Fuels of the future: Hydrogen fuel-cells

Like batteries, hydrogen fuel-cells generate electricity by mixing two chemicals that react to produce an electric current. So, whilst they both technically fall under the term ‘electric car’, the technologies however vary enough in application and use to warrant a separate discussion. The wide range of potential applications for this technology, and its versatility to power both large and small vehicles makes it an interesting and ultimately viable alternative to fuel. Pros:
  • Capable of producing a greater electric output than batteries or petrol (more energy rich per kilogram than petrol or battery-operated vehicles): Whereas battery-powered electricity is unable to generate enough energy to effectively power large vehicles, hydrogen fuel-cells on the other hand have larger outputs and therefore are not restricted in this sense; effectively eliminating one of the problems inherent with electric battery-only vehicles.
  • Produces only water as exhaust, reducing harmful greenhouse emissions by as much as 45% less than an internal combustion engine. Although as you will see, any tangible benefits of this reduction to the environment are negated by the energy cost of manufacture, production and transportation.
  • Refuels faster than electric cars: Gone are the eight hour plus recharge times required for battery-operated vehicles, the process instead being completed within minutes.
  • Extremely expensive to manufacture and produce: Unlike fossil fuels, pure hydrogen doesn’t naturally occur in large ground deposits so must be manufactured from scratch.  Despite some promising new technologies, the price of hydrogen exceeds that of petrol. These additional costs, until rectified, will remain a factor in the continued use of petrol based vehicles for large volume vehicle purchasers, for example commercial fleets and car hire companies in Sydney.
  • Environmental Impact: Despite the fact that hydrogen produces nothing other than water as a by-product, the amount of energy required to produce hydrogen negates any positive environmental impact that the use of such technology in vehicles would confer.
  • Difficult to store and transport: Hydrogen is a gas, and as such it needs to be compressed at a very high pressure to be usable in fuel cells, which makes it difficult to both transport and store.
  • Incompatible with current infrastructure: The level of infrastructure required for hydrogen fuel cells to be efficient, cost-effective and most importantly, consistently available across national networks is immense.  For example, it is currently estimated to cost US$2 million to build hydrogen filling stations. Add to this the cost of transporting hydrogen in its compressed state, along with the facilities to produce it, and the total comes to a significant up-front investment.
Summary: Whilst there is certainly potential for hydrogen fuel-cell operated vehicles to replace the petrol based internal combustion engine, there remains some significant challenges in the areas of manufacture, production and transport to be addressed before hydrogen can be economically viable and competitive with other technologies. For this reason it is highly unlikely that in the near future hydrogen based vehicles will become profitable or efficient enough to be used for large scale vehicle operations such as car rental in Sydney. Currently the main proponent of hydrogen fuel cell technology is Honda, although they are by no means the only company exploring hydrogen as an effective replacement to petrol.