Solar makes electricity. Electricity makes pressure. Pressure helps with lift.
The compressed-air lift system is the companion to the gravity-block concept. Gravity is good at pulling a heavy block down. The question is what happens after the block has dropped. How does the system control it, recover it, reset it, or assist movement underwater?
In the Solar Power Rig manga universe, the answer is compressed air. Solar panels on the old offshore rig power compressors. The compressors fill pressure tanks. That stored air can then be sent through pipes, hoses, valves, lift chambers, or underwater equipment to help manage buoyancy and recovery.
Solarjack calls it “putting the sun in a tank.” The engineer calls that phrase “not technically acceptable, but emotionally useful.”