Science – The motoring revolution

We are at the start of an extraordinary and exciting decade of evolution in automotive technology – progressing from internal combustion vehicles, to hybrid electric vehicles, to plug-in hybrid electric vehicles, to plug-in electric vehicles, to hydrogen fuel-cell electric vehicles. Electric autonomous, in other words driverless, electric vehicles will appear soon. We will see over the coming two decades the emergence of electric airliners. In the short term, new forms of local transport will appear, including driverless taxis and driverless flying-drone taxis. Electric buses and long-haul trucks have already appeared in some countries.

A year ago, I wrote a column describing the factors that are expected to reduce the price of electric vehicles. These included the recovery of costs associated with new battery research and development and rapidly expanding competition. The advantages of electric vehicles are persuasive. In a recent US study, the cost of “fuel” for an electric vehicle was estimated to be one third of that required for an internal combustion vehicle. A full electric vehicle has 20 moving parts, while a conventional internal combustion vehicle has about 2,000. This means electric vehicle maintenance costs are much lower.

Many major car manufacturers are planning to exit internal combustion technologies over the next few years. Governments – 10 at last count – are declaring deadlines for discontinuing internal combustion vehicles within the next decade or so given serious environmental health concerns. The UK Government has indicated that internal combustion vehicles will be discontinued within 15 years. Short-term limitations on the deployment of electric vehicles include the limited number of charging stations. However, California has installed 50,000 charging stations and McDonalds is planning to have charging stations at their many food outlets.   

Lithium-ion is the main battery of choice for electric vehicles at present, but the limited availability of lithium is a challenge. Recycling technology for lithium-ion batteries will help, but not solve ,this problem. The limited supply of lithium has driven the pursuit of alternative battery sources, and we are now seeing the advent of hydrogen fuel-cell cars from manufacturers such as Toyota, Mazda and Hyundai. These boast water-only emissions. However, the industrial production of hydrogen by a process known as steam reforming also produces the greenhouse gas carbon dioxide. A recent development from Australia involves the direct production of hydrogen using highly efficient solar panels. This may prove to be the best low-cost ultra-green source of hydrogen.

Another promising source of power is the ammonia fuel cell. This provides more power than hydrogen and is easier to transport. Ammonia fuel cells may be useful in applications where increased power is important, such as for long-haul trucks and ships. Ammonia has the advantage that it is not considered a greenhouse gas, though unfortunately it is regarded as a soil pollutant.  

A difference has emerged between Tesla and Toyota. The latter intends to produce both electric vehicles and hydrogen fuel-cell vehicles, while Tesla considers that hydrogen fuel cells are unnecessary.

Finally, and importantly, the global shift from internal combustion vehicles to electric vehicles will significantly help remediate climate change by reducing greenhouse gases in the years ahead.

Emeritus Professor Ralph Cooney
r.cooney@auckland.ac.nz