RAS Energy Consumption

RAS energy consumption is the total electrical (and thermal) energy used per kg of fish produced, typically 2–8 kWh/kg for modern land-based salmon systems and 0.5–2 kWh/kg for simpler warm-water RAS — several times the figure for flow-through farms. The largest draws are pumping (30–50%, scaling with turnover rate and head), aeration and oxygenation (20–35%), heating or cooling (10–30%, dominant where intake and culture temperatures differ), and lighting, feeding, and monitoring. Because pumping dominates, the decisive design choices are low-head layout, gravity-fed treatment sequences, and high-efficiency pumps and blowers; a well-conceived plant can halve kWh/kg without new technology. Energy is usually 20–40% of total production cost, second only to feed, so even small efficiency gains move farm economics materially. Benchmarking uses kWh per kg per production cycle, and monitoring per-subsystem meters is essential to locate losses. Operators manage demand by scheduling backwashes and oxygen generator runs off-peak, exploiting thermal storage, and sizing backup power for the life-support subset rather than the whole plant.