- 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.
He’s making a point about instantaneous versus overall energy use, which it sounds like you already understand. “Power” and “energy” are kind of loose terms IMO, which could confuse that conversation a bit.
But for anyone still scratching their head:
The typical energy consumer need only consider watts (w, kw) when accounting for circuit capacity. For example, if your hair dryer pulls 1600 watts, don’t use it on a 1500 watt outlet, or you will likely trip the circuit breaker.
Otherwise “watt-hours” (wh, kwh) is likely the metric you’re looking for when considering energy use. This is a certain amount of power drawn over a period of time, where 1 watt over 1000 hours and 1000 watts over 1 hour are both equal to 1 kilowatt-hour (kwh), which is the standard unit you likely see in your electric bill.
It’s why low but constant power draw can significantly impact energy use. For example, a typical laptop pulls fewer than 100 watts, lower than many appliances in your house, but if it draws that much power all the time, it might significantly impact your electric bill. Conversely, an electric kettle / coffee maker might pull as much as 1300 watts while in use, more than most appliances in your house, yet it probably represents a minuscule portion of your electric bill, since it only runs long enough to boil a small amount of water with each use.
Edit: include tea drinkers, add more concrete examples
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.