太陽能電池如何爲農村地區發電?

Solar energy is becoming more and more popular as prices drop, yet a home powered by the Sun isn't free from the grid because solar panels don't store energy for later. Now, researchers have refined a device that can both harvest and store solar energy, and they hope it will one day bring electricity to rural and underdeveloped areas.

隨着價格的降低，太陽能越來越受到大衆的歡迎，但太陽能供電的家庭仍離不開電網，因爲太陽能電池板並不能儲存能量以備後用。現而今，研究員改進了一個設備，既可以獲得太陽能又可以儲存太陽能，他們希望有朝一日能爲農村地區和欠發達地區供電。

The problem of energy storage has led to many creative solutions, like giant batteries. For a paper published today in the journal Chem, scientists trying to improve the solar cells themselves developed an integrated battery that works in three different ways. It can work like a normal solar cell by converting sunlight to electricity immediately, explains study author Song Jin, a chemist at the University of Wisconsin at Madison. It can store the solar energy, or it can simply be charged like a normal battery.

能量存儲問題帶來了多種創造性的解決方案，比如巨型電池。今日在《化學》雜誌發表的一篇文章中，試圖自行提高太陽能電池的科學家開發了一種集成電池，這種電池可以三種不同的模式工作。它可以像普通的太陽能電池一樣立刻將太陽光轉爲電，研究作者Song Jin解釋道，他是威斯康星大學麥迪遜分校的一名化學家。這種電池可以存儲太陽能，也可以像普通電池一樣充電。

It's a combination of two existing technologies: solar cells that harvest light, and a so-called flow battery. The most commonly used batteries, lithium-ion, store energy in solid materials, like various metals. Flow batteries, on the other hand, store energy in external liquid tanks.

這一電池結合了兩種現有技術：捕獲太陽光的太陽能電池以及一種所謂的液流電池。最常用的電池--鋰離子電池--將能量存儲於固體材料，比如各式各樣的金屬。而液流電池卻將能量存儲於外部的液體罐中。

This means they are very easy to scale for large projects. Scaling up all the components of a lithium-ion battery might throw off the engineering, but for flow batteries, "you just make the tank bigger," says Timothy Cook, a University at Buffalo chemist and flow battery expert not involved in the study. "You really simplify how to make the battery grow in capacity," he adds. "We're not making flow batteries to power a cell phone, we're thinking about buildings or industrial sites.

這就意味着，這種方法可被拓展至大型項目中。加大鋰離子電池的所有組件可能會擺脫工程技術，但對於液流電池而言，'只需讓液體罐更大即可，'蒂莫西·庫克說道，他是布法羅大學的一名化學家，也是一位液流電池專家，並未參與這項研究。"真的簡化了擴大電池容量的方法，"他補充道。"我們製作液流電池並不是爲了給手機供電，我們想的是爲大廈或工業用地供電。"

Jin and his team were the first to combine the two features. They have been working on the battery for years, and have now reached 14.1 percent efficiency. Jin calls this "round-trip efficiency" - as in, the efficiency from taking that energy, storing it, and discharging it. "We can probably get to 20 percent efficiency in the next few years, and I think 25 percent round-trip is not out of the question," Jin says.

Jin和他的團隊是將這兩種功能結合起來的'第一人'。多年來，他們一直在研究電池，現在他們所研究的電池已達到14.1%的效率。Jin將其稱爲'往返效率'--獲取、存儲和釋放能量。"接下來的幾年，我們或能將電池提高到20%的效率，我認爲25%的往返效率也並非不可能，"Jin說道。