5 ms·

> 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 am

> 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. 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't understand why we don't just use that instead. "The typical house in the U.S. has 100 amp service or about 28 horsepower" -- seems that it would be way more interesting to say that "the typical house has 100 amp service at 120V, which means 12,000 J/s". 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't addressed the main question, which is "is the energy in a lightning bolt a significant amount of energy compared to household usage". For all I know 28 horsepower is 1,000,000 J/s, so a lightning bolt would only power a house for a second. 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.

themitigating 4y ago
The typical house has 240 volt service in the US (two legs of 120v). I would also say a decent number of homes have 200amp as well
- samatman 4y ago
  This is true, but I'm fairly certain that the amps of available power are calculated on a 120v basis, a 10 actual-amp washing machine would use 20 accounting amps at maximum power.
  - sokoloff 4y ago
    The rating of a service (and by extension, the main breaker) is available at 240V. It's true that if all of your 200A load is consumed on a single leg, with zero amps consumed on the opposing leg, that you would only be able to consume 200A * 120V nominal or 24kW, but if the load is balanced, you can pull 200A @ 240V nominal or 48kW.
- csdvrx 4y ago
  > The typical house has 240 volt service in the US (two legs of 120v). Can we wire that in a way to would allow installing .uk or .de Schuko Type-F plugs? It would be funny (and weird!) to have 220V available on a european socket for say a desktop equipped with a 1.5kW PSU for the upcoming Nvidia 4090 :)
  - trelane 4y ago
    There may be ordinances requiring a specific plug type, and I'm pretty sure the NEC has opinions on outlets. :) That said, it's your house, so you may be able to do that in some places. I've thought about it myself, so I can get a euro tea kettle. That said, the power will still be at 60Hz not 50, which will matter for some uses (e.g. impedances will change).
  - AnotherGoodName 4y ago
    You probably have a few such sockets around. Not the UK or eu form factor but 240v at least. Look at how your dryer or AC plugs into the wall and you'll see something different to the usual plugs.
    - trelane 4y ago
      These are all standardized and have meaning. https://www.electronicshub.org/electrical-outlet-types/ https://www.electronicshub.org/electrical-outlet-types/ There are definitely 240V for higher power usage (because they will need half the current for the same power with double voltage, and current (current density, technically) is what causes joule heating and melts wires/ starts fires. The sockets will be incompatible with Euro or UK sockets. You could change the socket to a euro socket, bit the frequencies will be wrong for euro or uk devices (60Hz in the us, 50 in europe & UK.) This may or may not be important depending on what you're hooking up to it (understand that impedance and other electrical things are a function of frequency). The safest option would be to get something to convert the power (there seen to be products to do that) and put _that_ behind the Euro or UK outlets.
  - jeramey 4y ago
    You’d probably need to do this with an AC-DC-AC transformer to also get the circuit converted to the 50hz cycle European power systems use, but it’d just be a waste because of the power losses involved (not to mention the expense of the transformers). Also, a typical 15A circuit in a home will handle ~1.8kw of sustained load, so as long as you can dedicate a circuit to such a rig, you’d be fine.
- yourapostasy 4y ago
  A surprising (but still tiny) number of US houses also can have three-phase brought out to them by the electric utility. Some utilities will charge you upfront for stringing it up and lighting up the wires, but another surprising number of utilities will just amortize it from the monthly cost of service. It's still rare enough you have to ask ahead of time if you want it for any building you get into, but in some major metro areas it has gone from "you have got to be joking" to "sure, let me check on that". Now if only I can find a reliable, durable three-phase solar inverter...
  - themitigating 4y ago
    3 phase gets you 108v on each hot leg. Many items will specify 110v/120v . 108v is close enough
greenbit 4y ago
Idk, I think OP indicated that a typical lightning bolt would power a typical house (presumably at the stated nominal full load) for about 15 minutes. I.e., you'd need 4 strikes per hour, per hour. Now granted most houses won't run at peak load all the time, maybe you'd only need one strike per hour per house - but that's still clearly a lot more lightning than is generally seen.
- andrewla 4y ago
  The article is short and such an indication should be easy to cite directly. If I missed it, please let me know. As far as I can see, nowhere in the article does it give enough information (even if you take into account unit conversions) to say how much of a house's electricity would be supplied by a lightning bolt.
samatman 4y ago
The kWh is of course exactly what you want if you're working with power over time. Example: a 100 amp house circuit running maxed out in the US will use 12 kWh per hour, or 0.2 per minute. Try doing it in your head with joules. Annoying right? 12 kWh / h? Am I a crazy person? No. I'm working on a useful problem.
jfim 4y ago
The kilowatt hour is a fantastic unit when talking about electrical consumption. Are you running a 100W load (0.1kW) for an hour? That's 0.1kWh. Running it for ten would make a whole kilowatt hour. This allows for easy calculations of how much something is going to cost in electricity, and the units are such that it's easy to do the math in your head.
- andrewla 4y ago
  You're using a toy example to strawman the Joule counterpoint. How much do you use in a month, which is the typical billing cycle? Off-peak vs. on-peak cost?. In the end there's no practical utility to this. We just pretend that we're living in a world where you get a 100W light bulb and know exactly what it will cost you, and not a world where half your bulbs claim to be 100W but are actually 14W with 100W-incandescent-equivalent and such.
  - 2Gkashmiri 4y ago
    >In the end there's no practical utility to this. We just pretend that we're living in a world where you get a 100W light bulb and know exactly what it will cost you, and not a world where half your bulbs claim to be 100W but are actually 14W with 100W-incandescent-equivalent and such. Where i live, the pricing is based on the amount of energy "consumed" during a month. plus we use 220v. i use the kwh extensively, my induction cooker is rated at 1300Watts so i know by running it for 1 hour i am consuming 1.3kwh. my monthly "consumption" before installing a 5kwh solar on-grid used to be around 300Kwh during summer months so over time i have learned to "reduce" my monthly usage, aka kwh by reducing my electric hot water geyser( going to solar water heater) (2kw geyser). the kwh is definitely a good indicator for me
  - trelane 4y ago
    > You're using a toy example to strawman the Joule counterpoint. Not a toy example. That's exactly how I estimate energy consumption for off the shelf devices. And for battery life (W*h but still). > 100W light bulb and know exactly what it will cost you, and not a world where half your bulbs claim to be 100W but are actually 14W with 100W-incandescent-equivalent and such. If you've lived with lighting you're responsible for, you've replaced bulbs. You know the different technologies and the packages say how much power they require.
flyinghamster 4y ago
> 100 amp service at 120V Strictly speaking, 240V. Normal electric service in North America is 240V split-phase, with the distribution transformer's center tap grounded and serving as the neutral line. We normally only use the full 240V for heavy loads like electric ovens, arc welders, large air conditioners, and such. Large buildings often use 208V three-phase power, yielding 120V phase-to-neutral, and large commercial lighting installations are often 277V taken from one leg of a 480V three-phase feed. Voltages greater than 240 are not permitted in residential service, and I wouldn't be surprised if phase-to-neutral > 120 is out as well for homes.
- mepiethree 4y ago
  Do you work in clean energy tech by any chance? Software people who know these things are like unicorns
  - trelane 4y ago
    The residential side can be discovered if you're a DIY homeowner.
  - breakingcups 4y ago
    There's probably a large overlap between software people and people who subscribe to Technology Connections: https://www.youtube.com/watch?v=jMmUoZh3Hq4 https://www.youtube.com/watch?v=jMmUoZh3Hq4
csours 4y ago
I thought that quoting in horsepower was very interesting as many people are currently thinking about the load that EVs put on the grid.
ravi-delia 4y ago
The KwH makes sense if you consider that while units are largely path-independent, mental calculations are not. At any given moment, the sensible measure of your house's electricity usage is in kW. And to work backwards to figure out consumption, the hour certainly beats the second. Sure, you could call it 3.6e6 joules, but at that what point what does it buy you? Horsepower is clearly insane though, I have no idea why you'd bother.
- andrewla 4y ago
  For most realistic conversations you'd be talking about the relative consumption of two devices. Watts/kW is totally fine for this. Regardless, head-math or otherwise, the vast majority of people will never do this calculation at all, except maybe to weigh the relative power consumption. And if they do the math, having a calculator and having all the units be compatible with each other (so just a natural conversion of W to J/s) is totally fine.
Schroedingersat 4y ago
> 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't understand why we don't just use that instead. kWh/yr is worse. It's just watts but obfuscated. Gets used for appliances.
deleted 4y ago
[deleted]

themitigating 4y ago

The typical house has 240 volt service in the US (two legs of 120v). I would also say a decent number of homes have 200amp as well

samatman 4y ago
This is true, but I'm fairly certain that the amps of available power are calculated on a 120v basis, a 10 actual-amp washing machine would use 20 accounting amps at maximum power.
- sokoloff 4y ago
  The rating of a service (and by extension, the main breaker) is available at 240V. It's true that if all of your 200A load is consumed on a single leg, with zero amps consumed on the opposing leg, that you would only be able to consume 200A * 120V nominal or 24kW, but if the load is balanced, you can pull 200A @ 240V nominal or 48kW.
csdvrx 4y ago
> The typical house has 240 volt service in the US (two legs of 120v). Can we wire that in a way to would allow installing .uk or .de Schuko Type-F plugs? It would be funny (and weird!) to have 220V available on a european socket for say a desktop equipped with a 1.5kW PSU for the upcoming Nvidia 4090 :)
- trelane 4y ago
  There may be ordinances requiring a specific plug type, and I'm pretty sure the NEC has opinions on outlets. :) That said, it's your house, so you may be able to do that in some places. I've thought about it myself, so I can get a euro tea kettle. That said, the power will still be at 60Hz not 50, which will matter for some uses (e.g. impedances will change).
- AnotherGoodName 4y ago
  You probably have a few such sockets around. Not the UK or eu form factor but 240v at least. Look at how your dryer or AC plugs into the wall and you'll see something different to the usual plugs.
  - trelane 4y ago
    These are all standardized and have meaning. https://www.electronicshub.org/electrical-outlet-types/ https://www.electronicshub.org/electrical-outlet-types/ There are definitely 240V for higher power usage (because they will need half the current for the same power with double voltage, and current (current density, technically) is what causes joule heating and melts wires/ starts fires. The sockets will be incompatible with Euro or UK sockets. You could change the socket to a euro socket, bit the frequencies will be wrong for euro or uk devices (60Hz in the us, 50 in europe & UK.) This may or may not be important depending on what you're hooking up to it (understand that impedance and other electrical things are a function of frequency). The safest option would be to get something to convert the power (there seen to be products to do that) and put _that_ behind the Euro or UK outlets.
- jeramey 4y ago
  You’d probably need to do this with an AC-DC-AC transformer to also get the circuit converted to the 50hz cycle European power systems use, but it’d just be a waste because of the power losses involved (not to mention the expense of the transformers). Also, a typical 15A circuit in a home will handle ~1.8kw of sustained load, so as long as you can dedicate a circuit to such a rig, you’d be fine.
yourapostasy 4y ago
A surprising (but still tiny) number of US houses also can have three-phase brought out to them by the electric utility. Some utilities will charge you upfront for stringing it up and lighting up the wires, but another surprising number of utilities will just amortize it from the monthly cost of service. It's still rare enough you have to ask ahead of time if you want it for any building you get into, but in some major metro areas it has gone from "you have got to be joking" to "sure, let me check on that". Now if only I can find a reliable, durable three-phase solar inverter...
- themitigating 4y ago
  3 phase gets you 108v on each hot leg. Many items will specify 110v/120v . 108v is close enough

greenbit 4y ago

Idk, I think OP indicated that a typical lightning bolt would power a typical house (presumably at the stated nominal full load) for about 15 minutes. I.e., you'd need 4 strikes per hour, per hour. Now granted most houses won't run at peak load all the time, maybe you'd only need one strike per hour per house - but that's still clearly a lot more lightning than is generally seen.

andrewla 4y ago
The article is short and such an indication should be easy to cite directly. If I missed it, please let me know. As far as I can see, nowhere in the article does it give enough information (even if you take into account unit conversions) to say how much of a house's electricity would be supplied by a lightning bolt.

samatman 4y ago

The kWh is of course exactly what you want if you're working with power over time. Example: a 100 amp house circuit running maxed out in the US will use 12 kWh per hour, or 0.2 per minute. Try doing it in your head with joules. Annoying right? 12 kWh / h? Am I a crazy person? No. I'm working on a useful problem.

jfim 4y ago

The kilowatt hour is a fantastic unit when talking about electrical consumption. Are you running a 100W load (0.1kW) for an hour? That's 0.1kWh. Running it for ten would make a whole kilowatt hour. This allows for easy calculations of how much something is going to cost in electricity, and the units are such that it's easy to do the math in your head.

andrewla 4y ago
You're using a toy example to strawman the Joule counterpoint. How much do you use in a month, which is the typical billing cycle? Off-peak vs. on-peak cost?. In the end there's no practical utility to this. We just pretend that we're living in a world where you get a 100W light bulb and know exactly what it will cost you, and not a world where half your bulbs claim to be 100W but are actually 14W with 100W-incandescent-equivalent and such.
- 2Gkashmiri 4y ago
  >In the end there's no practical utility to this. We just pretend that we're living in a world where you get a 100W light bulb and know exactly what it will cost you, and not a world where half your bulbs claim to be 100W but are actually 14W with 100W-incandescent-equivalent and such. Where i live, the pricing is based on the amount of energy "consumed" during a month. plus we use 220v. i use the kwh extensively, my induction cooker is rated at 1300Watts so i know by running it for 1 hour i am consuming 1.3kwh. my monthly "consumption" before installing a 5kwh solar on-grid used to be around 300Kwh during summer months so over time i have learned to "reduce" my monthly usage, aka kwh by reducing my electric hot water geyser( going to solar water heater) (2kw geyser). the kwh is definitely a good indicator for me
- trelane 4y ago
  > You're using a toy example to strawman the Joule counterpoint. Not a toy example. That's exactly how I estimate energy consumption for off the shelf devices. And for battery life (W*h but still). > 100W light bulb and know exactly what it will cost you, and not a world where half your bulbs claim to be 100W but are actually 14W with 100W-incandescent-equivalent and such. If you've lived with lighting you're responsible for, you've replaced bulbs. You know the different technologies and the packages say how much power they require.

flyinghamster 4y ago

> 100 amp service at 120V Strictly speaking, 240V. Normal electric service in North America is 240V split-phase, with the distribution transformer's center tap grounded and serving as the neutral line. We normally only use the full 240V for heavy loads like electric ovens, arc welders, large air conditioners, and such. Large buildings often use 208V three-phase power, yielding 120V phase-to-neutral, and large commercial lighting installations are often 277V taken from one leg of a 480V three-phase feed. Voltages greater than 240 are not permitted in residential service, and I wouldn't be surprised if phase-to-neutral > 120 is out as well for homes.

mepiethree 4y ago
Do you work in clean energy tech by any chance? Software people who know these things are like unicorns
- trelane 4y ago
  The residential side can be discovered if you're a DIY homeowner.
- breakingcups 4y ago
  There's probably a large overlap between software people and people who subscribe to Technology Connections: https://www.youtube.com/watch?v=jMmUoZh3Hq4 https://www.youtube.com/watch?v=jMmUoZh3Hq4

csours 4y ago

I thought that quoting in horsepower was very interesting as many people are currently thinking about the load that EVs put on the grid.

ravi-delia 4y ago

The KwH makes sense if you consider that while units are largely path-independent, mental calculations are not. At any given moment, the sensible measure of your house's electricity usage is in kW. And to work backwards to figure out consumption, the hour certainly beats the second. Sure, you could call it 3.6e6 joules, but at that what point what does it buy you? Horsepower is clearly insane though, I have no idea why you'd bother.

andrewla 4y ago
For most realistic conversations you'd be talking about the relative consumption of two devices. Watts/kW is totally fine for this. Regardless, head-math or otherwise, the vast majority of people will never do this calculation at all, except maybe to weigh the relative power consumption. And if they do the math, having a calculator and having all the units be compatible with each other (so just a natural conversion of W to J/s) is totally fine.

Schroedingersat 4y ago

> 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't understand why we don't just use that instead. kWh/yr is worse. It's just watts but obfuscated. Gets used for appliances.

deleted 4y ago

[deleted]