Floating Solar Aquaculture Aerator with Secondary Renewable Energy Option

Although globally there has been growing interest in innovative marine renewables for use with offshore aquaculture, the U.S has not seen a concomitant increase in the use of floating solar- powered aeration systems designed for inland pond aquaculture, where the beneficial mixing effects from offshore wind and waves are precluded. Efforts in the U.S. to combine solar power with aquaculture pond aeration systems have, to date, been limited to land-based photovoltaic systems. A U.S. manufactured floating photovoltaic-powered aeration system purposefully designed to accommodate and enhance inland pond aquaculture operations and production does not yet exist. The Phase I objective is to pioneer a floating solar-powered aeration system that is highly efficient, less intrusive to aquaculture operations, and more cost-effective for farmers. To achieve this, the system will use sub-surface air diffusers, which input dissolved oxygen and circulate water from the pond bottom or selected depths, with a floating photovoltaic-powered air compressor. While traditional surface aerators mechanically aerate only the upper pond waters, the sub-surface diffusers efficiently aerate and circulate the entire pond volume, bringing the entire pond ecosystem into use to produce and store dissolved oxygen to support healthy aquaculture stocks. Diffuser aeration will enable a reduction in the air compressor size, load, and power requirement and be well suited to a photovoltaic power source, making the system more compact, sustainable, and affordable. Additionally, unlike traditional grid-tied paddlewheel aerators or land-based solar aeration systems, this free-floating solar aerator can be positioned away from the erodible pond banks and shade of shoreline trees to take full advantage of the sun’s energy. Recognizing that a single floating solar-powered aeration system design will not meet the needs of all inland aquaculture farms, the approach for Phase I is to create a design to enable pond operators to select the air compressor, number of photovoltaic panels, and battery storage system from multiple options to meet their individual aeration needs. The design will include three subsystems: 1) a photovoltaic power subsystem, 2) an aeration subsystem, and 3) a floatation subsystem; therefore, Phase I will include determining the performance of each subsystem using varying parts and selecting the most efficient for assembly into a working prototype for field testing validation and demonstration of project feasibility. The floating solar-powered aeration system innovation will enable a paradigm shift in aquafarm management focused more on long-term sustainability and profitability rather than increasing unprofitable practices of ever higher stocking and feeding rates supported by ever increasing use of fossil fuel-based mechanical aeration. Such a paradigm shift would result in farmers adjusting their stocking densities, biomass loading rates, and feeding rates to be in balance with the enhanced natural phytoplankton-based dissolved oxygen production supported by these more sustainable and economic units on an annualized cost basis. This paradigm shift in aquafarm management practices will, in turn, enable aquafarmers to reduce their feeding costs, improve their system water quality and aquatic animal health, reduce their overall production risk, and improve aquafarm profitability and sustainability.