Assessment of the driving factors of CO2 mitigation costs of household biogas systems in China: A LMDI decomposition with cost analysis model

China has been placing a substantial focus on biogas for reducing energy consumption and carbon dioxide (CO2) emissions. The operation mode of systems may make the CO2 reduction target over-optimistic. There is limited research to investigate influential factors that be causing gap between actual theoretical costs in China. In this research, by using field survey data 209 users 489 non-biogas from 19 villages 2015, unit cost quantified at approximately 156 USD/t CO2. By employing Logarithmic Mean Divisia Index I (LMDI) model, it found both effect (48%) (52%) contribute gap. Four factors–household labor, accessibility resource, acceptance technology, subsidy–significantly narrow costs, while levelized subsidy contributes widening On average, should operated least four years substitution rate more than 67% order keep under 50%.