Unleashing potential energy in my EV

Bringing these rocks down from the mountain in my EV bought me one one free mile. The recent mountain regen thread in r/electricvehicles and my need for a few landscaping rocks inspire this post for your entertainment and cross-examination.

As you know, energy is Watt-hours or, in SI units, Joules = kg * m² / s² = kg * m * m/s²

So the mass of the rock times the height times gravity is the amount of potential energy available to regen.

Let's say they weigh 400 pounds total.

400lb * 0.45kg/lb = 180kg

180kg * 800m * 9.8 m/s² = 1.41MJ

Now convert to Watt-hours.

1.41MJ * 1Wh/3600J = 392 Wh

According to the internet regen is 60-80% efficient.

392Wh * 0.6 = 235Wh

That's roughly one free mile in my Model Y just for loading these rocks while I was 2600ft up the mountain. Just cost me a couple of deadlifts and some extra driving caution. 😂 You guys with Rivians in the Rockies can do a whole lot better!