Biogas and biohydrogen for net zero cooking and transportation in Bhutan

Abstract

Agricultural biomass is a promising renewable energy material for Bhutan to support net zero transition of its cooking and transport sectors. In this study, crop residue and animal manure biomass-based biogas and biohydrogen potential of Bhutan are assessed at district and regional levels using a spatial framework. Existing energy demand of the cooking and transport sectors and associated greenhouse gases (GHGs) emissions are also estimated spatially. To analyze the net zero transition potential in the cooking and transport sectors, current energy situations of the sectors are compared with biogas-based cooking and biohydrogen-based transportation. It is observed that, annual biogas potential of Bhutan is 105 million cubic meter (mcm), equivalent to 2091 tera joule (TJ) energy. The potential is higher than the current cooking energy demand of 1230 TJ. At individual district level, 16 out of 20 districts can 100 % substitute LPG and firewood with biogas to support net zero transition of the cooking sector. Estimated annual GHGs emissions from the cooking sector are 102,089 t CO2eq. Transitioning to biogas-based cooking would provide significant GHGs emissions savings benefits for Bhutan. For example, annual emissions savings of 93,443 t CO2eq could be achieved through crop residue biogas-based cooking. Similarly, estimated biohydrogen potential (111 mcm, equivalent to 1194 TJ) can meet 35 % of current transportation energy demand (3353 TJ) of Bhutan. Full realization of the biohydrogen potential (1194 TJ) could provide annually 27,187 t CO2eq emissions savings in the transport sector of Bhutan. The findings of the present research could be useful for net zero transition of cooking and transport sectors of Bhutan. Thus, by leveraging the potential of biogas and biohydrogen, Bhutan can accelerate net zero transition and circular growth.