From seawater to drinking water, with the push of a button

Re:From seawater to drinking water, with the push of a button by zmgsabst on Friday April 29, 2022 @02:14AM (#31201978)

This is what the other person was trying to say:

“Watt” is the unit of power which is the rate of change in “joules”, which is the unit of energy. In the way that “velocity” is the rate of change in “position”.

1w = 1J/s

A “watt-hour” is another way to represent joules/energy by integrating watts/power over time.

30 watts * 30 minutes = 15 watt-hours or 54 kJ.

30 miles/hour * 30 minutes = 15 miles or 24km

> Does it matter if those 3 watts are provided over an hour via a 3wh power source or over 10 minutes via a 16wh power source?

You have the units backwards:

You can get 3wh from 1 hr @ 3w or 10 min @ 18w.

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Re:From seawater to drinking water, with the push of a button by MichaelApproved on Friday April 29, 2022 @12:49PM (#31207565)

Thanks. I’ll need to read that a few times because I struggle with this constantly.

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Re:From seawater to drinking water, with the push of a button by zmgsabst on Friday April 29, 2022 @01:00PM (#31207712)

I think part of the confusion is we don’t normally have units for rates of change.

So let’s create one: the “walk” is the speed a person can walk — 3mph.

Then I can say the store is “3 walk-hours away”, even if I normally drive the 9 miles with my car.

3 walk-hours = 3 hours @ 1 walk = 18 minutes @ 10 walk (or 30mph)

Batteries are rated in “watt-hours” for the same reason:

3wH = 3 hours @ 1 watt = 18 minutes @ 10 watt

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Re:From seawater to drinking water, with the push of a button by MichaelApproved on Monday May 02, 2022 @09:07AM (#31234658)

Then I’d say you walked 1.5 miles in 30 minutes. The equivalent to saying generated 15 watts of power over 30 minutes from a panel that’s providing 30wh of power.

I’m assuming what I’m saying is wrong, I just can’t spot it. Thanks for the help.

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