Are alternative fuels the future?

Alternative fuels are in the news because the European Commission has recently decided to exempt synthetic ‘e-fuels' from the European Union-wide ban on sales of new internal combustion-engine vehicles, due to come into force in 2035. On top of that some EU states now want to expand the exemption to include biofuels, another kind of alternative fuel.

This is all still up for debate in the corridors of European politics. But if alternative fuels are a good decarbonisation solution, why haven't they been in the plan all along? The answer to that lies in the tricky technological details of the alternative fuels that are either already on the market or expected soon.

Let us start with biofuel, which is the best-known alternative fuel because in many countries it is already present in gasoline. Most drivers will recognise the blend called E10, which is 10 per cent ethanol biofuel and 90 per cent fossil gasoline. Such blends are common because while many governments want to encourage biofuel consumption, most vehicles cannot run on pure ethanol. Another version of biofuel is biodiesel, which is the most common biofuel in Europe – Europeans got through 17 million tonnes of the stuff in 2021.

These biofuels have been around for a long time and most of them are produced through fermentation processes from crops such as soya or maize. When used they emit carbon dioxide just like fossil fuels, but this is carbon that has been captured from the air when the feed crops are grown, so in theory it is a case of carbon in, carbon out, without any overall contribution to atmospheric carbon.

But as you may have guessed, it is not all good news. The manufacture of some biofuels actually consumes fossil fuels and emits carbon through various stages of the production process – one study from the International Institute for Sustainable Development claimed that there was no net-carbon benefit in using biofuels compared with fossil fuels.

There's another drawback: biofuels which are known as ‘first generation' fuels also take up the agricultural resources needed for food production, potentially pushing up the price of basic foodstuffs. And this is why there is increasing interest in ‘second generation' biofuels, which instead of using food crops rely on waste products from such crops, or from forestry, so they don't displace food production.

Then there are ‘e-fuels'. These are synthetic fuels that work like fossil gasoline and diesel, but are made from hydrogen and atmospheric CO2. Unlike most biofuels they can be used just like conventional fuels, without blending with fossil fuels. This means that newer e-fuels could provide what is known as a ‘drop-in' solution that can be used in existing vehicles without modification.

But again, there are downsides. One is the fact that commercial e-fuel production has yet to come on stream (although several auto companies are investing in e-fuel development). And a problem yet to be solved is that most existing production methods consume a lot of electricity.

In the end, the future of these fuels and the internal combustion engines that use them comes down to a question of conviction. Do we insist that the future of mobility must be purely electric, because no CO2 comes out of the tailpipe of an electric vehicle? Or do we accept that the future might be more complicated, with numerous exceptions for vehicles that do emit CO2 but in a way that may not add to the carbon load in the atmosphere?

It comes down to a choice – and consumers, manufacturers and politicians have to decide what will really power the shift to zero carbon in the real world.

Choose wrong and they may find that in the race to net-zero they are running on empty. Choose right and we might just all get there in the end.

Illustration by Elisa Macellari