Beyond electric: lifting the lid on four alternative fuels
Battery electric has become the powertrain of choice for sustainable motoring – driven by stringent environmental regulations, upcoming bans on internal combustion engines (ICE) and a global push to mitigate climate change.
But are there other, less discussed, fuels that could still have a future in our fleet transport ecosystem?
From a fuel derived from vegetable oils to one made from water and CO2, we shine a spotlight on some of the lesser-known alternatives.
Will hydrogen be the ‘next big thing’?
People have long lauded the virtues of hydrogen as an alternative vehicle fuel but, unlike electric, it has yet to become commonplace.
The exorbitant cost of technology required to convert the gas into electricity to power the vehicles certainly has not helped its cause.
What’s more, despite generating zero exhaust emissions, producing hydrogen on an industrial scale uses large amounts of fossil fuels, meaning it isn’t as eco-friendly as electric. Although green hydrogen production, which uses renewable energy to produce hydrogen from water, is now available, the process is still in its infancy and not widely available.
So, does hydrogen still have a role to play on our road to net zero? Perhaps.
Unlike electric batteries which take a protracted period of time to recharge, hydrogen-fuelled vehicles can be refuelled in just a matter of minutes – from this perspective, they are comparable to petrol and diesel vehicles.
They also deliver a greater driving range as they can store more energy than batteries, without compromising the weight of the vehicle. This may prove particularly beneficial for HGVs, which require significant energy to haul heavy loads over long distances.
It is because of these advantages that investments in hydrogen fuel continue to be made.
The EU’s ‘European Clean Hydrogen Alliance’, and governments globally, have allocated considerable funds to advance green hydrogen production, build infrastructure and drive the transition to a hydrogen-based economy. Cities such as London have already introduced hydrogen buses into their public transport fleets, while countries like France are offering subsidies for hydrogen developments and innovation.
Biodiesel under the microscope
Derived from vegetable oils, animal fats or cooking grease, biodiesel is certainly one of the more readily available alternative fuels on the market.
It works as a direct replacement or supplement to standard diesel fuel, but it burns cleaner, leading to fewer emissions. It is also more biodegradable and less toxic, meaning road traffic accidents pose less of a threat to the environment.
Biodiesel can be used in diesel engines, so unlike many other alternative fuels, fleets don’t have to face additional costs to transition. However, what they save here risks being offset by higher fuel prices, resulting from high ingredient costs and complex processing requirements.
As technology improves, production increases and cheaper ingredients, such as waste oils, are utilised, the price gap may narrow.
Other considerations include its feasibility in colder climates. Biodiesel gels at low temperatures which can lead to potential engine and fuel system issues. This calls for the use of additives or blended fuels.
What are the prospects of natural gas mobility?
There are two types of natural gas fuels – compressed natural gas (CNG) and liquified natural gas (LNG) – both of which are seen as cleaner alternatives to petrol and diesel.
Natural gas, however, is still considered a non-renewable fossil fuel as it is made from methane and its extraction and processing have environmental impacts.
To address these concerns, renewable natural gas (RNG) – also known as biomethane – has been developed from the decomposition of organic matter, resulting in a significantly lower carbon footprint.
Natural gas vehicles are typically quieter than diesel vehicles and, consequently, are particularly well-suited for urban environments where noise pollution is a concern. They may prove a panacea for industry sectors such as recycling, for example, where companies operating rubbish trucks in the early hours of the morning can benefit from the quieter operation of natural gas vehicles.
A spotlight on e-fuel propulsion
E-fuels – also known as synthetic fuels and electrofuels – have been hitting the headlines of late.
The German government recently advocated for a loophole in the EU’s proposed phase-out of ICE cars, pushing to allow the continued production of ICE vehicles that run on e-fuels. This, it is argued, would allow for a more gradual transition from fossil fuels.
But what are they, and is mass adoption possible?
Made from water and CO2, e-fuels are carbon neutral and don’t require a vehicle to be modified due to their compatibility with ICE engines. Refuelling is also quick, while existing infrastructure, such as petrol stations and pipelines, can also be utilised.
Cost, however, remains a downside. E-fuels are expensive to produce, cost fleets more to refuel and have a complex supply chain.
A number of initiatives are currently spearheading the e-fuel movement, including the eFuel Alliance, which is lobbying for policy frameworks that support synthetic fuels in the EU.
Similarly, Porsche and Siemens Energy’s Haru Oni project in Chile is ambitiously pioneering the generation of e-fuels using wind power.
E-fuels hold great promise as a viable alternative to conventional fossil fuels, however continued innovation and a reduction in costs are essential for their widespread adoption.