SCIENCE ESSAY

Science Essay

Science Essay

Energy, Alternative Energy and Conversion

Energy has different meanings in different contexts. Energy can occur in various forms: kinetic, potential, electromagnetic, sound, and so on. Energy of a moving car is kinetic energy, where as the energy of water stored in a dam is potential energy. Energy can be converted from one form to another (Cassedy, Grossman, 2008).

For example, when water falls from a dam, the potential energy of water gets converted into kinetic energy, which drives turbines to produce electrical energy. When a car crashes into a wall, the kinetic energy of the car is converted into heat and sound energy.

Fossil Fuels

Fossils fuels comprising petroleum, natural gas, and coal are primary energy sources. The phrase Alternative energy implies that these energy sources are alternatives to nuclear and traditional fossil fuels such as coal, petroleum, or natural gas. Alternative energy, therefore, is a catchall category of energy sources that proponents argue can replace traditional fossil fuels in daily life, while causing less harm to the environment (Berinstein, 2007). Advocates of alternative energy argue that alternative energy sources need to be developed now, so that when fossil fuels are gone, there will be other dependable energy resources.

Alternative Sources

Solar Energy

The solar energy technologies can be broadly categorized into four groups: passive heating, active heating, solar-thermal electric and solar photovoltaic. A photovoltaic system converts solar energy to electrical energy when solar rays fall on the p-n photvoltaic device, causing the release and migration of electrons from an n-type semiconductor to a p-type semiconductor (Sorensen, 2006).

Wind Energy

Wind power technology utilizes the energy of the sufficiently strong winds to drive turbines and produce electricity. The differential heating of the earth's land and sea surfaces produces winds by creating a pressure gradient. Air moves from the area of high pressure to ...