For those interested in the numbers on pumped hydroelectric storage, we can get more energy by increasing ‘head’ or the distance that the weight falls, from 6 meters to up to 500 meters for some of the largest projects (and we could in theory go bigger).
Let’s pick a more reasonable number like 60 meters:
Calculations on Hydroelectric Energy Storage
For those interested in the numbers on pumped hydroelectric storage, we can get more energy by increasing ‘head’ or the distance that the weight falls, from 6 meters to up to 500 meters for some of the largest projects (and we could in theory go bigger).
Let’s pick a more reasonable number like 60 meters:
MASS/house = 15 kWh/house / (9.8 m/s² × 60 m) = 91,836 kg/house = 91 m^3/house
Let’s say we have a dam with ~20 meters of water level fluctuation (drawdown). Then that’s 5 m^2 per house of surface area.
As a sanity check, Bath County Pumped Storage Station in VA stores about 24000 MWh/ 30 KWh/house = 800,000 houses worth of energy.
800,000 houses * 5 m^2 = 4 km^2
The Bath County reservoir is about 1km^2 so we’re in the right range here (the reservoir has a little more drawdown and a way bigger head).