• Specific heat capacity of water: 4.184J/(gC)
• Average shower temperature: 37C
• Cold tap water temperature: T
• Shower head output: 2gallon/min = 7.57L/60s = 126ml/s = 126g/s

1s * (126g/s) * (4.184J/(gC)) * (37C - T) = 524J/C * (37C - T)

120Wh = 432000J

T = -787C

So I guess the math checks out if your city’s water supply temperature is way below absolute zero.

Scratch that, let’s assume the water actually flows, so T=0C. What water throughout do we need to achieve this level of power consumption?

1s * (X g/s) * (4.184J/(gC)) * (37C) = 432000J

X = 2791g/s = 44gpm

You would have to be showering with 17 showerheads simultaneously using showerheads that are rated at the highest legal flow rates in the US (2.5gpm).

Early 30s now. I’ve been on this path since I was 18, so I guess I’d be happy to hear that I stuck with it. I’d probably also be disappointed to hear that I’m actually kind of bad at it.