Mitigation strategies for transitioning towards ‘Net-zero’ emissions from energy systems

Abstract

Net-zero emissions from energy systems are essential to meet the Paris climate goals. These transitions require intensive efforts from national governments, in addition to deeper climate commitments. As a coal-dependent, fast-growing economy, India’s future emissions are important for the global climate targets. Recent studies have discussed strategies involving alternate fuels and technologies along with negative emissions using bioenergy with carbon capture and storage (BECCS) but their role in the net-zero transitions have uncertainties, with implications for society and the environment. In this research, we investigate the mitigation strategies for net-zero energy systems in India and study their policy implications. In the first study, we develop a mixed integer linear programming model to study a bottom-up, BECCS-based energy system. We find that BECCS through the crop residue-based ethanol route is feasible at small scales and could deliver carbon-neutral crude oil in the short-term. In general, policy integration in areas like bioenergy, agricultural residue management, farmers’ welfare, groundwater conservation and enhanced oil recovery, with the objective of net-zero energy systems, could improve the understanding about long-term feasibility and potential of newer technologies like BECCS. In the next two studies, we apply TIMES-India energy systems bottom-up optimization model, developed for this research, for national-scale assessment of mitigation strategies. We compare the current policy scenario (CPS) based on current climate commitments by India, with the net-zero emission scenarios (NZES) designed for deep decarbonization of energy systems. We also compare electricity generation alternatives like renewables with battery storage, next-generation nuclear technologies and fossil fuels with carbon capture and storage. The NZES decarbonizes energy (and electricity) systems around 2050 and also improves the affordability and consumption of electricity. However, it requires higher investments and policy actions beyond promotion of energy efficiency and renewable energy, especially in the difficult to decarbonize sectors like industrial processes. It demands policy support for early research and investments in newer technology-fuel alternatives, carbon pricing and consultations with a wider set of stakeholders to address the feasibility aspects of upcoming technologies. Our work contributes to the growing literature on net-zero energy systems and is relevant for the 2023 global stocktake of national policies under the Paris agreement.