BMW Hydrogen 7 is a gas

BMW has announced its intention to market the world's first production (albeit of the low-volume variety) hydrogen-powered car.

The zero-emissions Hydrogen 7 is not to be confused with a hydrogen fuel cell, which generates electricity by combining hydrogen and oxygen -- and this charge is subsequently used to power one or more electric motors that drive the car.

Instead, the greenie-friendly 7 Series uses a conventional internal combustion engine, albeit one that can run on both petrol and hydrogen. When running in the latter mode it emits only water vapour.

In hydrogen mode it puts out 191kW (well down on the 'regular' 760Li's 327kW) and, consequently, it requires a leisurely 9.5 seconds to accelerate to 100km/h -- nearly four seconds more than the 760Li takes to dispatch the same increment.

Top speed is also lower at around 230km/h (electronically governed).

BMW says the Hydrogen 7 has a range of over 700km between refuelling stops (about 220km in hydrogen mode, and around 480km from the petrol tank).

The space that the two fuel tanks take up means only the limo-like 7 Series can be offered with the 'hydrogen package' for now. However, the company's long-term goal is to offer hydrogen-compatible powerplants in all its cars.

The Hydrogen 7 hits the European and US markets early next year and will be shown to prospective buyers at the Los Angeles motor show in November.

There have been significant moves to establish hydrogen refuelling points in the US, particularly in California, where 'Governator' Arnold Schwarzenegger has been a staunch advocate of the clean-burning fuel.

A BMW spokesman was quoted as saying the Hydrogen 7 would be leased to selected customers rather than sold through mainstream channels due to its high asking price.

Leasing rates are said to be similar to those for a top-end BMW 760Li with a full-service package.

The Hydrogen 7's local prospects are non-existent as there is no refueling infrastructure currently in place for the volatile fuel -- nor is there likely to be in the foreseeable future, given that promoting alternative fuels appears to be low on the Australian Government's agenda.