Against the backdrop of the UN Climate Change Conference (COP28), and with our 2023 MOVE pledge in mind, we recommend reflecting on this haunting new video from the World Wildlife Fund (WWF):

Despite what event president Sultan Al Jaber (also chief exec of the Abu Dhabi National Oil Company!) might think, the hugely respected WWF emphasises that oil, coal and gas use is a “main driver” of climate change.

To help people and nature, it therefore urges COP28 leaders to agree on a plan to phase out fossil fuels and move towards more efficient, sustainable, renewable energy “now”.

Clearly this doesn’t sit comfortably with Prime Minister Rishi Sunak pushing the deadline for new petrol and diesel car sales back to 2035. Amidst some support for this controversial move (mainly on cost grounds), but plenty of vocal criticism, we look at three leading clean fuel contenders: batteries, biofuels and hydrogen.

Battery electric

First up, the champion elect: battery electric vehicles (BEVs). With roots dating back to Robert Davidson’s 1830s electric locomotive, BEVs use a rechargeable lithium-ion battery connected to at least one electric motor.

In September, the Society of Motor Manufacturers and Traders (SMMT) reported the 41st consecutive month of BEV sales increases, and an impressive 18.9% year-on-year uplift. Bestsellers include Tesla’s Y and 3, Kia’s e-Niro, VW’s ID.3 and Nissan’s Leaf.

Leaving aside the question of who’s to blame for the lack of infrastructure, the UK government has committed £1.6bn to the mission, equating to 300,000 new public chargers by 2030. According to charging map provider Zap Map, there are currently 50,000 points across the UK, up 43% in just 12 months.

Serious advances are being made on recharging times too, with BP claiming its new Pulse 150kw charger can deliver up to 100-miles-worth of juice in around 15 minutes.

The range anxiety argument is fading as ever more models deliver 300+ miles on a full charge, and amazing battery advancements are being announced almost daily. For instance, Mahle recently claimed a ‘leap forward’ in cooling plate technology: 10% better cooling performance and 20% less pressure loss, all while saving 15% on materials.

This all sounds so positive, why isn’t everyone switching? Well, purchase price is still an issue. The RAC provides the example of MG Motor UK’s ZS Hatchback, with the electric version £8k more than its petrol equivalent, even with the plug-in grant. Attractive finance options help to soften this blow.

The picture gets even rosier when you look at running costs. Research by Compare the Market found an average saving of £600 per annum for EVs over petrol cars, taking into account insurance, fuel and road tax. Some suggest that fewer mechanical parts lead to lower service, maintenance and repair bills too.

Perhaps the last serious obstacle is the long waiting lists, with semiconductor supply chain problems making global headlines.

Biofuels

As with rechargeable batteries, experimentation with biofuels began in the mid-nineteenth century, using methanol or ethanol with potassium/sodium hydroxide as the catalyst. Their biggest selling point is that they are derived from renewable sources.

Millions of UK motorists use biofuels every day, whether they realise it or not. E10 unleaded petrol contains up to 10% bioethanol and B7 diesel up to 7% biodiesel. The bioethanol is made by fermenting crops such as corn and maize, while the biodiesel comes from vegetable oils combined with alcohol.

Their main drawback is that they still produce emissions when burned. The RAC also warned of E10 issues for up to 600,000 older vehicle owners. Although most would run E5, doubling the amount of ethanol caused a whole variety of issues in classics – from troublesome condensation in fuel lines to perished rubber hoses and seals.

The technology is improving though. One of the ‘second-generation’ biofuels, Hydrotreated Vegetable Oil (HVO), can be used in many standard diesel engines, and is endorsed by the likes of Caterpillar, Scania and Volvo.

What’s more, bespoke fuel specialist Coryton recently launched the Sustain Classic range, which it says is “The UK’s first publicly available sustainable petrol”. It includes three grades: Super 80, with at least 80% renewable content; Super 33, with at least a third renewable; and Racing 50, with at least 50% renewable.

David Richardson, business development director at Coryton, said: “We’re setting truthful and realistic goals, producing fuels that have a meaningful impact while meeting the demands of the user.”

At the very least, biofuels can be an effective bridging technology, with the US Renewable Fuels Association backing wider adoption in both road transport and aviation.

Hydrogen

Finally, we come to that long-touted rival to BEV, hydrogen. This has the longest history of all, with Swiss inventor François Isaac de Rivaz patenting a hydrogen-powered internal combustion engine in 1807.

Again, such vehicles are already on our roads, albeit in small numbers. Toyota makes great play of the fact that its hydrogen fuel cell electric vehicle (HFCEV) Mirai emits only water vapour.

“We’re fully committed to fuel cell, particularly for larger vehicles, because of the advantages in terms of range and refuelling time, but we’re also pursuing hybrid, plug-in hybrid, battery electric and hydrogen combustion, keeping all options open,” explained Katherine Chamberlain, senior manager for new product development at Toyota Motor Manufacturing UK.

In March, JCB unveiled a new hydrogen combustion engine designed specifically for heavy construction and agricultural equipment. Despite investing in battery electric for its smaller vehicles, the Staffordshire-based manufacturer needed a different solution for large machines working long shifts with little available downtime for recharging.

JCB Chairman, Anthony Bamford, said: “The unique combustion properties of hydrogen enable the hydrogen engine to deliver the same power, torque and efficiency that powers JCB machines today, but in a zero-carbon way.

“Hydrogen combustion engines also offer other significant benefits. By leveraging diesel engine technology and components, they do not require rare earth elements and, critically, combustion technology is already well proven.”

A major issue is that well over 90% of all hydrogen produced globally comes from natural gas, coal and oil. However, huge sums are being invested in industrial electrolysis – splitting water into hydrogen and oxygen – to overcome this thorny hurdle.

Clean fuel choices

Transport & Environment (T&E), Europe’s leading NGO campaigning for cleaner transport, has produced a handy chart detailing why direct electrification is “by far” the best technology.

The headline figures on the drive towards 100% renewable fuel production by 2050 are stark: 94% for direct electrification, 68% for hydrogen and only 55% for power-to-liquid (petrol and diesel). Pure electric is also the clear winner in terms of the amount of original energy required, up to five times more efficient than power-to-liquid alternatives.

Matt Finch, UK Policy Manager at T&E, said: “By 2050, the vast majority of cars around the world, certainly in the UK, will be 100% battery electric. There are a few good reasons for this. The first is blindingly obvious: the grid infrastructure exists and every household has an electricity supply. It might be slow, and we advise people to use proper chargers, but technically you can already charge an electric car from billions of points around the UK.

“Using electricity is dirt cheap compared to burning oil, biofuel or hydrogen. That’s the main reason everyone will switch, apart from a few classic cars running on efuel. EVs are also quieter, smoother and generally nicer to drive. 

“Biofuels are useful, although we massively over-rely on Malaysia and China for our feedstocks. What happens if they decide to refine it themselves to meet their own climate change targets? There’s an additional UK problem in that we still put millions of litres of palm-derived biodiesel into our cars. In the current round of policymaking for sustainable aviation fuel, palm is explicitly banned for environmental reasons, yet the Department for Transport still allows its use for road vehicles. That’s plain stupid.

“The fuelling question gets more interesting when you look at HGVs, but my personal take is that they will also all be battery electric. Batteries have been getting better for years and solid state is coming very soon. During the 2030s, HGVs with solid state batteries and decent ranges will arrive en masse. Then all the compelling car arguments come back in – smoother drive and far cheaper to run.

“I doubt we will ever have hydrogen trucks in the UK. There’s potentially a tiny tail of use cases, but then why should HGVs get this scarce resource ahead of aviation, shipping or the chemical industry? For various reasons, environmentally or societally, it’s hard to make a case. When you consider all the processes required to use hydrogen fuel cells, ultimately to power an electric motor, you end up asking: why bother when we can just use electricity?

“Virtually every major OEM has now stopped R&D on combustion vehicles in favour of battery vehicles. Some are funding their own battery development, some are buying them from the likes of Panasonic, but they’re all investing millions. There are tens of thousands of people in universities and manufacturing facilities around the world working on battery chemistries. That simply isn’t happening with combustion vehicles. The aviation industry is keeping a close eye on what’s happening in automotive, and it’s all focused on direct electrification.”