Someone mentioned that the inclusion of a closed hydraulic loop...

Someone mentioned that the inclusion of a closed hydraulic loop made it possible to drive anything that basically spins or pumps.  I assume that would also include the ability to compress air for storage.

Perhaps someone might like to comment whether this feature could be incorporated into a Ceto 5 system.

"Offshore renewable energy systems which compress air directly are economically viable. ► Integration of energy storage (4 days rated power) is feasible and economic. ► Simulations indicate effective turnaround efficiencies of 85%. ► Marginal conversion efficiencies of solar heat to electricity of >60%. ► Even poor heat exchangers do not degrade performance severely."

http://www.sciencedirect.com/science/article/pii/S0960148111004630