An optimisation approach for the design and operation of recirculating aquaculture systems integrated with sustainable hybrid energy systems

Efficient energy utilisation and reducing environmental pollution are pivotal factors for the advancement of contemporary aquaculture. The integration of recirculating aquaculture system (RAS) with renewable energy can create synergies that not only improve the sustainability of the overall operation but also potentially lower costs by reducing operational expenses. This paper proposes a novel approach to designing sustainable energy systems for aquaculture, addressing sector-specific energy demands. An optimisation model for energy system design in RASs is developed, simultaneously considering fish growth requirements and geographical location to evaluate economic and environmental performance criteria under different grid-connected modes. The model under consideration incorporates constraints related to the healthy growth of fish and constraints within the energy system, all aiming at achieving the objective of minimum annualised lifecycle cost. The case studies highlight the advantages of the proposed system, showcasing substantial cost reductions and CO 2 emission cuts compared to conventional methods. Water, due to its large specific heat capacity, moderates the challenges posed to the system by the stochastic nature of renewable energy output, rather than choosing to install batteries. The adoption of this model can lead to a cost reduction of 35% with pay-back times of around 7 years. The results also showed that bespoke installation strategies are essential for scenarios like rearing warm-water fish in cold-water environments and vice versa. The model allows the systematic analysis of the synergy between aquaculture, energy, and the environment and is demonstrated by annual carbon reduction benefits attributed to renewable energy generation. • Novel optimisation model integrates fish growth and energy needs for sustainable aquaculture. • 35% cost reduction achieved in case study with optimised RAS energy system design. • CO2 emissions cut significantly through renewable energy in aquaculture systems. • Water's thermal properties reduce need for costly energy storage solutions. • Bespoke energy strategies vital for optimising aquaculture in diverse climates.