Alternative Energy Sources - Essay Example

One possible alternative is the oil shelf, which constitutes a potential energy resource much larger even than coal. Hydroelectric energy and the energy of the wind and tides will always be available (Manwell and Rogers 41). The rate at which these energy sources can be exploited, however, is limited by the global flow of energy in the form of falling water, wind, and tides at any given time. It is also limited by the number of sites where these processes can be exploited economically. Power is the rate at which energy flows or is used.

Continuous energy sources, such as the water cycle, are usually characterized in terms of power -- say in kilowatts -- although they could easily be characterized by the amount of energy flowing per day or per year (Beggs 76). The world's potential production of hydroelectric power is roughly half of the amount of power now being produced by fossil fuels. There are, however, serious problems in utilizing it to the utmost. Much of the potential lies in international conventions, where the power could not be used unless those countries were industrialized; global ecological factors and the inability of the international conventions, to mobilize capital and high-grade resources will impede industrialization in most of them.

Furthermore, reliable hydroelectric power depends on dams, which under present conditions of technology are temporary structures. In a few hundred years -- sometimes more, sometimes less, depending on the river -- their reservoirs fill with silt and become useless (Birkeland 28). Wind-electric technologies also may be competitive. Hot water, space heat where needed, and much industrial process heat lend themselves to wind supply. Wind energy will have a positive impact on climate change and global warming (through reduced emissions) and will support economic growth (Beggs 87).

In sum, wind energy is good because it is cheap and is available in all nations, even though some have short winter days and overcast skies. Wind energy is a renewable source while coals and oil are exhaustible natural resources. Thereafter, power production from the waterfall occupying the dam site hinges on the daily and seasonal variations of river flow. Unfortunately, tidal power comprises only a minute fraction of all potential water power, and will presumably never be of more than local importance.

Wind energy has the disadvantages of low concentration and of being unpredictable and intermittent in most locations.