Dar es Salaam, Tanzania’s largest city with over 6 million inhabitants, has one of the fastest-growing populations in Africa. This rapid urbanisation poses significant challenges for the city administration in terms of waste management and energy supply. The widespread development of informal settlements also hinders efficient waste collection, meaning that significant quantities of waste are disposed of uncontrollably or washed into watercourses, leading to blockages and hygiene issues.
Against this backdrop, the port cities of Hamburg and Dar es Salaam have launched the ‘Construction of a Composting Plant for Market Waste’ project, which has been converting market waste into valuable compost since 2022. Funded by flight compensation funds from the Free and Hanseatic City of Hamburg (FHH) and by funds from the SKEW programme for municipal climate protection and climate adaptation projects (FKKP), the plant closes the biomass cycle and reduces methane emissions.
A large proportion of market waste in Dar es Salaam is organic and biodegrades rapidly. Depending on the method of disposal, this can produce methane, which contributes to the greenhouse effect many times more than CO2. Composting minimises these methane emissions and produces a valuable product that can be used to improve soil quality in agriculture. In addition, the environmental impact is reduced by cutting down on waste transport and blockages in waterways.
Despite these measures, there remains untapped potential. In addition to composting, organic waste could be used to produce biogas, a sustainable energy source that both reduces environmental impact and offers economic benefits.
The use of biogas offers particular advantages in Dar es Salaam, as the city struggles with an unreliable and expensive energy supply. Households are heavily reliant on charcoal and firewood, which not only incurs high costs but also contributes to deforestation and air pollution. Biogas can offer a sustainable alternative here.
Furthermore, biogas produced from organic waste can be stored as compressed biogas (CBG) and bottled for use in rural areas as well. Such systems are already being successfully implemented in India. Integrating them in Dar es Salaam could help to improve both waste management and energy supply simultaneously.
By combining composting and biogas production, multiple challenges facing the city – including waste management, greenhouse gas emissions and energy shortages – can be systematically addressed.
Project objective
The potential expansion of the existing bio-waste treatment infrastructure to produce sustainable biogas was assessed for feasibility and financial viability, and an option for further action was identified in consultation with local stakeholders.