• kELAL@lemmy.blahaj.zone
    link
    fedilink
    English
    arrow-up
    8
    ·
    5 months ago

    I felt a great disturbance in the Force, as if thousands of physics teachers suddenly cringed and started yelling “Get your units right!”.

    spoiler

    Wh is a unit of energy (1 Wh = 3.6 kJ) and by nature cumulative. And cumulative units can’t peak, so Whp [sic] is impossible as a unit. What you really meant is Wp, as W is a unit of power (1 W = 1 J/s), which is a momentary value and momentary values can peak.

    • 31ank
      link
      fedilink
      English
      arrow-up
      2
      ·
      5 months ago

      Luckily I’m not in school anymore xD

      But thx for correcting me, edited my post, should be correct now :)

    • elrik@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      arrow-down
      1
      ·
      5 months ago

      I’m sure the original comment had incorrect units as used, but this explanation that cumulative units “can’t peak” seems wrong.

      If you consider the total stored energy (Wh) over time of a solar-battery system under load, there certainly will be peaks or, in other words, maximal excess capacity of the system.

      So no, it’s not impossible to define a unit of Whp as such. “Cumulative” and “momentary” values are not exclusive and also do not have any bearing on whether a function of such values has maxima and minima.