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points by OJFord 1 day ago | 0 comments
Pretty sure GP understands that, their point being you can't just wave away 'per unit time' when talking about it relative to generation, it matters.
[–] buran77 1 day ago
"30kW per day" makes no sense. It's like saying "100km/h per day". W is a unit of power, Wh is a unit of energy.

It's unintuitive because a guy named Watt decided "Joule per second" is Watt, so the intuitive units Joule and Joule per second got turned on their head to W times hour and Watt. This is opposite to usual intuition of distance and speed for example, km and km/h. If I redefined the km/h to a "tick", then a km would become "tick times hour".

If you want a "better than nothing" but imperfect analogy, Wh is how much water you have in a bottle, and W is how quickly you can get the water out.

[–] LtdJorge 1 day ago
The naming of the unit is posthumous
[–] OJFord 9 hours ago
Where are you getting "30kW per day" from?
[–] ffsm8 18 hours ago
And yet all utilities of the world decided to use kWh as the thing to measure. Also basically all smart measurement devices settled on this being the default to show. Exactly in the way he used it here, kw per day, kw per week, kw per month, kw per year.

This discussion seems super silly, considering he's just using the measurement that the industry adopted decades ago...

Are y'all just coming out of a time travel device from the 70s or something?

[–] buran77 12 hours ago
> Are y'all just coming out of a time travel device from the 70s or something?

I'll put aside the two-bit attitude and that you don't know that power (W) and energy (Wh) were measured in the exact same way in the "70s or something" (just ask your grandparents).

> the world decided to use kWh as the thing to measure

> kw per day, kw per week, kw per month, kw per year.

There is no such thing as "kw per day". You switched between units from one sentence to the next? The world indeed measures kWh per day, not kW per day. The lazy use kW per day as a shorthand and drop the "hour" to speak faster. The less educated measure "kW/day" because they don't understand the concepts and just parrot a common mistake. When they say "kW/day" what they should actually say is "kWh/day". It's where the unintuitive part comes in, they omit the "hour" or assume kWh is the same as kW/h, like km/h, instead of kW times h.

> This discussion seems super silly, considering he's just using the measurement that the industry adopted decades ago...

The industry adopted the correct measurement units decades before your grandparents were born. You just have a hard time understanding because it's easier to do cheap snark.

Unlike those people from the 70s or something, y'all live in a world with all the information you could want at your fingertips, you even have machines (AI) that digest it for you, and you even had me bothering to give an explanation a kid could process. To be unapologetically ignorant today is the same as being intellectually incompetent, ffsm8.

[–] SamBam 1 day ago
"30kWh per day" isn't waving away anything.

30kW is a rate.

30kWh is a measure of energy, about 100MJ.

30kWh/day is a rate again, 100MJ/day.

It seems clunky, but it's a way energy usage in a house is typically measured.

[–] OJFord 9 hours ago
Thanks, I went to school too.

I said the time period matters when you're talking about it relative to generation. 30kWh over the course of a day is very different to 30kWh over ten minutes.

[–] SamBam 3 hours ago
Um... My reply was to you saying "I'm sure GP understands that [explanation]"

Except that GP (pmontra) had asked "Is that 30 kW each hour of the day?"

Clearly someone asking that doesn't understand what kWh/day means, and since you were backing GP, it seemed reasonable to guess that you might not understand either.

[–] stavros 21 hours ago
Wh is a unit of energy. They're saying how much energy they consume per day.
[–] OJFord 9 hours ago
And I'm saying how much energy you use 'per day' is vague when you're talking about it wrt your energy generation. If you have 30kW solar and no battery then 'all my usage is during peak sun' and 'all my usage is over a split second at 1am' and 'my usage is uniform across 24h', etc. are all very different even if all amount to 30kWh usage 'per day'.
[–] imtringued 21 hours ago
No, their point is wrong either way and there is no way to steel man it without saying the comment is extremely poorly articulated.

30kWh is 1.25kW for 24 hours or 30kW for one hour.

30kW every hour means 720kWh per day. 30kW all day is also 720kWh per day.

The comment is nonsense.

The only way you can steel man it is by saying he isn't concerned about the 1.25kW, he is concerned about the swings, but he said 30kW twice for two different time spans so that can't be it either.