Natural gas is becoming an increasingly mainstream alternative to diesel for heavy-duty and long-haul transport. Fleet operators and policymakers alike are attracted to the lower fuel cost and the smaller carbon and air quality footprints. However, in other areas of road transport, the future of mobility appears to lie with electric and, in the longer-term, hydrogen.

At Gasrec, we’re passionate about providing the UK heavy-duty road transport sector with low emission, lower-cost solutions to diesel. Our customers know this, that’s why we’re frequently asked two things: Why are electric trucks not a viable alternative to diesel? And if they’re not viable now, when will they be?

Why isn’t electric viable for heavy-duty transport?

First and foremost, battery technology is not ready for heavy-duty electric transport. Replacing the equivalent energy of 100 litres of diesel would require a 3.5-tonne battery. Try fitting a battery that size onto a truck for which every inch of space holds commercial value and the downside is clear. In simple terms, fleet operators are confronted with a trade-off between range and payload that can’t be reconciled. Payload wins every time.

The issue of the trade-off was clear at the IAA Commerical Vehicles Exhibition in Hanover in October. The longest-range electric truck on display had a quoted range of 300km but a payload of only 17 tonnes. The heaviest fully laden payload was 37 tonnes but had a maximum range of only 100km. Whereas, some natural gas trucks can provide a range of over 1,000km and a payload of 44 tonnes.

The above graph shines a light on one of the biggest concerns over of electric vehicles, their range. Simply, range, with the flexibility it offers and the fewer refuelling times, is crucial to profitability.

However, there is another factor crucial to profitability – charging (or refuelling) time. In general, the more time a vehicle spends on the road the more cost-effective it can be – hence why heavy-duty vehicles will frequently double-shift. The aforementioned Volvo FL Electric needs around two hours on a DC charger and all of ten hours on AC mains. The DAF’s 100km range can be achieved in a 90-minute charge. For any operation, that’s a considerable amount of time out. Time not spent making money.

What are the other challenges for electric?

Another challenge electrification will face is the UK’s – and the wider world’s – capacity switch to renewable energy. It’s a truism that electric vehicles are only as environmentally friendly as the source of their electricity. Electricity from diesel or nuclear is no better for global warming than direct diesel sources.  Thus, if the UK is to electrify the transport industry it will need to massively increase its capacity to produce low-carbon electricity or risk a future as unsustainable as that threatened by diesel.

Tesla on the charge?

On the topic of electric trucks, Tesla’s Semi can’t be ignored, given the widespread media attention which partly led to pre-orders from companies such as Walmart. However, Tesla’s claim their Semi will achieve 800km, 40-tonne payload on a single charge has been met with some raised eyebrows and some commentators claiming the Semi ‘breaks the laws of physics’.

Bloomberg report that in order to meet Musk’s claims of 600km of range added to the Semi with a 30-minute charge, the proposed Megachargers would need an output of 1,200 kW—about ten times what a Tesla Supercharger is able to supply today.

According to Bloomberg’s estimates, to attain an 800km range, the Semi would need a 600 to 1,000 kWh battery. Assuming the middle ground, an 800 kWh unit, the battery itself, they say, would weigh 4.5 tonnes and cost over £78,000. Needless-to-say that does not amount to cost-effectiveness, For many, such a project will have to be seen to be believed.

Costs aside, others have raised concerns that the politics, supply chain problems, and lack of global scientific experience with battery technology mean the “European battery push is too frenetic to work well”.

If not now, when?

The prospects of battery technology improving sufficiently in the next decade are slim, especially with manufacturers aware that by the end of same period hydrogen technologies may have already made electric trucks all but obsolete. Battery technology will improve from other catalysts but by that stage it may be irrelevant to truck. Safe to say then, for many businesses electric will remain unworkable for at least two or three truck procurement cycles.

Towards a mixed transport model

The state of battery technology and the lack of prospects for any near-term improvement are likely to continue to hamper the technology from reaching any sort of maturity. Spatial constraints of batteries in their current state make them impractical for the task of hauling 40-plus tonnes of goods across continents, and even countries. And we haven’t even mentioned the environmental fall-out of mining of lithium, the vital component in lithium-ion batteries, or the various problems caused by cobalt mining. 

Air pollution and greenhouse gas emissions are the main drivers behind the move to electrification of road transport. However, it would be naive to assume these are at the forefront of the minds of operators who are judged primarily on their ability to run a profitable fleet.  Payload and range will remain the two most important factors to profitability, with environmental factors a secondary concern.

At Gasrec we don’t claim to be impartial. However, it may be that the impartial observer would consider that gas covers more bases than electric with its ability to achieve a 1,600km range with a 40-tonne payload or a 1000km range with a 44-tonne payload. Add to that an engine half as quiet as a diesel, a 15% lower carbon footprint than diesel, and a 70-90% lower air quality footprint and all the elements of a successful and viable technology are there. Until hydrogen arrives – and that may be another two decades – gas is likely will hold sway as a diesel alternative.