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A lightning bolt would be worth only about a nickel (2015)

55 pointsby porlunealmost 3 years ago

17 comments

andrewlaalmost 3 years ago
&gt; The average lightning strike contains about 1 million joules, enough energy to fry the founding father in his boots. “The typical house in the U.S. has 100 amp service or about 28 horsepower,” says Kirtley.<p>Boy do I get frustrated when using compatible units without conversion. The unit that I hate more than any other unit in the universe is the KwH, which is dimensionally equivalent to the Joule, so I don&#x27;t understand why we don&#x27;t just use that instead.<p>&quot;The typical house in the U.S. has 100 amp service or about 28 horsepower&quot; -- seems that it would be way more interesting to say that &quot;the typical house has 100 amp service at 120V, which means 12,000 J&#x2F;s&quot;.<p>The way the original quote is phrased (and the introduction of horsepower of all things) seems insane to me; the clarification adds zero value. You still haven&#x27;t addressed the main question, which is &quot;is the energy in a lightning bolt a significant amount of energy compared to household usage&quot;. For all I know 28 horsepower is 1,000,000 J&#x2F;s, so a lightning bolt would only power a house for a second.<p>EDIT: as many commenters have pointed out, apparently most houses get 240V service, so just double the number above. Still, this is easily fixable, and the main point is that horsepower does not add any value to this discussion.
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photochemsynalmost 3 years ago
Fun facts &amp; questions from Feynamn lectures:<p>&gt; &quot;On an ordinary day over flat desert country, or over the sea, as one goes upward from the surface of the ground the electric potential increases by about 100 volts per meter. Thus there is a vertical electric field E of 100 volts&#x2F;m in the air. The sign of the field corresponds to a negative charge on the earth’s surface. This means that outdoors the potential at the height of your nose is 200 volts higher than the potential at your feet! You might ask: “Why don’t we just stick a pair of electrodes out in the air one meter apart and use the 100 volts to power our electric lights?”<p>&gt; &quot;Although the electric current-density in the air is only a few micromicroamperes per square meter, there are very many square meters on the earth’s surface. The total electric current reaching the earth’s surface at any time is very nearly constant at 1800 amperes. This current, of course, is “positive”—it carries plus charges to the earth. So we have a voltage supply of 400,000 volts with a current of 1800 amperes—a power of 700 megawatts! With such a large current coming down, the negative charge on the earth should soon be discharged. In fact, it should take only about half an hour to discharge the entire earth. But the atmospheric electric field has already lasted more than a half-hour since its discovery. How is it maintained? What maintains the voltage? And between what and the earth? There are many questions.&quot;<p><a href="https:&#x2F;&#x2F;www.feynmanlectures.caltech.edu&#x2F;II_09.html" rel="nofollow">https:&#x2F;&#x2F;www.feynmanlectures.caltech.edu&#x2F;II_09.html</a>
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joostersalmost 3 years ago
Lightning-powered bitcoin mining is obviously the next big thing for green energy!<p>Now you need a double helping of luck - first that you get struck by lightning, and second that your miner guesses the right hash to make a block. But maybe the two somehow combine? After all, people who survive a lightning strike are said to be so lucky that they should buy a lottery ticket... so following this logic, lightning powered mining would be extra efficient!<p>Now I&#x27;m off to patent my new PoS invention - proof of strike :)
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typedef_structalmost 3 years ago
TIL one gallon of gas is 120 lightning bolts, and the relative cost of energy between electricity and fuel is near equilibrium.
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Gibbon1almost 3 years ago
The energy needed to bring a teapot to boil is enough to fling a nickel into orbit.
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a9h74jalmost 3 years ago
This reminds me of an old (misleading) graphic in Wired magazine suggesting that people on treadmills could be significantly reducing their electricity bills.
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david_dracoalmost 3 years ago
Therefore, one could easily generate lightning with equal destructive power? Why is it not used yet in war (airplane to ground) or for entertainment (airplane to airplane)?
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praptakalmost 3 years ago
This looks like the opposite of a low hanging fruit. That fruit is hanging very high and on top of that it is very small and hard to get to the edible part.<p>Solar, wind, hydro, biofuel, geothermal, maybe even day-night temperature cycles - all of these look much more promising in the &quot;free&quot; energy department. Actually it&#x27;s hard to think about a <i>worse</i> energy source. Earthquakes maybe? :-)
1970-01-01almost 3 years ago
A lightning bolt is literally the opposite of clean power. Clean in this sense is lack of electrical noise. Random.org have created their RNGs using lightning strikes.<p><a href="https:&#x2F;&#x2F;api.random.org&#x2F;features" rel="nofollow">https:&#x2F;&#x2F;api.random.org&#x2F;features</a>
coldteaalmost 3 years ago
I call BS. A lighting bolt generates at least 1.21 gigawatts, which is good for many purposes...
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londons_explorealmost 3 years ago
Some websites suggest the average lightning bolt has 5 GJ of energy, which is 5000x what this page quotes. I think someone has done a math error.<p>Eg. <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Harvesting_lightning_energy#:~:text=A%20single%20bolt%20of%20lightning,in%2038%20gallons%20of%20gasoline" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Harvesting_lightning_energy#:~...</a>).
dehrmannalmost 3 years ago
At one point, I realized that lightning is the breakdown of the dielectric material of a capacitor. This means you harvest electric by draining it with a large sheet or web of conductors at cloud level. No idea how well this would work or how much energy there is to collect, and it would be pretty impractical.
londons_explorealmost 3 years ago
To say this another way... A lightning bolt would have to hit the average US home every 12 minutes to keep everything powered (assuming perfect conversion and no losses)
raverbashingalmost 3 years ago
I wonder if instead of the bolt itself we could capture the charge accumulation on a continuous basis<p>That might be &quot;easier&quot; in some aspects
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giardinialmost 3 years ago
But worth a fortune if you can put it in a small package deliverable on command (i.e., a weapon).
whoomp12342almost 3 years ago
if so little power, how does it fry a tree?
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abujazaralmost 3 years ago
And this is why Nikola Tesla died poor.