this post was submitted on 30 Mar 2025
430 points (95.9% liked)

Technology

70266 readers
3969 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related news or articles.
  3. Be excellent to each other!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
  9. Check for duplicates before posting, duplicates may be removed
  10. Accounts 7 days and younger will have their posts automatically removed.

Approved Bots


founded 2 years ago
MODERATORS
 

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.

top 50 comments
sorted by: hot top controversial new old
[–] [email protected] 2 points 1 month ago

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.

[–] [email protected] 20 points 1 month ago (1 children)

In here absolutely everyone knows this stuff and it’s all just common knowledge.

[–] [email protected] 1 points 1 month ago

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).

[–] [email protected] 8 points 1 month ago

Also check out his other video on his Connextras channel where he basically suggests dismantling capitalism.

https://m.youtube.com/watch?v=Y2qSaD1v4cQ

[–] [email protected] 8 points 1 month ago

So I’m just wondering if this is really any new information for anyone.

It's never wise to underestimate most people's ignorance.

[–] [email protected] 0 points 1 month ago

I started to watch this video and gave up mid way. It spends like 15 minutes on gas stoves. Maybe I’ll revisit it.

Btw, I really liked his other video on microwaves.

[–] [email protected] 16 points 1 month ago (2 children)

Saved you a click: power = rate of energy use (energy/time)

[–] [email protected] 12 points 1 month ago

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.

[–] [email protected] -4 points 1 month ago (1 children)

I haven't watched it but its really simple. If you receive 1kW within 1hr and you compare that amount of power to 1kW over one second things are much different. The first is like a nice heater in a cold winter night...nice steady energy, a little bit of power. The second is like hell hole, tons of energy but still only a little bit of power. Power is the ability to do work or simply move things. Energy is the total amount of moving things regardless of the actual power used. So if you toasted a toast, that was a lot of power delivered quickly, but you could also do all that work slowly over centuries and eventually end up with the same molecular arrangement using the same amount of energy.

[–] [email protected] 2 points 1 month ago (1 children)

“1kW within 1hr” isn’t power. That’s energy.

“nice steady energy”? You mean nice steady power, right?

“The second is like hell hole, tons of energy but still only a little bit of power.” No. They are both precisely the same energy.

“So if you toasted a toast, that was a lot of power delivered quickly.” No. That is a lot of energy delivered quickly.

I typically wouldn’t be pedantic about this, except that this is precisely the point the video is making. These two unit types are often confused.

[–] [email protected] 2 points 1 month ago

“1kW within 1hr” isn’t power. That’s energy.

The watt is always power, not energy. I'm assuming OP here got some prepositions mixed up and meant 1 kW delivered for 1 hr. That amounts to an energy of 1 kWh.

The second is like hell hole, tons of energy but still only a little bit of power.” No. They are both precisely the same energy.

No, they are the same power. The energy in the case where 1 kW of power is delivered for 1 hour is 1 kWh. The energy in the case of 1 kW delivered for 1 s is about 0.28 Wh.

If instead 1 kWh was transferred over the course of 1 hour, that is an average power of 1 kW (but does not have to be uniform, without more information we can't know the power profile). If 1 kWh is transferred over the course of 1 s, that is an average power of 3.6 MW which is the example I think OP was getting at (ref. hell hole comment).

[–] [email protected] 15 points 1 month ago

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.

load more comments
view more: next ›