Techno-economic analysis of Spirulina biomass production in the floating photobioreactors for fishmeal replacements

The use of Spirulina as an alternative to fishmeal for the sustainable development of the aquaculture industry has gained significant attention, but its higher production cost than fishmeal has limited its wide application. Sustainable wave-driven floating photobioreactors, which offer low cost and high production efficiency, hold great potential for producing Spirulina at a lower cost to replace fishmeal. However, the economic feasibility of this method has not been evaluated. This study assessed the economic viability of producing Spirulina biomass in floating photobioreactors, with the widely used raceway ponds for commercial Spirulina production as the comparison. The results indicated that the total production cost of Spirulina in the floating photobioreactors is approximately $ 2.57 per kg for a 20-ha production area, lower than the $ 3.89 per kg cost in raceway ponds. Expanding the production area to 100-ha could reduce the cost of Spirulina in the floating photobioreactors to be lower than the price of fishmeal ($ 2.27 per kg), while the cost in the raceway ponds would remain higher than fishmeal ($ 3.55 per kg). A sensitivity analysis revealed that the production cost could potentially be further reduced to $ 1.26 per kg for the floating photobioreactors and $ 1.76 per kg for the raceway ponds with the proposed strategy. These findings suggest that using the floating photobioreactors to produce Spirulina as a sustainable substitute for fishmeal is promising and economically feasible.