Crop Residues Utilisation for Renewable Energy Generation in Ghana: Review of Feedstocks Assessment Approach, Conversion Technologies and Challenges*

Abstract

Crop residues have a significant role to play in the quest to provide off-grid and mini-grid electricity for unelectrified rural agricultural communities in Ghana. The aim of the study was therefore to review available literature on current state of art of crop residues assessments and utilisation for thermochemical energy generation in Ghana. Overall, 20 relevant literature were identified. The study revealed that, the level of crop residue assessment is on theoretical and technical assessment, employing either field survey or statistical modelling methods. There was major difference between quantities of residues reported due to differences in methods, crop production figures, Residue-to-Product Ratio (RPR) and recoverability ratio. The Northern, Brong-Ahafo and Eastern regions have the highest potential in terms of total residues. The major crop residue types that were identified to be underutilised and therefore available for energy generation include, rice husk, cassava peels and oil palm residues. Fourteen biomass energy installations using thermochemical conversion technologies with total installed capacities of 10.7 MW were identified. These consist of six biomass powered cogeneration plant, three gasifiers, four biomass boilers and one hybrid solar biomass dryer. The major challenges identified for these installations were: unsustainable biomass supply, lack of tailor-made technology to suit locally available residues and inability of conversion technology to utilise all available residues. Further studies are required particularly on the determination of residue to product and recoverability ratios across communities and districts as well as economic and sustainable residue assessments.