Development of a Solar Cooling and Drying Technology for the Milkfish (Chanos chanos) and Kimarawali (Stolephorus delecatulus)

Duration: 09/2018 - 03/2022
Contracting Authority/ Sponsors:
Bundesministerium für Ernährung und Landwirtschaft (BMEL)
Project Partners: Innotech Ingenieursgesellschaft mbH (Deutschland); Kenya Industrial Research and Development Institute (KIRDI, Kenia); Kenya Marine and Fisheries Research Institute (KMFRI, Kenia); Technical University of Mombasa (TUM, Kenia)
Project Focus:
System concept of solar cooling and drying
© Fraunhofer ISE
System concept of solar cooling and drying.

The project aims to develop a 100% solar-powered and off-grid system for cooling and drying fish. It includes both the production and supply of flake ice for cooling during transport and storage as well as the thermal drying of fish. Photovoltaic and electrical storage technologies on the one hand and solar thermal systems and thermal storage on the other hand will be used to generate and supply the required energy. The project is being implemented in close cooperation with the project partners in Kenya so that the sustainable operation of the system beyond the project duration is ensured.


Mariculture is becoming increasingly important in Kenya as natural fish stocks (e.g. tilapia in Lake Victoria) are shrinking, a situation that is now forcing Kenya to import fish from China. Milkfish (Chanos chanos Forskal) is currently raised in cultivated ponds by farmers on the Kenyan coast. Fishermen also harvest a local sardine called Kimarawali (Stolephorus delecatulus) along the shores of the Kwale and Kilifi counties. Milkfish fishermen are dependent on fluctuating and seasonal wild stocks of milkfish fingerlings from local mangroves and therefore need to produce seasonally and adjust their yields. Kimarawali catches are also subject to strong seasonal fluctuations. The lack of suitable transport facilities and processing technologies forces fishermen to sell their products while they are fresh - often at uneconomical prices. Unsuitable processing and handling technologies also deny access to high-end markets.

Against this background, a system for providing ice and drying capacity for the transport, storage and processing of fish is being developed in cooperation between the partners in Kenya and Germany. The energy needed for the various processes is generated both locally and off-grid by means of photovoltaics and solar thermal energy. Electrical and thermal storage systems ensure reliable plant operation during the day and partial plant operation during the night. Thus, the requirements for supplying the ice and for guaranteeing the quality of the drying process can be met.

While the ice is mainly used by fishermen for cooling during transport between catch and sale, the dryer is used to produce storable fish products. To produce high quality dried fish (first class nutritional value, texture and taste), dehydration is achieved through optimized temperature and humidity control.

The selection of the location and also the involvement and training of the local fishermen is carried out in close cooperation with the Kenyan partners. This is to ensure that, on the one hand, the know-how regarding processing and quality assurance is built up and, on the other hand, the operation of the system is possible beyond the project duration itself.