Implementation of biogas digester to clean up pig live-stock and provide the community with biogas renewable energy (CBRE)

Abstract

The community biogas renewable energy (CBRE) model allows for effective renewable energy recuperation and reducing greenhouse gas (GHG) emissions as well. In order to evaluate the feasibility of this model, the aspects of economic efficiency, society and environment, and farmer consensus were investigated to project the CBRE model for a five-household group. The result shows that the percentage of households accepting to share surplus CBRE was 63,3%, while those accepted to use CBRE was 86,7%. A medium-scale livestock around 37 pigs per farm (ranging between 26 and 52 pigs) in the CBRE model provided enough biogas used by 5 households with 25 members in total (i.e. 1.5 pigs for a person), with the average of biogas-combustible time and biogas-consumption of each household volume was 1.87 h/day and 0.74 m³/day, respectively. The CBRE model helped farmers reduce GHG 12.9 tons CO₂eq/year (~70%) in terms of the utilization of traditional energy sources combined with biogas, and with shared biogas, farmers reduced GHG 2.58 CO₂eq/year. Cost savings was 1.04 million VND/year per household. It is essential to develop a clearly financial mechanism for paying relevant costs related to biogas use for improvements in efficient and long-term use of CBRE model.