“Harvesting lightning energy”的意思、由来-开放百科全书

Since the late 1980s, there have been several attempts to investigate the possibility of harvesting lightning energy. A single bolt of lightning carries a relatively large amount of energy (approximately 5 billion joules^[1] or about the energy stored in 145 litres of petrol). However, this energy is concentrated in a small location and is passed during an extremely short period of time (microseconds^[2]); therefore, extremely high electrical power is involved.^[3] 5 billion joules over 10 microseconds is equal to {{val|5e14}} (or 500 trillion) watts. Because lightning bolts vary in voltage and current, a more average calculation would be {{val|1e10}} (or 10 billion) watts.^[4] It has been proposed that the energy contained in lightning be used to generate hydrogen from water, to harness the energy from rapid heating of water due to lightning,^[5] or to use a group of lightning arresters to harness a strike, either directly or by converting it to heat or mechanical energy,^[6] or to use inductors spaced far enough away so that a safe fraction of the energy might be captured.^[7]

Overview

A technology capable of harvesting lightning energy would need to be able to rapidly capture the high power involved in a lightning bolt. Several schemes have been proposed, but the ever-changing energy involved in each lightning bolt renders lightning power harvesting from ground-based rods impractical – too high, it will damage the storage, too low and it may not work.{{Citation needed|date=August 2013}} Additionally, lightning is sporadic, and therefore energy would have to be collected and stored; it is difficult to convert high-voltage electrical power to the lower-voltage power that can be stored.^[5]

In the summer of 2007, an alternative energy company called Alternate Energy Holdings, Inc. (AEHI) tested a method for capturing the energy in lightning bolts. The design for the system had been purchased from an Illinois inventor named Steve LeRoy, who had reportedly been able to power a 60-watt light bulb for 20 minutes using the energy captured from a small flash of artificial lightning. The method involved a tower, a means of shunting off a large portion of the incoming energy, and a capacitor to store the rest. According to Donald Gillispie, CEO of AEHI, they "couldn't make it work," although "given enough time and money, you could probably scale this thing up... it's not black magic; it's truly math and science, and it could happen."^[8]

According to Martin A. Uman, co-director of the Lightning Research Laboratory at the University of Florida and a leading authority on lightning,^[9] a single lightning strike, while fast and bright, contains very little energy, and dozens of lightning towers like those used in the system tested by AEHI would be needed to operate five 100-watt light bulbs for the course of a year. When interviewed by The New York Times, he stated that the energy in a thunderstorm is comparable to that of an atomic bomb, but trying to harvest the energy of lightning from the ground is "hopeless".^[8]

Another major challenge when attempting to harvest energy from lightning is the impossibility of predicting when and where thunderstorms will occur. Even during a storm, it is very difficult to tell where exactly lightning will strike.^[1]

Lightning strikes the most in northwestern Venezuela and the far east of the Democratic Republic of Congo.^[10] The Guinness Book of World Records lists Venezuela’s Lake Maracaibo as having 28 lightning flashes each minute.^[11]

Directed plasma channels

To facilitate the harvesting of lightning, a laser-induced plasma channel (LIPC) could theoretically be used to allow lightning to strike in a predictable location. A high power laser could be used to form an ionized column of gas, which would act as an atmospheric conduit for electrical discharges of lightning, which would direct the lightning to a ground station for harvesting. (Discovery News Lighting Control https://www.youtube.com/watch?v=eBzxn2LEJoE)

Teramobile,^[12] an international project initiated jointly by a French-German collaboration of CNRS (France) and DFG (Germany), has managed to trigger electric activity in thunderclouds by ultrashort lasers. A large amount of power is necessary, 5 terawatts, over the short pulse duration. For the moment, the application of laser-channeled lightning is to use energy to divert the lightning and prevent damage instead of harvesting the lightning energy."^[13]

See also

References

1. ^¹{{cite web|title=Could you power a city with lightning?|url=http://www.physics.org/facts/toast-power.asp|publisher=physics.org|accessdate=1 September 2011}}
2. ^{{cite journal|author1=Yasuhiro Shiraishi|author2=Takahiro Otsuka|title=Direct measurement of lightning current through a wind turbine generator structure|journal=Electrical Engineering in Japan|date=September 18, 2006|page=42|ref=measurementtoko|doi=10.1002/eej.20250|volume=157|issue=4}}
3. ^"The Electrification of Thunderstorms," Earle R. Williams, Scientific American, November 1988, pp. 88–99
4. ^{{cite web|last1=Dvorak|first1=Paul|title=How Much Power in a Bolt of Lightning|url=http://www.windpowerengineering.com/featured/business-news-projects/how-much-power-in-a-bolt-of-lightning/|website=Windpower|accessdate=1 October 2016}}
5. ^¹{{Cite news| title=Why can't we capture lightning and convert it into usable electricity?| last=Knowledge| first=Dr.| newspaper = The Boston Globe| date = October 29, 2007| url = http://www.boston.com/news/globe/health_science/articles/2007/10/29/why_cant_we_capture_lightning_and_convert_it_into_usable_electricity/| accessdate = August 29, 2009}}
6. ^{{cite journal|author=Bhattacharjee, Pijush Kanti|date=2010|title=Solar-Rains-Wind-Lightning Energy Source Power Generation System|journal=International Journal of Computer and Electrical Engineering|volume=2|pages=353–356|url=http://www.ijcee.org/papers/160.pdf|accessdate=March 20, 2014|doi=10.7763/ijcee.2010.v2.160}}
7. ^{{cite journal|author=Helman, D.S.|date=2011|title=Catching lightning for alternative energy|journal=Renewable Energy|volume=36|issue=5|pages=1311–1314|url=http://www.sciencedirect.com/science/article/pii/S0960148110004982|accessdate=March 5, 2013|doi=10.1016/j.renene.2010.10.027}}
8. ^¹{{Cite news| title=Lightning Farms| last=Glassie| first=John| work = The New York Times| date = December 9, 2007| url = https://www.nytimes.com/2007/12/09/magazine/09lightningfarm.html?_r=1| accessdate = August 29, 2009}}
9. ^[https://web.archive.org/web/20080706160058/http://www.agu.org/inside/awards/bios/uman_martina.html Uman Receives 2001 Fleming Medal]. www.agu.org
10. ^{{cite web|last1=Breslin|first1=Sean|title=Think Lightning Strikes the Most in Florida? Think Again.|url=https://weather.com/safety/thunderstorms/news/lightning-strikes-around-the-world|website=Weather.com|accessdate=1 October 2016}}
11. ^{{cite web|last1=Davies|first1=Ella|title=The Most Electric Place on Earth|url=http://www.bbc.com/earth/story/20150810-the-most-electric-place-on-earth|website=BBC}}
12. ^http://www.teramobile.org/teramobile.html
13. ^{{cite journal|author1=Jérôme Kasparian |author2=Jean-Pierre Wolf|title=On lightning control using lasers|journal= Progress in Ultrafast Intense Laser Science|date=2010|pages=109–122|url=http://www.teramobile.org/publications/PUILS_kasparian_lihgtning_revised_compact.pdf|volume=98}}