RAS OPEX: Energy, Oxygen and Feed per Kilogram

Part 3 of the RAS cost and sizing series. RAS system cost conversations focus on CAPEX, but operating cost is what closes or kills the business case. Commercial RAS typically runs USD 3-6 per kg harvested. Model your own case in the RAS system cost calculator.

Feed is the largest single line

Feed usually accounts for 40-55% of OPEX. FCR discipline is worth more than any equipment discount: a shift from 1.3 to 1.1 moves cost per kilogram more than most CAPEX negotiations. Test it in the FCR calculator.

Energy is the line that varies most by site

Specific energy use of 3-8 kWh per kg produced is normal, split across pumping head, oxygen transfer and temperature control. Tariff differences between markets can move total OPEX by a third on identical equipment, which is why energy belongs in the feasibility model before the equipment list.

Oxygen is a design decision with an operating price

At 0.4-0.6 kg of oxygen per kg of feed, the choice between diffused aeration, liquid oxygen delivery and on-site generation is a lifetime cost decision made at design stage. On-site generation raises CAPEX and installed kW; LOX raises recurring logistics cost and creates supply dependency.

Labour, juveniles, maintenance and mortality

Labour is relatively fixed and favours scale. Juvenile cost tracks survival assumptions, and mortality events hit both revenue and the feed already invested in that biomass. Maintenance of 2-4% of equipment CAPEX per year is a reasonable planning provision.

Bringing it together

Sized flow and feed load produce the energy and oxygen lines directly — see from RAS sizing to RAS cost. Real operating outcomes across six builds are in the RAS case studies.

FishMatch Group is a managed sourcing service; supplier outreach happens only after a person reviews the brief. Start with a human-reviewed RFQ.