Engineering Net Zero Part 2: How We Can Give Consumers Choice in the Push for Green Transport

Article by David Simmonds CEng FIChemE

David Simmonds discusses the need to accelerate flexibility when it comes to cleaner transport options

OUR JOURNEY to net zero is being mapped out by government and policy makers, but they are pushing consumers and businesses down an uncertain path, and one which may not lead to success. As engineers I believe we must support a range of transitional technologies which can transport society to that greener future. Our community must develop technologies that offer savings, efficiency, flexibility and, most importantly, the choice needed to convince consumers to embrace change and come along for the ride.

In my first article about Engineering Net Zero, I highlighted how engineers need to communicate plans to underpin net zero policies. I stressed that these plans are difficult to prepare because of the uncertainties around energy demand and technology development, and perhaps more importantly, the scale of the transition. In this and my next feature I address the need for engineers to join forces in supporting two sectors that the UK’s independent Climate Change Committee (CCC), in its recent report to Parliament, says should have the most immediate impact: light transport and domestic heating. More on the CCC findings can be found in this YouTube video and there are also the two features Justin Rowlatt presented on BBC One that provide relevant analysis and unsettling conclusions.

The uncertainties about how we will achieve emissions reductions are perhaps best demonstrated by looking at Figure 1 which is taken from the UK government’s Net Zero Strategy. The figure’s title pretty much says it all as the chart blurs the emission reduction contributions from each sector; effectively straight-lining those reductions. I do not blame the government for creating such a chart, as they don’t have the data to present anything more convincing.

Figure 1: Indicative delivery pathway to 2037 by sector. Source: BEIS Analysis (2021)

You’ll notice that the most significant contributors to today’s emissions are indeed “domestic transport” and “heat and buildings”, represented by the dark red and orange areas in the chart. The pathways for their reductions, which primarily rely on electrified solutions, are far from certain and public support for any such measures are not guaranteed. They are hard nuts to crack due to their scale and the lumpy nature of energy demand. Engineers will need to keep their options open and anyone expecting a single technology to deliver this alone will be disappointed. Perhaps surprisingly, both transport and heat have the potential for similar solutions that benefit from the synergies between competing technologies, and would allow the government to tell a more compelling and convincing net zero story to both consumers and investors.

Driving change

The UK government’s one-track plan for cars and vans is somewhat clearer than its plan for domestic heating. In order to promote increased efficiency and reduce emissions, its stated policy is to terminate sales of all internal combustion engine models for petrol and diesel by 2030, though some plug-in fossil fuel hybrids are likely to be allowed until 2035. The take-up of electric cars over the last few years has been startling with the Society of Motor Manufacturers and Traders (SMMT) reporting that the total number of plug-in cars registered has jumped from less than 500,000 in 2020 to more than 1.25m today. And the government’s goal appears to be gaining traction as demand for diesel cars has seen an 17% decline year to date, though new car sales have fallen to their a 30-year low. This was partly due to Covid and its associated impacts on production, but more recently due to inflation and cost of living pressures.

In spite of the government introducing an ambitious zero emission vehicle mandate in March and major carmakers blowing their advertising budget on new models, the high price for electric vehicles, uncertainty over possible future changes to policy and calls from think tanks to introduce a levy on electric car drivers are no doubt putting the brakes on consumer confidence. Commentators, like Giles Coren who used his column in The Times to outline why he’s pulled the plug on his electric car, are certain to amplify consumer fears.

Electric vehicle charging

Beyond price, there are concerns within industry that the government mandate will be undermined by consumers being unable to recharge their cars, as the complete replacement of our transport fleet on a like for like basis will double today’s electricity demand. The government has set a target of installing 300,000 public charging points by 2030, but local councils, which are crucial for delivering this target, are reportedly not on track. But while car charging presents challenges, there are also opportunities.

Home charging: For those who have space to install a domestic electric vehicle charger, charging at home presents little or no problem as they can trickle-charge directly. Indeed the RAC Foundation noted in 2021 that the average vehicle is parked at home for 73% of the time. Electric vehicle owners can also benefit from the lower night-time electricity rates offered by companies such as Octopus or on a regulated schedule basis as offered by Ovo. But of course, many households do not have space to install their own charger so have to rely on public charging points. On-street charging is under the remit and planning consent of local authorities but implemented by companies such as Trojan Energy. Roll-out of these regulated street charging schemes is slow, indeed very slow outside of London, and this delay and the cost are significant deterrents to many drivers. It is why SMMT is asking the government to cut VAT on electricity at public chargers to accelerate installation and use.

In journey charging: range control is a stress factor for many who regularly drive long distances. Again the provision of fast electric chargers is being left to private enterprise, such as Gridserve, who have a demonstrator service station on the A131, near Braintree in Essex. The numbers are increasing, but not at the rate needed to satisfy the increasing number of electric vehicles on the road. Furthermore, drivers experience significant inconvenience at peak times such as bank holidays and the start of summer holidays – the lumpy demand I mentioned. The provision of sufficient high-rate chargers for those high demand days will mean there is low average utilisation, reducing the capital efficiency of these chargers and, more significantly, the viability of their connection to the grid. The possible light at the end of the tunnel here could be the development of higher efficiency and higher energy density batteries that increase driving ranges.

Vehicle to grid systems: tomorrow’s electric vehicles will enable drivers to power their homes during periods of peak demand. Yes, electric vehicles will become little personal power plants that form part of the solution to power peak shaving.

Battery lifetime: a high-quality battery with an efficient battery management system can ensure a long battery life. However, as we are aware from the degradation of our phone batteries, their life is impacted by the number of times we recharge them, and by even how we charge them. Along with battery technology, battery management systems, which protect and prolong the life of battery banks, are also improving. However, as manufacturers rush out new models, they are limited by today’s technology. Most buyers of new cars are not worried about their vehicle’s life beyond say three to four years, but recent reports on the increasing depreciation rates on electric vehicles may prompt some consumers to think twice.

Pros and cons of electric vehicle charging methods

For many, an electric vehicle provides an ideal transport solution, but it is certainly not nirvana for everyone, especially those who cannot recharge at home or frequently drive long distances. At today’s fuel prices, petrol/diesel cars run at about 15p/mile. With a domestic 30p/kWh electricity price, an electric vehicle will run at about 10p/mile, though this can be halved when recharging at home using a night-time or scheduled rate. With average motoring at 6,500 miles per year, savings range from £300 to £600/year, a rate unlikely to repay the cost premium of an electric car, especially if you account for the cost of replacing the battery within the lifetime of the car. Clearly, higher mileage would bring forward savings but that is also likely to coincide with a higher utilisation of fast chargers at premium rates, and possibly having to replace the battery earlier.  

The growth in electric vehicles is likely to be limited by the capacity and flexibility of our power grid, and indeed this was one of the reservations coming from Rowlatt’s BBC programme. Electrical and mechanical engineers have a key role to play in not only extending our grid to capture new renewable resources, but also extending it to supply major car-charging hubs. Chemical engineers should be actively assisting their electrical colleagues by enhancing battery technologies, improving battery performance and life, and facilitating recyclability.

The manufacture of electric vehicles is another dimension we need to consider, though I will cover the resources required to make them in a future article, and, as we are seeing, the manufacturing base is likely to change. Indeed, the recent announcement that Tata will invest £4bn building a battery factory in the UK is good news, though our track record in attracting investment in this sector was marred by the failure of Britishvolt. We need this investment to retool the UK car and van manufacturing sector and deliver the models required to achieve the government’s targets. We have seen China capitalise on new technologies and they are now building cheaper electric vehicles as they use their domestic market as a test base for scaling up production. Indeed, one industry insider predicted that 80% of all new cars sold in China by the end of 2025 will be electric. New and old brands including BYD, Geely, and MG Motors (now under Chinese ownership) are and will be actively sold in the European marketplace undercutting traditional brands. As we will see in a later feature, they are achieving this through a stranglehold on lithium processing.


A green alternative to an electric vehicle is a hydrogen fuel cell car, though these have experienced a chequered development. Toyota led the way with its Mirai (which means future in Japanese) but its future is less than rosy because even on home territory, sales are dropping. Meanwhile, in the UK, Shell and Motive have closed their hydrogen refuelling stations, leaving just five operational sites. This is primarily due to the cost of both cars and the fuel, though companies, including BMW, are looking at the technology as a longer-term option. Indeed, Europe as a whole actually saw a 22% growth in hydrogen refuelling stations during 2022. China, too, is developing its hydrogen car capabilities. A few manufacturers are looking at hydrogen internal combustion engine cars, as these run on less than pure hydrogen, but they operate at lower efficiency and produce pollutants (NOx). Hydrogen-fuelled cars, with faster and easier refuelling options, may start to find their place once the cost of hydrogen drops as the infrastructure for industry and other sectors becomes established – something that will be covered in a later feature. However, the reduced efficiency of hydrogen cars will continue to be a factor for policymakers and consumers alike.

In his BBC programme, Rowlatt also covered powering transport with bio- or synfuels, demonstrating an old E-type Jaguar running on synfuel. It was noted as being very expensive, and therefore it will only be used for niche applications, though, as I will mention in a later feature, these should be prioritised for aviation.

More prescient government action is required on light transport, particularly to manage demand, especially if we foresee a reduction in UK capacity to directly supply the car and van market. The green lobby are calling for better public transport, and I would agree that there are huge gains to be made if, as part of its levelling up agenda, the government took a more progressive stance on public transport and adopted measures similar to those in Europe. For instance, we can look to Luxembourg’s lead to create a free local transport service, established in 2020, while late last year, Germany introduced a monthly travel card, available to everyone at a reasonable price of €49 (US$54). As well as reducing private car mileage, such schemes create jobs for the engineering community, both in building new public service infrastructure and in operating these services. A recent example is the decision to use hydrogen buses at Gatwick Airport.

The policies for heavy transport are yet to be determined, and emissions reduction targets here have been deferred until the government publishes the second half of its net zero 2050 plan. That said, engineers are already engaging in the design of greener technologies through companies including Wrightbus for buses; Tevva, ULEMCo, Hyzon, and HVS for trucks; Angus Lift Trucks for forklifts; and JCB for diggers.  

As I said, in the longer term I see the opportunity for synergies between technologies, through, for example, the development of hydrogen fuel cell hybrid cars and trucks. By building these vehicles with much smaller and replaceable battery sets, engineers can increase their range as the fuel cell can be set to recharge the batteries, real-time, on longer journeys. A hydrogen fuel cell car is already a hybrid as it uses a battery, but a full hybrid specification offers both hydrogen refilling and plug-in charging. Such models offer efficiency and flexibility. Importantly, it puts the driver in charge of their own destiny as they can select between the high efficiency battery and high flexibility hydrogen modes in accord with their needs.

Interestingly, Ford prototyped a hydrogen hybrid 15 years ago, their Ford Edge HySeries, while more recently Mercedes prototyped a hybrid fuel cell version of their GLC model. Indeed, with an appropriately sized battery pack, a hybrid hydrogen car would operate most of the time, for journeys up to say 100 miles, on its batteries charged at home or in the local street. That means the average driver, with relatively infrequent longer journeys, would spend as little as 10% in the more flexible but less efficient hydrogen mode. Dependent upon usage, it could be as fuel efficient as a pure electric vehicle once car weights are considered.

Hydrogen hybrids offer a huge opportunity for engineers to help provide consumers with more flexibility by allowing manufacturers to develop models that range from a full electric vehicle specification through hybrids to full hydrogen specifications for those customers who are not able to regularly recharge.

Delivery of the new technologies for net zero

I hope this and my previous article has fairly highlighted some of the challenges in communicating a robust plan for the delivery of net zero for transport. You will conclude that I too have not delivered a detailed plan, which, as I raised in my first feature, is due to the range of uncertainties. However, I believe governments need to be more open about the challenges and maintain a focus on multiple technologies, especially as multiple solutions will help bring along consumers, their voting public, by providing more choice and less hassle. One size does not fit all. To pretend or claim otherwise will only delay our journey to reaching net zero.

To be a little more specific though, I would strongly recommend that:

  • carmakers pursue increasing the efficiency and range of battery electric vehicles
  • government prioritise extending public transport, using both electricity and hydrogen, while sticking to its plans to phase out new petrol and diesels by 2030
  • government continue to allow consumers to buy plug-in petrol hybrids for an extended period to provide more time for rollout of the “connected” charging network and reduce absolute demand for lithium batteries during the 2030s
  • government provide more detailed plans for hydrogen roll-out for heavy transport
  • carmakers seriously consider the opportunity for hydrogen hybrids which, once more widely available, can replace petrol hybrids and, again, cap absolute demand for batteries and recharging stations

On the back of these recommendations, while heavy transport will mostly depend upon hydrogen, the light car and van sector would still run between 80–90% on efficient electricity. However, the strategy gives consumers more choice and flexibility and reduces peak demand on our grid network and chargers.

A fundamental part of the UK government’s strategy is to deliver the transition through market forces and private investment, be it through the deployment of renewables such as offshore wind farms, charging schemes from the likes of Gridserve and Trojan, or new application technologies from the likes of JCB or Wrightbus. However, to secure impactful transitional change, as foreseen by the UK Carbon Code of Conduct (UKCCC), it is essential there is an appropriate level of governmental policy support.

I recently read Ha-Joon Chang’s book Edible Economics and, in his chapter on prawns, he highlights the need for governments to give some support or even protection for the deployment of evolutionary or transitional technologies, quoting South Korea’s support of Hyundai in its infancy as an example. This advice has already been accepted in spades by US president Joe Biden through his Inflation Reduction Act legislation, with clean energy companies already announcing 100,000 new jobs, while the EU is planning similar support. The UK government has stepped up to meet the needs of the investment by Tata, but it will fail to deliver on its net zero commitments if it does not continue to provide support to its nascent industries, and provide better public services. As hopefully we will see from the Tata investment, such government support will create many opportunities for our engineering and general trades communities, and policies can be designed to ensure effective collaboration.

The government’s recent announcements on industrial clusters and carbon capture are to be welcomed as they open up the opportunity for a nascent hydrogen sector which can underpin the wider hydrogen needs, both blue and green, for our future transport system. However, there are also local schemes which can come into play and, again, they will support levelling up. For example, farming communities see a need to convert their farm vehicles to hydrogen as part of their energy transition. With engineering support, these communities are well placed to produce hydrogen from agricultural waste and wind. This in turn would supply local hydrogen refuelling stations for their community, particularly in more remote areas where fast charging may be problematic.

I believe we can develop and communicate a rational plan, one based upon open collaboration between government, businesses, and consumers to deliver more choice to consumers who need more push than pull. My next feature on domestic heating will elaborate more on the opportunities for engineers to build on synergies between technologies to give consumers that choice as we push to deliver net zero.

Article by David Simmonds CEng FIChemE

Retired engineer. Former director of Simmonds Energy and senior manager at BG Group and Shell

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