SINGAPORE: The availability of an environmentally friendly car has just widened. Besides popular choices like hybrid cars or even those running on compressed natural gas, the hydrogen car is another choice.

However, it is more than just a case of supply and demand when purchasing these cars.

Touted as one of the greenest cars available today is the BMW 7 Series. Its only emission is water, when it is powered by liquefied hydrogen.

BMW believes using hydrogen fuel will help save the environment and reduce the dependence on crude oil.

This next generation green car can also run on petrol in the same engine as hydrogen fuel is not readily available yet.

Running a car using hydrogen, however, will cost more. A kilogramme of liquid hydrogen costs about US$11 or about S$16.

Covering 100 kilometres with a hydrogen car will end up costing US$42 or about S$60 for the fuel. If it ran on petrol, it will cost US$27 or about S$38. These figures are based on European petrol and hydrogen fuel prices.

The Hydrogen 7 model is likely more expensive than petrol only versions.

Roland Krueger, Managing Director of BMW Group Asia, said: "The comparison is not really fair, meaning that today the infrastructure is not as developed as fossil fuel structure. So given that we will have a comparable base with the same kind of infrastructure, then the price of liquid hydrogen will be much more comparable."

However, it still boils down to the question of which comes first - building refuelling stations or making more hydrogen cars?

Fred Zheng from Hydrogen Solutions said: "The first, I believe is government support, second is establishing infrastructure in place."

"The third is - we need to have economies of scale with the production of cars to make the cars cheaper and fourth is - find a way to have R&D and making hydrogen cheaper," he added.

In Singapore, this hydrogen push has the support of the National Environment Agency, the Singapore Environment Council and the Urban Redevelopment Authority.

It still remains to be seen if this would be enough to generate a nationwide network of refuelling stations.

So far BMW has made some 100 hydrogen vehicles, but it will be some years to go before it becomes commercially available.

BMW will bring several of its latest hydrogen cars to Singapore in early March for trials. - CNA/vm