SBIR-STTR Award

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.

Problem Statement: The U.S. aquaculture pond industry remains an untapped market for floating solar- powered aeration systems (FSAS), despite the industry’s significant dependence on aeration to maintain adequate dissolved oxygen (DO) levels for fish survival, growth, and commercial production. The U.S. aquaculture pond industry currently relies on land-tied and fossil fuel-dependent aeration systems that incur high reoccurring operating costs for farmers. These grid-tied aerators also exclude off-grid farmers with remote ponds that could otherwise be utilized for aquaculture to generate additional revenue. Overall Objective: HFC’s project objective is to pioneer FSAS technology that is designed to meet the varied needs of the aquaculture pond industry and provide highly efficient, cost-effective aeration options for farmers. HFC’s FSAS will provide cheap, effective daytime aeration that will offset the need for industrial farmers to run their costly traditional systems nightly, thereby reducing farmers’ overall aeration operating costs. HFC’s product will also enable off-grid pond operators to stock or increase the stocking of their ponds to support fish sales and recreational fishing. Phase I Results: Phase I research consisted of research trials that tested potential components to inform the design of the individual aeration, power, and floatation subsystems. Initial prototypes were then fully fabricated and assembled for field trials in HFC’s 7-acre aquaculture pond as proof-of-concept. HFC also conducted extensive interviews and developed strategic relationships with manufacturers, aquaculture research centers, and professors and extension agents who will serve as important points of contact between HFC and the farming community. Phase II Work Plan: In Phase II, HFC will conduct additional R&D to optimize the product design and component selection and field test the device at renowned aquaculture facilities, including Auburn University’s E.W. Shell Fisheries Center and Kentucky State University’s Aquaculture Research Center, to create an industry-relevant and market-ready product. These facilities are also strategically located to serve as demonstration sites of the product to HFC’s main customer base and potential partners. Commercial Applications and Other

Benefits:
HFC’s novel FSAS technology will introduce much- needed improvements in efficiency and sustainability to commercial pond aquaculture aeration, helping to improve farm profitability, lead the industry away from dependence on increasingly costly fossil fuels, and meet the U.S.’s increasing demand for sustainable, domestically-produced sources of protein. This will in turn help to improve the nation’s food security, nutrition, rural employment, and seafood balance of payments, and reduce the nation’s carbon footprint and impact on climate change.