Steel is 36 cents per pound. Assume you can move it up and down 300ft (30 story building). This will get you 1pound * g * 300ft of energy storage. This comes ou

Steel is 36 cents per pound. Assume you can move it up and down 300ft (30 story building). This will get you 1pound * g * 300ft of energy storage. This comes out to 300,000 USD/kWh, about a 1000 times more expensive than Li-ion batteries, per kilowatt-hour.