Well, thats how "calculating" and "doing" differ, I guess. Might be worthwhile to take a step or three back and see if you can reproduce the values used originally.

Things like head, flow volume, etcetera.

It could simply be that some prior "expert" either miscalculated or was not much of an "expert"

Quoting like you did leads me to believe that person was inexperienced.

I am no expert in anything but that looks like something a college professor would write up rather than saying "23KW of energy is available".

Its your baby so do what suits you.

Tom

Torque is decided by the speed for a given power. Each stage of conversion is less than perfect so you will loose a little in the gearbox so your input to the generator may be down to 22kW. Efficiency of 93% for a 20kW alternator is good going if you can manage it.

How accurate the 23kW calculation is is another matter I can only take that as given.

Can you explain what that is meant to mean?

Have you tried this and found that you can't get near the 20kW or is just some speculation where you are still confused about the issue of changing torque with speed.

As I said before I can only take your figures for the predicted 23kW. If you really have 23kW available at 100 rpm then you have 23kW available at 250 rpm with reduced torque.

As I see it from your original statement you have 2000Nm at 100 rpm ,if so you have 20kW. If you mean a static torque of 2000Nm and a speed of 100rpm then you don't have the details to calculate power.

Unless you can explain properly what you have and  what you are bothered about there is little hope of help.