Indian Institute of Technology Madras (IIT Madras) researchers have published a focused study examining whether renewable energy can realistically lead the global net-zero transition by 2050.

The findings offer a critical reality check: under current growth rates, renewables will not match fossil fuels in the global energy mix until the mid-2050s. Only under the most aggressive, accelerated scenarios, which require unprecedented levels of investment, could renewables dominate the energy sector by the late 2040s.

The researchers have published their findings in Transactions of the Indian National Academy of Engineering (https://doi.org/10.1007/s41403-025-00556-0), a peer-reviewed journal that publishes research, reviews, and perspectives on engineering science, practice, and policy with relevance to India and global technological challenges.

The paper was co-authored by Prof. Jitendra S. Sangwai, Department of Chemical Engineering, IIT Madras, and doctoral scholar Mr. Rajat Dehury.

Elaborating on this Research, Prof. Jitendra S. Sangwai, Department of Chemical Engineering, IIT Madras, said, "The transition to renewables is not just an environmental imperative, it is an economic and geopolitical one. Our study shows that the technological pathways exist, but the world is not yet investing at the speed or scale required. The gap between ambition and action remains dangerously wide. What we need is not optimism, but urgent, coordinated, and well-funded action."

Co-author, Mr. Rajat Dehury, Doctoral Research Scholar, Department of Chemical Engineering, IIT Madras, added, "Our analysis is grounded in actual renewable energy growth data from the past decade. The observations are sobering. Without a dramatic acceleration in investment, policy reform, and grid infrastructure, we risk missing every major climate target of the coming decades."

INDIA & GLOBAL ENERGY TRANSITION

The research highlights India's complex position. As one of the world's largest CO₂ emitters in gross terms, India is simultaneously among the lowest in per-capita emissions. The country must build vast new infrastructure, drive economic growth, and extend electricity access to rural populations, all energy-intensive imperatives.

India has committed to reaching 485 GW of renewable capacity by 2030, including 293 GW of solar, 100 GW of wind, 78 GW of hydro, and 15 GW of bioenergy. The study underscores that meeting these ambitions is critical not only for India's development goals but also for global climate targets.

Despite a rapid global rise in renewable energy installations, with global renewable energy capacity growing 128% between 2014 and 2023 to reach 3,869.7 GW — renewables still account for only 14.56% of total global primary energy consumption. Fossil fuels (coal, oil, and natural gas) continue to supply more than 81% of the world's energy needs, contributing over 95% of global CO₂ emissions.

The IIT Madras team considered seven distinct renewable energy growth scenarios, drawing on a decade of data from leading global energy reports, including those from the International Energy Agency (IEA), the International Renewable Energy Agency (IRENA), and the Energy Institute. Each scenario was evaluated under two conditions: constant global energy demand and a steadily rising demand of 1.1% per year. It is important to note that this study does not factor in the possible surge in energy demand projections due to rapidly expanding AI and data centres.

The central question was: when can renewables exceed 50% of the total global energy mix, the threshold at which they would surpass fossil fuels? The study also calculated the CO₂ emissions that could be avoided by switching to renewables, and the scale of global investment required.

Key Findings

Timelines for Renewables to Cross 50%:

O Under the current growth trajectory (based on the 10-year annual average growth rate of approximately 5.48%), renewables are projected to reach 50% of the global energy mix between 2047 and 2053, depending on energy demand assumptions — well past the 2050 net-zero deadline.

O Under an aggressive scenario where renewable growth doubles the 10-year average rate (10.96%), the crossover point arrives as early as 2035 under constant energy demand, or 2037 accounting for rising demand.

In the most conservative scenario, renewables may not surpass fossil fuels even by 2074, or not at all by the end of the century.

MULTI-TECHNOLOGY APPROACH

A crucial insight from the IIT Madras study is that renewable energy alone is insufficient to achieve net-zero by 2050. The researchers stress that fossil fuels, particularly coal and oil will continue to play a significant role in the global energy mix for at least the next two to three decades, especially in rapidly developing economies.

The path to net-zero must therefore be complemented by:

O Carbon Capture, Utilisation, and Storage (CCUS) technologies

O Advanced energy storage solutions (batteries, pumped hydro, green hydrogen)

O Improvements in energy efficiency across all sectors

O Smart grid modernisation to handle the intermittent nature of solar and wind power