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Powering remote islands
給偏遠島嶼賦能
High-water mark
高水位線
A clever way to turn the atolls into power stations
把環礁變成發電站的聰明辦法
Your latest electricity bill may have been a rude shock.
你最近的電費賬單可能讓你大吃一驚。
But chances are it is way less than the bills facing inhabitants of remote islands such as those of the Federated States of Micronesia.
但很可能比密克羅尼西亞聯邦等偏遠島嶼的居民需要繳費的賬單要少得多。
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.
在這個由西太平洋600多個島嶼組成的群島國家，居民每千瓦時的電費大約是美國標準的三倍。
Small Pacific islands generally rely on diesel generators.
太平洋小島一般依賴柴油發電機發電。
Connecting them to grids is too expensive.
將它們接入電網的費用太高了。
Solar power takes up too much space.
太陽能占據空間太大。
And wind turbines are not designed to withstand the hurricanes that sometimes blow through.
風力渦輪機的設計不能承受偶爾的颶風天氣。
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，正如英國班戈大學的馬特·劉易斯在2月28日舉行的今年海洋科學會議(虛擬舉行)上所說的那樣，答案可能就在于這些島嶼本身的地理位置。
Lots of Pacific islands are atolls.
許多太平洋島嶼都是環礁。
Others, though more substantial, have fringing reefs.
其他的一些更堅固，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.
這兩種都包括由珊瑚礁隔開的瀉湖，通過一些狹窄的通道與海洋相連。
The lagoons themselves are kept filled slightly above sea level by waves overtopping the reef.
礁湖本身被淹沒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.
在劉易斯博士看來，這種結構看起來很像水電站，珊瑚礁充當大壩，瀉湖充當背后的水庫。
All that is missing is the generating turbines, which he proposes to put in the channels.
唯一缺少的就是發電渦輪機，他建議將其安裝到渠道中。
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.
為了弄清楚細節，他與澳大利亞海洋學家瑞安·洛合作，后者研究珊瑚礁的生態學，并設計了一個簡單的數學公式來計算由海浪驅動的瀉湖流出量。
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.
在把一些關于環礁的大小和一般形狀的數字帶入洛博士的模型后，加入世界海洋中的海浪和潮汐水平的數據，綜合得出的結論是對于太平洋任何一個典型的環礁來說，如果有五個通道穿過它的珊瑚礁，合理地放置發電機可以產生超過50千瓦的電能。
This would provide power for at least 250 islanders.
這將至少為島上250名居民提供電力。
They reckon that a turbine on such an atoll would run for about 75% of the time.
他們估計，在這樣一個環礁上的渦輪機大約有75%的時間是運轉的。
That is promising, Dr Lewis says, considering that the average wind turbine manages only 40%.
考慮到風力渦輪機平均只有40%，劉易斯博士說，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.
下一步將是盡可能多地統計有瀉湖的，有人居住的島嶼。
By combining satellite images with Dr Lowe's formula, Dr Lewis reckons this should be fairly easy.
劉易斯博士認為，通過將衛星圖像與洛博士的公式相結合，這應該是相當容易的。
He expects to find hundreds of lagoons suitable for conversion, and is already talking to firms which might be interested in developing appropriate turbines.
他希望找到數百個適合改造的瀉湖，并已經在與可能對開發合適的渦輪機感興趣的公司洽談。
