把环礁变成发电站

Science & technology

科技版块

Powering remote islands

给偏远岛屿赋能

High-water mark

高水位线

A clever way to turn the atolls into power stations

把环礁变成发电站的聪明办法

Your latest electricity bill may have been a rude shock.

你最近的电费账单可能让你大吃一惊。

But chances are it is way less than the bills facing inhabitants of remote islands such as those of the Federated States of Micronesia.

但很可能比密克罗尼西亚联邦等偏远岛屿的居民需要缴费的账单要少得多。

In that country, an archipelago of just over 600 islands in the western Pacific Ocean, the residential rate per kwh is about three times the norm in America.

在这个由西太平洋600多个岛屿组成的群岛国家，居民每千瓦时的电费大约是美国标准的三倍。

Small Pacific islands generally rely on diesel generators.

太平洋小岛一般依赖柴油发电机发电。

Connecting them to grids is too expensive.

将它们接入电网的费用太高了。

Solar power takes up too much space.

太阳能占据空间太大。

And wind turbines are not designed to withstand the hurricanes that sometimes blow through.

风力涡轮机的设计不能承受偶尔的飓风天气。

But, as Matt Lewis of Bangor University, in Britain, told this year’s Ocean Sciences Meeting (held virtually) on February 28th, the answer may lie in the very geography of the islands themselves.

但是，正如英国班戈大学的马特·刘易斯在2月28日举行的今年海洋科学会议(虚拟举行)上所说的那样，答案可能就在于这些岛屿本身的地理位置。

Lots of Pacific islands are atolls.

许多太平洋岛屿都是环礁。

Others, though more substantial, have fringing reefs.

其他的一些更坚固，但是是暗礁。

Both of these set ups involve lagoons separated from the ocean by the reef, yet connected to it via a number of narrow channels.

这两种都包括由珊瑚礁隔开的泻湖，通过一些狭窄的通道与海洋相连。

The lagoons themselves are kept filled slightly above sea level by waves overtopping the reef.

礁湖本身被淹没在略高于海平面的海浪中。

To Dr Lewis, this arrangement looks a lot like a hydroelectric power station, with the reef acting as the dam and the lagoon as the reservoir behind it.

在刘易斯博士看来，这种结构看起来很像水电站，珊瑚礁充当大坝，泻湖充当背后的水库。

All that is missing is the generating turbines, which he proposes to put in the channels.

唯一缺少的就是发电涡轮机，他建议将其安装到渠道中。

To work out the details he teamed up with Ryan Lowe, an Australian oceanographer who studies the ecology of reefs and has devised a simple mathematical formula for the wave-driven outflows of lagoons.

为了弄清楚细节，他与澳大利亚海洋学家瑞安·洛合作，后者研究珊瑚礁的生态学，并设计了一个简单的数学公式来计算由海浪驱动的泻湖流出量。

After putting some numbers about the size and general shape of atolls into Dr Lowe’s model, together with the levels of waves and tides in the world’s oceans, the pair conclude that, for a typical atoll anywhere in the Pacific, with, say, five channels through its reef, suitably placed generators could yield more than 50kw.

在把一些关于环礁的大小和一般形状的数字带入洛博士的模型后，加入世界海洋中的海浪和潮汐水平的数据，综合得出的结论是对于太平洋任何一个典型的环礁来说，如果有五个通道穿过它的珊瑚礁，合理地放置发电机可以产生超过50千瓦的电能。

This would provide power for at least 250 islanders.

这将至少为岛上250名居民提供电力。

They reckon that a turbine on such an atoll would run for about 75% of the time.

他们估计，在这样一个环礁上的涡轮机大约有75%的时间是运转的。

That is promising, Dr Lewis says, considering that the average wind turbine manages only 40%.

考虑到风力涡轮机平均只有40%，刘易斯博士说，那是有可能的。

The next step will be to do this calculation for real, for as many inhabited islands with lagoons as possible.

下一步将是尽可能多地统计有泻湖的，有人居住的岛屿。

By combining satellite images with Dr Lowe's formula, Dr Lewis reckons this should be fairly easy.

刘易斯博士认为，通过将卫星图像与洛博士的公式相结合，这应该是相当容易的。

He expects to find hundreds of lagoons suitable for conversion, and is already talking to firms which might be interested in developing appropriate turbines.

他希望找到数百个适合改造的泻湖，并已经在与可能对开发合适的涡轮机感兴趣的公司洽谈。