NEW DELHI: A new report has revealed hybrid electric vehicles (HEVs) in India exhibit the greatest disparity between laboratory-tested and real-world fuel efficiency, consequently, leading to more carbon emission.
The joint study conducted by IIT Roorkee and the International Council for Clean Transport (ICCT) suggests India’s HEV emission warrants a closer examination and highlights the urgency of closing the gap between lab results and on-road performance to enhance passenger car efficiency and reduce their climate impact.
Transportation sector is responsible for nearly 14 per cent of the country’s total greenhouse gases (GHGs) emissions. It also is the fastest-growing sector in terms of annual GHG emissions.
In 2022-23, approximately 3.9 million passenger cars were sold in India, making it the third-largest passenger vehicle market after China and the United States. The battery electric vehicles (BEV) sales share in the country stood at 2 pc but is fast gaining traction as government policy aggressively promotes it.
At COP26, India committed to achieve net zero by 2070 and the Centre has reaffirmed the climate goal from time to time.
Reality Check for India’s Transport Emissions
The study, titled Review of Greenhouse Gas Life-Cycle Assessments of Passenger Cars in India, indicates that the discrepancy in emission data for real-world adjustments is most significant for HEVs, followed by internal combustion engine vehicles (ICEVs) and lowest in BEVs.
Its findings show that the mean values of energy consumption adjustment factors for HEVs range from 1.27 to 1.50, whereas ICEVs fall between 1.24 and 1.34. For BEVs, the adjustment factor range is between 1.34 and 1.46. Nevertheless, the study demonstrates that BEVs consistently outperform both ICEVs and HEVs regarding life-cycle GHG emissions. Specifically, BEVs in India emit up to 38 pc less CO2e per km than ICEVs in the passenger car segment.
In the sedan category, the mean test-cycle energy consumption value for BEV is in the range of 0.5-0.6 MJ/km (megajoules per kilometer), whereas ICE is in the range of 1.7-2.1 MJ/km and HEV is in the range of 1.1-1.3 MJ/km. MJ/km is a unit of measurement for energy consumption or efficiency.
Similarly, under the SUV section, the mean test-cycle energy consumption value of BEV is in the range of 0.3-1.0 MJ/km against the values of 1.7-2.0 MJ/km and 1.2-1.3 MJ/km for ICE and HEV segments respectively.
Besides, there is a significant potential for emission reduction if India’s power grid shifts towards cleaner or renewable energy sources, the report points out. Coal power predominates India's energy grid, accounting for over 70 pc of total energy production.
Experts emphasise that more rapid adoption of BEVs can significantly diminish the environmental impact of greenhouse gas emissions throughout the ICEV's life cycle.
“Differences in grid mix and real-world driving conditions can swing life-cycle emissions by up to 368 g CO2e/km, which is roughly equivalent to adding the emissions of two to three petrol cars for every km driven,” said Sunitha Anup, a researcher at IICT and co-author of the study.
The report further highlights the need for faster adoption of BEV passenger vehicle fleet, which is a critical step toward broader climate and sustainability goals and mitigating climate change impacts. While recommending acceleration in the adoption of BEVs and continued grid-decarbonisation efforts, it also urges policymakers to enforce real-world adjustment factors to close the gap between lab results and on-road performance. Moreover, the need for onboard fuel and energy consumption meters (OBFCMs) to improve transparency and data accuracy across all vehicle types is emphasised by the researchers. The report also points out the current adoption of biofuels without accounting for the impacts it is causing on land-use change and the environment.