五大妙招巧獲清潔能源

譯/游瓊瓊 審訂/鄢宏福

五大妙招巧獲清潔能源

譯/游瓊瓊 審訂/鄢宏福

5 Sneaky Ways to Harness Clean Energy

By now， we’re all familiar with the mainstays of renewable energy. They’re the solar panel arrays and massive turbine systems that span great lengths， collecting energy from the sun， wind and water and churning out megawatts of energy. It’s these behemoths that we point to as bellwethers of a future where the world no longer depends on fossil fuels.

[2] But recently， some researchers have started to tinker with more subtle ways to harvest energy. They’re mostly unconventional ideas， such as layering tiny and transparent solar cells onto a phone’s touchscreen or a sound conversion technology that allows it to recharge simply by talking into it.

[3] Though these out-of-box approaches1out-of-box approach創造性方法。don’t receive nearly as much attention as some of the more elaborate industrial-scale projects， they may well turn out to be game-changers2game-changer改變游戲規則的人，即創新的人。in their own right. As such， here are instances where eeking out even a modest amount of energy may make a real difference:

1. Infrastructure power

[4] Hydroelectric power came about as a way to take advantage of the enormous fl ow of energy produced from reservoirs. However， the same principle can also work wherever there’s a strong and steady stream of water， whether it be dams or sewage pipes.

[5] Catching on to this fact， the city of Portland is testing a power-generating water turbine system specially suited for municipal drainage systems.The technology， developed by local start-up LucidEnergy， is projected to contribute up to 1，100 megawatts of electricity annually， enough to power approximately 150 homes.

[6] Roadways are also hotspots for untapped energy. In 2011， a research team were able to harvest energy from the vibrations produced by moving cars by coating a section of the road surface along a Dutch highway with energyabsorbing piezoelectric materials.During the course of three months， they found that， on average， net electrical output was suf fi cient to run the motion sensors on a traf fi c light.

2. Ambient energy

[7] To ensure coverage over a given area， WiFi hubs blast signals in all directions. Satellite transmission is somewhat similar， scattering signals across a wide region. As a result， a lot of energy is wasted.

[8] But there are ways to recover some of these lost signals. Researchers at Duke University have converted them into electricity. Employing a special microwave-scavenging metamaterial，they were able to build a device capable of generating up to 7.3 volts. The goal is to eventually incorporate the technology into cell phones， which in many instances can use a little extra juice.

[9] While the idea has been kicked around for some time， the challenge has been fi guring out how to implement it on a consumer level. RCA3Radio Corporation of America的簡稱，美國無線電公司。， an electronics brand， caused a bit of stir back in 2010， when representatives unveiled an early prototype of a USB dongle they claimed can give laptops a power boost by trapping stray WiFi signals and storing them as converted energy in an internal battery. However，the Airnergy charger4Airnergy charger無線信號充電器。was never released.

3. Body energy

[10] Every person is， in some respect，a walking power plant. Even at rest， the human body generates as much energy as a 100 watt light bulb. Much of this dissipates in the form of heat， though a coat with good insulation properties can momentarily trap enough of it for us to stay comfortably warm at times when temperatures are unbearably cold.

[11] With that line of thinking，Jernhusen， a Swedish real estate firm，had an ambitious proposal. In 2008， the group outlined a plan to construct an office building in Stockholm equipped with a unique heating system that so happened to be powered by the excess body heat of 250，000 some commuters that pass though the nearby central train station each day.

[12] The system， in operation today，is made possible through a series of heat exchangers situated inside the train station’s ventilation system. This is where body heat is converted into hot water and piped in to warm the building. In total， costs are reduced by about 25 percent compared to regular heating systems. And closer to home，the Mall of America in Minneapolis recycles body heat from shoppers to more better regulate the indoor climate.

[13] On a smaller scale， scientists are looking into ways to make good use of energy generated by the body’s internal machinations. Engineers in the United States and China have collaborated on a technology that uses the mechanical energy of a beating heart to pump power to pacemakers. In Boston， a team at the Massachusetts Institute of Technology is developing a tiny chip that pulls in energy from natural processes that take place within the ear canal as a way to extend the long-term implantation of hearing aids.

4. Kinetic energy

[14] In motion， the human body ramps up to where it’s a sort of de facto energy factory. Case-in-point is the Cadbury House gym near Bristol，England， the first in the world to be powered by nothing but the grunt and sweat of members who frequent the exercise facility.

[15] Power is supplied by a network of treadmills， stationary bikes and step climbers custom-made and sold by Technogym5泰諾健，意大利健身器材廠家。， a manufacturer of hightech training equipment. When in operation， each machine powers itself and channels surplus energy in the form of electricity. The costs for the equipment come in at about 600，000 euros ($630，000). Similar human- powered gyms can be found in Hong Kong and in the United States.

[16] Systems designed to harvest kinetic energy can also supplement power systems anywhere people take part in activities that collectively add up to lots of high-intensity workouts. In 2007， a pair of MIT students proposed using these “crowd farms” as a way to extract energy for such things as LED lights. More recently， the concept popped up as an “eco-nightclub” in London where energy is amassed using blocks made of piezoelectric material，positioned just beneath the dance fl oor.

5. Self-powered energy (for gadgets)

[17] While you would be hard pressed to find anyone who isn’t pining for a bit more battery life for their mobile devices， keeping pace with the rigorous demands of day-to-day commuting is a whole different story. The “range anxiety6range anxiety里程焦慮，意思是駕駛電動汽車時因擔心突然沒電引起的精神痛苦或憂慮。” consumers have over a vehicle’s typical per-charge rating is often mentioned as one of their most pressing concerns.

[18] And it’s a problem the industry seems to be looking at from every conceivable angle. For instance， earlier this month， Goodyear unveiled the BH03 concept tire， which feature a combination of piezoelectric materials and black textured thermoelectric patches to absorb energy from vibrations， light and heat. This in turn can be fed to the battery or sensors. But drivers shouldn’t hold their breath since the company hasn’t detailed how they plan to turn the proof-of-concept into a reality or released any cost estimates.

[19] For those getting around on foot，Pittsburgh-based startup SolePower is in the later stages of finalizing a shoe insert that charges up an external battery as the wearer walks or runs.But unlike other technologies that harvest energy from pressure-induced vibrations， the insoles don’t employ piezoelectric materials. Instead， energy is produced， converted and stored through a series of tiny “mechanical linkages and generators” in the heel，similar to how hand-cranked fl ashlights work， according to the company’s Web site.

With the insoles， the company claims that an hour of walk time provides about 2.5 hours of talk time on a smartphone. ■

時至今日，我們對主要的可再生能源已經耳熟能詳——即密布的太陽能電池陣列和綿延的龐大渦輪系統，將太陽能、風能及水能轉化為數兆瓦的電能。當化石燃料在未來的世界里退出歷史舞臺，這些龐然大物將引領能源的發展潮流。

[2]但最近一些研究人員開始搗鼓更加微妙的方法來生產能源。這些方法大多不循常規，例如，在手機觸摸屏上設置微小透明的太陽能電池，或是利用聲音轉換技術、只需對手機說話便可為手機充電。

[3]這些天馬行空的方法雖不像一些業已形成產業規模的項目一樣引人矚目，卻可能憑借其自身的優勢在未來領跑能源領域。因此，盡管以下方法產出的能量微乎其微，卻可能帶來真正意義上的改變。

1.基礎設施發電

[4]水力發電利用的是水庫巨大水流產生的能量。這一原理同樣適用于流速強勁穩定的水體，包括堤壩及污水管。

[5]基于這一認識，美國波特蘭市正在測試一套適用于城市排水管網的渦輪發電系統。該技術由當地一家新公司魯西德能源公司開發，計劃每年提供1100兆瓦的電力，可供約150戶家庭使用。

[6]公路也是獲取未開發能源的熱點。2011年，一個研究小組在荷蘭一條公路的部分路段鋪設壓電材料，從行經車輛產生的震動中獲取能源。經過三個月的研究，該團隊發現，電力凈輸出足以維持交通信號燈的運動傳感器正常運作。

2.環境能源

[7]為覆蓋某一特定領域，無線路由器向各個方向發射信號。衛星傳輸信號的方式與此類似，即在大范圍內散播信號。這種傳播方式伴隨大量的能量損耗。

[8]不過，部分損失信號能夠加以回收。杜克大學的研究人員已經成功將其轉化為電能。研究人員借助一種特殊的微波凈化超材料，制作出一種最高可產生7.3伏電壓的裝置。這項研究的最終目標是將該技術應用在手機上，在很多情況下，可以使手機獲得一些補充電能。

[9]盡管對這種設想的討論已經持續了一段時間，但是如何將其應用于產品之中仍然是一項挑戰。美國無線電公司（RCA）曾因2010年發布了一款USB軟件狗的早期原型而轟動一時。據該公司稱，這款軟件狗能夠捕捉游離的無線網絡信號，將其轉化成能量儲存在筆記本電腦內置電池中。不過，無線信號充電器一直未能問世。

3.人體能源

[10]從某種程度上說，每個人都是一座移動的發電站。即使休息的時候，人體產生的能量猶相當于一盞100瓦燈泡的能量。這些能量大部分以熱量的形式散失，不過絕熱性能良好的外套能暫時保存足夠的熱量，讓我們在極度寒冷的環境中保持舒適的溫度。

[11]順著這個思路，瑞典房地產公司杰恩胡森推出了一項雄心勃勃的計劃。2008年，該公司計劃在斯德哥爾摩建造一幢裝有特殊供熱系統的辦公大樓。這座辦公大樓的供熱源是每天通過附近中心火車站的25萬名通勤者身體所散發的熱量。

[12]這套系統現已投入使用，其關鍵是位于火車站通風系統內的一系列熱轉換器。轉換器將體熱轉化成熱能給水加熱，再利用熱水管網為整棟建筑供暖。總的來說，相比普通供熱系統，該系統成本降低了約25%。再來看看我們的身邊，美國明尼阿波利斯市的美國摩爾購物中心利用商場內顧客產生的熱量，有效調節室內溫度。

[13]科學家們已經開始在更細微的層面尋找方法，有效利用身體內部機制產生的能量。美國和中國的工程師已經在合作開發有關技術，利用心臟跳動產生的機械能為起搏器提供能量。波士頓麻省理工學院的研究團隊正在研發一種微型芯片，通過攝取耳道里自然產生的能量，延長植入式助聽器的使用壽命。

4.運動能源

[14]人體在運動時，會變成一座名副其實的能源工廠。英格蘭布里斯托爾附近的吉布里之家健身館就是一例。該館的電力全部來自光顧健身設施的會員的喘息和汗水，這在全世界首開先例。

[15]該健身館的電力供應來自在高科技運動器械制造商泰諾健定制的運動器械系統，包括跑步機、固定單車及登山機等。系統運作時，每個單一器械實現自我驅動的同時還可將剩余能量以電能形式輸出。設備的成本約為60萬歐元（63萬美元）。美國和香港也有類似的人力供電健身館。

[16]用來收集動能的系統也可以用作電力系統的補充。

不管人們在哪里活動，只要產生高強度的運動就行。2007年，麻省理工學院的兩名學生建議利用這類“人群農場”為LED燈等采集能源。最近，倫敦出現“生態夜吧”這一概念，即在舞廳地板下鋪設成塊壓電材料用以收集能量。

5.自供電能（小型裝置）

[17]盡管沒有人不希望自己的移動設備電池壽命更久，但要滿足日常通勤的嚴格要求則完全是另一回事。消費者對交通工具的標準平均充電頻率的“里程焦慮”常被視為最緊迫的問題之一。

[18]企業似乎在想盡一切辦法解決這一問題。例如，這個月初，美國固特異輪胎公司發布了一款BH03概念輪胎，這種輪胎主體由壓電材料和有黑色織紋的熱電材料構成，能夠吸收振動、光、熱產生的能量，進而將能量輸送到電池或傳感器中。然而，司機們沒必要焦急企盼，因為該公司尚未公布將此概念產品化成現實的具體計劃，也沒有公布任何成本預算。

[19]也有些公司致力于在腳上“做文章”。位于匹茲堡的創業公司索萊電力的一款鞋墊產品研發已進入后期階段。該產品可以把走路或者跑步時產生的能量轉化為電能，儲存到外部的蓄電池上。與其他技術從壓力產生的振動搜集能量不同，這款鞋墊并未采用壓電材料。從該公司網站上我們可以得知，電能的產生、轉換和儲存均是通過鞋跟內一系列微小的機械裝置及發電機完成，原理類似于手搖式手電筒。

該公司宣稱，穿上這種鞋墊走路一小時，可供智能手機通話2.5小時。 □