It’s a nice idea but impractical. Energy = mass x gravity x height

Say 10 tonnes of water pumped into a massive 20m high tower… E =10000x9.8x20 Joules. ≈ 2 mega joules.

Theres 3600 joules to a watt hour so divide that and you get:

≈ 550 watt hours (0.55kWh) of storage (assuming perfect efficiency of the turbines). About the same a half a dozen big cordless tool battery packs.

Thank you for actually answering OPs original question and the follow up.

Mathologer (YouTube did a good explanation of creating cube algorithms). Search something like: mathologer design rubiks algorithm

No. I see where they’re coming from. You’re not embracing the spirit of The Fucking Corolla.

You think you’re replacing just a radio but who knows what kind of imbalance you’ll introduce.

It’s a Corolla, without Bluetooth. That’s the rules. Dont fuck with it.