Domestic hydroelectric battery and storage

[Colinx]

Hello,

I have a large plot of land on two levels, is creating my energy reserve via a large water reserve feasible?
The idea would be to have two tanks, one at the top and one at the bottom, it would be very easy to set up with flexible tanks, to place a pump and a turbine between the two levels. The pump would operate when there is photovoltaic overproduction and the turbine would restore energy when there is not enough sun. We can imagine two pumps and two turbines depending on the quantity of energy to take or charge, as well as a battery to act as a buffer. All with a few valves and a little automation,

Now on paper, a simple Google search gives me this calculation: 5m (height difference) x 14L/s (flow) x 9,81 (gravity) x 0,75 (efficiency) = 515 watts of power.
This is where I have a doubt, 14L/sx 60 seconds x 60 minutes = 50.000l in an hour? This is good, this volume seems quite manageable to me.
On the other hand, if it is to get only 500Wh out of it, that is of no interest, I may have a maximum difference in height of 10m, so for 50.000l that would bring the capacity to 1.000Wh, barely enough to do laundry.
Have I made a mistake somewhere or is this the sad reality?

[izentrop]

These are theoretical figures corresponding to much more powerful models.
A low height 500 W turbine requires a flow rate of 45 l/s https://www.energiedouce.com/hydro-turb ... 02510.html
Or have more elevation gain
And the efficiency of a lifting pump is much lower.

[sicetaitsimple]

Without wanting to be a killjoy, especially since I really like hydraulics (my first job was in this field), have you just thought about the cost of the equipment and their installation which would be necessary
to carry out your project?
Frankly, there are individual domestic batteries of 5kWh or more on the market today which in my opinion would meet your needs more easily, simply and for less money, if it involves "mopping up" photovoltaic surpluses. .
But I would not want to be the gravedigger of the 7th STEP in France (if you are in France)

Complement: your figures are good, except the efficiency of 0,75 which corresponds to very "sharp" machines

[Remundo]

I actually believe that Lithium batteries will restore 85% of the stored energy with much more optimal maintenance, volume and operation.

Hydraulic storage is justified for GWh, but not for a few kWh.

[Colinx]

Thank you for your answers, too bad it would have been a great project.
Concerning lithium, I don't really like the chemical, electronic side, dependence on the manufacturer,... But we actually have to face the facts.

[Remundo]

your calculation is correct, even if the yield you propose is a tad optimistic.

You realize the volumes mobilized, in fact for a meager kWh recovered.

But nothing stops you from trying the adventure.

There are now "2nd life" batteries, reformed for EVs, they can nevertheless still provide good service in stationary storage.