剑桥雅思9Test3阅读Passage2原文翻译 Tidal Power 潮汐发电
剑桥雅思9 Test3 Passage2阅读原文翻译
Undersea turbines which produce electricity from the tides are set to become an important source of renewable energy for Britain. It is still too early to predict the extent of the impact they may have, but all the signs are that they will play a significant role in the future
Operating on the same principle as wind turbines, the power in sea turbines comes from tidal currents which turn blades similar to ships propellers, but, unlike wind, the tides are predictable and the power input is constant. The technology raises the prospect of Britain becoming self-sufficient in renewable energy and drastically reducing its carbon dioxide emissions. If tide, wind and wave-power are all developed, Britain would be able to close gas, coal and nuclear plants and export renewable power to other parts of Europe. Unlike wind power which Britain originally developed and then abandoned for 20 years allowing the Dutch to make it a major industry, undersea turbines could become a big export earner to island nations such as Japan and New Zealand.
Tidal sites have already been identified that will produce one sixth or more of the UK’s power—and at prices competitive with modern gas turbines and undercutting those of the already ailing nuclear industry. One site alone, the Pentland Firth, between Orkney and mainland Scotland, could produce 10% of the country’s electricity with banks of turbines under the sea, and another at Alderney in the Channel Islands three times the 1,2000 megawatts of Britain’s largest and newest nuclear plant, Sizewell B, in Suffolk. Other sites identified include the Bristol Channel and the west coast of Scotland, particularly the channel between Campbelltown and Northern Ireland.
已经确定潮汐发电站将产生英国六分之一或更多的电力。其价格与现代燃气涡轮机相比具有竞争力，并削弱本已陷入困境的核能发电的竞争力。位于奥克尼和苏格兰大陆之间的彭特兰峡湾（Pentland Firth）一个地方，就可以利用海底涡轮机产生全国10％的电力。而位于海峡群岛奥尔德尼岛的另一个发电站所产生的电量是英国最大、最新的位于萨福克的Sizewell B核电厂发电量（12000兆瓦）的三倍。其他已经确定的位置包括布里斯托尔海峡和苏格兰的西海岸，尤其坎特伯雷和北爱尔兰之间的海峡。
Work on designs for the new turbine blades and sites are well advanced at the University of Southampton’s sustainable energy research group. The first station is expected to be installed off Lynmouth in Devon shortly to test the technology in a venture jointly funded by the Department of Trade and Industry and the European Union. AbuBakn Bahaj, in charge of the Southampton research, said: ‘The prospects for energy from tidal currents are far better than from wind because the flows of water are predictable and constant. The technology for dealing with the hostile saline environment under the sea has been developed in the North Sea oil industry and much is already known about turbine blade design, because of wind power and ship propellers. There are a few technical difficulties, but I believe in the next five to ten years we will be installing commercial marine turbine farm. Southampton has been rewarded £215,000 over three years to develop the turbines and is working with Marine Current Turbines, a subsidiary of IT power, on the Lynmouth project. EU research has now identified 106 potential sites for tidal power, 80% round the coasts of Britain. The best sites are between islands or around heavily indented coasts where there are strong tidal currents.
南安普敦大学可持续能源研究小组的新型涡轮叶片和站点设计工作已经取得了很大进展。第一站预计将很快在德文郡林茅斯附近安装，以便在由贸易和工业部与欧盟共同投资的合资企业中测试该技术。负责南安普敦研究的阿布巴肯· 巴哈伊（AbuBakn Bahaj）表示：“潮汐产生的能源前景远胜于风能，因为水流是可预测的且恒定的。在北海石油工业中已经开发出用于应对海底不利环境的技术，并且由于风力和船舶螺旋桨，涡轮叶片设计已广为人知。技术上有一些困难，但是我相信在未来的五到十年中，我们将安装可用于商业化的海底涡轮发电厂。南安普敦在过去三年中获得了215,000英镑的资助，用于开发涡轮机，并正与IT电力子公司Marine Current Turbines合作进行Lynmouth项目。欧盟的研究现已确定了106个潜在的潮汐发电点，其中80％位于英国沿海。最好的地点是在岛屿之间或在有强烈潮汐的深凹海岸附近。
A marine turbine blade needs to be only one third of the size of a wind generator to produce three times as much power. The blades will be about 20 meters in diameter, so around 30 meters of water is required. Unlike wind power, there are unlikely to be environmental objections. Fish and other creatures are thought unlikely to be at risk from the relatively slow-turning blades. Each turbine will be mounted on a tower which will connect to the national power supply grid via underwater cables. The towers will stick out of the water and be lit, to warn shipping, and also be designed to be lifted out of the water for maintenance and to clean seaweed from the blades.
Dr Bahaj has done most work on the Alderney site, where there are powerful currents. The single undersea turbine farm would produce far more power than needed for the Channel Islands and most would be fed into the French Grid and be re-imported into Britain via the cable under the Channel.
One technical difficulty is cavitation, where low pressure behind a turning blade causes air bubbles. These can cause vibration and damage the blades of the turbines. Dr Bahaj said: ‘We have to test a number of blade types to avoid this happening or at least make sure it does not damage the turbines or reduce performance. Another slight concern is submerged debris floating into the blades. So far we do not know how much of a problem it might be. We will have to make the turbines robust because the sea is a hostile environment, but all the signs that we can do it are good.