Fabrication of a Biogas-Powered Electricity Generation System with Automatic Fuel Switching for Rural Households in Taraba State

Taraba State in North East Nigeria is predominantly rural, with low electricity access rates and abundant agricultural biomass waste available for biogas production. This project presents the fabrication of a biogas-powered electricity generation system incorporating an automatic fuel switching controller that transitions between biogas and liquefied petroleum gas as backup when biogas pressure falls below operational threshold. A fixed-dome biogas digester was constructed using locally available materials to process livestock dung from a 30-head cattle farm. The generated biogas is piped to a modified single-cylinder gasoline generator engine converted for biogas operation through carburetor jetting adjustment and air-fuel ratio tuning. A solenoid valve array controlled by an Arduino Nano microcontroller and a gas pressure sensor manages automatic switching between biogas and LPG supply lines. The 2.5 kVA generator powered a household load comprising two bulbs, a fan, a television, and phone chargers. Biogas availability averaged 5.2 hours per day of generator operation during the four-month evaluation, with LPG backup activating for the remaining demand period. System reliability was assessed at 94 percent over the monitoring period. The study includes a construction guide for the digester and biogas purification scrubber. Total system cost was 178,000 Naira. This project demonstrates a replicable rural electrification model using local organic waste resources available across Taraba and neighbouring states. Keywords: biogas generation, automatic fuel switching, rural electrification, biogas digester, Taraba State