The development obstacles F1’s power roadmap has to clear

Motorsport in general, and F1 in particular, has always been an enabler of automotive progress. The relevance of development has been variable. Some innovation has been so esoteric as to be of little practical value, but most has, over time, fed back to consumers in an extremely positive way - be it through improved safety, functionality or efficiency.

Today the traditional internal combustion engine faces threats to its existence through legislation driven by environmental concerns. We cannot pretend these concerns are ill-founded, even if some of them are driven by hyperbole. The spectre of global warming is no longer a matter for debate, and local emissions of noxious gases and damaging particulates are phenomena which cannot be denied.

Consequently, we need to examine closely just what F1 can do to continue the contribution it has traditionally made to mobility.

Formula E has taken a very worthwhile, staged approach, through two generations of car which have gradually introduced technology relevant to electric vehicles. FE is doing it well and has produced a unique form of city-centre racing which brings motorsport to the people and highlights the benefits of a fully electric vehicle in an urban environment.

Formula 1 is different. Our mission is to produce the greatest racing spectacle on the planet, and as such we need high performance demonstrated in the open environs and super-fast corners of circuits like Silverstone and Suzuka. To do this we need a lot of power and a lot of energy.

Readily available liquid hydrocarbon fuels have a very high energy density which has, in the past, always fulfilled that requirement. We were able, in 2014, to temper that singular quest with the introduction of the current hybrids and, by altering the philosophy of performance, ensured the push for efficiency became paramount to success.

The introduction of sustainable synthetic or biofuels in the near future will further this objective and produce a fundamental reduction, and ultimately elimination, of this aspect of our carbon footprint. This is a good step forward, but we need to do more.

Unfortunately, to achieve the desired level of performance, a battery electric solution is not viable. Over a 305km race distance, a car will use around 105kg of fuel. This fuel has a chemical energy of 1,224kWh. If we can convert this at an efficiency of 50% then we have available 612kWh of energy. Add to that the kinetic energy we harvest under braking and we can draw on a further 20kWh, giving a total of 632kWh or about 2.27GJ.

Let's say we increase the brake harvesting by having large electric motor/generators front and rear and can then harvest five times as much energy (much bigger starts to get impractical), then we would need a battery of over 500kWh to make up the difference. That is ten times the size of a Formula E battery, and even with expected advances in technology in the near future the cells alone would weigh around 1.8 tonnes.

While hydrogen is very light it needs to be stored either cryogenically or at high pressure and this means heavy fuel tanks

Of course we could, and would, look at improving chassis efficiency, and active aerodynamics could give a big drag reduction thereby requiring far less energy, but realistically, given the constraints of open wheels and open cockpits, we could probably only reduce the energy store requirement to around 1.2 tonnes.

An alternative is hydrogen fuel cells, 
which produce electricity through a chemical reaction between hydrogen and the oxygen in the air. The products of the reaction are electricity, water and heat. The efficiency of a fuel cell is not as high as that of a battery and typically sits at around 50%, meaning that for every kW of electricity it produces, a similar amount of energy has to be dissipated by 
a cooling system.

If we consider that the mean [average] power produced around a lap is around 500kW, then we have a very high cooling requirement and unlike the internal combustion engine, none of this goes into an exhaust system. Of course, this is not impossible but it does represent a cooling requirement which is significantly higher than that of a conventional engine.

There is also the problem of hydrogen storage. While hydrogen is very light it needs to be stored either cryogenically or at high pressure and this means heavy fuel tanks. As an example, the Toyota Mirai, one of the first fuel cell road cars, holds 5kg of hydrogen but the tank containing it weighs 87.5kg...

Of course, F1 engineering would reduce this considerably, but it is still a dead weight that needs to be considered. Remember also that a fuel cell vehicle needs some form of battery to act as a buffer of energy for instant demand.

Finally, there are the environmental and cost aspects. Fuel cells are not yet available at the power required for F1. They could, and would, be developed but there is a steep and expensive learning curve for this relatively immature technology. Electric motors at present use rare earth magnets; batteries high amounts of cobalt, both of which lead to environmental concerns. Fuel cells contain many thousands of dollars worth of platinum.

None of this precludes a future F1 power unit moving away from the internal combustion engine. In fact, I would say it is an inevitability. However, just as in other high-power applications like aircraft and heavy vehicles, there is much to be said for liquid hydrocarbon fuels providing they are CO2 free and sustainable.

The best solution for now is undoubtably a highly efficient engine with a high level of electrical hybridisation. But the best solution 20 years from now is, I believe, more likely to be hydrogen fuel cell-based.