Solar drying research of medicinal and aromatic plants: An African experience with assessment of the economic and environmental impact

Performances of solar dryers for the drying of medicinal and aromatic plants (MAP) in Africa were reviewed. Policy formulation indicators, including the economic and the environmental impact analysis that was lacking in almost all research, were presented in this study. Three countries, Nigeria, Egypt and Algeria, were used as case studies. Key indicators analyzed were the amount of money saved and CO2 reduction based on 10% to 100% rate of utilization and cost of a kWh of energy in each country. Results showed that as the rate of usage increased from 10% to 100% for drying Lemongrass in Egypt, the amount of money saved increased from $102.5 – $1025/year. While, in the same country at the same drying condition and mass, it increased from $123.5 – $1235.44/year for drying Oregano. Drying of Chilli in the coastal area of Nigeria saved more money than drying of Basil in Egypt under the same rate of usage. About 40702.38–407023.8 kg of CO2 per year can be reduced in the drying of Grape in Egypt, while 2308.5–23085 kg of CO2 can be reduced for drying of Chilli in Nigeria.