A 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. A 同风能涡轮的原理一样，海洋涡轮的能量来自于潮汐洋流推动像船桨一样的涡轮叶片。但是，不同于风能的是，潮汐是可预知的，能量输入是稳定的。 The technology raises the prospect of Britain becoming self-sufficient in renewable energy and drastically reducing its carbon dioxide emissions. 这一科技加大了英国能够在可再生能源方面自给自足的预期，并且大幅减少了二氧化碳的排放量。 If tide, wind and wave power are all developed. 如果潮汐能、风能和波浪发电都能得以发展，那么英国就可以关闭天然气、煤和核电站，同时还能向欧洲其他地区出口可再生能源。 Britain would be able to close gas, coal and nuclear power plants and export renewable power to other parts of Europe. 英国曾是最早发展风能的国家，但已经放弃了近 20 年，这使得荷兰得以将其发展为主要工业。 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. 与之不同的是，通过向日本和新西兰这样的岛国出口，海洋涡轮能够给英国带来经济利益。

B Tidal sites have already been identified that will produce one sixth or more of the UK's power - and at prices competitive with modem gas turbines and undercutting those of the already ailing nuclear industry. B 可以确定的是，潮汐电力站将会占据英国能源的六分之一甚至更多，其价格可以和现代化天然气涡轮相竞争，并且低于已经处于困境的核能。 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 1,200 megawatts of Britain's largest and newest nuclear plant, Sizewell B, in Suffolk. 仅仅是位于奥克尼岛和苏格兰大陆之间的彭特兰湾的海底涡轮组就可以产生全国电力的 10%；英国最大最新的位于萨福克的核电站 Sizewell B 所产电量为 1,200 兆瓦，而另一个位于海峡岛屿奥尔德尼岛的电站产生的电量是它的三倍。 Othep sites identified include the Bristol Channel and the west coast of Scotland, particularly the channel between Campbeltown and Northern Ireland. 其他已经确定的潮汐站点包括希里斯托尔海峡和苏格兰的西海岸，尤其是坝贝尔敦与北爱尔兰之间的海峡。

C Work on designs for the new turbine blades and sites are well advanced at the University of Southampton's sustainable energy research group. C 南安普敦大学的可持续能源研究小组关于新型涡轮叶片和选址的设计研究已经很先进了。 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. 第一个站点不久后将被安装在德文郡的林茅斯，用来测试由贸易与工业部和欧盟联合承办的企业的技术。 AbuBakr 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. 负责这项研究的 AbuBakr Bahaj 说：“潮汐能的前景要比风能好得多，因为水的流量是可以预测并且稳定的。 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. 北海的原油工业已经研究了应对海底不利的盐水环境的科技，而风能和船桨可以提供关于涡轮叶片设计的信息。 There are a few technical difficulties, but I believe in the next five to ten years we will be installing commercial marine turbine farms. 至今仍存在一些技术上的难题，但是我相信在未来的五到十年间，我们将会安装商业化的海洋涡轮处理机。” Southampton has been awarded £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. 过去的三年间，南安普敦已经获得了 215,000 英镑的资金支持，用以研究涡轮机，而如今我们正与 IT 能源公司的一家子公司 Marine Current Turbines 进行合作，共同开发林茅斯项目。 EU research has now identified 106 potential sites for tidal power, 80% round the coasts of Britain. 欧盟的一项研究已经确定了 106 个有潜力发展潮汐能的站点，其中 80% 位于英国的海岸线。 The best sites are between islands or around heavily indented coasts where there are strong tidal currents. 最佳的选址就在岛屿之间或者是非常迂回的海岸线附近，因为那里有非常强的潮汐洋流。

D A marine turbine blade needs to be only one third of the size of a wind generator to produce three times as much power. D 一个海洋涡轮的叶片只是风能发电机的三分之一大小，却能产生三倍于风能的电量。 The blades will be about 20 metres in diameter, so around 30 metres of water is required. 这些叶片的直径有 20 米长，因此至少需要 30 米的水域。 Unlike wind power, there are unlikely be environmental objections. 不同于风能的是，潮汐电力不会引发环境的抵触。 Fish and other creatures are thought unlikely to be at risk from the relatively slow-turning blades. 由于海洋叶片转动得相对较慢，他们不会对鱼及其他生物造成威胁。 Each turbine will be mounted on a tower which will connect to the national power supply grid via underwater cables. 每一个涡轮都会被安装在一个塔上，这些塔通过海底电缆与国家电力网相连。 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. 这些塔会伸出水面并且点亮照明，用以警示船只避让，同时也能够完全提升到水面以上，以方便维修和清理叶片上的水草。

E Dr Bahaj has done most work on the Alderney site, where there are powerful currents. EBahaj 博士已经做了关于奥尔德尼岛的大多数研究，那里有非常强的洋流。 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. 单一的海底涡轮组所产生的电量就已经远远超出了海峡岛屿的需求，大多数还会被送往法国电网，然后通过海底电缆再重新进口到英国。

F One technical difficulty is cavitation, where low pressure behind a turning blade causes air bubbles. F一个技术难题是气穴现象，也就是在转动的叶片后面的低压导致的气泡。 These can cause vibration and damage the blades of the turbines. 这些气泡会产生震动，损伤涡轮的叶片。 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. Bahaj 博士说：“为了避免这一现象，我们不得不测试很多叶片类型，或至少确保不要损伤叶片或降低效率。 Another slight concern is submerged debris floating into the blades. 另一个小问题是漂浮进叶片的残骸。 So far we do not know how much of a problem it might be. 目前为止我们尚且不知这个问题到底有多严重。 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.' 我们必须把涡轮做得更坚硬强大，因为海洋是一个不利的环境，但所有的信息表明我们目前完成得很好。”