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A comment on Towing a Tesla at 70 MPH replenishes battery at fast charger rates. Parent comment

Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by rpmisms on Monday June 21, 2021 @05:49PM (#27584975)
Maybe this could be applied to water towers? That's a lot of potential energy just sitting there.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by Guvante on Monday June 21, 2021 @06:04PM (#27585142)
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.

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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by hnuser123456 on Monday June 21, 2021 @06:27PM (#27585349)
https://www.wolframalpha.com/input/?i=gravitational+potentia...

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

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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by Guvante on Monday June 21, 2021 @11:27PM (#27587625)
Must have been a bad calculator. It claimed 1000L/s was 400W.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by avalys on Monday June 21, 2021 @06:21PM (#27585300)
You’re telling me I could fill a typical water tower in 1 hour with a 500 W pump running off a kitchen outlet?
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by ClumsyPilot on Monday June 21, 2021 @09:04PM (#27586757)
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?

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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by bigiain on Monday June 21, 2021 @09:18PM (#27586859)
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.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by ClumsyPilot on Monday June 21, 2021 @09:40PM (#27587005)
Sounds like they confused W and kW then?
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by rightbyte on Monday June 21, 2021 @07:13PM (#27585773)
Really good sanity check concept!
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by Guvante on Monday June 21, 2021 @11:34PM (#27587683)
Calculator said 400W for 1000L/s and my mental sanity check missed the duration units and thought 400W can move a ton of water.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by Aperocky on Monday June 21, 2021 @06:21PM (#27585304)
You probably made a mistake somewhere.

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

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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by NemuriBaku on Monday June 21, 2021 @06:30PM (#27585368)
I suspect the k in kWh leads to the occasional factor of 1000 error.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by dharmab on Monday June 21, 2021 @05:56PM (#27585052)
Water towers are already used that way- water is pumped in during off-peak time and used during peak time.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by mikepurvis on Monday June 21, 2021 @07:03PM (#27585686)
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.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by ClumsyPilot on Monday June 21, 2021 @09:05PM (#27586762)
Pressure is energy
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by bigiain on Monday June 21, 2021 @09:23PM (#27586898)
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.)

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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by sigstoat on Monday June 21, 2021 @05:57PM (#27585068)
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.

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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by twobitshifter on Monday June 21, 2021 @09:27PM (#27586915)
Before electricity there were many household appliances that operated on water pressure.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by mr_toad on Monday June 21, 2021 @10:51PM (#27587414)
Water wheels were used in industry for over two thousand years.
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Re:Towing a Tesla at 70 MPH replenishes battery at fast char... by cobaltoxide on Monday June 21, 2021 @05:57PM (#27585062)
Not enough volume.

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

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