Feasibility analysis and trial of air-lift artificial upwelling powered by hybrid energy system

Artificial upwelling can lift nutritious deep ocean water to sunlit layer, as a result, it is able to promote primary production and is being paid more and more attention all over the world. Kinds of artificial upwelling method have been invented in recent years, however, few of them can fulfill the requirement of desired flow rate and balanced budget. The design of an air-lift artificial upwelling device powered by hybrid energy system is presented in this paper, where solar, wind and wave energy is exploited together to induce artificial upwelling. The preliminary results of an open sea trial lasted for 7 days have demonstrated that the hybrid system assembled in a floating platform with surface area of 12.5 m2 can lift 4234 m3 deep seawater from more than 20 m depth. In particular, the operation based on optimal dispatch strategy showed that the unit cost of induced artificial upwelling is only 0.005 US $/m3. The work presented in this paper constitutes a step towards the development of an advanced hybrid energy system used for artificial upwelling.