EVs are not the future—hybrids are

There has been a wild surge in optimism in EVs—really, a kind of hysteria—with the EU and UK governments hoping to ban combustion engines in new cars as recently as 2035. In my opinion, this is a mistake, and I suspect the law will be repealed (or at least amended) before it comes into effect. Here’s why we shouldn’t be cheering for EVs, but looking at hybrid options, as well as alternatives like public transport and electric bikes.

Problem no.1: a ticking timebomb for residual value

If you haven’t seen it already, I recommend watching this video of a Finnish guy blowing up his Tesla with a doll of Elon Musk inside. Why did he blow up his own car? Because the battery was faulty and it was not economical to repair. Batteries are the single most expensive component in an EV, and they have a limited lifespan.

Problem no2: too expensive

The next problem is that EVs—and particularly, long-range EVs with big batteries—are expensive, moreso than combustion cars, and well beyond the ability of many people to afford. Second-hand EVs are not necessarily an attractive buy because of the reason above, at least, not unless secondhand prices fall dramatically.

Problem no3: where’s the infrastructure?

I’m not just talking about public chargers, which are overpriced, and totally insufficient to meet demand. I’m also talking about the fact that many people cannot charge at home because they live in apartments or rentals. Furthermore, in slightly less developed countries like Eastern Europe, public charging points are almost non-existent. Likewise, even in developed countries, people living in rural areas will struggle with an EV.

You’ll notice that I haven’t mentioned range, although range is a problem for some people, especially those who do long journeys regularly, or people who are, let’s say, more spontaneous. Many people will not plan a journey around EV charging points.

So what are the alternatives?

At present, green hydrogen is a bit of a pipe dream. Instead, we should be focusing on improving the mileage of combustion cars, using hybridisation and advancements in combustion technology.

Let’s talk about plug-in hybrids first. In many ways, they are the best of both worlds: they can use a much smaller battery, anywhere from 5–10x smaller, which is lighter, cheaper, and crucially, won’t cripple the car if starts to fail later down the line. Plus, a smaller battery is cheaper to replace. A plugin car can travel on battery power around town and in traffic, where combustion engines are least efficient, and use combustion on the motorway.

But do not discount non plugins either, as many people do not have the ability to charge their car at home. Not only can these cars use regenerative braking and reduce engine idling, but there are other tricks they can benefit from. For example: turbo company Garrett has recently developed an E-Turbo, that is, a turbine that uses exhaust gases from the engine to run a generator and charge a battery. This technology is similar to what is being used in Formula 1.

A device like this can essentially boost the thermodynamic efficiency of the engine. The trouble with car engines is that they do not reach the Carnot efficiency limit, that is, the theoretical limit imposed by physics. A high compression ratio petrol engine might have a Carnot limit of 57%, but only achieve an efficiency of 25%. Diesel engines are a bit better, but not by much.

The reasons for why real-world engines don’t reach their theoretical limit are manyfold and complicated; I won’t go into them here. What I can say is that, by adding a turbine in the exhaust, you are essentially extracting useful kinetic energy from heat energy that would otherwise be wasted.

Hybridisation can be combined with new developments in combustion: Mazda, for example, produced the first production petrol engine with a 14:1 compression ratio (the theoretical maximum), and have even developed Skyactiv X, an engine that combines compression ignition, like a diesel engine, to increase the compression ratio beyond the theoretical limit.

Electrified motorways

Countries like Sweden are already piloting schemes where they add electrified rails or overhead cables to motorways. This is primarily intended for big trucks, but could be applied to cars as well—and even hybrids could benefit.

In the future, cars with huge 100kWh+ batteries will look like dinosaurs; their batteries are expensive, heavy, and have a limited lifespan, while cars with smaller batteries will be much more practical. Notably, cars that don’t need a huge capacity can have lower utilisation of their nominal capacity. For example, a plugin with a 15kWh battery might have a 12kWh capacity (80% utilisation), rather than a car with a 100kWh battery and 95kWh capacity (95% utilisation). Batteries with lower utilisation generally have a longer lifespan.