“Start your engines” - A phrase that might soon go extinct along with the fuel powering them. Fossil fuels like petrol and diesel have been the mainstay of all our automotive needs for over a century, but their harmful environmental impacts are on the verge of rendering these obsolete. Moreover, India doesn’t have enough oil wells to fuel its mass needs and has to rely on exported barrels for sufficient supply. The import costs of fossil fuels burn a significant hole in our country’s budget, ultimately leading to inflation. 

Electric propulsion appears to have caught on as the favourite replacement. Its primary advantage of zero emissions has drawn not only the carmakers towards it but also the masses and state leaders. The European Union has already announced a strict ban on the sale of new ICE or internal combustion engines from 2035 and sees EVs or electric vehicles as the ones to fill the mobility gaps. Even carmakers like Mercedes-Benz and Volkswagen remain confident of transitioning their entire product line to EV-only by 2030 or beyond. However, EVs pose their own share of disadvantages which may raise issues upon mass adoption. So, is it the only way forward? Let’s assess.

Challenges With Battery Propulsion
Touted to be the transportation fuel of the future, electrification has been around longer than it is given credit for. Over the past two decades, battery-powered electric propulsion has elbowed its way into hybrid guise. The recent past sees electric motors and battery packs graduating from mere assisting power generators to a standalone powertrain by themselves. While these battery-powered cars have enabled emissions-free mobility, the initial electricity production may not be a clean and green process.
 
Coal plants are the primary source of electricity generation for most countries. Hence, charging up these EVs via these thermal powered electric grids ultimately shifts the emissions source from the ICE-powered car’s tailpipe to the coal plant. So, while the end consumer may boast of having a zero-emissions vehicle, the emissions or the harmful environmental impact continues to sustain upon charging these vehicles using a thermal powered electricity grid. 

To sustain a fuel source that remains green throughout its production process, we must look beyond batteries and the associated charging scheme. Here are some alternatives for the same.

Hydrogen Fuel Cells
Hydrogen, more commonly known as a subset of water, is one potential energy source being looked over by carmakers. It traces its fuel-source origins back to NASA, the American space organisation using hydrogen as rocket fuel to deliver its cargo and crew into space. Essentially, if a fuel source can sustain extreme conditions faced by space shuttles, it most certainly can be utilised to power our vehicles.
 
Japanese carmakers like Toyota and Honda have already readied production-spec Hydrogen Fuel Cell-powered vehicles called the Mirai and FCX Clarity, respectively. The feasibility of the Toyota Mirai was even advocated by Nitin Gadkari, India’s Road and Transport Minister, as he continues to test the same on Indian roads. And in principle, hydrogen fuel cell electric vehicles or FCEVs combine the best of battery-powered EVs and the conventional car. It boasts a zero carbon emission output, courtesy of an electric motor powertrain and a quick refuelling time via a hydrogen gas pump. The only emission an FCEV puts out is water, which some claim is as clean as drinking water.

The principle behind hydrogen fuel cells consists of hydrogen being stored in tanks within the vehicle, similar to conventional petrol tanks. These hydrogen gas tanks react with oxygen in the air to produce electricity by an electric motor that propels the car. Excess energy generated gets stored in a small battery pack embedded within the car that can also power the vehicle to reduce dependency on hydrogen. The only point of concern is the fuel and its feasibility in the mass-market application. 
Scaling hydrogen down for daily usability is becoming an expensive venture for car manufacturers. Developing hydrogen for mass utilisation incurs high initial production costs that can get difficult for manufacturers to bear. Apart from production, even distribution of hydrogen via pipelines would require a suitable infrastructure built with compatible materials, increasing the upfront costs much further. Plus, hydrogen storage is a complicated affair as hydrogen is notably less dense than gasoline and needs compression under high pressure. Any hydrogen gas leaks can be fatal for users as they remain a highly flammable substance whilst lacking odour, making tank or gas leaks challenging to detect.
 
Even the end consumer faces issues with FCEV cars, such as a lack of options and an almost non-existent hydrogen station infrastructure. The United Kingdom, one of the more receptive countries to newer technologies, reportedly had over 26,000 EV charging stations by 2021 but just 16 hydrogen refuelling stations. The subcontinent is seeing an exponential increase in electric charging stations but boasts of just two hydrogen pumps, both inaugurated in 2022 in the Delhi NCR area. Though, policies such as implementing commercial hydrogen buses in metropolitan Indian cities in the near future are signs of this alternative fuel gradually picking up pace.

Ethanol
Ethanol is one fuel source that enforces minimal alterations to our existing setup. Ethanol (or ethyl alcohol or grain alcohol) is a clear, colourless alcohol liquid produced from various biomass materials called feedstocks. This feedstock ranges from crops grown in fields (wheat, maise, sugarcane) to crop residues and wastes (rice straw, wood chips). Ethanol gets used as a mixture with petrol to feed the engine. The engine also requires changes to its combustion process to utilise the ethanol fuel source effectively. Such engines are called flex-fuel engines, and the same is being pushed or rather mandated by Mr. Nitin Gadkari for all carmakers operating in India. 
Last year, Mr. Gadkari announced an upcoming legislation that would mandate the carmakers to release vehicles equipped with flex-fuel engines. Such engines would mean cars can be filled up with either pure petrol or pure 100 per cent ethanol or even a mixture of both petrol-ethanol, known as biofuel. Burning biofuel has a greener environmental impact than conventional fossil fuels as the carbon emissions get offset by the carbon intake of the feedstock crops grown to produce ethanol.
The biofuel can carry petrol-ethanol combinations in various amounts, ranging from E5, that is, 5 per cent ethanol and 95 per cent petrol, to a full-blown E100, which is pure 100 per cent ethanol. For the unaware, India already sees blended fuel from as early as 2018. The proportion of ethanol blended with petrol was a mere 2 per cent then and a paltry 0.1 per cent in diesel. But the updated targets will see these figures increase to 20 and 5 per cent respectively. This shall put India in the same league as the USA and Brazil, which have deployed biofuel for decades.

Biofuel presents a host of benefits that build upon the existing mobility infrastructure. For instance, biofuels are retailed using conventional petrol pumps entailing minimal upfront infrastructural costs. Biofuels can be deployed on the existing array of cars till a permissible limit. Being a food produce derivative, the production costs are low and can further benefit from India’s dominant agricultural sector with increased feedstock production. Additionally, increased ethanol concentration results in lower fossil fuel requirement resulting in a reduced fuel import bill, thereby minimalising India’s economic inflation.

Though a 100 per cent ethanol blend does affect the combustion inside the engine, leading to discrepancies in performance and efficiency. Plus, bioethanol is difficult to vaporise at low temperatures making it difficult for E100-filled vehicles to start in cold weather. Ethanol may have a higher octane number than petrol, but the energy derived from it is lower than fossil fuels, meaning one would require ethanol in larger quantities to obtain the same performance, so what one gains in reduced per litre costs is lost due to increased quantity needs.

Synthetic Fuel
Not all car companies want to transition from making conventional cars to EVs, and Porsche is certainly a frontrunner on this list. Though the only way to retain ICE cars is to minimise the associated emissions, the German sports carmaker may have found just the alternative. Porsche calls it eFuel, and it is made out of carbon dioxide and hydrogen and produced using renewable energy. The final result is a liquid that an engine will burn the same as if it was petrol or diesel made from crude oil, requiring no alterations to the existing automotive architecture.

Frank Walliser, Porsche’s Vice President of Motorsport said, “Synthetic fuel is cleaner and there is no byproduct, and when we start full production we expect a CO2 reduction of 85 percent”. A complete transition from our current ICE fleet to an electric-propelled one will take decades to materialise, and these eFuels can help acquire sustainable and low-emission mobility until we’ve reached the said stage. While most global carmakers have set 2030 as the deadline year to electrify their product line-up, Porsche has the same deadline but for testing eFuels so it could get implemented on a mass market scale. The firm even invested USD 75million in August 2022 to acquire a Chilean startup called HIF Global that develops eFuels. 

While the initial costs of eFuels might be steeper, increased supply and efficiencies in production are said to bring those costs down. Porsche envisions the eFuel to get sold in the usual crop of petrol stations. Furthermore, Porsche plans to supply these eFuels to not just road cars but even the most prominent motorsport federations, including Formula 1. Though before these fuels get adopted by the pinnacle of motorsport, Porsche would like to vehemently assess the fuel with its homegrown one-maker racing series in European countries.

Natural Gas
LPG or Liquefied Petroleum Gas and CNG or Compressed Natural Gas is energy sources already used by many carmakers and users. Its feasibility stems from its clean-burning attributes, easy availability, and large-scale domestic application in India. Additionally, LPG is said to rank third in the world’s most common transportation fuel behind petrol and diesel, so it already boasts of a widespread application and reliable infrastructure for its supply. One may have seen the local auto-rickshaws that are mandated to run on LPG, which further provides the user with reduced expenses than petrol, one of the few advantages of LPG. 

Another advantage is the natural gas’ high octane rating which makes it prone to perform well in spark-ignited internal combustion engines. Moreover, a low carbon count in LPG allows it to put out close to 50 per cent lower emissions than petrol or diesel while also ensuring minimal engine maintenance costs, courtesy of no carbon deposits on spark plugs. Plus, LPG works well in retaining the life of an engine as this alternate fuel doesn’t wash off the lubrication from the piston walls in case of leakage to the crankcase. 

However, there is little to no development initiative being taken up by carmakers to shift to natural gas. This alternate fuel is being offered only by carmakers like Maruti Suzuki and Hyundai in their affordable vehicles but only in the capacity of a secondary fuel source as these gas energy sources aren’t capable of providing fossil-fuel-levels of performance. While one can have LPG or CNG tanks retrofitted on their existing vehicles, the boot space ultimately gets compromised to house the same. Adding these natural gas tanks to your car can also void the manufacturer warranty of your vehicle. Furthermore, these natural gas’ burn entirely rather than partially with fossil fuels, entailing high temperatures across the engine that may reduce the power unit’s overall life.

Tailpiece
While batteries may seem like the absolute favourite in our future of mobility, it continues to pose problems that alternate fuel sources can minimise or, in some cases, even eliminate. Not to mention, our conventional cars already run their auxiliary functions such as infotainment, lights and software on a battery and adding powertrain duties to the mix may not be a wise choice. 

Besides, the human race already enjoyed a choice between petrol and diesel even before our current technological advancements.  Therefore why should we pin all our mobility activities to a single energy source in our future when we are bound to achieve more technological prowess than ever before.