Talk:Harvesting lightning energy

Trivia sections[edit]

Trivia sections are discouraged in WP, see WP:NOTRIVIA. A random list of appearances of X in the movies is not good encyclopediac content for an article on X. "In popular culture" sections are trivia lists, almost always. --Wtshymanski (talk) 14:59, 21 April 2017 (UTC)[reply]

That rather depends on whether sections on popular culture constitutes trivia. The policy that you linked to does not state that it is, so that can be dismissed. You then provide a malformed link to an essay. But essays are not policy just someone's opinion (whether right or wrong). There are so many articles that have sections on popular culture that it is fair to say that their existence has been de facto accepted as part of Wikipedia. 86.153.129.112 (talk) 12:57, 22 April 2017 (UTC)[reply]

I have no opinion as to whether 'popular culture' sections qualifies as trivia. However, they are so ubiquitous throughout Wikipedia that, if there is a genuine issue, then a fuller discussion is warranted. However, at present, all I see is a lone voice that has unilaterally decided that they should not included. This is not how Wikipedia works. I would also observe that both Wtshymanski and 86.153.129.112 are at 3RR (though not in 24 hours). In my view, any further reverts by either would warrant a complaint at WP:AN3 for slow motion edit warring. HasAnyoneSeenMyMarbles (talk) 11:18, 23 April 2017 (UTC)[reply]

Spelling mistakes are also ubiquitous throughout Wikipedia; hopefully we're not redefining the English language here. I look forward to a listing of every time a cartoon animal gets hit by lightning. --Wtshymanski (talk) 18:46, 25 April 2017 (UTC)[reply]

This facetious and pointless comment is not aimed at improving the encyclopaedia and has no place here. Cartoon characters being struck by lightning is not even remotely an example of harvesting lightning energy. Spelling errors are seldom intentional and usually end up being corrected anyway. 86.153.129.112 (talk) 12:27, 27 April 2017 (UTC)[reply]

Umm, yeah. "In pop culture" sections have their place, but this article isn't that place. Both applications are for patently fictional uses (time travel and corpse reanimation) and don't add anything to this article. --Deacon Vorbis (talk) 01:01, 27 April 2017 (UTC)[reply]

There's been no argument given as to why this section should remain, while the arguments for removing it include:

it's pointless trivia
both examples are for fictional (and implausible) uses
it mixes up the distinction between power and energy (which might not be possible to fix, given the source material)

Given the weight of the arguments, I'm going to go ahead and remove it again. If anyone really wants to keep it, please discuss here first. Here's a copy of the removed content:

In the movie, Back to the Future(1985), protagonists Marty McFly and Doc Brown needed 1.21 gigawatts (1.21×10⁹ watts) to power a DeLorean time machine. To collect this energy, they harvested power from a lightning bolt.^[1] The 1931 movie "Frankenstein" based on a novel by Mary Shelly also capture the power of lightning, but to animate Dr. Frankenstein's creature.

--Deacon Vorbis (talk) 15:45, 27 April 2017 (UTC)[reply]

The section would be more acceptable with the heading clarified to refer to Popular Fiction instead of Popular Culture. In the 1931 movie "Frankenstein" based on a novel by Mary Shelly, Dr. Frankenstein captures the power of lightning to animate his monster. Blooteuth (talk) 14:46, 17 August 2017 (UTC)[reply]

References

^ "Back to the Future (1985)". IMDb. Retrieved 1 October 2016.

Lightning power and energy calculations[edit]

I have been investigating the noted self-contradictory tag and have found quite a bit out on the internet regarding the power, energy, voltage, current, and duration of a lightning strike:

Value(s)	Source
5 GJ	physics.org (source in this article)
5 kA to 200 kA 40 kV to 120 kV	windpowerengineering.com (source in this article)
1 GJ (avg)	realclearscience.com
1 MJ per meter of fulgarite created 10-1000 GW milliseconds to microseconds	sciencealert.com
1 MJ (avg) [0.25 kWh] several million volts microseconds	mit.edu
5 GJ (avg) [1,400 kWh]	independent.co.uk
5 GJ	howstuffworks.com
1 GJ (avg)	huffingtonpost.com
1 TW (peak) 30 kA (avg) 100-200 kA (peak)	aharfield.co.uk
avg: 35 coulombs, 30 kA, 100 MV max: 350 coulombs, 300 kA, 1 GV	llnl.gov (source in Lightning)
100 usec, 6kA, say 5 peaks during one lightning strike for 500 usec total...	https://www.youtube.com/watch?v=lakaE-fKQf4&feature=youtu.be

Of the ones that list an energy, most of the sources seem to be in the same ballpark of 1-5 GJ; the notable exception is the MIT page, which surprised me. It listed an average of only 1 MJ, which seems pretty low.

Converting amps and volts to power is straightforward: converting it to energy is less so, as a duration is needed and the durations are all over the board (milliseconds to microseconds). Voltages are similarly varied; most sources claim millions to hundreds of millions of volts, while the Wind Power Engineering article claims only 40 to 120 kV (and is challenged in the source's page comments).

Of all of the sources, the one that appears to me to give the most complete answer is the final one from Lawrence Livermore National Laboratory, which also happens to be the source used by the Lightning article. It gives numbers for an average (negative) strike, and the most powerful (positive) strike; what's interesting is it quotes a typical charge value rather than a duration, which makes the energy calculation much more straightforward, as we can simply use $E=C\cdot V$ . That results in the following:

${\begin{array}{lcl}E_{avg}&=&35C&\cdot &100MV&=&3.5GJ\\E_{max}&=&350C&\cdot &1000MV&=&350GJ\end{array}}$

These numbers, especially the "average" strike, line up pretty well with the 1-5 GJ figure that most of the rest of the sources quote.

We can also calculate an average duration:

${\begin{array}{lcl}T_{avg}&=&35C&\div &30kA&=&1.167ms\\T_{max}&=&350C&\div &300kA&=&1.167ms\end{array}}$

And we can also calculate power:

${\begin{array}{lcl}P_{avg}&=&100MV&\cdot &30kA&=&3TW\\P_{max}&=&1000MV&\cdot &300kA&=&300TW\end{array}}$

These are in the same ballpark as the other sources (milliseconds to microseconds, 1 TW peak), though the power output of the positive strike is substantially higher; I don't know if that is because the other sources are quoting negative strikes only, or if there's something else going on.

I don't recommend that we put any of the math in the article (if it isn't already WP:OR, it is staring it squarely in the face), but I showed this to validate that (most) sources are saying roughly the same thing (with the exceptions of the MIT and Wind Power Engineering articles). If we can agree on this, I think we can modify the wording in the article and remove the self-contradictory tag.

Comments and suggestions are welcome, especially if I've screwed something up. CThomas³ (talk) 07:00, 19 September 2017 (UTC)[reply]

Maybe good source for current/timming details? https://www.youtube.com/watch?v=lakaE-fKQf4&feature=youtu.be — Preceding unsigned comment added by PavelMachek (talk • contribs) 07:11, 9 August 2019 (UTC)[reply]

Hello. I realize that the conversation has been dormant for a while. I wonder if some sources are reporting total energy and the others are reporting energy delivered to the ground. Constant314 (talk) 01:06, 18 March 2021 (UTC)[reply]

I’m sure that’s it. Most of the energy is converted to heat, light and sound along the flash column. I don’t have references or analysis to back up this opinion. It’s based on my intuition as an electrical engineer. Dlflannery (talk) 14:56, 26 May 2024 (UTC)[reply]

Yes, that is what I was thinking. Constant314 (talk) 17:12, 26 May 2024 (UTC)[reply]

[1] "Back to the Future (1985)". IMDb. Retrieved 1 October 2016.

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