Pumped Hydro Energy Storage across Australia, page-125

How can a capacitor store power for more than a few seconds ?
Genuine question as I am not an electrical engineer .
Someone mentioned pumped hydro for domestic use using a tank on a stand as the potential energy source , and it was refuted to be possible by another poster as a tank stand would not be high enough to spin a turbine which is correct.
A possibility would be to use a pressure tank to store water under pressure , and then release it when needed to a pelton wheel , would mean a pump stand would not be necessary , but had the high CAPEX involved with having to have a pressurised container for a small storage volume , that would have to be pressure rated and signed off on .