Why electrifying your classic car probably doesn’t make environmental sense

Electrification of classic vehicles, especially cars, is a divisive subject. The position of the Historic and Classic Vehicles Alliance (HCVA), which is dedicated to ensuring the long-term sustainability of a UK industry with an annual turnover of £18.3bn, is that if a vehicle owner wishes to change the propulsion system in their classic car, then that is their choice. However, they should carefully consider the total environmental impact of a conversion that can often make no logical sense; in fact far from it!

If one regards the embedded carbon dioxide from the production of a classic car as a ‘sunk’ environmental impact, adding an electric powertrain and energy-storage system is re-embedding new CO₂ that is unlikely to be recovered due to the very limited use classic cars receive. The time taken to recover these additional emissions is likely to be measured in decades, and in fact may never be reached because the battery system will probably need to be replaced before the equilibrium point is achieved.

Naturally, calculating the timescales to reach net zero with these solutions depends on the source - and age - of the electrification system used. Previously used parts will always have less environmental impact than new, and locally produced will be better than imported.

Then there is the question of safety. Electrified propulsion systems run at high energy levels that are dangerous if handled incorrectly. Currently there are no legislated regulations for classic vehicle conversions. If an owner wishes to convert their car, they should ensure that the modification is done to a set of regulations which ensure crash protection of the battery pack, electrical isolation and its identification, battery management and overall systems functionality amongst a range of other safety systems.

Regulations do exist; one example is in motorsport. Wilson was part of a small group that helped develop regulations for the build and conversion of vehicles for UK motorsport, where safety implications go beyond the base electrification system. Typically, these systems are heavier, mainly due to a lithium-ion battery pack. The weight of the system, including the power electronics and electric motor, will result in a different and greater corner weight, and improvements to the suspension system will be required. Furthermore, most electric propulsion systems in classic cars produce more power and torque than the original internal combustion engine, so brake system enhancements will be required.

Although conversions often take account of these two elements, the chassis structure also needs consideration. As the torsional rigidity of classic vehicles is less than their modern counterparts, for example, the increased torque will have an impact on the body and chassis structure, and localised improvements to these elements will be needed. The computer modelling that modern manufacturers can use to identify the optimum location of chassis enhancements is rarely available to the small converter. Some conversions are built with the considerations embodied in regulations like those in Appendix J of the Motorsport UK Yearbook and considerations of functional safety.

During a recent Parliamentary Transport Select Committee evidence session looking at how government fuel policy will affect connectivity, capacity and sustainability across all transport modes, HCVA director Guy Lachlan was asked “What classic vehicles could be converted?” His answer was: “All of them; the real question is should they be converted.” Generally, they don’t do sufficient mileage to warrant conversion, and it certainly can’t be justified based on an environmental argument.

Historic and classic vehicles are part of our industrial heritage, and as worthy as our historic buildings are of being preserved in an unmodified state. In some cases, particularly where the coachbuilding rather than the powertrain is a car’s key characteristic, conversion to electrification may be preferable, given that it keeps such a heritage product on the road rather than it being scrapped or broken for parts.

The key is that the conversion should be done to a recognised standard or set of regulations, and many such UK companies exist that are capable of carrying out such work. We must also remember that electrification is ‘a’ solution not ‘the’ solution in the wider automotive context. Many manufacturers are working on electric vehicles, while they and others are actively developing hydrogen solutions - both as a combustible fuel and within a fuel cell. Many are also working on sustainable fuels as a viable alternative to fossil fuels. These fuels, whether from biomass or fully synthetic, are the HCVA’s preferred way forward to achieve a net-zero emissions position for the UK’s historic and classic vehicle fleet.

Garry Wilson FIET is CEO of the Historic and Classic Vehicles Alliance. He has spent many years working in the wider automotive sector supporting innovations in electrification and was part of the team that established then ran the UK Advanced Propulsion Centre.