@notsoloud @Amgine @bazcook The potential energy from elevated water is calculated using formula
mgh. Where result is in Joules; m is mass in kg which for water = litres; g=~10m/s2 h=elevation in meters. To convert to kWh=(mgh)/3600000. Let’s group mh and call it litre-meters. So you need ~ 360000 litre-meters of water to equal 1 kWh of storage. An Olympic sized swimming pool has 2.5M litres so 1kWh=0.144OSP-meters.
My 2026 modelling for my home shows I would need 3500kWh of seasonal storage for solarPV. Assuming my home roof to ground is ~10meters.
So I would need to pump 3500*0.144/10 = ~50 Olympic swimming pools worth of water to my roof height to meet my single home’s seasonal storage requirements.
IEA states that globally we have 8.5TWh of pumped storage. My modelling for California renewables+grid batteries for 2026 is showing that it would need an additional 450GWh of seasonal storage just to power a load profile equivalent to a 1 GW 24/7 data center.
That is 450/8500=~0.05 or 5% of global installed pump storage/GW
IMO believing pumped storage will enable renewables to produce firm power is at best a fantasy not supported by simple physics.
#pumpedstorage