Internal Publication
Technical, economic, and environmental performance of a chamber solar dryer for fonio (Digitaria spp) processing
Fonio is an underutilized cereal from West Africa, recognized for its exceptional nutritional profile and ability to thrive under climate stress. However, its processing, including drying, remains labor-intensive in rural areas. This study therefore aimed to design and evaluate the performance of a chamber-type solar dryer, considering the specific constraints of fonio drying in rural contexts. The dryer consists of a 10 m × 5 m concrete chamber with a sloped roof (3.0 m to 2.2 m). It is covered with translucent fiberglass sheets and powered by a photovoltaic system. Experimental trials were conducted in northern Benin during both rainy and dry seasons, to compare the dryer’s technical performance with traditional sun drying. Furthermore, economic and environmental assessments were carried out. Results showed that the new dryer significantly accelerated the drying process in both seasons. Fonio moisture content was reduced from 40% to below 9% (w.b.) in 4 hours during the dry season and 22 hours during the rainy season. This corresponds to a drying time reduction of 86% and 59%, respectively, compared to natural sun drying. Moreover, the dryer preserved nutrients and protected fonio from dust, insects, and other contaminants. The net annual profit was estimated at 54,224 USD (42.7% of revenue), with a payback period of 58 days. Over a 20-year lifespan, the system could mitigate 757.31 tons of CO₂ emissions, with an energy payback time of 1.27 years. The carbon credit value was estimated at 11,359.65 USD. This dryer offers a cost-effective and sustainable alternative to traditional fonio drying.
Uploaded by: Dona Samuel DjebouAuthor: Djebou, Dona Samuel | ORCID: https://orcid.org/0000-0001-8434-7711
Co-author: Tossa, Alain K. | ORCID: https://orcid.org/0000-0003-0795-9460
Co-author: Mensah, Grace A. J. | ORCID: https://orcid.org/0009-0008-4441-122X
Co-author: Ogoubi, Epiphane H. O. | ORCID: https://orcid.org/0009-0003-6246-9197
Co-author: Dossou, Joseph | ORCID: https://orcid.org/0000-0002-9572-7928
Institution: Université d'Abomey-Calavi | Centre: Promoting Academic Capacities for Sustainable Agricultural Resources Use in West Africa (Pro-RUWA)
Type: Journal article | English | Peer Reviewed
Subjects: Agriculture, Climate and Environment
Published in: Journal of Renewable Energy and Environment, EISSN 2423-7469, ISSN 2423-5547 | Vol. 13, No. 1
Publisher of document: Tehran, Iran: Materials and Energy Research Center (MERC) and Iranian Association of Chemical Engineers (IAChE)
Date: Winter 2026 | Pages: 159-173
https://doi.org/10.30501/jree.2026.529012.2469
Copyright: © 2026 The Author(s) | License: Creative Commons license CCY BY 4.0
