Urban aquaponics system in Palermo, Sicily

• Bonagia district, Palermo, Sicily, Southern Italy. 
• The pilot operates in an urban sports club facility. 
• Mediterranean climate provides favourable conditions for outdoor aquaponic production with minimal heating and cooling requirements. 
• Palermo has approximately 670,000 inhabitants, representing significant urban market potential for local food production.

To assess the financial feasibility of a small-scale aquaponic system producing lettuce and tilapia in an urban Mediterranean environment, including analysis of investment costs, operating expenses, revenues and break-even points.

Challenges addressed

The system addresses socio-economic challenges by providing an economically efficient way to produce food on non-agricultural urban land. It follows circular economy principles, reducing inputs and waste compared with conventional production.

Costs of NbS

The pilot aquaponic unit in Palermo produces lettuce and Nile tilapia on just 12 m² of urban land. Planning, construction and set-up required an investment of about EUR 1,960. Running the system costs around EUR 1,515 per year, bringing total costs in the first year to about EUR 3,480 (2023 prices).

The 12 m² unit produces lettuce and Nile tilapia for sale, with water and nutrients circulating between fish and plants, generating revenues of about EUR 1,865 in its first year (2023 prices). It shows that food can be produced sustainably on non-agricultural urban land with fewer inputs and less waste, and gives future urban farmers a basis for a business plan in the Mediterranean climate.

Benefit–cost ratio

Revenues exceed the yearly running costs, giving a BCR of 1.23. The system is therefore profitable from its first year, although its viability is sensitive to changes in sales prices.

Construction of pilot aquaponic unit using media bed technique with expanded clay and lava rock substrate. Integration of 500-litre fish tanks with 5 m² hydroponic cultivation area. Implementation of continuous water circulation via 400 W sump pump. Daily management including fish feeding, plant maintenance, and harvest operations. Comprehensive financial tracking of investment and operating costs against sales revenues.

Valeria Borsellino, Università degli Studi di Palermo, Department of Agricultural, Food and Forest Sciences (corresponding author).

Study overview

An experimental aquaponic system was established in an urban setting in Palermo, Sicily, to assess the financial viability of integrated fish and vegetable production in a Mediterranean climate. The AQUAPONICS PMO 3.0 pilot plant was constructed by the Empedocle Cooperative within a sports club in the Bonagia district. This represents one of several European pilot units testing aquaponic sustainability in urban environments.

Aquaponics combines Recirculating Aquaculture Systems (RAS) for fish farming with hydroponic cultivation of vegetables. The system uses nutrient-rich water from fish tanks to irrigate plants, which in turn purify the water before it returns to the fish. This circular approach eliminates the need for chemical fertilisers and pesticides while minimising water consumption and waste discharge.

The pilot unit occupies approximately 12 m² with a 5 m² cultivable area and a 1 m³ fish tank. It produces baby-leaf lettuce (Lactuca sativa) and Nile tilapia (Oreochromis niloticus). Production achieved nine annual lettuce cycles yielding 2,250 heads, and two tilapia cycles producing 72 kg of fish. Lettuce was sold to the sports club restaurant at €0.60 per head, while tilapia fetched €3.00 per kilogram.

Total investment cost was €1,648, with no subsidies or external funding received. Annual operating costs amounted to €1,272.95, with labour accounting for 49.5% of this total—a finding consistent with other studies. Energy costs remained below 7% of running costs due to the outdoor positioning, avoiding heating and lighting expenses typical of indoor systems.

First-year financial analysis showed a total revenue of €1,566, with 86.2% derived from lettuce sales. The net operating income was €293, yielding a benefit-cost ratio of 1.23, indicating financial feasibility. A break-even analysis determined the unit needed to produce 1,829 lettuce heads and 58.5 kg of tilapia annually, both targets have been exceeded in practice.

A sensitivity analysis demonstrated that net return remained positive even if running costs increased by 23% or total revenue decreased by 19%. This suggests reasonable resilience to market fluctuations. The study concludes that aquaponics have a promising potential for urban food production in Mediterranean climates, though EU organic certification remains unavailable for aquaponic produce which limits premium pricing opportunities.