energy to power our planet for a year." Solar power, however, has yet to deliver on this

供給地球一整年的電量。」但是，太陽能技術

promise from my children's television. Why is it so hard????

到我們的下一代卻還未實現承諾。這真的如登天般困難嗎？

The sun shines on us every day, it comes down here we gather it up and we use it for energy

陽光普照，我們收集陽光，轉換成電能

-- boom boom boom, done! But it's slightly more complicated than that, as you know.

鏘鏘！任務完成！但事情恐怕沒那麼單純

In 1873, electrical engineer Willoughby Smith discovered the element selenium was photoconductive

1873年，電機工程師Willoughby Smith發現硒元素具有光導電性

-- when exposed to sunlight the metallic form of selenium becomes a semiconductor! Three

在陽光下，原為類金屬的硒元素會轉換成半導體

years later, other scientists discovered selenium could be used to create electricity from sunlight

三年後，科學家發現硒元素可以將陽光轉換成電力

-- dubbed the photoelectric effect. When sunlight hits a metal like selenium the electromagnetic

也就是所謂的光電效應。硒接收陽光後，

radiation is absorbed into it -- this fueled a whole HOST of physics nerds who are still

可以吸收電磁輻射—這震驚了整個物理界，大部分人

arguing whether light is a particle or a wave to this day! It was such a big deal the 1921

至今還停留在爭論光到底是粒子還是波。這個重大發現讓

Nobel Prize in physics was awarded to Albert Einstein for explaining the photoelectric

愛因斯坦得到1921年的諾貝爾物理獎，因為他成功地解釋

effect, and for his contributions to theoretical physics… or whatever.

光電效應，也對理論物理學做出重大貢獻

Eventually, scientists discovered that the light energy causes the freeing of electrons

科學家最終發現，光可使電子獲得能量而成自由電子

which, if captured, could be used to generate electricity!. This photoelectric effect has

一旦掌握自由電子，便能產生能量。

since been cultivated and researched and cultivated again, and the discovery that many different

自此之後，科學家反覆研發光電效應，並發現許多

elements display a photoelectric effect opened it up for use in a number of inventions! Photosensitive

元素皆適用光電效應，因而有了更多新發明

cells are used in televisions, industrial processes, telecommunications, fiber optics,

例如感光電池可用於電視、工業生產、通訊、光纖

copy machines, spectroscopy and telescope, and to sense pollution or emphasize other

影印機、光譜學、望遠鏡、偵測污染，甚至可以用在

lights like in night vision or infrared cameras; plus, of course, solar panels via a photovoltaic

夜視鏡或紅外線攝影機，當然，太陽能板上的光伏電池也少不了它

cell. Photovoltaics were invented in the 1950s, and were popularized by the space program

光伏電池大約發明於1950年代，後來因一項太空計劃而普及

as a way to power satellites. In the 1970s, pushes were made to modernize photovoltaics

當時為了驅動人造衛星。到了1970年代，光伏電池進一步

for use in commercial and residential power -- but consumers mainly used them for calculators,

應用在商業及民生上，但多數消費者用得到的只限於計算機

watches, radios and the like. Like a battery, a photovoltaic cell has a positive and negative

手錶、收音機等等。就像一般電池一樣，光伏電池也有正負極

to guide the electrons into the system. Each cell uses a pair of silicon wafers -- one

並形成通路讓電子流通；電池以矽晶圓製成

doped with phosphorous (negative) and one with boron (positive).

摻雜磷和硼，分別為負極與正極

From 1995 to 2010 solar energy use grew 20 percent a year -- and now, new inventions

1995至2010年來，太陽能使用量每年增長20%，有賴新科技

are making it even more affordable. Firstly, in 2009, China created way more solar panels

現在太陽能成本更低了。首先，2009年時中國大量生產太陽能板

than the market needed, and the price collapsed. And secondly, state and federal governments

造成市場供過於求，價格因此下跌；其次，各國政府

in the United States, Germany, the United Kingdom and Japan are all giving subsidies

包括美國、德國、英國、日本等都提供補助

to cultivate better renewable energy systems. This means more supply and demand for this

以期進一步發展再生能源。太陽能科技的需求及供給量雙雙上升

technology, and as money flows through renewables, they get better!

一旦資金投入得越多，當然也就得以發展得更完善

Recently the University of Queen Mary in London revealed they can turn shrimp shells into

近來，倫敦瑪麗皇后大學的研究員發現蝦殼

cheap solar panels. The shells of crustaceans contain chitin and chitosan which can be extracted

可以用來製作廉價太陽能板。這是因為蝦殼含有甲殼素及殼聚醣

into CQD or carbon quantum dots -- CQD solar cells aren't new, but usually use expensive

可提煉出碳量子點（CQD）。CQD太陽能電池其實早就有了

ruthenium for its photoelectric properties. Instead, the researchers found this biomass

但之前是使用昂貴的釕達到光電效應的特性。現在，科學家發現

byproduct of the shrimp industry can be used to extract CQDs and create fully renewable,

蝦子的副產品竟然也可以提煉CQD，這樣一來就真的做到

cheap solar cells!

便宜的再生太陽能電池！

Pretty cool, huh? Fortunately solar cells aren't the only place finding greener solutions

很酷吧！不過太陽能電池並不是唯一發展綠能的產業

for energy use -- Toyota is, too! The new Toyota Mirai is looking to the future with

豐田汽車也朝同樣目標邁進，新推出的Mirai車款

sustainability in mind; fueled by hydrogen and leaving zero emissions behind.

將以永續發展為目標，以氫燃料驅動，完全零排放

Every year renewable energy is getting better, but it's not yet as efficient as we'd hope.

再生能源不斷進步，但效率似乎並不如預期

For more on the efficiency of the most common types of energy production, check out my video

想知道更多有效的電力生產方式

about that here

請點以下連結

What do YOU think is the most promising type of energy? Solar? Wind? Nuclear? Or plain

你認為哪種再生能源最有看頭呢？太陽能？風力發電？核能？

old coal, oil and gas? Why? Tell me your thoughts in the comments, and thanks for watching.

還是傳統的煤、石油、天然氣？請留言讓我知道你的想法，謝謝

If you haven't subscribed yet, go up there and subscribe. We need you here! Thanks again.

若你還沒訂閱本頻道，快去訂閱吧，感謝大家收看