4 ms·
The power density for gravity storage such as this is directly proportional to the density of the storage medium. Water is 1 tonne per cubic meter. Steel is 7.
by pkphilip 6y ago
The power density for gravity storage such as this is directly proportional to the density of the storage medium.
Water is 1 tonne per cubic meter. Steel is 7.9 tonnes per cubic meter. Lead is 11.34 tonnes per cubic meter - which means that in the same amount of space, you can store vastly more energy if you use these metals instead of water.
The initial cost of set up will also vary depending on the metal you use but lead is cheap.
Also, water evaporates etc.
- gkfasdfasdf 6y agoWow the density makes a lot of sense. But why stop at lead, depleted uranium is 19 tonnes per cubic meter (1.67 times as dense as lead)!
- pkphilip 6y agoCost / density. You quite literally want the cheapest dead weight. Cost of lead/tonne : USD 1900 (approx) Cost of Uranium/tonne: At least USD 60000 (approx regular uranium) even if you are able to source it.. and then you still have to build containment for this, get permits etc.. For that price, you could get much higher efficiencies if you went for a cheaper metal - even something like Tungsten which is extremely dense will be much cheaper.