A different way to use solar

[plumber]

The two ideas I've mulled over for years are:

 

#1. Using solar insolation to lift water, just through evaporation at a low level and then condensation at a higher level. Basically it's ~ :)

 

I like this thread, along the lines of lifting water...I stumbled upon the opposite. I am amazed at how much force is needed to keep a air filled receptacle submerged under water and the force generated when released. The energy to compress this air is small and there are many ways to turn a compressor.

[alexander]

Plumber, so you are proposing something like a piston-like design that will use compressed air to power a bobbing float that will sink, then be filled with compressed air and raise, release the air and sink again, and repeat... question is though, whether one will extract enough usable energy from the stroke to power the compressor and still make some energy...?