Resource optimisation in aquaponics facility via process monitoring and graph-theoretical approach

Abstract

Energy efficiency and economic viability are the often-quoted issues in aquaponic farming. This work aims to (i) identify process technologies and technical measures which would enhance the profitability of aquaponics business while conserving energy and other resources, and (ii) to validate the determined optimal measures on the testing aquaponics farm. The process network synthesis technique was used to search for an optimal process pathway while the image processing technique was applied to automatically monitor the growth rate of produce since it is the main revenue stream in aquaponics. With the aid of P-graph method, the optimal feasible structure has 9 times higher annual net income than that of the existing process. This optimal solution includes the integration of electrical heat pump, biogas system, and utilizes black solider fly (BSF) facility to produce fish feed. Additional light energy savings were achieved by practical installation of reflective foils which improved 16.88% of Photosynthetic photon flux density (PPFD) on growth beds. These measures can help the aquaponics farms to become more competitive and to decrease their ecological footprint.