42 Renewable Energy Sources

 

Renewable Energy Sources

可再生能源

Today petroleum provides around 40% of the world’s energy needs, mostly fuelling automobiles. Coal is still used, mostly in pover stations, to cover one-quarter of our energy needs, but it is the least efficient, unhealthiest and most environmentally damaging fossil fuel. Natural gas reserves could plug some of the gap from oil, but reserves of that will not last into the 22nd century either. Most experts predict we will exhaust easily accessible reserves within 50 years. We could fast reach an energy crisis. We need to rapidly develop sustainable solutions to fuel our future. Less-polluting renewable energy sources offer a more practical long-term energy solution. They may benefit the world’s poor too. “Renewable” refers to the fact that these resources are not used faster than they can be replaced.

今天石油提供约40%的世界能源需求，主要是汽车。煤仍被使用，主要是在贫困站，以解决我们四分之一的能源需求，但它是最有效的，不健康的和最环保的化石燃料。天然气储量可以填补部分石油短缺，但储量，不能维持到第二十二世纪。大多数专家预测我们将竭方便储量在50年。我们可以快速达到能量危机。我们需要迅速发展可持续的解决方案，为我们的未来提供燃料。污染少的可再生能源提供了一个更现实的长期解决方案。他们可能有利于穷人的太。“可再生”是指这些资源不是用来速度比他们能被取代。

The Chinese and Romans used watermills over 2,000 years ago. But the first hydroelectric dam was built in England in 1870. Hydroelectric power is now the most common form of renewable energy, supplying around 20% of world electricity. China’s three gorges Dam, which has just been completed, is the largest ever. At five times the size of the US’s Hoover Dam, its 26 turbines will generate the equivalent energy of 18 coal-fired power stations. It will satisfy 3% of China’s entire electricity demand. Surprisingly, some argue that hydroelectric dams significantly contribute greenhouse gases.

中国人和罗马人使用风车2000年前。但第一个水电大坝建于1870年的英国。水力发电是目前最常见的可再生能源，提供约20%的世界。三中国三峡大坝，它刚刚完成，是有史以来最大的。在五倍的规模，美国的大坝，其26台涡轮机可产生的能量相当于18个燃煤发电站。它将满足中国3%的电力需求。令人惊讶的是，有些人认为，水坝大大促进温室气体。

In 2003, the first commercial power station to harness tidal currents in the open sea opened in Norway. It is designed like windmill, but others take the form of turbines.

2003，第一个商用电站利用潮汐开放海域在挪威开幕。它设计得像风车，但是其他的形式，涡轮机。

As prices fall, wind power has become the fastest growing type of electricity generation – quadrupling worldwide between 1999 and 2005. Modern wind farms consist of turbines that generate electricity. Though it will be more expensive, there is more than enough wind to provide the world’s entire energy needs. Wind farms come in onshore and offshore forms. They can often end up at spots of natural beauty, and are often unpopular with residents. And turbines are not totally benign – they can interfere with radar and leave a significant ecological footprint, altering climate and lilling sea birds. Migrating birds may have more luck avoiding them. Scotland is building europe’s largest wind farm, which wil power 200,000 homes. The UK’s goal is to generate onefifth of power from renewable sources, mainly wind, by 2020. But this may cause problems, because wind is unreliable.

随着价格的下降，风电已成为增长最快的类型的发电–翻两番世界之间的1999和2005。现代风力农场由产生电。虽然这将是更昂贵，有足够多的风提供全世界能源需求。风力发电场，在陆上和海上的形式。他们往往最终在景点的自然美景，而且往往是不受欢迎的居民。与发电机不完全良性–他们可以干扰雷达和留下一个重要的生态足迹，改变气候和杀伤海鸟。迁徙鸟类可能有更多的运气，避免他们。苏格兰是欧洲最大的风力农场，这将00000家电力2。英国的目标是产生onefifth电力来自可再生能源，主要是风，2020。但这可能导致问题，因为风是不可靠的