Assignment 1

Energy can be converted from one form into another in three basic ways know as the action of force. The first one is gravitational forces which is when gravity accelerates a falling object, its converts its potential energy to kinetic energy. Likewise, when an object is lifted the gravitational field stores the energy exerted by the lifter as potential energy in the earth-object system. The second one is electric and magnetic force fields which is charged particles, upon which electrical fields exert forces, possess potential energy in the presence of an electric field in a way similar to that of an object in a gravitational field. These force fields can accelerate particles, converting a particle's potential energy into kinetic energy. Particles can interact via the electric and magnetic fields they create, transferring energy between them, and in the case of an electrical current in a conductor, cause molecules to vibrate, for example converting electrical potential energy into heat. This leads to the third action of force which is frictional forces(www.powerincooperation.com)This is defined as macroscopic energy of an object, that is, the potential and kinetic energy associated with the position, orientation, or motion of the entire object, not counting the thermal or heat energy of the system, can be converted into heat, whenever the object slides against another object. The sliding causes the molecules on the surfaces of contact to interact via electromagnetic fields with one another and start vibrating.

This occurs when atoms absorb photons of light, the light falls on an object, an incident photon passes through the object, the object reflects or absorb sthe atoms making up the object. If most of the photons pass through, the object is transparent. Depending on the smoothness of the surface on the scale of the photon's wavelength, the reflection may be either diffuse or coherent. On the other hand watts are a very convenient unit when working with appliances, for example, for specifying the power of light bulbs. There are also times when you are interested in the total energy use, for example, when you are calculating how much your utility bill is going to be. Kilowatt hours is a much better unit for large amounts of energy. Finally amps and voltage is another method on how energy is converted (www.epa.gov/cleanrgy/energy-and-you/affect/non-hydro.html) Voltage measures how much electrical energy is delivered if a certain charge, that is, a certain number of electrons, are transmitted through a circuit. In other words, it tells you that such and such an amount of energy will be delivered if such and such a number of electrons pass through the circuit of power. In a typical house with alternating current say, from a utility line, the power outlets in the wall supply all run off of volts.

Natural gas is a fossil fuel source of energy, which represents more than one fifth of total energy consumption in the world. It has been the fastest growing fossil fuel since the seventies. Due to economical and ecological advantages that it presents as well as its safety qualities natural gas is an increasingly attractive source of energy in many countries. At present, natural gas is the second energy source after oil. It has excellent perspectives for future demand. Natural gas is considered the fossil fuel of this century, as petroleum was last century and coal two centuries ago. The oil and gas are then squeezed out of the marine shales in which they were deposited, and from there go into porous sedimentary rocks. Oil and gas migrates upward through the porous rock, as it is less dense than the water, which fills the pores. Several different types of oil and gas "traps" exist. Natural gas is found throughout the world in reservoirs deep beneath the surface of the earth and floor of the oceans. It forms as pockets of gas over crude oil deposits or is trapped in porous rock formations. Natural gas can be found in oil deposits, as associated natural gas, although non associated natural gas is often found without the presence of oil. Natural gas is considered as a clean fuel because of its environmentally friendly properties such as being practically sulphur free and it produces virtually no sulphur dioxide or SO2. (http://environment.about.com/fossilfuels/Environmental_Issues_Fossil_Fuels_Alternative_Fuels.htm)

Two different energy alternatives that came to mind is wind power and hydropower. Societies have taken advantage of wind power for thousands of years. The first known use was in 5000 BC when people used sails to navigate the Nile River. Persians had already been using windmills for 400 years by 900 AD in order to pump water and grind grain. (www.epa.gov/cleanrgy/energy-and-you/affect/non-hydro.html)Windmills may have even been developed in China before 1 AD, but the earliest written documentation comes from 1219. Cretans were using hundreds of sail rotor windmills to pump water for crops and livestock. Wind power is one of the most promising new energy sources that can serve as an alternative to fossil fuel generated electricity. The cost of wind has dropped by 15% with each doubling of installed capacity worldwide, and capacity has doubled three times during the 1990s and 2000's.As of 1999, global wind energy capacity topped 10,000 megawatts, which is approximately 16 billion kilowatt-hours of electricity. That's enough to serve over 5 cities the size of Miami, according to the American Wind Energy Association. Though wind energy is now more affordable, more available, and pollution free source of energy, it does have some drawbacks. Wind power suffers from the same lack of energy density as direct solar radiation. (http://www.awea.org/)

The fact that it is a very diffuse source means that large numbers of wind generators are required to produce useful amounts of heat or electricity, however wind turbines cannot be erected everywhere simply because many places are not windy enough for suitable power generation., building and maintaining a wind farm can be costly, and technology would be intensive. As for hydropower it is one of most established true renewable energy source. Originally this was used in old fashioned water mills, however in the first half of the 20th century more modern devices using turbines to generate electricty were used. Hydropower is a useful source of electricity, as it is not only renewable but it is also possible to control when the water is released in many systems, allowing control to happen. Famous hydropower dams are the Hoover Dam in the US, the Aswan Dam in Egypt and the Three Gorges Dam in China. Out of all of the renewable energy technologies hydropower is probably the most economic, assuming there is a suitable resource. Whilst there is the potential for further hydropower projects to produce renewable energy, the majority of good sites in developed countries have already been used, and so out of all of the renewable energy technologies this is probably the one with the lowest chance of serious percentage growth. (www.scienceclarified.com)

References:

www.powerincooperation.com http://environment.about.com/od/fossilfuels/Environmental_Issues_Fossil_Fuels_Alternative_Fuels.htm www.scienceclarified.com www.epa.gov/cleanrgy/energy-and-you/affect/non-hydro.html Assignment 1