India is one of the fastest-growing economies in the world. While the expansion and improvement of road transport improves socio-economic development, they have also brought significant environmental challenges in India, including a sharp rise in CO2 emissions and air pollutants such as nitrogen oxides (NOX) and fine particulate matter (PM2.5). As per International Energy Agency’s report, 12% of India’s energy related CO2 emissions come from road transport. As India aims to meet the rising demand for private mobility and goods transportation, energy use and CO2 emissions from road transport could potentially double by 2050. Air pollution is one of the most urgent environmental issues in India. Among the 50 most polluted cities worldwide, 35 are in India. Reducing transport-related emissions would directly benefit public health.
Oil products, primarily gasoline and diesel, dominate the energy consumption in this sector, accounting for 95% of the demand and road transport is the largest oil-consuming sector in India. According to GlobalData, transport is set to become India's fastest-growing sector, with an estimated compound annual growth rate of 7.5% until 2035. India's fuel consumption for FY2024 increased by 5%, reaching a record high as growth in trade boosted the transport sector. With limited domestic oil resources, the increasing transport activity and fuel consumption have significantly raised India’s dependence on crude oil imports over the past two decades (Figure 1). Hence, decarbonizing transport by reducing oil dependency, enhancing energy efficiency and cutting vehicle emissions is a critical need for India as it rapidly develops.
Figure 1: India's Crude Oil Imports from 1980 to 2022 (Barrels/Day) | Organisation of Petroleum Exporting Countries
Renewable fuels in transportation
Electric vehicles (EVs) are at the forefront of India's sustainable transport revolution. In 2023, India's EV market experienced impressive growth, with over 1.5 million units sold, marking a 50% increase from the previous year. Government initiatives like the Faster Adoption and Manufacturing of Hybrid and Electric Vehicles (FAME) India scheme have been instrumental in this expansion by providing subsidies and promoting the development of advanced batteries.
But India's push for sustainable transportation extends beyond electric vehicles to include alternative fuels like hydrogen fuel cells and biofuels. The National Hydrogen Energy Mission aims to establish India as a global hydrogen exporter. Likewise, the National Policy on Biofuels, 2018 expands the scope of raw material for ethanol production. These policies and strategies, by reducing reliance on non-renewable resources, are paving the way for a more sustainable future in India's transportation sector.
Electric vehicles: Electric vehicles use electric power for propulsion, eliminating the emission of polluting exhaust gases unlike internal combustion engines. This results in a significant reduction of the vehicle’s onroad carbon footprint. While EVs may have a higher initial cost, owners benefit from lower maintenance and operating expenses compared to traditional vehicles. Electric cars have fewer moving parts than conventional vehicles, making them less complicated to service and reducing maintenance costs. The annual maintenance of EVs can be as low as one-fourth the cost of petrol cars. In terms of running costs, a small petrol car typically costs around Rs. 7-8 per kilometre, whereas an electric car costs only Rs. 1-1.5 per kilometre, which is significantly lower. Additionally, renewable energy sources, especially solar power, are being utilised to charge EVs, making the shift to electric transport both sustainable and economically viable.
Hydrogen fuel cell vehicles: Hydrogen fuel cell vehicles use a propulsion system similar to that of electric vehicles, converting hydrogen into electricity through a fuel cell. They are more efficient than conventional internal combustion engine vehicles and produce no harmful tailpipe emissions, emitting only water vapour and warm air. One of the key advantages of hydrogen fuel cells is their rapid charging time, comparable to that of re-fuelling conventional internal combustion engine vehicles and significantly faster than charging battery-powered electric vehicles. While electric vehicles take between 30 minutes to several hours to charge, hydrogen fuel cells can be refuelled in under five minutes, offering the same flexibility as conventional cars.
Hydrogen fuel cells also provide greater efficiency regarding distance covered. A hydrogen vehicle has a range comparable to fossil fuel-powered vehicles, which is superior to most electric vehicles currently available. Additionally, hydrogen fuel cells are not significantly affected by outside temperatures and do not deteriorate in cold weather, unlike electric vehicles. Adding to these benefits, hydrogen fuel cells also produce no noise pollution.
Biofuels: Biofuels are derived from biomass, such as plants, and can be used as transport fuel. Biomass offers various options for creating substitutes for both gasoline and diesel fuel. Well-known examples include ethanol as a gasoline replacement and processed vegetable oils (biodiesel) as a diesel substitute. The CO2 emissions of current biofuels vary depending on their production methods. For instance, ethanol made from Brazilian sugarcane produces about 70% lower CO2 emissions from production to use compared to petrol. Ethanol, the most widespread biofuel today, is typically made from starchy or sugary plants.
Figure 2: Reduction in emission of greenhouse gases by biofuels compared to petrol | Bentivoglio and Rasetti
According to the International Renewable Energy Agency (IRENA), biodiesel and compressed natural gas (CNG) emit 70% fewer carbon emissions than conventional fossil fuels. Many countries use a blend of petrol or diesel with biodiesel to power their vehicles and reduce carbon emissions. Bioethanol, a common type of biodiesel, can be mixed with petrol in cars without requiring any engine modifications. European countries have already started incorporating biodiesel into their fuel mix. E10, a type of fuel which has 10% blended bioethanol, is available in countries such as Germany, Denmark, Belgium and others.
Additionally, biodiesel from microalgae appears to be the most promising renewable biofuel, with the potential to completely replace petroleum-derived transport fuel without negatively impacting the supply of food and other crop products. This is because microalgae can be cultivated on land and in water unsuitable for food production, thereby alleviating pressure on already scarce resources. Despite these advantages, the primary obstacle to the widespread use of algae for biofuel production is their high cultivation cost.
Challenges
Electric vehicles: Currently, the electricity demand for India is met by burning fossil fuels, mostly coal. Thus, using coal-powered electricity for EVs would undermine the goal of reducing carbon emissions through EV adoption. Improper disposal of EV batteries can release toxic heavy metals into ecosystems, posing long-term threats to the environment and human health. Additionally, mining raw materials for electric vehicle batteries has a significant carbon footprint. To support the growing number of EVs, increasing amounts of lithium, cobalt, nickel are being extracted and refined for vehicle batteries, posing serious environmental threats. These minerals are concentrated in specific geographical regions, and as nations ramp up EV production, securing these resources becomes a major politico-economic and environmental concern. Also, electric vehicles (EVs) need robust charging infrastructure, longer driving ranges, and cost-effective battery technologies to be competitive with conventional vehicles.
Hydrogen fuel cell vehicles: Hydrogen fuel cells face significant challenges due to hydrogen not existing on its own, despite being the most abundant element in the universe. It must be extracted from water through electrolysis or separated from carbon-based fossil fuels, both of which require substantial energy. This energy input can exceed the energy obtained from hydrogen and is costly. Precious metals like platinum and iridium, essential for catalysis in fuel cells and some water electrolysers, contribute to the high initial cost of fuel cells. Additionally, if fossil fuels are used, the environmental benefits of hydrogen are compromised.
Hydrogen-powered vehicles also require extensive refuelling infrastructure and face hurdles related to hydrogen production, distribution, and storage.Transporting and storing hydrogen is more complex than handling fossil fuels. Currently, the cost per unit of power from hydrogen fuel cells is higher compared to other energy sources. When compared to electric vehicles, hydrogen vehicles also tend to have lower tank-to wheel conversion efficiency.
Figure 3: Comparison of efficiency of electric and hydrogen vehicle power trains | Copenhagen Centre on Energy Efficiency
Additionally, safety concerns arise due to hydrogen's highly flammable nature, burning in air at concentrations of 4 to 75%. Overcoming these challenges demands significant investments in infrastructure development and technological innovation.
Biofuels: Challenges related to feedstock availability and infrastructure requirements are hindering biofuel production in India. Establishing production facilities, transportation networks, and storage infrastructure demands significant investments. Biodiesel production faces obstacles such as low procurement by oil companies and limited incentives for farmers to cultivate feedstock.
For biofuel production, converting new land for cultivation involves clearing existing natural vegetation, which releases stored carbon. Additionally, the use of chemical fertilisers releases nitrous oxide, a greenhouse gas with a global warming potential 300 times greater than carbon dioxide. Energy used in transporting feedstock further contributes to overall carbon emissions. As a result, there is uncertainty at each stage of the fuel supply chain, and emissions can vary significantly based on land availability and the efficiency of the agricultural system in a given country. Increasing the blending ratio of biodiesel can pose risks such as engine compatibility issues, degradation of vehicle equipment, increased local pollution, and ultimately undermining the environmental benefits of using biofuels.
Conclusion
Using vehicles powered by alternative fuels such as electricity, hydrogen, and biofuels is seen as an ideal way to reduce harmful vehicular emissions. However, the sustainable use of these alternative fuels raises questions about resource availability, potential risks, and end-of-life management, necessitating a comprehensive assessment of factors influencing their use in transportation. Although battery and fuel cell vehicles are locally zero-emission vehicles (ZEVs), they face challenges such as resource scarcity, infrastructure limitations, and high costs, which hinder their market penetration and consumer acceptance. Biofuels, while compatible with existing vehicles, present challenges in securing adequate feedstock and addressing food versus fuel issues.
Overcoming these challenges is crucial for the sustained use of alternative fuels as primary vehicular fuels. To effectively compete with fossil fuels, renewable fuels must be economical, widely available, and sufficiently energy-dense to significantly reduce emissions. Otherwise, there is a risk of favouring petrofuels over renewables. The use of alternative fuels presents certain challenges that require immediate attention but can be addressed through continuous efforts and innovation.
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