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Sun on the rails

铁路上的阳光

Solar-powered trains could make rail transport greener

太阳能火车能使铁路运输更加环保

Solar panels are connected directly to the line

太阳能电池板与铁路直接相连


Commuters may not have paid them much attention, but a small array of solar panels next to the railway line at Aldershot, a town 50km (30 miles) south-west of London, could herald a greener future for train travel. The site is an experiment to supply electricity generated from sunlight directly to a railway line. It is the “directly” bit that is novel. In Britain, as in many places, solar power is already fed into the grid, and it is the grid which train operators plug into. So, in a sense, many electric trains already use some solar power. But by connecting the panels to the line itself, trains can be powered more efficiently.

在伦敦西南50公里的艾迪索特镇,通勤族可能没太注意铁路旁的一小排太阳能电池板,它们可以使未来的火车旅行更加环保。该地区试验将太阳能电力直供给铁路,它的新奇之处就在于“直供”。与许多国家一样,太阳能已经馈入英国电网,火车司机连接的正是该电网。所以在某种意义上,许多电力火车已经用上一部分太阳能。但如果将太阳能电池板与铁路本身连接,火车的供电效率将得到提升。

Admittedly, it is not at present a lot of power. At around 37 kilowatts the site could easily top up the battery of a Tesla electric car, but it might not move an electric train very far. That does not matter at this stage, because it is there to test a concept rather than run a railway. And the concept is working, says Stuart Kistruck, director of engineering for the southern region of Network Rail, the government-owned operator of railway infrastructure in Britain.

不可否认,目前电力还不充足。在大约37千瓦的功率下,该地能轻而易举地为“特斯拉”电动汽车充满电,但电力火车可能无法行驶很远。这没有关系,因为现阶段是概念性试验而非铁路运营。这一概念是可行的,英国国有铁路基础设施运营商“铁路网公司”的南方工程总监斯图尔特·基斯特朗说道。

Network Rail is working on the project in collaboration with Imperial College, London, and Riding Sunbeams, a not-for-profit company set up by climate activists to promote locally owned renewable-energy projects. The plan now is to scale up the idea and roll it out elsewhere.

在该项目上,铁路网公司正在与伦敦帝国学院、Riding Sunbeams公司开展合作,后者是气候活动人士创立的一家非盈利企业,旨在推动本土的可再生能源建设项目。现在的计划是扩大规模,并在其他地区推广。

Connecting up the Aldershot site was made easier by a quirk of history. When the electrification of Britain’s railways began in the late 19th century, two systems were used. In much of the country overhead lines were installed, but in crowded south-east England a “third rail” was used instead. This consists of a conductor rail placed alongside the track on insulated brackets. A pickup shoe near the wheels of the train draws power from this rail.

历史的偶然方便了艾迪索特地区的电力接通。英国铁路电气化始于19世纪末,当时采用了两种系统。英国大部分地区安装了接触网,而人口密集的东南地区采用了“第三轨”。该系统包括与铁轨并列放置、安装于绝缘支架上的接触轨,车轮附近用于取电的集电靴。

Third-rail systems tend to be employed in urban railways because they are easier and cheaper than making tunnels and bridges large enough to accommodate overhead cables—and the railway lines of southern Britain have plenty of low bridges and tunnels. For safety and other reasons, third-rail systems typically operate at 750 volts dc, a much lower voltage than overhead lines, which in Britain run at 25 kilovolts ac. As it happens, solar arrays typically put out dc current at 600-800 volts, which reduces the complexity and cost of connecting them to the railway line. Another convenience is that, to reduce transmission losses, third-rail networks have more closely spaced substations. These provide handy feed-in points for lineside solar power.

“第三轨”系统多用于城市铁路,因为相比建造足以容纳接触网的隧道和桥梁(英国南方的铁路有许多低矮的桥梁和隧道)第三轨的建造难度更小,成本更低。出于安全和其他因素考虑,“第三轨”系统的电压通常为直流750伏,远低于英国接触网的交流25千伏。凑巧的是,太阳能电池板输出的直流电通常为600-800伏,降低了与铁路连接的复杂性和成本。另一个便利之处是减少输电损耗,“第三轨”网络的变电站间隔较小。这一切都为铁路沿线的太阳能提供了便利的馈入点。

Plug’n’play
One problem facing groups like Riding Sunbeams is that electricity grids are rarely designed to accept power from small and varied sources, so feed-in arrangements can be hard to set up. A passing railway line, however, provides an alternative, says Leo Murray, the company’s director. Along with Network Rail, Riding Sunbeams has drawn up a list of other sites that might be suitable for larger installations.

像Riding Sunbeams这样的企业面临一个难题,电网很少被设计成接受小型和不同来源的供电,所以很难布置馈入装置。但接触轨提供了新的方案,公司负责人里奥·默里说道。该公司与铁路网公司拟定了一份适用于安装更大装置的地区名单。

Apart from green pr, what does Network Rail get out of this? First, there is a lot of unused land next to railway lines, where solar panels could be placed. Those panels would also shade vegetation, reducing its growth and the amount of cutting-back required. The “leaves on the line” excuse for late-running trains is a bit of a joke in Britain, but the slippery conditions leaves cause for train wheels are a big problem.

除了绿色公关,铁路网公司还能从中得到什么?首先,铁路两旁有许多闲置土地,可供太阳能电池板的安装。电池板会给植被遮挡阳光,减缓其生长,减少必要的修剪。将“铁轨上有树叶”当作火车晚点的借口多少成了英国的笑料,但火车车轮因树叶打滑的现象是个大问题。

Second, it is a good deal. Lineside solar electricity will be cheaper than that from the grid, Mr Kistruck calculates. Overall, he reckons, 10% of the southern region’s power needs might be met this way. Such savings are not to be sniffed at. With around 40% of the country’s rail system electrified, Network Rail is Britain’s biggest single user of electricity. It has an annual bill of around £300m ($390m) just for traction.

其次,这笔交易很划算。据基斯特朗先生估算,铁路沿线的太阳能电力比电网提供的电力更便宜。总体而言,他估算这种方式可满足南方地区10%的用电需求。可别小看省下来的这笔钱,由于英国约40%的铁路系统已实现电气化,铁路网公司是英国最大的电力用户,每年光是用于牵引的电费就高达约3亿英镑(3.9亿美元)。
原创翻译:龙腾网 http://www.ltaaa.cn 转载请注明出处


The idea could also be employed elsewhere, and not just on urban lines. With additional work it might be adapted for overhead-powered systems as well. It looks particularly promising in countries beyond cloudy Britain. India, for instance, is keen on using solar power to electrify its rail system. Indian Railways has been fitting solar panels onto the roofs of some train carriages. They are still pulled by dirty diesel-powered locomotives, but the panels run the lights, fans and information displays, which saves some fuel.

这种方法也可用于其他国家,而且不局限于城市铁路,经过改造还可用于接触网供电系统。除了多云天气的英国,这种方法在其他国家有很好的应用前景。例如,印度渴望用太阳能实现铁路系统电气化。印度铁路公司一直在给某些火车车厢的顶盖安装太阳能电池板,车厢依然使用污染环境的柴油机车牵引,但太阳能电池板为照明、风扇、信息显示器提供电力,从而节省一部分燃料。

The limited space available for solar panels on train roofs means that not enough power could be produced to propel an entire train. However, the Byron Bay Train, a heritage railway near Brisbane, Australia, comes close. It is a two-car unit that runs entirely on energy from solar panels on its roof and on the roof of its shed. The converted train, originally dating from 1949, can carry 96 passengers on a route just 3km long—but in a part of the world blessed with plenty of sunshine. London’s commuters have no such luck.

火车厢顶盖安装太阳能电池板的空间有限,这意味着发电量不足以驱动整列火车。然而,位于澳大利亚布利斯班附近的史迹铁路“拜伦湾火车”接近这一目标。这辆火车由两节车厢组成,完全依靠火车顶盖和停车棚上的太阳能电池板产生的电量运行。这辆经过改造的火车始建于1949年,载客量96人,全程线路仅3公里——但澳大利亚是一个阳光充沛的国家,伦敦的通勤族可没这样的好运气。