The wet air question is an interesting one. It seems like the compressed air would have more moisture in it than a piston-driven compressor, but at the same time having oil-contaminated air is problematic for moisture removal systems, especially dessicant-based ones. So you might need more thorough moisture removal, but with the dryer system having more life.
As far as efficiency goes, it's hard to tell because it's mostly a paper-company at this point and they don't have much in the way of product. Another press release mentions they can provide large volumes of air which usually translates to efficiency. The major source of work done in their system is to accelerate the water, so if you want more air, accelerate more water. It sounds pretty efficient to this armchair critic.
The other press release mentions they are targeting 10hp and 20hp systems, and 100hp systems are feasible. I'd imagine 10hp is where industrial compressors start.
[edit] Found a press release from 2014 where they claim better energy efficiency than conventional methods. This really does sound like a breakthrough.
If you look at the linked article in TFA that discusses the trompe it claims that the air that comes out is completely dehumidified. I’m not sure how that process works but I guess big, if true.
The work done accelerating the water doesn't seem to be recovered anywhere...?
I would assume that to get any kind of respectable efficiency the high pressure water needs to go through an energy recovery turbine before being cooled and reused.
The wet air question is an interesting one. It seems like the compressed air would have more moisture in it than a piston-driven compressor, but at the same time having oil-contaminated air is problematic for moisture removal systems, especially dessicant-based ones. So you might need more thorough moisture removal, but with the dryer system having more life.
As far as efficiency goes, it's hard to tell because it's mostly a paper-company at this point and they don't have much in the way of product. Another press release mentions they can provide large volumes of air which usually translates to efficiency. The major source of work done in their system is to accelerate the water, so if you want more air, accelerate more water. It sounds pretty efficient to this armchair critic.
The other press release mentions they are targeting 10hp and 20hp systems, and 100hp systems are feasible. I'd imagine 10hp is where industrial compressors start.
[edit] Found a press release from 2014 where they claim better energy efficiency than conventional methods. This really does sound like a breakthrough.