PV-Aquaponic plant

Idea: Aquaponic with photovoltaic (PV) for a triple purpose:               Vegetable cultivation  + fish farming  + power generation

 1) Planned project stages

2) PV-aquaponic training facility

Composition of our PV-Aquaponic training facility

  • Under steel construction: Fish tanks and plant beds in greenhouse tunnel for temperature, light, humidity and air flow regulation
  • Cistern: Rainwater harvesting from roof with rain gutters
  • Well: Fresh water for aquaponic system
  • Cold storage: processing fish + cooling fish and vegetables
  • PV panels on roof for electricity generation: for running the pumps, and for charging the solar batteries, which are necessary on the one hand for the nocturnal pump operation and on the other hand are intended for rental to households

Concept training facility

  • Program: 25-week training + final examination à national recognized certificate
  • Theoretical lessons + practical training on 4 thematic areas:       aquaponics, photovoltaics, drinking water supply from wells, business basics
  • Supervision: recruitment of 4 teachers + administrative staff
  • Goals: creating future prospectives for young persons through training –> higher chance for employment                                                    + year-round, public grid-independent and sustainable production of fish and vegetables                                                                                        + dissemination of PV aquaponics approach for food security and food diversification

3) Large-area PV aquaponics farm

  • After a successful test phase of the training facility’s aquaponic system in the sense of a pilot plant, the system will initially be extended to about 1.2 ha and finally to 10 ha. The area is divided as follows:
    • A PV park covers about half of the area.
    • On the edge of the area, there is a market area for the direct sale of the products, a parking lot, a slaughterhouse and cold store for the fish, a building for to store and sell the charged batteries and sale as well as a technical building.
    • On the remaining approximately 30% of the property, several aquaponic plants are built, each in groupings of three – a greenhouse tunnel with fish tanks, a greenhouse tunnel with inorganic substrate filled beds and a greenhouse tunnel with deep water culture beds. Wells with water storage tanks supply fresh water to the systems. Above the fish tanks and a small battery container, a roof with PV panels is set up that generates electricity for running the pumps during the day and for charging the batteries for the nocturnal pump operation.

Aquaponic concept

  • Supervision of aquaponics plants: former trainees of our training facility take over the handling of daily tasks (including fish farming, vegetable cultivation and harvest, control of system components and water quality parameters)
  • Sale of fish and vegetables: Carried out as well by former trainees.   At present, there is a high demand for fish, as annually 40,000 tons are being imported into Zambia (see article). Reliable supply of vegetables all year round, independently of seasons.

Concept for battery rental

  • Use of excess electricity from PV park to charge additional solar batteries
  • Renting of charged solar batteries to households without public grid connection and with low power requirement:
    • Utilization for light, radio, mobile phone charging
    • Prepaid: clients pay for the energy stored in the battery at battery deliver
    • Battery remains the property of 7×7 Zambia Limited

4) Positive aspects

Job creation

Jobs in the context of this project are generated in manifold ways:

  • Staff will be hired for supervision of the aquaponic plants, sale of the products, delivery / collection of the charged solar batteries to / from the households, etc.
  • Furthermore working positions for project manager and finance administrator
  • Additionally needed are construction workers and technicians for constructing the buildings and systems

Dissemination of knowledge

Dissemination of knowledge about aquaponics and photovoltaics through our PV aquaponics farm, training facility, workshops –> contribution to food security + environmentally friendly power supply in Zambia

Operation

Year-round, environmentally conscious and sustainable production of fish and vegetables independently of season and public grid

Sustainability

This project is oriented towards the principle of sustainability, including:

  • Recycling: of batteries and PV panels
  • Closed water cycle with reduced supply of fresh water:  water circulates between fish tanks and vegetable beds –> By this up to 90% lower water consumption compared to conventional cultivation. Collection of rainwater in cistern
  • Closed nutrient cycle: no adding of artificial fertilizers, but use of processed fish excretion
  • Self-reproductive system: own cultivation of plant seedlings, fish and fish feed