Sensor-enabled Household Biodigester: A Student-driven IoT Prototype

Biogas offers a renewable energy source for rural households. However, many small-scale digesters exhibit unstable yields due to a lack of process monitoring and control. This paper presents the design and evaluation of a small-scale household biodigester equipped with an IoT (Internet of Things) sensor system integrating an ESP32 microcontroller with low-cost sensors for methane concentration, slurry temperature and pH value, and gas-side environmental conditions. Data is transmitted to a cloud backend and visualized in real time through a web dashboard. The construction and evaluation of the prototype system was undertaken as a cooperative students’ project within a long-term international collaboration between a Kenyan and a German university. The digester was constructed from accessible materials and operated with cow dung substrate over a four-week test period. The project demonstrates that low-cost hardware combined with IoT monitoring can produce a functional educational biodigester prototype. It further highlights potential for rural energy applications and international collaboration in digital agriculture.