We’ve been living alongside the internal combustion engine for well over 100 years now and while it’s a mainstay of our daily lives, work and travels, it can’t last forever. In its current form, it’s too reliant on fossil fuels, so we’re busy looking for alternatives to take over from it when the time comes.
There are lots of alternatives, some hark back to earlier technology and others are pretty high-tech, but they all aim for one feature – to be sustainable. Here are ten of the fuels we will – and may – be using in the future.
Yes, petrol is still there. We have reserves and the capacity to find more, but the major drive is to use it more sparingly to make it last. As petrol is ubiquitous, just small tweaks in efficiency have great knock-on effects so the science bods will be using kit like the flame imaging camera to make sure each drop of petrol gives us as much as it can.
While diesel is more efficient than petrol, it does kick out more pollutants, especially NOx and particulates. We need to make diesel cleaner and more efficient if it’s to stay with us for a while.
Biofuels can be used instead of petrol and we can make them from sugarcane, corn, vegetable and animal fats. Biofuels are especially valuable as they’re sustainable. Want more fuel? Grow more corn. Second generation biofuels are being developed that don’t require sources like corn – we can harvest them from algae and bacteria.
We have big hopes for the electric car, but we have a long way to go yet as it’s still not very efficient. Most of these cars have a range of 100 miles and the batteries take hours to recharge – and they’re expensive. Still, it’s a start.
Hydrogen could give us the next generation of combustion engine – only an engine that has no noxious emissions, just water. However, as critics point out, a lot of energy is needed to process the hydrogen and there are as yet no hydrogen garages…
Hydrogen could be used to power fuel cells for electricity though, and this is the likeliest use for it in cars. At present, however, fuel cell tech is very expensive.
A bit of a retro touch, but it could lower emissions as the fuel is combusted away from the engine, making by-products easier to collect. There are a few concepts in development, so it could be a goer.
More and more internal combustion cars and most electric cars have brake energy regeneration tech that harnesses the energy spent during braking and converts it to electricity. It’s a small gain, but if every car has this feature, it’ll reduce the consumption of whatever fuel it’s using.
A petrol or diesel car loses as much as two-thirds of its energy as heat, so thermoelectric systems could capture some of this lost heat and convert it into electricity. Fed back into a hybrid engine, it could cut fuel consumption by 5%.
Compressed air (at around 4,500psi) could drive pistons and move cars along. Admittedly it doesn’t produce a lot of energy, but it doesn’t produce any emissions, either. Tata, among other car manufacturers, is looking at this route.
In this concept, liquid nitrogen is kept in a tank and heated to produce high-pressure gas to drive a piston or rotary engine. It’s not as energy-dense as petrol, and it takes a lot of energy to produce it.