terms of time and money (buzzle.com).
 Geothermal energy can be used for both heating and producing electricity on the contrary, when digging for geothermal energy can release hazardous gases, which are trapped underground (climatedebtagents.com).
Biomass converts waste into fuel and helps in dealing with waste yet, if biomass is over used, than deforestation and other environmental problems can develop (whatabiomass.weebly.com).
Natural gas industry employs 1.2 million people and is Widely used contributing to 21% of the world’s energy production today (triplepundit.com).
Nuclear power is readily available, it does not have to be developed first, on the other hand, the waste from nuclear energy is extremely dangerous and it has to be carefully looked after for several thousand years (timeforchange.org)
Now I would like to focus on different aspects of Wind energy-
Wind is the movement of air from an area of high pressure to an area of low pressure. Because the sun unevenly heats the ground, warm air, which weighs less than cold air, rises. Then cool air moves in and replaces the rising warm air. This movement of air is what makes the wind blow (weatherwizkids.com). Wind energy is called a renewable resource because As long as the sun shines, there will be winds on the Earth and we will never run out of wind energy because it is free since no one can own the sun or the air (http://www.need.org).
Wind power involves converting the kinetic energy of wind into electricity by using wind turbines. A wind turbine is made of 3, 60-meter long propellers-like blades called a rotor, which is attached to 20 story high, pole like tower (environment.nationalgeographic.com). The wind spins the blades, which turn a shaft connected to a generator that produces electricity. The wind turbines don’t run all the time, most wind turbines run between 65 and 90% of the time (need.org).
Small wind turbines erected in a backyard can produce enough electricity to pump water or provide power to a home and larger turbines can be used to a power an entire community or to provide power to the electricity grid (eere.energy.gov). The biggest wind turbines generate enough electricity to supply about 600 U.S. homes! (environment.nationalgeographic.com).

 There are a few Natural advantages to wind energy. Wind energy is green. Using wind to make electricity does not pollute the nature like fossil fuels do. Remote areas that are not connected to the electricity power grid can use wind turbines to produce their own supply. Although wind turbines can be very tall each takes up only a small plot of land. This means that the land below can still be used. This is especially the case in agricultural areas as farming can still continue. (hobbyfarms.com) Much of the energy used to manufacture turbines is contained in the rotor and nacelle. One-third of the total energy is consumed in making the concrete foundation and tower. However, The energy generated by wind turbines balances with the energy used to make them in a matter of months (mge.com).
Although there are many environmental advantages to wind energy, there are some natural disadvantages too. “Wind is unpredictable and the availability of wind energy is fluctuating. If the wind speed is too slow, it is not economical to run the turbine. If the wind speed is too high, the wind turbines must be shut down due to safety concerns.” (howtopowertheworld.com) This basically means that wind turbines are not entirely reliable. Wind turbines kill 10,000 -- 40,000 bats and birds per year, which of course is not sustainable (http://science.howstuffworks.com).
There is an economic advantage to wind energy that it creates job opportunities. People are needed to manufacture, set up and maintain the wind turbines; also, the energy produced may be used to run businesses, which can create jobs. Another disadvantage is that several people complain about the noise pollution from the wind turbine and some complain about how wind turbines are ugly. (http://energyinformative.org)

Citing from Slideshare.net, the newest designs for wind turbines allow 70 to 80 % efficiency of creating power using the wind. According to decc.gov.uk “In 2011 onshore wind generated 10,372 GWh of electricity, enough to power 2.4 million homes. This represented about 44% of UK renewable electricity production, and just under 4% of all electricity produced. “


“Although wind produces only about 1.5% of worldwide electricity use, it is growing rapidly, having doubled in the three years between 2005 and 2008. In several countries it has achieved relatively high levels of penetration, accounting for approximately 19% of electricity production in Denmark, 11% in Spain and Portugal, and 7% in Germany and the Republic of Ireland in 2008” (listverse.com) Industry experts predict that if this pace of growth continues, by 2050 the answer to one third of the world's electricity needs will be found blowing in the wind (http://environment.nationalgeographic.com) and claims that “by 2020 it is estimated that onshore wind could provide 24-32TWh electricity, enough to power up to 7.7 million homes”.

A combination of solar, hydroelectric, wind power and others can provide a totally reliable supply of renewable energy. With the advancement in technologies related to various renewable resources of energy, the “right” mix of these resources is rather dynamic. Geological, Social and Economic considerations would decide the optimal mix of these renewable resources for a specific location and time. It is heartening to see that the renewable resources of energy are gaining more focus from the powers that be.

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