Comment by dole a day ago
This [1] article claims that the electricity from 115 strikes could power the entire US grid for a year, but it's surely napkin math. Awesome tech, though!
[1] https://www.treehugger.com/how-much-energy-is-in-lightning-8...
This comment made me wonder about the idea of harvesting lightning as a power source. Obviously it’s incredibly challenging, but I wondered if we had magic sci-fi technology that allowed it, how useful would it be?
Back of the napkin math suggests that even with theoretically perfect prediction, capture, storage and distribution you’d still get at best ~1% of the US’ energy through lightning capture.
Secondary school physics teacher here: The article is conflating power (watt or joule per second) and energy (joule or kilowatt-hour), so any claim they make is nonsense and the article shouldn't be taken seriously. My students make the same mistake all the time but they don't get to publish it :-)
Power is energy per time unit (thus: energy = power x time), so while the power of a lightning strike is very high (~10GW), the overall energy isn't because it only lasts for a very short duration (apparently the duration of a lightning event is hard to define, [1] says about 0,5 seconds, other places mention much shorter durations, ~10us). So if that 10GW lasts for 0,5 seconds, the total energy is 1,4MWh, which is 1/6 to 1/10 of the electrical energy an average American household consumes in a year[2].
[1] https://amt.copernicus.org/articles/16/547/2023/ [2] https://www.eia.gov/energyexplained/use-of-energy/electricit...
That article seems very very wrong. I think they missed the difference between GW and GWh.
I think it does:
Right at the bottom under Frequently Asked Questions:
How much lightning would we need to capture to power the entire U.S. electricity grid?
Merely capturing the energy from 115 lightning strikes would supply all of the U.S.'s annual electricity needs.Just for fun: 2023 US electrical power generation was 4,178 terawatt-hours [1], or 1.5e19 joules [2]. Divided by 115 that would be approx. 1.3e17 joules. The Hiroshima bomb was 6e13 joules [3]. Which would leave each of those lightning strikes that can supply the US annual electricity needs as outputting approximately 2200 Hiroshima bomb's worth of energy.
I think we'd have a very different relationship to lightning if each of them were 2200 nuke's worth of energy.
Incidentally, this puts the US electrical power generation per year at 250,000 bombs/year, which is an intriguing way of looking at it.
[1]: https://en.wikipedia.org/wiki/Electricity_sector_of_the_Unit...
[2]: https://www.google.com/search?hl=en&q=4178%20terawatt%20hour...
[3]: https://www.justintools.com/unit-conversion/energy.php?k1=hi...
Apparently a single lightning strike contains the equivalent of about 40 gallons of gasoline. It’s very powerful but not that significant on the scale of a whole city.
In fact a quick back of the napkin math suggests it would only power a city of a million people for half a second.
https://en.m.wikipedia.org/wiki/Harvesting_lightning_energy