Biogas for mobility: Feasibility of generating biogas to fuel City of Johannesburg buses

Biogas is a renewable fuel that can be used for electrical power, heating/cooling, and as a transport fuel. This study assessed the feasibility of using biogas to fuel buses in the city of Johannesburg, South Africa. The use of biogas for transportation delivers more financial value-adding compared to using biogas for electricity-R235/GJ for transport fuel and R111/GJ for electricity. The cultivation of land and use of energy crops as feedstock for biogas production will require at least seven hectares per bus; which will place additional demands on the city's scarce land resources and create potential conflicts with food production. Biodegradable wastes are alternative feedstock for biogas production that avoids these impacts, while diverting organic waste from landfill. Using size-location modelling, we identified the optimal locations for two large (>2000Nm
³
/h) biogas facilities that use the organic fraction of municipal solid waste as feedstock to produce upgraded biogas (bio-methane) that can fuel up to six-hundred city buses. Benefits of using biogas for city buses include reducing carbon emissions, improving local air quality, increasing transportation efficiency, delivering new opportunities for transit orientated development and facilitating the transition to a Green economy.