Development of a solar photovoltaic-biogas hybrid microgrid for off-grid rural communities in Uganda

Abstract

Electricity is vital for social-economic growth and development. However, over 80% of rural dwellers in Uganda do not have access to it due to the absence of the national electricity grid. Most rural inhabitants use biomass to meet their energy needs using primitive conversion devices, e.g., the 3-stone stoves. They are mainly agricultural and generate a lot of waste, whose disposal is usually open dumping and burning. Such practices lead to environmental concerns and limited economic opportunities. This research aimed to address energy poverty and waste management in off-grid Ugandan communities. The study focused on solar photovoltaic (PV)-biogas hybrid microgrids as a potential solution, given the abundance of solar and bio-waste, particularly animal dung. Field surveys were conducted in Mubende District to gather data on energy usage, appliances, and demographics. Technical simulations and financial analyses were performed for different energy supply scenarios. The results indicated that the solar PV-biogas hybrid system was financially viable, with positive internal rate of return, net present value, and return on investment, whereas solar PV only was not. A pilot project was successfully implemented in one community with seven end users and has been operating since April 2024. The feedback from the end users is full of praise and excitement, and many more users wish to be connected. The study concluded that solar PV-biogas hybrid microgrids can be a valuable solution for providing energy access to off-grid communities in Uganda. Scaling up such systems is recommended to address the energy needs of such areas.