In the past few years many manufacturers who were developing prototype hydrogen powered cars have dropped them in favour of hybrids or pure electric cars. Ford, Nissan and Renault have all dropped their programs although BMW, Toyota and Mazda have been the three notable proponents of this technology who are pushing on with their development. Hyundai and Honda have also been working to get to market with a car.
There are actually two types of hydrogen-powered cars: one uses the internal combustion engine and the other uses a fuel cell with an electric motor. Mazda use the internal combustion engine that has been hardened and the fuel system has been redesigned to cope with a gas rather than a liquid. Mazda have reworked their Renesys Rotary engine for the RX8 and the Premacy models. The hydrogen versions deliver less power than the petrol versions and ultimately have a reduced range, which may not be as important for town driving. Perhaps if these cars ever make it to market, range anxiety will have eased.
Like many technologies, hydrogen powered engines have been around for years – the first was developed in 1807! With petrol becoming the dominant fuel in the early years of the industry due to volume and cost, many other technologies were parked. BMW started to look at hydrogen-powered cars back during the late 1990s. In fact they have built 100 6-litre V12 powered 760’s capable of running either hydrogen or petrol however they have licensed Toyota technology to kick start their developments.
One feature of hydrogen-powered cars is the fuel economy – it is very poor compared to petrol. For example, the BMW 760 does about 14 litres per 100 kms on petrol and 50 litres when running hydrogen. With the knowledge of converting a petrol engine to hydrogen well known, the manufacturers are now looking at the difficulty of the onboard storage. If they get that right, hydrogen-powered engines may become more realistic. The gas is cooled to store it as a liquid, thus getting more in the tank. The problem is that the tank needs to be super strong and insulated – the liquid needs to be kept at -253C! Crash protection needs to be much stronger too – you certainly don’t want a liquid spilling out, converting (and expanding) to gas due to the temperature difference and then igniting!
On the fuel cell side, hydrogen has become another source for those cells, which act like a combination of a battery and generator. The hydrogen is reacted with a base – a precious metal like platinum for example to produce electricity that drives the motor. Honda are claiming a 300% increase in energy efficiency with their FCX Clarity model over a conventional petrol powered car.
The other big issue for any new fuel source is the infrastructure required to refuel cars on the road. There are only 5 fuel stations that can support the BMW 760 in Germany and there are a growing number of refuelling stations in California for the Honda FCX. Mazda is encouraging various cities to provide a system for their Premacy as well.
Honda are developing a home recharge system that burns natural gas to generate the hydrogen for the fuel cell. The beauty of the system is that the natural gas is burnt to provide heating and electricity for the house and the hydrogen is actually a by-product! A classic example of recycling!
Like any new technology, and the electric car market is in the same situation, two conditions need to be met for success. The first is the fuel source infrastructure. People will only buy a car if the vehicle meets safety standards and they can recharge or refuel easily. The second is the support of the local or country government. This ensures proper regulations and can heavily influence the price of the fuel. I have stated many times, once a government loses oil excise revenues it will target something else and this will determine which fuel source becomes the next dominant player. Clearly Honda, Toyota and Hyundai who have hydrogen based models already in some markets along side electric or hybrid cars are hedging their bets!