Yup, internal space is a very valid issue, given that cheap weights are probably big. I'd worry about oscillations for a high-up, suspended weight too. Regardi

Yup, internal space is a very valid issue, given that cheap weights are probably big. I'd worry about oscillations for a high-up, suspended weight too. Regarding justifying the cost--obviously depends what the cost is. If it's really just the generator, cabling etc, it might work as a short term load balancer. I saw somewhere about GE investing $X millions to smooth turbine output over 5min intervals.