Environmental, social and health benefits of alternative renewable energy sources. Case study for household biogas digesters in rural areas

摘要

In rural areas of Colombia, liquefied petroleum gas (LPG) is the preferred option available for cooking. However, the poorest households rely on firewood (FW) to meet their daily cooking needs, because is the most accessible and affordable energy source. This high level of dependence on traditional solid fuels and the use of non-optimized cook stoves results in high health, environmental, economic and social costs on developing countries' households. This study aimed at assessing the environmental and health benefits of implementing grass-fed household biogas digesters in rural areas of Colombia, through Life Cycle Assessment (LCA) methodology. Functional Unit was the annual demand of cooking energy by a typical family in those rural areas, which means 2400 MJ of useful heat. There were evaluated two sources of biogas obtained from Pennisetum grass: Biogas from minerally fertilized grass (BMFG) and from organically fertilized one (BOFG). Results showed that FW had the highest impacts from fuels assessed, while the lowest impacts were found with BOFG, showing half of LCA total impacts compared with LPG and more than two orders of magnitude lower in non-methane volatile organic compounds and particulate matter (PM2.5eq) emitted compared with FW. Therefore, BOFG appears as an environmentally feasible alternative for cooking, which allowed the reduction LCA impacts among most of the categories assessed, as the fuel purchase expenses and of the wood collection time. Moreover, health impacts including the indoor emissions exposure showed also more than two orders of magnitude less impact compared with FW. It can be concluded that household digesters could improve the living standard of rural families. (c) 2021 Elsevier Ltd. All rights reserved.