The amount of space needed is just gargantuan. Hydro only works because you can declare that an entire valley is now energy storage, in one fell swoop. As soon as you have to construct each unit of storage instead of letting nature do it for you, it becomes completely impractical. Yes you can store energy in a tower of concrete blocks... if you can make enough concrete blocks to fill a lake.
replyAFAIK problem with all physical energy storage solutions is just one of cost.
replyBatteries are scheduled to become so cheap that these type of physical storage systems just won't be able to keep up in terms of cost.
Most pumped hydro projects are now put on hold as batteries have been coming down.
I've recently learnt about sodium ion batteries, such as this uk company:
replyhttps://www.elevenenergy.co.uk/#sodium-ion
They are larger than lithium batteries, but potentially cheaper and better performing around temperature extremes.
It looks like Energy Vault, the people with the tower crane and big stack of concrete blocks scheme, gave up on that. Energy Vault is now selling large battery systems that actually work.
replyThing is that you need incredible large masses in incredible heights.
replyExample: Lifting a 10-metric-ton stone by 36 meters stores just about 1 kilowatt-hour (kWh) of energy. This is roughly equivalent to the capacity of a small power station used for a camping trip.
If you’ve got very large containers of sand you can just store energy as heat instead, especially if you’re planning to use the energy for heating eventually: https://en.wikipedia.org/wiki/Thermal_energy_storage
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