Seven Castles

Alternative Energy

                                      

April 22, 2008

 

"Alternative energy" is a term used for some energy source that is an alternative to using fossil fuels. Generally, it indicates energies that are non-traditional and derived from sources that do not harm the environment or deplete the Earth's natural resources. Typical sources include wind and solar. Nuclear energy is usually excluded from this definition. Some sources may use "alternative energy" interchangeably with "renewable energy".

 

The alternative energy technologies include solar energy, wind power, tidal power, wave power, hydroelectric power and geothermal energy. The amount of energy in such renewable and virtually pollution-free sources is large in relation to world energy needs, yet at present only a small portion of it can be converted to electric power at reasonable cost.

 

As we deplete our oil resources, it is time to look for alternative energy sources. Whereas there is a limited amount of oil, the power from the sun, wind and other alternative energy sources is practically limitless.

 

In truth, many fossil and renewable energy sources actually ultimately come from solar energy. Of course, for all intensive purposes, we are going to refer to solar power as energy directly collected from the sun. The benefits of solar power are zero emissions of air pollutants and greenhouse gases; easy to install; virtually no energy costs once installed; the technology for solar power is constantly improving. However, the problems with solar power are that it is not available at night; cloudy or smoggy skies etc. can affect how much solar energy you will get (same with wintertime vs. summertime, etc.); solar panels can be very expensive and for a lot of solar power, you need a lot of installations. Though there is an equal amount of benefits and negatives, the benefits clearly outweigh those negatives.

 

Wind power has such benefits: no contribution to greenhouse gases; no emissions; the giant turbines can actually look quite beautiful in some landscapes. The negatives are: the wind turbines can be a bit of an eyesore, especially because some of the best places for them (windy areas) are in beautiful landscapes that would be marred by giant "windmills"; wind strengths vary; it is difficult to guarantee any continuous power; it can be noisy and many birds become martyrs to our cause for alternative energy (they run into the turbines and die).

 

Biofuel is any type of fuel that comes from biomass (like living organisms or manure, etc.). To get energy from biofuel, it is generally burned. Its benefits include: under the right conditions, biofuel is renewable; lower emissions when used in automobiles (liquid biofuel like ethanol and biodiesel); biofuel like renewable natural gas (a biogas) can be easily distributed to the mass market through the already existing gas grid. Its drawbacks are: before biofuel is ready, it must undergo many steps: grown, collected, dried, fermented, then burned, etc.; to complete each step, resources must be used; the gathering of any use of wood (a biofuel) has lead to erosion in some places; when corn is turned into ethanol, many say that it takes even more energy to produce it than is obtained from it. (And if we are using corn as fuel, it means it cannot be used as food). Also, ethanol produces nitrous oxides and carcinogens.

 

It is best not to rely on just one alternative energy source. In this way, if one energy source fails, there is another one to back it up. This is one of our problems with our reliance on oil: unless we start coming up with more alternative energy sources now, when we run out of oil, we will be out of luck!

 

And although none of these alternative energy sources are perfect yet, the technologies behind them are constantly improving. Scientists are finding ways to store the power created by solar panels and wind turbines so that in days (and nights) with no sun or no wind, we will still have power, etc.

【作者: zhangliping】【访问统计:】【2008年04月22日 星期二 05:27】【注册】【打印】