Audi is again at work on a fuel cell version of one its cars, in this case, its well-regarded A7 sedan.

In 2009, Audi also tested a fuel cell version of another of its models it called the Q5 HFC which utilized two high-pressure hydrogen cylinders to supply the vehicle’s two electric motors.

As a member of the Volkswagen Group, Audi’s A7 work comes despite Volkswagen AG CEO Martin Winterkorn’s denying viability for fuel cells in March, saying, “I do not currently see a situation where we can offer fuel cell vehicles at a reasonable cost that consumers would also be willing to pay.”

The disclosure of the A7 development work was to UK publication, Autocar by Audi’s technical head, Wolfgang Dürheimer, with scant additional details offered.

As many readers here know, fuel cell vehicles are a form of electric car that instead of a battery rely on an electro-chemical reaction between fuel and oxygen which in turn generates electricity and heat.

Byproduct emissions are only water, thus fuel cell vehicles are effectively zero (toxic) emissions vehicles for which legislation around the globe is calling. These types of vehicles are also seen as advantageous give that they can be refueled as quickly as a convention liquid-fuel burning vehicle, but their costs are highly prohibitive, and infrastructure is decidedly lacking.

A raft of of naysayers pointing to a technical obstacles and a proverbial chicken-and-egg problem notwithstanding, automakers are in process of overcoming said hurdles with some like Hyundai, already producing fuel cell vehicles, and projecting long-term prominence for this technology.

A recent study by Navigant Research titled “Fuel Cell Vehicles” forecasts worldwide sales of FCVs will reach the 1,000 mark in 2015 and then begin a period of strong growth, surpassing 2 million vehicles annually by 2030.

It would Audi too, does not plan to be left behind.