I attached a generator with some supercaps and an inverter to a stationary bicycle a few years ago, and even though I mostly use it as a way to feel less guilty watching Youtube videos, it does give me a quite literal feel for some of the items on the lower end of the scale.
- Anything even even halfway approaching a toaster or something with a heater in it is essentially impossible (yes, I know about that one video).
- A vacuum cleaner can be run for about 30 seconds every couple minutes.
- LED lights are really good, you can charge up the caps for a minute and then get some minutes of light without pedaling.
- Maybe I could keep pace with a fridge, but not for a whole day.
- I can do a 3D printer with the heated bed turned off, but you have to keep pedaling for the entire print duration, so you probably wouldn't want to do a 4 hour print. I have a benchy made on 100% human power.
- A laptop and a medium sized floor fan is what I typically run most days.
- A modern laptop alone, with the battery removed and playing a video is "too easy", as is a few LED bulbs or a CFL. An incandescent isn't difficult but why would you?
- A cellphone you could probably run in your sleep
Also gives a good perspective on how much better power plants are at this than me. All I've made in 4 years could be made by my local one in about 10 seconds, and cost a few dollars.
Where I am at least, people using less power because power because power need to profit more, is wild.
They literally had record profits the last few years, rather than being forced to lay down solar. I think power should be a global endeavor, not some local for profit business with complete regulatory capture that makes competition illegal.
Yes I'm angry, because I pay more in electric than most anywhere in the world. If I charge my care with LEVEL 2 using city provided charges, during the day, it's more expensive than gas.
> They literally had record profits the last few years, rather than being forced to lay down solar. I think power should be a global endeavor, not some local for profit business with complete regulatory capture that makes competition illegal.
Sounds more like you guys should be lowering barriers to entry, not setting up a global non-profit cartel.
Did you try charging an e-bike with your contraption?
I don't know what you can take of this, maybe you can see it as advance pedaling, or to get a feel for energy conversion losses. Anyways, it is the kind of harmlessly stupid idea that I would want to try just because I could.
Once I did a little bike training and looking at my power curve, I was incredibly impressed by how cheap energy is. 100W is an all day number, 200W less so, 300W is exactly 20 minutes when I do an FTP test. 400W is 4x Tour de France winner Tadej Pogačar for an hour and he's a mutant. 1 horsepower is under a minute iirc, definitely under 2. 1kW is maybe 10 seconds. So I could keep my laptop and phone charged probably indefinitely as long as I have food, but not a ton more than that.
Amazing stuff, have you written up a blog post? I could see a video being a fun format for this as well. Might help people develop the intuition for watts/power consumption in a different way
I did do a video back then going against the infamous "bicycle toaster challenge" video (in which I determined it was probably less real than they made it out to be). I'm nowhere as fit as those guys, so in my attempt I was only able to turn a bagel into a dry crouton over the course of an hour.
I'm as curious as you to be honest - putting a strain gauge on the pedals for measuring mechanical power has been on my list for quite a while. My own (probably inaccurate) measurements right after the generator says I can get 60-70Wh in an hour, but I can get to 100Wh if I try harder. I have reason to believe my setup underestimates power because my ammeter clamps at 5A and I know I can peak over that on the down stroke of the pedal.
I've seen numbers like 250W mechanical power for an average trained cyclist, so either my setup is rather inefficient, my measurements are off, or I'm going to find out that I'm nowhere near as strong as a real cyclist.
On the other hand, the stationary bike I got originally had a rubber belt, which it would chew excessively and I eventually swapped it for a chain because it kept slipping in spite of tensioning it more, suggesting I'm hitting the thing harder than it was originally designed for (how that translates into power I'm not sure).
The author Hannah Ritchie works on Our World In Data and also publishes the fantastic Sustainability by Numbers substack. It's in the same vein as the late, great David MacKay's Sustainable Energy Without the Hot Air.
This tool has its own recent substack post. See the comments too, especially the one by Chris Preist that contextualizes the energy usage of streaming video (a topic that has also been discussed on HN before).
She's employed by Our World In Data. She is also a published author of printed books. Her substack does not have paid subscriptions enabled (or at least it did not as of last summer; see this post [1]). Our World In Data is funded by donations:
I think stuff like this really crystalises how people misunderstand how much energy stuff uses.
My parents for example sweat the small stuff and go around the house turning LED driven lights off to "save electricity" even though it would barely make a dent in their bill.
Granted, they come from a time of incadescants burning 60-100w at a time so I can see why that habit might be deeply ingrained.
The ridiculously dramatic drop in power we dedicate to lighting is one that is just tough for folks to internalize. As you said, used to, you could have ~10 lights in your house that would add to upwards of 1kw. Nowadays, you can have 50 lights and barely hit 500w. Just mind blowing how far we dropped energy on those.
Same goes for televisions. Your modern TV is probably closer to the basic light bulbs before LEDs.
I'm assuming the general trend is true for all things solid state. That said, lighting is by far the biggest drop for most houses. Remarkably so.
> I'm assuming the general trend is true for all things solid state. That said, lighting is by far the biggest drop for most houses. Remarkably so.
For commercial and industrial installations, VFDs have probably been the biggest efficiency gain, even moreso than lighting. Half of all electricity consumed is used by motors. Thank goodness for solid state power electronics!
I turn LED lights off because of the difference in operational life, and I don't like changing bulbs. M GE bulbs say they have a rated lifetime of 13 years......at 3 hours of usage per day. So if they don't get turned off, then that 3 hours can very easily become 12, and now you are at a rated lifetime of ~4 years instead.
A ‘standard’ (A19 shape, E26 base) 8W 800 lumen LED lamp costs around $5 and will use about $20 of energy over a 15,000 hour lifespan, assuming $0.15/kWh.
That works out to around $0.035 per day for the lifespan of the lamp if you run it constantly for 24 hours a day, I wouldn’t waste time thinking about it. It’s an extra $10 over 12 years, you’re still using the energy.
Investing in occupancy or vacancy sensor wall switches at $25 a piece would be the best option, then you don’t need to remember to turn the lights off!
Yup. In my experience, average non-nerd folk very very little feel for this stuff. I suspect some believe energy consumption of phone vs car is basically a toss up.
It was genuinely a surprise to see how much relative energy petrol cars use (and shame on me - I'm an electrical engineer). I mean I think I knew it intuitively, but this simple chart blew my mind.
When one gets in the weeds on EVs or ICE cars two things become shockingly clear: internal combustion is hilariously inefficient YET gasoline is hilariously energy dense. Most people's intuition is wrong on both of these points but then they cancel each other out.
Edit: another important point is that the "cost" to acquire gasoline is only the very end of the process. The energy has already been gathered, stored, and most of the processing is complete. Our cost (in money and energy) to "make" gasoline is really just gathering it. This is why the comparison to renewables is often a hard sell, it's just apples to oranges. Gasoline started on third base, renewables are batting from the plate. Some of the internal combustion enthusiasts are holding up e-fuels or synthetic fuels as the solution but then we have to pay for the entire energy gathering and processing pipeline and still be using a conversion method that's not at all efficient. It's the worst of both worlds.
It's inefficient but not hilariously so. Modern ICE are quite amazing technology.
Combined gas turbines (you know, the energy source that powers your electric car) are about 60% efficient for the really good ones, minus 5-7% transmission losses, minus 10-12% charging losses, minus 20% loss in cold climates, lands you at around 35-40% efficiency from fuel source to the wheel.
The Atkinson-cycle engine in the Toyota Prius gets around 40% give or take some losses in the drivetrain. Electric have plenty of upsides, but for some people with cheap gas+high electric costs+cold climate you would honestly be better driving a hybrid.
Train locomotives have used diesel powered generators that then powers electric motors. Would this be less efficient than battery powered EVs? Or better asked, what would be the most efficient use of gasoline?
In Japan, my country, this looks a bit different. A lot of electricity still comes from oil- and gas-fired plants. The mechanics differ (gas turbines vs. car engines), but in both cases we’re still relying on combustion. I suppose some countries have the same issue.
The presentation is nice, but some of the conversions are questionable.
For instance: The cost section, wherein 1kWh in the US is figured as having a cost of 9.7 cents.
In reality, it's not that way at all. Unless we're fortunate enough to live in an area where we can walk over to the neighborhood generating station and carry home buckets of freshly-baked electricity to use at home, then we must also pay for delivery.
On average, in 2025, electricity was 17.3 cents per kiloWatt-hour -- delivered -- for residential customers in the US.
I looked at the electric car example for the United States. It has 3 kilowatt hours priced at $0.51, 17 cents per kilowatt hour, which seems about right. The "petrol car" example at the top of the chart isn't powered by electricity so its cost number is not directly comparable to the things that consume electricity.
The electric shower also seemed pretty optimistic. I live in an area with about 50°F/10°C ground temperature and my 14.4 kW water heater can just keep a relatively efficient shower head flowing at a comfortable temperature.
Interestingly, the latest generation of LED lights are so efficient that it makes little financial sense to bother having a light switch. 330 lumens per watt from recent Phillips bulbs!
The cost of having an electrician wire that switch is probably more than a little 2.5 watt light will use in it's lifespan - particularly when you account for the fact lights in hallways are probably in use most of the time anyway.
Add in the effort of switching the light switch a few times a day for many years and it's certainly the case! Or the risk of fumbling in the dark for a light switch at the far end of a room or in a house you aren't familiar with.
Obviously you might still want to turn it off for maintenance, but you have the breaker for that.
They are direct AC bulbs, no inverter needed. They do have smoothing capacitors so they don't flicker, and I think a slight redesign of the drive circuitry could add ~10% more efficiency...
> So, if I wanted to analogize the energy usage of my use of coding agents, it’s something like running the dishwasher an extra time each day, keeping an extra refrigerator, or skipping one drive to the grocery store in favor of biking there. To me, this is very different than, in Benjamin Todd’s words, “a terrible reason to avoid” this level of AI use. These are the sorts of things that would make me think twice.
I end up shrugging. For a Claude Code power user, today, a day's use uses less electricity than a morning commute in an electric car. To say nothing of the costs to keep your workstation running, your building heated or cooled, etc. Not quite a rounding error, but a relatively minor component of overall usage.
At least for programming usage the power usage seems worth it. For starting up 1 million bots to argue with each other on facebook it's obviously a total waste.
At any rate, the power usage will become more apparent when these products stop being subsidised, where power usage is being charged to the end user.
I also was under the impression that queries cost were mostly meaningless, but it seemed only is true for fresh sessions and short queries. I have to say, the result is less dramatic than I expected but still more significant for heavy users (such as myself).
I'm not sure it's even a particularly relevant comparison to an hour of use of various other electronic devices. I'm sure the median user is running a lot fewer queries than a Claude Code power-user, but I would guess it's still more than one in a typical session.
One thing missing but important to understand is the energy embodied in buying 'stuff'. At a very rough approximation, the cost of stuff, especially consumer goods manufactured cheaply, is quite a high percentage energy.
When you look at people's energy usage, quite a lot of it ends up being the embodied energy in the stuff they buy. For quite a lot of people, it's probably the largest category of energy consumption. I once had a very rough go at calculating this here: https://www.robinlinacre.com/energy_usage/
One gram of finished 3nm packaged semiconductor is roughly equivalent to half a kilogram of refined aluminum in terms of energy cost. If you want to spend a lot of energy for not much mass, photolithography is fantastic.
Readit News
- Anything even even halfway approaching a toaster or something with a heater in it is essentially impossible (yes, I know about that one video).
- A vacuum cleaner can be run for about 30 seconds every couple minutes.
- LED lights are really good, you can charge up the caps for a minute and then get some minutes of light without pedaling.
- Maybe I could keep pace with a fridge, but not for a whole day.
- I can do a 3D printer with the heated bed turned off, but you have to keep pedaling for the entire print duration, so you probably wouldn't want to do a 4 hour print. I have a benchy made on 100% human power.
- A laptop and a medium sized floor fan is what I typically run most days.
- A modern laptop alone, with the battery removed and playing a video is "too easy", as is a few LED bulbs or a CFL. An incandescent isn't difficult but why would you?
- A cellphone you could probably run in your sleep
Also gives a good perspective on how much better power plants are at this than me. All I've made in 4 years could be made by my local one in about 10 seconds, and cost a few dollars.
They literally had record profits the last few years, rather than being forced to lay down solar. I think power should be a global endeavor, not some local for profit business with complete regulatory capture that makes competition illegal.
Yes I'm angry, because I pay more in electric than most anywhere in the world. If I charge my care with LEVEL 2 using city provided charges, during the day, it's more expensive than gas.
Cheap electricity means you can do things that made "no sense" with expensive electricity. (e.g. smelt aluminum)
Cheap electricity means you can underbid regions that have expensive electricity...
As Technology Connections said, "Panels that cover your electrical needs for the next 25+ years? In the Midwest, we call that a good deal!"
Sounds more like you guys should be lowering barriers to entry, not setting up a global non-profit cartel.
I don't know what you can take of this, maybe you can see it as advance pedaling, or to get a feel for energy conversion losses. Anyways, it is the kind of harmlessly stupid idea that I would want to try just because I could.
https://velo.outsideonline.com/road/road-racing/tour-de-fran...
https://hackaday.io/project/191731-practical-power-cycling
and is also a few years out of date.
I did do a video back then going against the infamous "bicycle toaster challenge" video (in which I determined it was probably less real than they made it out to be). I'm nowhere as fit as those guys, so in my attempt I was only able to turn a bagel into a dry crouton over the course of an hour.
https://www.youtube.com/watch?v=AcNXp86BJ-o
I've seen numbers like 250W mechanical power for an average trained cyclist, so either my setup is rather inefficient, my measurements are off, or I'm going to find out that I'm nowhere near as strong as a real cyclist.
On the other hand, the stationary bike I got originally had a rubber belt, which it would chew excessively and I eventually swapped it for a chain because it kept slipping in spite of tensioning it more, suggesting I'm hitting the thing harder than it was originally designed for (how that translates into power I'm not sure).
This tool has its own recent substack post. See the comments too, especially the one by Chris Preist that contextualizes the energy usage of streaming video (a topic that has also been discussed on HN before).
https://hannahritchie.substack.com/p/does-that-use-a-lot-of
It's interesting to see how upset people are on Goodreads about that book:
https://www.goodreads.com/book/show/145624737-not-the-end-of...
The top reviews are mostly people angry with Ritchie for not being a catastrophist.
https://ourworldindata.org/funding
[1] https://hannahritchie.substack.com/p/reflections-on-substack
Deleted Comment
Could be wholesome and altruistic. Or it could be something else.
Someone can be an honest ideologue (useful idiot) without being directly funded by someone shady.
My parents for example sweat the small stuff and go around the house turning LED driven lights off to "save electricity" even though it would barely make a dent in their bill.
Granted, they come from a time of incadescants burning 60-100w at a time so I can see why that habit might be deeply ingrained.
Same goes for televisions. Your modern TV is probably closer to the basic light bulbs before LEDs.
I'm assuming the general trend is true for all things solid state. That said, lighting is by far the biggest drop for most houses. Remarkably so.
For commercial and industrial installations, VFDs have probably been the biggest efficiency gain, even moreso than lighting. Half of all electricity consumed is used by motors. Thank goodness for solid state power electronics!
That works out to around $0.035 per day for the lifespan of the lamp if you run it constantly for 24 hours a day, I wouldn’t waste time thinking about it. It’s an extra $10 over 12 years, you’re still using the energy.
Investing in occupancy or vacancy sensor wall switches at $25 a piece would be the best option, then you don’t need to remember to turn the lights off!
Edit: another important point is that the "cost" to acquire gasoline is only the very end of the process. The energy has already been gathered, stored, and most of the processing is complete. Our cost (in money and energy) to "make" gasoline is really just gathering it. This is why the comparison to renewables is often a hard sell, it's just apples to oranges. Gasoline started on third base, renewables are batting from the plate. Some of the internal combustion enthusiasts are holding up e-fuels or synthetic fuels as the solution but then we have to pay for the entire energy gathering and processing pipeline and still be using a conversion method that's not at all efficient. It's the worst of both worlds.
It's inefficient but not hilariously so. Modern ICE are quite amazing technology.
Combined gas turbines (you know, the energy source that powers your electric car) are about 60% efficient for the really good ones, minus 5-7% transmission losses, minus 10-12% charging losses, minus 20% loss in cold climates, lands you at around 35-40% efficiency from fuel source to the wheel.
The Atkinson-cycle engine in the Toyota Prius gets around 40% give or take some losses in the drivetrain. Electric have plenty of upsides, but for some people with cheap gas+high electric costs+cold climate you would honestly be better driving a hybrid.
There's a good reason so many sprawling civilizations of the past involve leveraging wind-power for transport.
The problem with gas is not that burning it doesn’t maximally capture all energy, but that there are externalities to doing so.
Like, if you "save energy" by not driving a petrol car, you can't "use the same energy" on electric car, or lighting.. not even prower a generator.
They are not interchangeable.. But this chart encourage us to think them as the same.
For instance: The cost section, wherein 1kWh in the US is figured as having a cost of 9.7 cents.
In reality, it's not that way at all. Unless we're fortunate enough to live in an area where we can walk over to the neighborhood generating station and carry home buckets of freshly-baked electricity to use at home, then we must also pay for delivery.
On average, in 2025, electricity was 17.3 cents per kiloWatt-hour -- delivered -- for residential customers in the US.
https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...
On the costs tab, for the United States: It says that this has a cost of $0.97.
97 cents ÷ 10kWh = 9.7 cents per kWh
(I didn't look further than that. Perhaps I should have.)
---
edit: I now see a note at the very bottom stating that it is using an assumed "$0.17 for electricity".
$0.17 per kWh is plenty close enough for rough figurin', so I'd like to take this opportunity to retract my previous complaint.
It turned out that it had been plumbed backwards.
The cost of having an electrician wire that switch is probably more than a little 2.5 watt light will use in it's lifespan - particularly when you account for the fact lights in hallways are probably in use most of the time anyway.
Add in the effort of switching the light switch a few times a day for many years and it's certainly the case! Or the risk of fumbling in the dark for a light switch at the far end of a room or in a house you aren't familiar with.
Obviously you might still want to turn it off for maintenance, but you have the breaker for that.
I think that mostly only applies bulbs without inverters.
They are direct AC bulbs, no inverter needed. They do have smoothing capacitors so they don't flicker, and I think a slight redesign of the drive circuitry could add ~10% more efficiency...
Here's a post that makes an estimate:
https://www.simonpcouch.com/blog/2026-01-20-cc-impact/
> So, if I wanted to analogize the energy usage of my use of coding agents, it’s something like running the dishwasher an extra time each day, keeping an extra refrigerator, or skipping one drive to the grocery store in favor of biking there. To me, this is very different than, in Benjamin Todd’s words, “a terrible reason to avoid” this level of AI use. These are the sorts of things that would make me think twice.
At any rate, the power usage will become more apparent when these products stop being subsidised, where power usage is being charged to the end user.
I also was under the impression that queries cost were mostly meaningless, but it seemed only is true for fresh sessions and short queries. I have to say, the result is less dramatic than I expected but still more significant for heavy users (such as myself).
When you look at people's energy usage, quite a lot of it ends up being the embodied energy in the stuff they buy. For quite a lot of people, it's probably the largest category of energy consumption. I once had a very rough go at calculating this here: https://www.robinlinacre.com/energy_usage/