Technology

1. Energy can be defined as the ability to do work (Pahl, 2008). Energy exists in several forms including kinetic energy, potential energy, electrical energy and mechanical energy. One of the laws of nature is that energy can never be destroyed, but can be converted from one form to another through a process known as transduction (New Mexico Solar Energy Association, 2010). A device that converts energy from one form to another is called a transducer.

One of the best examples of energy transduction is the process of generating electricity from a hydroelectric power station to the lighting of a house. The hydroelectric power station holds water in a reservoir, which has potential energy (New Mexico Solar Energy Association, 2010). When this water is channeled to a tunnel bearing a gravitational gradient, it converts its energy from potential to kinetic (New Mexico Solar Energy Association, 2010). The slanted tunnel can therefore be referred to as the transducer. When the flowing water reaches the turbine, its kinetic energy is transformed into mechanical energy, putting the turbine into rotation. The turbine is coupled to an alternator, which acts as a transducer, converting the mechanical energy of the rotating turbine into electrical energy, which then flows into the final transducer, the light bulb (New Mexico Solar Energy Association, 2010). The bulb has a filament that converts electrical energy into excessive heat energy, producing light.

Another example of energy conversion is the conversion of potential chemical energy in gasoline and oxygen into kinetic energy through compression and combustion in the pistons. The kinetic energy is converted into translational movement (mechanical energy) through the crankshaft, the transmission assembly and to the differential, causing the automobile to move (New Mexico Solar Energy Association, 2010).

2. Fossil fuels are substances that can be consumed to produce energy which have been formed through anaerobic decomposition of living organisms that died millions of years ago (Shannon  Chughtai, 2010). Fossil fuels contain a very high percentage of hydrocarbons and include petroleum, coal and natural gas. The conditions necessary for the formation of fossil fuel deposits are absence of oxygen and the presence of much heat and pressure (Shannon  Chughtai, 2010). That is why deposits occur deep under the earths surface. Fossil fuels cater for over 85 percent of the worlds energy needs and this use is mainly through combustion, either directly or combustion of products generated after they have been subjected to refinement processes. Such is the case with petroleum, which is refined into finer products like petrol, kerosene and diesel.

Fossil fuels are an attractive source of energy since they are combusted into carbon dioxide and water, producing very high amounts of heat (Shannon  Chughtai, 2010). Furthermore, products from fossil fuels are very portable making them suitable for mobile applications, for example in motor vehicles and ships. Almost all motor vehicles run on petroleum products while seagoing vessels like ships and tankers mostly use coal. Another advantage of fossil fuels is that they can efficiently be transported and stored to be used when the need arises (Shannon  Chughtai, 2010). Gasoline and diesel can be stored in tanks, either stationary or mobile, for later use. Natural gas, used for lighting, cooking and heating can be stored under pressure in specially designed cylinders for prolonged time periods without expiring.

The efficiency of using fossil fuels is that they do not need a support infrastructure to use their application is purely stand-alone (Shannon  Chughtai, 2010). Other sources like electricity for example need an elaborate cable system to deliver power to the point of consumption. If an area is not covered by this cable network, then electricity cannot be used there but fossil fuels can be transported for use even in the remotest areas.

3. With world population increasing rapidly, the load on energy sources has risen sharply. The world is struggling to meet its energy needs and the situation is made more severe by the fact that fossil fuel deposits are getting depleted. There is thus an urgent need to find alternatives to fossil fuels.

Biodiesel is one of the alternatives to fossil fuels. It is very much similar to diesel derived from petroleum, only that it is extracted from vegetable oils and fat from animals. Chemically, biodiesel is an alkyl ester obtained through a process called trans-esterification of vegetable oils or animal fats by using ethyl alcohols (Pahl, 2008). One of the plants most commonly used in manufacturing biodiesel is Jatropha. Biodiesel however does not compare to diesel derived from fossil fuels in terms of efficiency but once mixed with fossil diesel at certain ratios, the mixture has a higher efficiency and reduces carbon emissions, which have been the subject of very much heated debate because of their perceived contribution to global warming (Shannon  Chughtai, 2010).

Bio-alcohol is another emerging type of fuel that can excellently supplement fossil fuels. Organic alcoholic substances such as ethanol, butanol, methanol and propanol have similar characteristics as gasoline and are efficiently applicable in internal combustion engines, for example in light automobiles (New Mexico Solar Energy Association, 2010). The good thing with bio-alcohols is that they can be readily extracted from biological sources. Like fossil fuel derivatives, bio-alcohols also produce carbon emissions even though at a much lower rates. The preferred bio-alcohol is ethanol, which is readily manufactured by fermenting natural sugars and starch.

Finally, liquid hydrogen as emerged as the most environmentally friendly alternative of fossil fuels as a source of energy. Under normal circumstances, hydrogen exists as a harmless gas in the atmosphere, needing an external source of energy to ignite. However, technologies have been formed that utilize its chemical properties to produce energy. Fuel cell technology is one such invention, and chemically combines hydrogen and oxygen atoms with the aid of a catalyst to produce an electric current and water as the only by-product (New Mexico Solar Energy Association, 2010). Fuel cells find wide application in spacecrafts and are currently being used to power electric cars. Even though not as reliable as fossil fuel derivatives in terms of capacity, fossil fuels are more efficient energy converters and do no harm to the environment.