- cross-posted to:
- videos@lemmy.world
- cross-posted to:
- videos@lemmy.world
So, Alec over the Technology Connections channel made an hour long video explaining the difference with kW and kWh (obviously with other stuff around it).
I’m living in northern Europe in an old house, with pretty much only electric appliances for everything. We do have a wood stove and oven, but absolute majority of our energy consumption is electricity. Roughly 24 000 kWh per year.
And, while eveything he brings up makes absolute sense, it seems like a moot point. In here absolutely everyone knows this stuff and it’s all just common knowledge. Today we went into sauna and just turned a knob to fire up the 6,5kW heaters inside the stove and doing that also triggered a contactor to disengage some of the floor heating so that the thing doesn’t overload the circuit. And the old house we live in pulls 3-4kW from the grid during the winter just to keep inside nice and warm. And that’s with heat pumps, we have a mini-split units both on the house and in the garage. And I also have 9kW pure electric construction heater around to provide excess heat in case the cheap minisiplit in garage freezes up and needs more heat to thaw the outside unit.
And kW and kWh are still commony used measurement if you don’t use electricity. Diesel or propane heaters have labels on them on how many watts they can output right next to the fuel consumption per hour and so on. So I’m just wondering if this is really any new information for anyone.
I assume here’s a lot of people from the US and other countries with gas grid (which we don’t really have around here), is it really so that your Joe Average can’t tell the difference between 1kWh of heat produced by gas compared to electricity? I get that pricing for different power sources may differ, but it’s still watt-hours coming out of the grid. Optimizing their usage may obviously be worth the effort, but it’s got nothing to do with power consumption.
So, please help me understand the situation a bit more in depth.
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People complaining about this video have clearly not watched much Technology Connections; I enjoyed it immensely. It’s right in line with how Alec normally does his videos. We who are loyal to the Great Alec expect the pedantic content.
In here absolutely everyone knows this stuff and it’s all just common knowledge.
Fair point, but basic physics has been a part of our education program for at least 60 years. Also for few years the ‘exchange priced’ or ‘market valued’ electricity has been somewhat popular and on the news, which adds up to the general understanding as if you know your stuff it means quite literal money as your bills are smaller. So, maybe ‘absolutely everyone’ is a bit of a stretch, but in general the majority of adult people understand the concept.
And also a ton of common folk understand it at least a bit on a deeper level as basic physics is included to studies beyond elementary school regardless on what you study. Sure, not everyone understands (or cares) how 3 phase AC in here adds up to 400V or why you need to have 2,5mm² wires for 16A fuse, but it’s still pretty common that people, specially in a separate house, understand how you can only pull 2300W out of a 10A circuit or 3600W from a 16A one (10 and 16A being the most common fuses in a household in here).
Also check out his other video on his Connextras channel where he basically suggests dismantling capitalism.
So I’m just wondering if this is really any new information for anyone.
It’s never wise to underestimate most people’s ignorance.
kW/kWh aren’t commonly used outside of electrical applications in the US, so people are less readily able to quantify and compare in other contexts. Looking at a variety of natural gas companies’ bills, you’ll get volume multiplied by a therm factor instead of simply using kWh; horsepower for not just cars but even electrical motors and pumps.
I think the average person will have looked at their electricity bill and put the basics together about watts and watt hours. As for comparison with natural gas, I think he didn’t touch on the real metric people then turn to- cost. Depending on the state it can be much cheaper to use gas vs electricity.
Yeah, electric motors are what I notice the most. Be it on washers/dryers, garbage disposals (which range from 1/3, 1/2, 3/4, 1HP) and more.
Saved you a click: power = rate of energy use (energy/time)
He says it so many times in so many ways that he actually starts to make it seem more complex than it is. You start wondering if you’re missing something, because you got it in 6 seconds but 12 minutes later he’s still talking about it.
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If you think the average person understands watts, you live in a bubble, straight and simple. You have a very skewed notion of the average person.
Yep that video is leagues beyond most peoples capabilities to understand. Thinking they already knew and understood it is crazy.
Nah, the video is pretty straightforward, but it’s presented in a way that most people would lose interest unless they’re actually into the subject matter. I see three problems with the video:
- it’s too long
- very few analogies
- mostly a talking head
Power vs energy is fairly simple with a good explanation. Power is simply the speed at which energy gets used up. For example:
- if you make a big campfire, it’ll use up your wood (energy) faster
- if you’re playing games on your phone, your battery (energy) will die sooner
- if you sprint, you’ll use up your energy faster than if you jog
That’s extremely intuitive. All a regular person needs to know is that simple concept, plus a way to measure it (the Kill-a-watt example). Boom, 5-10 min video.
But the talking head made it way more complicated by starting with gas. That’s just belabouring the point that you can increase or decrease power, which is already intuitive with batteries or things we can see (wood) or feel (tiredness).
They could then segue into gas, once the power vs energy issue is established. A can of butane is like a battery, and the valve (e.g. screen brightness, game vs texting) controls how quickly it’s used. We can compare gas and electricity directly because electricity can be turned directly into heat, just like gas can.
And then you segue into heat pumps. Basically explain how your AC/fridge works (i.e. moves heat instead of creating “cold”). Make a demo where you move heat vs create heat and show how much energy is used. As in, heat a room from 72F or whatever to 90F, one using a heat pump and the other using a space heater. Show how temps compare on both sides of the heat pump vs space heater (other rooms shouldn’t change w/ space heater). Then use that to show a real-world example of a house that swapped from furnace to heat pump to really drive the point home that moving heat is more efficient than creating it.
This is way beyond majority of peoples capabilities. Everything in your post and his video is, both are long too. Majority of people just do not care, otherwise we’d all be engineers.
The part about electricity is pretty short, just a few bullet points and a couple paragraphs. If it was video form, I could cover it in 2-3 min complete with visuals.
I don’t know why this video is so long.
All his videos are like that, he enjoys being long winded
Explaining to people learning to cook that oil is liquid pan that carries heat is just too mind blowing. The simple shit is wayyyyyyyyyyyyyyyyyyyyyyyyyyyyy beyond the average smartwatch wearing doof
We live in a world where people demanded (and succeeded) in having the Meteorological Service of Canada to report windchill as “feels like C” instead of, ya know, a measure of actual heat loss in Watts / M^2 / s
You say that like it’s a bad thing? I prefer not to dust off my slide rule everytime I want to know how cold it is out.
Yeah, just give me actual temp and wind speed, and I’ll get a feel for what’s cold by going outside.
Idk, I kind of like knowing how many layers of clothes I need to put on before I leave the house. Especially when the wind chill can make it feel like another -10°C pretty easily.
Same. I just look at the temp and wind speed and make an educated guess, erring on the side of more layers.
The first time they did the feels like scale… My father’s colleagues were involved. They took a sample of people and put them in wind tunnels and sprayed them with water and said hey how’s it going over there.
I wish more than anything I was joking right now.
I think you are greatly overestimating the basic functional knowledge of the general public…
In here absolutely everyone knows this stuff and it’s all just common knowledge.
Absolutely not. Not even close.
After watching the video it was a bit over explained. I think he got his point across in the first 10 minutes, though I am an engineer by trade.
I appreciate his rigour in explaining and it is a good refresher on the power/energy calculations.
Follow-up video idea: speed ≠ distance
The one that I think more people misunderstand is temperature Vs heat Vs something feeling hot/cold. One is a property, one is energy, and the other is the transfer of energy.
You know a nation of people who may not be able to articulate their understanding, but definitely have a high intuitive understanding of that?
We Finns.
100C sauna and no problem sitting on wood, but happen to touch something metal and oooh-weee.
Also same thing happens the others way around when it’s - 20c outside. I don’t think there’s many people in Finland who don’t have a core memory of what cold metal tastes like in winter, because of the resulting trauma. And it doesn’t even need to be metal to stick.
Nicely explained.
100C sauna???
It’s perfectly commonplace to have at least a 100 degree sauna.
I think something like 140 is around the hottest I’ve been in.
The air is that temperature, but there’s also a ton of moisture in the air. You can take it for a few minutes at a time, then optimally you go take a dip off a pier into a lake or the sea. When I was in that 140c sauna it was a proper wood heated large sauna at my confirmation camp, it was on an island in the Baltic so we could run out the sauna and jump into the Baltic Sea. It wasn’t warm at all, but the intense heat of the sauna having warmed all the top tissues and muscles, you get a sort of immunity to the cold. Which lasts for a little while, and when you start getting cold enough, you go back to the sauna, and because the cool water has now cooled the skin and muscles, you get a resistance to the heat for a while.
Rinse and repeat. Literally.
This cycle supposedly has benefits for circulation and muscles.
And having done it ton in my life I don’t doubt that at all.
Usually I have to settle for the sauna in my apartment though. (I live in a cheap rental but a sauna is default in pretty much all buildings built after the 90’s.) And then either going to balcony to cool off a while or take cool shower. It’s not as nice, but it’s more or less the same.
Although I don’t rip the most out of my electric stove to get the most heat. I have it set on pretty low and I just use a lot of löyly. Probably I’d say my normal saunas are maybe around 90-110 degrees at the most. A sauna below 80 degrees is considered a “Swedish sauna”, which is to say we mock them as not being strong and manly as us and so Swedes would be afraid of having a “proper” sauna.
And to be honest the Swedes are pretty on board with this whole stereotype I guess, seeing us as mute emotionally distant brutes. Here’s a cool Swedish commercial featuring a Finnish man. They made it. (that’s not the real title though just the yt video title)
I’d really like to try that someday
I believe, internationally, lots of places which have saunas also have pools or even cold pools. I imagine. Like high class gyms or smth.
But I’ve heard several stories of Finns being abroad and going to a sauna and being prevented from tossing water on the stones (löyly = it’s sort of the water and the heat that results from throwing it, roughly how you’d use “gas” in relation to cars, more gas can mean more petrol or pressing on the gas pedal harder, that sort of word), and the employees saying “you can’t do thaw to it’ll break the stove” because they don’t understand how saunas work.
And to do this to the best effect you need a proper löyly to the point you pour cold water from the löyly bucket on top of your head to bear it for a while longer for all the muscles to really warm up. And then for maximum shock quick jump to cold water, or sometimes just a snowbank. That’s common as well. Hurts like bitch though if you do it with the wrong kind of snow, like jumping on a bed of freezing razors. (The top of snow that was quite soft earlier had frozen and I didn’t see it in the dark and jumped into the bank and there was like a half an inch of raspy ice on top before I broke through to the softer snow. Or I just didn’t care being either so young as not to or so drunk as not to. Probably both.)
And if you’re gonna throw a strong löyly, or even löyly at all in a public sauna, it’s proper etiquette to ask for consent from everyone. Although now that I wrote that I have a feeling asking for consent in some non-Finnish public saunas may have a different meaning, as far as I’ve understood from popular media.
Yeah, what the hell is this video subject. I honestly thought this stuff was common sense.
Should be but search for “kwh per hour” and there’s plenty of people who seem confused by it all.
New Technology connections video drops:
I’m going to go buy a kill-a-watt.
I moved into a tiny home and got one for measuring the current draw of my kitchen appliances and keeping track of the cost of my electric space heater ($40/month so far, yeesh)
Do it, it teaches you things.
Most of your power isn’t going where you think.
Oh I love this stuff.
My dishwasher pulls over 1000W, but overall actual usage pales in comparison to my server cluster, which utilizes a multiple 35W mini PCs.
I started measuring a bunch of things in February (using zigbee-compatible smart plugs to HA), so here is a graph of the above for the entire month of March:
It was eye opening, to say the least.
Yeah, my rack is a beast too, especially since it runs 24/7.
I have PGE though, so I get absolutely reamed constantly, they play a lot of games so my solar helps me as little as possible.
Oh, I had a whole-house meter connected to my smart meter by zigbee, but then PGE disabled that a few years ago.
Worst part of california :(
I’m over here heating water in a kettle because of Technology Connections (and also pre-heating my dishwasher)
Its the midwest pragmatism that sells it.
I just do what he says because it sounds so practical.
is it really so that your Joe Average can’t tell the difference between 1kWh of heat produced by gas compared to electricity?
Most people don’t even know what a watt or watt/hour is. And have no idea how energy from gas relates to energy from electricity.
watt/hour
Oh yeah I’ve seen that used before, makes me cringe every time.
Anyway, do must people not go to high school? Or is stuff like that not part of the physics curriculum in some places?
A W/h either is a big problem or will be soon.
I mean that depends on the sign of the W/h as well as your W/h2 and higher orders too. Maybe you’re actually approaching zero watts :P
Even if it was covered in high school, I think because most people never use it again in daily life it’s easy to forget.
In my highschool physics was optional. You had multiple options for science credits and could get through without taking it.
Oh, in my country you have to take physics, chemistry and biology. That actually goes for middle school too. Plus geography which actually also contains geology. And math could be considered science I guess.
We have elective courses too, but all the basics are mandatory. That includes at least two foreign languages, history, our own language, literature (becomes separate subject from language in high school), music, art (including history of both), basic computer usage, shop class for boys and home ec for girls (with trades in between so us boys still got to cook and stuff, plus in elementary school everyone gets to knit and crochet IIRC). Oh and physical education unless you’re disabled, in which case you either get to watch or just do something else I think.
I’m actually sure I’ve missed something. These are all mandatory. You can do shit like folkdance or choir for electives, or many other things depending on school. I had philosophy as one of my electives lol
I think people in some countries (the US) don’t even know what they’re missing out on tbh.
It was kind of complicated at my high school; Depending on if you were on a college prep or prison prep track they would or wouldn’t bother trying to teach the science classes that had math in them to you. The “going to community college or trade school” program I was on gave you an option of chemistry or physics but I ended up taking both.
I never took chemistry, and I didn’t take a real physics course until college, though we had survey courses like “physical science” throughout school.
I don’t recall if we talked about watt hours specifically, but joules were certainly mentioned, though I doubt most people remember it. Most of the emphasis was on things like friction equations (given an ideal pulley and an incline with slope…), not real world things like understanding your electricity bill.
That said, I think most people intuitively understand the difference between instantaneous consumption and total consumption over a time period. They know playing games will drain their phone or laptop battery way faster than browsing the web, for example. They just tend to not stop and think about it and they simplify things in the wrong way (power rating on device), though a total energy estimate does work (e.g. when comparing refrigerators).
In our case, we had the pulleys and stuff too, but we had different modules and the later ones showed how they connect to eachother, so you start up with optics, mechanics (as in movement, not car parts lol), thermodynamics and electricity in middle school, then you get all of the same with a lot of new information in high school and also very basic nuclear physics, like atom models, electron levels and stuff. Essentially first you learn about power and energy in the context of movement and thermodynamics, and then later also electricity (at which point you’ll understand how heat at the power station converts to electrical energy at your home car charger converts to movement of your electric car, or similar with fuel and internal combustion engine car - of course the efficiencies are simplified greatly).
Of course you heard a lot of bored classmates go “But why do I have to learn this, I’ll never need it in real life”, but at least electrical bills are so much easier to predict when you know how power and energy relate.
I’m very happy with how the education system in my country works and how it prepared me for university (which I just didn’t have the attention span for) and life. It’s the reason I’m OK with paying a fair bit higher tax than I would in some other countries. Our income tax is at 22%, but a bunch is hidden from regular peoples’ view by making it part of the employer’s tax burden, meaning if I pay myself a decent salary, the tax rate is ~43% or if I pay myself less than I need to live I can make it 31-33% and get a visit from the taxman asking why I’m paying myself so little and paying the rest out in dividends. Luckily the economics course in high school included our tax system in addition to macroeconomics concepts, so I can navigate all this fairly easily. Not sure if that one was mandatory nationwide, or just part of my own school’s curriculum, because we basically had 3 types of subjects: Absolutely mandatory (like 60% of total course load), school specialty curriculum (like 20-30% of total) and then the rest was up to you to choose what you wanted to learn.
However, now they’re talking about making universities charge tuition from everyone as well as all kinds of cuts in other sectors WHILE raising taxes, despite the fact that we barely even use debt as a nation so if all that happens, I’ll find some creative ways to reduce my taxes or pay them in another country.
Okay, long ADHD rant about our education system aside, I do agree with you that most people will probably intuitively understand the differences. But man do I feel like some countries’ curriculums have been half-assed. It’s entirely possible to give young people an understanding of the universe from astronomical scales down to microscopical AND teach them things like tax systems, energy consumption calculations and other things that can be used in real life.
In our case,
Yeah, we had all that stuff too. This was many years ago, but I remember the electricity section being fairly basic, as in mostly covering how volts and amps interact (i.e. high voltage, low amps is way worse than low voltage, high amps, in terms of safety). And that’s really about it. Maybe we covered other stuff, but it really wasn’t important to go further, probably because I went to school before EVs and whatnot were commonplace.
I think my education was quite good. I was very much prepare for the university I went to, but that kind of meant we skipped some important stuff. For example:
the economics course in high school included our tax system
We didn’t really learn economics or taxes in high school. I mean, we discussed basic supply and demand, but that was more in the context of history than anything actually applicable to life (i.e. Great Depression’s impacts on supply and demand). I learned the vast majority of what I know about economics, investing, and taxes on my own because I’m interested in it. It just didn’t seem to make the cut for high school, where we learned a wide variety of other stuff, like biology, math, history, English, etc. A basic high school day was broken up into 6 periods, usually consisting of:
- math - start w/ geometry and end at pre-calc or calculus (depending on which track you took)
- history - US, European, world, etc
- english - literature, writing, etc
- foreign language - needed 2 years; select between Spanish, German, Japanese, or French (maybe one or two more); the other two years were electives IIRC (but more restrictive than the next group)
- electives - PE, shop, etc; there were several options, no guarantees as to what people took
- science - biology, chemistry, physics, etc
I did two years at the high school and two years at the local community college so I could get a 2-year college degree at the same time as my high school diploma. That was pretty rad, but I wonder if maybe I got super compressed education since I had about half the class time as my peers (about 3 hours/day vs 6), but we had more reading at home, which I think made up for it (I’d spend 3-4 hours/day studying vs 1-2 hours from regular high school).
However, at the end of it, there were some gaps:
- didn’t know how taxes worked - pretty easy to learn later, but I did need to teach myself (I think we had a PF elective option)
- didn’t know how economics worked - basically anything at the government policy level was a black box - we covered basic supply and demand, but not how the fed creates money, tariffs, etc, outside of some brief mentions in US history
- very basic overview of how consumables like electricity and natural gas work - i.e. what a watt hour is, or how to compare electricity and gas; school mostly stuck to principles and theory, not practical things like understanding your gas bill
I don’t think that was a failure per se, it just wasn’t deemed important since the whole point of high school was to prepare you for college, and anything that didn’t help with that seemed to get dropped. I think this is unfortunate, and that high school should have you ready to make a decent wage outside of school (i.e. finish w/ marketable skills, like the German system does).
Absolutely mandatory (like 60% of total course load), school specialty curriculum (like 20-30% of total) and then the rest was up to you to choose what you wanted to learn.
Yeah, we were pretty similar, except we didn’t have “school school specialty curriculum” since I went to public school, and public schools are standardized in what they teach. So we had something like 70-80% as mandatory curriculum, which prepares you for college, and 20-30% electives, which hopefully prepare you for life. I did shop (make stuff out of wood), home ec (cooking), drawing (nearly failed, I suck at art), and visual communications (graphic design, photography, etc survey course).
I actually also went before EVs were commonplace, I was more referring to the fact that you got the knowledge to instinctively make that connection (and probably nowadays they have exercises on the subject too).
Yeah, we were pretty similar, except we didn’t have “school school specialty curriculum” since I went to public school, and public schools are standardized in what they teach
I went as, I believe, the second or third year of an experimental new system under which schools offered different specialty tracks that were up to the schools themselves to design. We had like a science-focused track, an art focused one, and then one that was basically “cool shit we threw together” that included stuff like psychology and law (first all kinds of basic legal concepts, which in of itself was a really big course, and then a second course focusing mostly on Estonian contract law, as that is hugely important, as well as some looks into stuff like employment law, consumer protection law, etc. This probably was not too common in schools in our country either, we just had a really awesome principal that was a former lawyer and took it upon herself to teach all this.
As of the 2024/2025 school year, the system is abolished and now the student gets to pick more of the electives, instead of the school tracks. So more freedom of choice, which I reckon is a good thing. The mandatory basics are still really solid.
He’s making a point about instantaneous versus overall energy use, which it sounds like you already understand. “Power” and “energy” are already kind of loose terms, which could make that conversation confusing IMO.
But for anyone confused by this:
For the typical energy consumer, Watts (W, kW) are relevant when considering circuit capacity. Otherwise, Watt-hours (Wh, kWh) is likely the metric you’re looking for when considering energy use.
Concretely, your coffee maker might pull 1.2 kW while in use, more than most appliances in your house, yet it probably represents a minuscule portion of your electric bill, perhaps less than 1 kWh, since it only needs to boil a small amount of water with each use.
How are energy and power “loose terms”? Energy might be difficult to fully explain rigorously, but it’s one of the fundamental elements of our universe. And power is just energy over time
How are energy and power “loose terms”? Energy might be difficult to fully explain rigorously, but it’s one of the fundamental elements of our universe. And power is just energy over time
Well, you yourself just provided the example, since your definition of energy and power are the inverse of the definitions used in the video.
It’s the fact that people use them differently or interchangeably that makes them “loose” IMHO.
