Could someone please help me out here. I'm doing a project on a wind powered pumped storage unit. A pump will pump fluid from a low tank to high tank and the Head is 2 meters. When the high tank is full the pump no longer pumps and the high tank begins to drain. This then turns a turbine which powers a small LED. The tanks are 50 litres and the high tank will be fully empty after 1 hour. I need to compare the power output of the above system to a system where the high tank is replaced with a hydraulic bladder accumulator. Could someone please tell me how i determine which size accumulator i need. And any else important you think I should know.

Any help is greatly appreciated.
Thank you

the hydraulic bladder will have high pressure at its fully inflated size
and zero pressure when deflated.
so it will be the equivalent of a tall narrow tank where its static pressure when full is the same as the bladders pressure when inflated and will have no water and zero pressure when empty.
so your calculations will roughly calculated on the average pressure delivered but this will not take into account the inefficiencies of the lower flow as against the higher pressure and flow
unless you are expert in algebra

Ah, I came too late. What he said.

- A hydraulic bladder generally works at 300 bar as compared to 0.2 bar with your two tanks, so its volume is (very roughly) 1500 times more efficiently used.

- When emptied of oil, the hydraulic bladder doesn't have zero bar pressure but something like 200 bar. It's roughly a constant-pressure accumulator, except that the nitrogen's temperature varies if oil is stored or extracted quickly.