论文代写：化石燃料
世界目前的能源概况包括大量化石燃料。虽然天然气和石油产品几乎用于从房子的烹饪和加热到运输的所有环节，但煤炭主要用于工业和发电。化石燃料的使用非常广泛，因为它们具有一定的优势。他们很容易获得，很容易点击。它们是可靠的能源，价格相当便宜，尤其是与可再生能源相比时。但是，它们并不是无限的能量来源。所有的化石燃料都是有限的，尽管目前的库存量可能足以维持人类的前途，但从长远来看，它们将耗尽。但是，这并不是这些燃料的更大缺点。化石燃料燃烧产生几种温室气体，如二氧化碳和甲烷，这是全球变暖的唯一罪魁祸首。虽然它们可以负担得起且可靠，但它们具有非常强烈的负面外部性 – 污染。发展中国家的一些城市，如印度的新德里和中国的北京，已经成为世界上污染最严重的城市之一。
论文代写：化石燃料
另一方面，可再生能源不仅自然丰富，而且干净。可再生能源主要用于发电，进而用于满足烹饪，空调和机动车等最终用途需求。可再生能源包括小型水电站，基于废弃物的发电，地热能源和潮汐能，太阳能和风能能量是目前最受欢迎的。这是因为重要的研究已经以不同方式利用这些能源形式并以一种理想的方式使用它们。但是，他们有自己的一套限制。由于可再生能源的间歇性和不可靠性，可再生能源并不容易控制。例如，太阳能仅在白天可用，而风能随时可用。目前的估计表明，尽管可再生能源的单位发电成本已经降至十年前的成本的四分之一（Paddison，2014），但高昂的前期成本仍然很高。
论文代写：化石燃料
The current energy profile of the world includes a large amount of fossil fuels. While natural gas and petroleum products are used for almost everything starting from cooking and heating of houses to transportation, coal is mainly used in industries and for power generation. Fossil fuels are used so extensively because they offer certain advantages. They are easily available and are easy to tap. They are a reliable source of energy and are reasonably cheap, especially when compared to renewable energy. However, they are not infinite sources of energy. All the fossil fuels are limited and while their current stock may seem large enough to sustain mankind for immediate future, they will run out in the long run. However, this is not the bigger drawback of these fuels. The fossil fuels burn to produce several greenhouse gases like carbon dioxide and methane which is the sole culprit of global warming. While they may be affordable and reliable, they have very strong negative externality- pollution. Some of the cities in the developing countries like New Delhi in India and Beijing in China have become some of the most polluted cities of the world.
论文代写：化石燃料
Renewables, on the other hand, are not only abundant in nature, but also clean. Renewable energy is primarily used to generate electricity which in turn is used to meet the end-use demands of cooking, space conditioning and mobility etc. While renewables include small hydro plants, waste based power generation, geothermal energy and tidal energy, solar and wind energy are the most popular ones right now. This is because significant research has already gone into different ways of tapping these energy forms and using them in a desirable way. However, they have their own set of limitations. Renewable energy is not as easy to control owing to their intermittency and unreliability. For instance, solar energy is only available in day time while wind energy can be available at any time. The current estimates show that while per unit electricity generation cost of renewables has fallen to one-fourth of the cost a decade ago (Paddison, 2014), the high upfront cost is still significant.
