Transition pathways towards a 100% renewable energy-industry system for the regional grids in India

Abstract

India's energy demand and reliance on fossil fuels are increasing rapidly, this makes the transition towards a renewable energy-industry system climate imperative and a strategic opportunity for long-term energy security. This study describes techno-economic transition pathways for India from 2020 to 2070 using the LUT Energy System Transition Model (LUT-ESTM), applying hourly resolution, five-year transition steps, and four interconnected regional grids. The model integrates the power, heat, transport, industry, and desalination sectors within a least-cost optimisation framework and compares the Best Policy Scenario (BPS), Delayed Policy Scenario (DPS), and Current Policy Scenario (CPS). The results demonstrate an accelerated transition that yields a technically feasible, least-cost system. In the BPS, renewable electricity becomes the dominant energy source, increasing from 3.3% of primary energy demand in 2020 to 92% in 2050 and 94% in 2070. Solar photovoltaics accounts for about 95% of installed electricity capacity and 94% of electricity generation by 2070, supported by wind power, storage, transmission expansion, and sector coupling. This transformation enables defossilisation, with greenhouse gas emissions declining from 2035 MtCO₂eq in 2020 to zero by 2050, while delayed and current policy pathways retain fossil fuel dependence for longer. By 2070, the BPS achieves a levelised cost of final energy of 39 €/MWh and a levelised cost of electricity of 20 €/MWh, highlighting the economic benefits of early action. Power-to-X technologies, including e-hydrogen, e-FTL, e-ammonia, and emethanol, support in defossilising hard-to-electrify transport and industry segments. These findings show that accelerated renewable energy deployment, sector coupling, and system flexibility can deliver a least-cost, climate-compliant, flexible, and cost-effective energyindustry future for India.