Fuel cells are not a “green” technology in themselves, but in theory fuel cells can be very efficient at converting chemical energy contained in a fuel into electricity. This means that up to two-thirds of the energy contained in a fuel (sometimes more) can be recovered as electricity, the rest being converted to heat.
Although the focus of recent fuel cell publicity has been on their use in cars, fuel cells can be used in a very wide range of applications where they can convert energy more efficiently than current technologies. The main obstacle to their uptake has been the high cost of fuel cell models with acceptable performance and durability.
Fuels
The simplest fuel that can be fed into a fuel cell is hydrogen, as all fuel cells will readily react this fuel with oxygen (usually from the air) to produce electricity (water and heat are also released in the process). Other fossil (e.g. petrol, natural gas) and renewable (e.g.biodiesel, biogas) fuels can also be fed to fuel cells, either directly, or after being converted to hydrogen by a fuel processing device (also called a reformer).
Applications
Fuel cells are already in use today in a range of uses and will probably gain access to new markets in the near future as their costs come down: for instance, the focus of our proposed Polymer Fuel Cell Challenge is to accelerate cost reductions and market uptake of polymer fuel cell technology.
In the medium term fuels cells are likely to be found replacing batteries in mobile devices such a laptops and phones, for home and commercial and for auxiliary power units for vehicles (used to produce the electricity needed onboard whether or not the vehicle is moving).
In the future, the automotive industry believes many road vehicles will be electric. They might store their energy in batteries, but fuel cells could also provide a convenient way of producing electricity on-board from a fuel – hydrogen or otherwise.