[rpmisms]

Maybe this could be applied to water towers? That's a lot of potential energy just sitting there.

[Guvante]

So I did the math and the average water tower holds something like 1/2 kWh worth of power. (50m tall, storage of 1m gallons, efficiency of 90%)

Hydro power storage is fantastic but needs truly ridiculous amounts of water and height deltas to make sense.

[hnuser123456]

https://www.wolframalpha.com/input/?i=gravitational+potentia...

I got 450 kWh? Maybe you meant 1/2 MWh

[Guvante]

Must have been a bad calculator. It claimed 1000L/s was 400W.

[avalys]

You’re telling me I could fill a typical water tower in 1 hour with a 500 W pump running off a kitchen outlet?

[ClumsyPilot]

500W is a lot, it is hypothetically enough to move 10 liters of water 50 meters up every second. A motor on a cycle an electric bike is 250w.

A kitchen tap provides like what, 0.2 liters per second?

[bigiain]

So in an hour that's 36000L of water pumped up into the hypotheticals 1 million gallon tank. Right on the three orders of magnitude short that a previous commenter pointed out.

[ClumsyPilot]

Sounds like they confused W and kW then?

[rightbyte]

Really good sanity check concept!

[Guvante]

Calculator said 400W for 1000L/s and my mental sanity check missed the duration units and thought 400W can move a ton of water.

[Aperocky]

You probably made a mistake somewhere.

3.8Mg * G * 50m ~ 1700M Joules which is about 500kWh.

[NemuriBaku]

I suspect the k in kWh leads to the occasional factor of 1000 error.

[dharmab]

Water towers are already used that way- water is pumped in during off-peak time and used during peak time.

[mikepurvis]

Right, but that's about maintaining pressure and supply when everyone wants a shower at the same time in the morning, not about harvesting the energy of it all flowing downhill.

[ClumsyPilot]

Pressure is energy

[bigiain]

Nope.

Energy is force times distance. You need to know more than just pressure to calculate energy.

(A bicycle tire at 120psi has a lot less energy than a truck tire at 90psi.)

[sigstoat]

pumped storage systems are so large as to be geographic features.

there isn't much energy in a water tower. and that water is already doing work, pressurizing the water system.

[twobitshifter]

Before electricity there were many household appliances that operated on water pressure.

[mr_toad]

Water wheels were used in industry for over two thousand years.

[cobaltoxide]

Not enough volume.

And you have to maintain water in the tower in order to keep the water distribution system pressurized.