F Mwanyasi, J Mbothu, S.Bachani

Abstract

Many nations have supported bioenergy in an effort to address issues with energy security, the environment, as well as to improve social- economic well-being of rural people. This paper evaluates lifecycle net greenhouse gas (GHG) emissions, energy consumption and energy balances in the production chain of bagasse- based electricity production in Kenya . Bagasse -based electricity production involves sugarcane cultivation, cane milling and co-generation. Economic allocation was used to partition GHG emissions and energy inputs between electricity, sugar and molasses. The lifecycle GHG emissions was estimated at 581.30 kg CO2eq/MWh of electricity produced. The total energy input was evaluated to be 4087.09 MJ per MWh of electricity produced, while the energy content of bagasse was 9846 MJ .The energy balances calculated values per MWh of electricity were; net energy value (NEV) = 5758.91 MJ, net renewable energy value (NREV) = 7227 MJ and net energy ratio (NER) = 3.8. The positive value of NEV indicates that to produce a MWh of electricity requires less energy than its energy content. The high positive values of NREV and NER indicates that low amounts of fossil fuels are required to produce a MWh of electricity. The results of this study were compared to results of sugarcane- bagasse based electricity production obtained in other countries.

Key words: Sugarcane-bagasse based electricity, greenhouse gas emissions, energy balances, life cycle assessment, Kenya.