Sustainable energies
Ling Huaqing
It is known that energy is absolutely necessary in humans’ lives and some kind of energies source such as coal and gas will be able to exhausted one day. Therefore, sustainable energy, which can be naturally replenished on a human timescale, is being exploiting by people nowadays. Exploiting sustainable energy has both advantages and disadvantages in supplying demand. This essay will analyse these advantages and disadvantages.

First of all, sustainable energies are environmental friendly. Using this kind of energy such as wind, water and waves will not discharge polluted air or waste. One of the most significant emissions when fossil fuels are burned is carbon dioxide, a gas that traps heat in the earth’s atmosphere. Over the last 150 years, burning fossil fuels has resulted in more than a 25 percent increase in the amount of carbon dioxide in our atmosphere. Scientists predict that as carbon dioxide levels continue to rise this century, so global warming will increase (Union of Concerned Scientists 2013). Unlike the power from fossil fuels, wind power is a vast and inexhaustible resource. It already supplies 20 percent of the electricity or more for several areas in Europe: Demark currently leads all nations with 20 percent wind penetration, and two states in Germany with a combined population of 4 million get 40 percent of their electricity from wind (Earth Policy institute 2010).

Secondly, sustainable and renewable energy can be used effectively. In some areas of the word, there is not sufficient fossil and fuels, it is unreasonable for the countries to import the resources from other countries because of the high price. Therefore, it is wise for them to use local sustainable resources to product energy to satisfy citizens requirement. For instance, just 20 days of sunshine contains more energy than the world’s entire supply of coal, oil, and natural gas. A range of technologies is used to convert the sun’s energy into electricity, including solar collectors and photovoltaic panels.

Admittedly, the exploration may cause some ecological problems. For example, if people want to use the wind power, people must provide huge space to offshore wind facilities for the reason that the turbines are bigger than land-based ones.( Fact Sheet on renewable energies 2012). People can see the wind facilities in many open lands. This occupying may have