3/4/2026 at 10:01:26 PM
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.
by alnwlsn
3/4/2026 at 10:25:15 PM
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.
by nomel
3/4/2026 at 11:02:23 PM
Energy security is national security.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!"
by NortySpock
3/5/2026 at 12:44:29 AM
I love Technology Connections, but he has no idea what discounting is in economics. Or at least he writes his videos as if he doesn't.by eru
3/5/2026 at 2:35:59 PM
What discount rate are you using?Solar has one of the lowest capital costs [1] so the discounting works in it's favor. And then the non-discountable operating costs also works in its favor since the fuel supply (light) is free.
[1]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...
by lesuorac
3/5/2026 at 9:06:51 PM
Yup. It's why even in fairly red states like my own (Idaho) solar, wind, and battery are going up everywhere. Even without significant subsidies the economics are really good for renewables.They'd be even better if we didn't have extreme tariffs on China.
That's actually what's convinced me that renewables are a better choice than nuclear. I still like nuclear, but renewables are just so much easier and faster to deploy while being a lot cheaper. To make nuclear competitive requires regulatory changes along with a government that's simply willing to tell it's NIMBY citizens YIMBY.
Government literally has to get in the way of renewable deployments at this point to stop them.
by cogman10
3/4/2026 at 11:43:49 PM
[flagged]by harrall
3/5/2026 at 12:46:53 AM
Where does that 0.3 TW figure come from? That seems awfully high.by dmd
3/5/2026 at 1:43:21 PM
You're trying to converse with a LLM. It's made up.by b40d-48b2-979e
3/5/2026 at 1:46:44 PM
jfc. What is the point? What do people get out of doing that?by dmd
3/5/2026 at 1:49:09 PM
I don't know, but HN in particular has an AI-sycophancy problem where I see this most common versus other link aggregator sites.by b40d-48b2-979e
3/5/2026 at 12:12:00 AM
is that a sustained 20TW? Absolutely crazy that we're generating 60kwh per person daily. Where does it all go?by hnav
3/5/2026 at 12:13:50 AM
Lots of it is lost to heat with legacy fossil generation.by toomuchtodo
3/5/2026 at 12:45:13 AM
You have pretty much the same heat losses with nuclear, or anything else where you heat water to turn a turbine.by eru
3/5/2026 at 1:38:22 AM
Nuclear is low carbon, it’s fine we lose heat to extract that energy versus stationary and mobile combustion generation, as there is no other effective way to extract that energy at this time.Quantification of global waste heat and its environmental effects - https://www.sciencedirect.com/science/article/abs/pii/S03062... - Applied Energy Volume 235, 1 February 2019, Pages 1314-1334
* 49.3–51.5% of global energy use would end up as waste heat in 2030.
* Transport sector accounts for the largest (43%) recoverable waste heat in 2030.
by toomuchtodo
3/5/2026 at 12:10:07 AM
To note, we are almost at installing 1TW of solar PV every year globally.by toomuchtodo
3/4/2026 at 11:05:54 PM
Most of those technologies also need uninterrupted power supplies. Something wind, solar and batteries for the next 50 years aren't.by noosphr
3/5/2026 at 12:15:16 AM
Pumped hydro is one solution. You bank the excess wind/solar using gravitational potential energy and then draw on that whenever you need to.by alexfoo
3/5/2026 at 3:01:44 AM
Yes, we just need to build the mountains first.by noosphr
3/5/2026 at 4:00:12 PM
Yeah, or water towers. No need to play god here.by Leno1225
3/5/2026 at 8:12:52 PM
Pumped hydro energy storage relies on the cheapness of water and existing geology. If you have to build the chambers instead of damming a river it's too expensive. Most of the good spots to have a reservoir are already used. If you have to manufacture the bulk media instead of just using water it's too expensive.by supertrope
3/5/2026 at 8:38:48 PM
There are exactly zero economically viable pumped water storage systems where water towers are involved. If you do the math for the amount of a mass of water, you'll see why! It's not feasible.by nomel
3/5/2026 at 12:45:30 AM
Have you heard of batteries?by eru
3/5/2026 at 12:10:48 AM
Ember Energy: Solar electricity every hour of every day is here and it changes everything - https://ember-energy.org/latest-insights/solar-electricity-e... - June 21st, 2025> Batteries are now cheap enough to unleash solar’s full potential, getting as close as 97% of the way to delivering constant electricity supply 24 hours across 365 days cost-effectively in the sunniest places.
What does this mean? It means we are most of the way there with solar and batteries alone, even if we need a bit of carbon based generation to bridge the gap while solar and battery deployments scale globally. Solar and batteries will only continue to get less expensive and better.
Our World In Data: Installed solar energy capacity - https://ourworldindata.org/grapher/installed-solar-pv-capaci...
Solar PV go brrr.
by toomuchtodo
3/5/2026 at 12:46:29 AM
> 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.
by eru
3/5/2026 at 1:57:19 AM
True. I suggested global because it allows for scale with copy/paste designs, where things like nuclear could actually become viable.Where I am, we have a solidly aligned state government. There's no concept of consequences for anyone in power. They're paid by the local companies to pass laws to make competition legal. Some are investors. All corrupt. That's what you get with a solid political alignment.
by nomel
3/5/2026 at 12:32:18 PM
Vote with your feet (and wallet), and support anything that makes people voting with their feet easier.It's the McDonald's theory of policy: you don't vote on their burgers at the ballot box, you just go to Burger King or get a doner kebab, if you don't like it.
by eru
3/5/2026 at 12:20:24 AM
Australia I assume?by realityloop
3/4/2026 at 10:33:21 PM
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.https://velo.outsideonline.com/road/road-racing/tour-de-fran...
by 1-more
3/4/2026 at 11:28:28 PM
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.
by GuB-42
3/5/2026 at 12:23:20 AM
What a ridiculous idea, I love it.by zymhan
3/4/2026 at 10:26:02 PM
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 wayby jborichevskiy
3/4/2026 at 10:36:54 PM
Kind of, it's in bits and pieces here: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.
by alnwlsn
3/4/2026 at 10:52:43 PM
Any sense what the efficiency ratio was for your setup?by Waterluvian
3/4/2026 at 11:14:33 PM
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).
by alnwlsn
3/5/2026 at 12:57:11 AM
> 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.Cyclists' power output is sometimes reported as a 'power curve' - a chart with power on the vertical axis, and duration-of-that-power on the horizontal axis.
For example, a cyclist might be be able to produce 500W for 15 seconds; 350W for 1 minute; 270W for 10 minutes; 200W for 1 hour; and 150W for 5 hours.
by michaelt
3/4/2026 at 11:38:57 PM
Oh don’t sell yourself short. It can certainly be both! (:Thanks for sharing the details.
by Waterluvian
3/4/2026 at 11:43:31 PM
All in good fun of course, it has to be healthier than watching Youtube just sitting around normally.by alnwlsn