The BIGGEST problem with clean energy

5:57 Replace the bricks with water, same principle like a steam engine, but with water instead of steam.
Also, I'd use large water globes or water cylinders, one above the other.
When energy goes in, the piston compressor moves water upwards, when energy comes out
another cylinder allows water to come in, and push the piston connected to a generator.
Easeh peaseh. And yes very energy efficient. But when energy comes at a surplus doing input,
well, you only need to look at the energy coming out, really.