What used to be the runway at the former Kai Tak airport site was the location for the Hong Kong launch of the BMW Hydrogen 7 - the world's first production model hydrogen-powered sedan. In performance, refinement and comfort BMW's hydrogen-petrol hybrid gives many equivalent luxury brands using C02-emitting fossil fuels a run for their money. The big difference is that when the H7 is in hydrogen mode it produces no emissions other than water vapour. BMW regards this as such a milestone in the development of sustainable motoring it has taken its flagship product and CleanEnergy programme on a global tour to elicit endorsement from governments, industry playmakers and Hollywood celebrities. Although backed by luminaries such as California Governor Arnold Schwarzenegger and talk show host Jay Leno, BMW insists the Hydrogen 7 is not all about hype. Unlike many previous hydrogen concept cars, the H7 meets the stringent international testing processes standard, petrol-driven cars adhere to. The move represents the marque's substantial commitment to hydrogen as the sustainable fuel source of the future. From behind the wheel, the car's main selling point is ironically an anti-climax: the Hydrogen 7 seems like any other up-market BMW. Smooth, comfortable and as fast, the H7 bears all the hallmarks of a standard BMW luxury sedan. Powered by an adapted six-litre engine, the Hydrogen 7 delivers a steady 260 brake horsepower, accelerates to 100 km/h in 9.5 seconds to an electronically limited top speed of 230km/h. The H7 can cover 200km in hydrogen mode plus another 500km in conventional petrol mode. Around the test track set up at Kai Tak, the dual-mode combustion power unit operates with no hint of delay or change in driving behaviour as the V12 engine switches from hydrogen to petrol - despite the different combustion qualities of the two fuels. BMW's energy partners, Linde Group, demonstrated the ease of refuelling the Hydrogen 7 at a purpose-built on-site service station, showing how the pressure-tight liquid hydrogen filler manifold that sits beside the petrol tank filler opens at the press of a button, to fill the tank with 8kg of liquid hydrogen in about eight minutes. The H7 has a predictably luxurious interior, replete with automatic air conditioning, adjustable electric memory seats, and a six CD/DVD-changer. Swathes of leather cushion your rump and multiple airbags cosset you from any mishaps. If it wasn't for the 'H2' button on the steering wheel (to switch between the fuel sources), a second fuel gauge for the hydrogen and a few discreet cabin insignias, the Hydrogen 7 could pass for a standard 760Li. The most significant difference is in the rear passenger area, where space has been made for the hydrogen tank, about the size of a washing machine drum, beneath the parcel shelf and behind the rear seat bench. With marginally smaller internal dimensions, the Hydrogen 7 is conceived as a four-seater, with 225 litres of boot space for a couple of golf bags. From the outside, there's little to delineate the bi-fuel car from a standard 7-Series other than a silver Hydrogen 7 badge on the boot. But in engineering, it has undergone a top-to-bottom refit. While retaining most of the driving and visual characteristics of a BMW 760Li, several components have been developed to offset the weight of the hydrogen engine, fuel tank and electronics systems. The chassis and suspension are based on the standard aluminium frame but a number of reinforcements have been made to the suspension, while the side frames have been strengthened with carbon-fibre-reinforced plastic to give the same crash protection as a 760. You can't talk about hydrogen without mentioning safety. Friendly to the environment it may be, but odourless and colourless hydrogen is easier to ignite than petrol when it mixes with air, and as a result, BMW has developed a multi-tiered safety system. A gas-warning system, which highlights any functional deficiencies while driving or parked, is backed up by two extra batteries to ensure a fail-safe power supply. The boil-off management system monitors the hydrogen fuel tank in the event of a significant build-up of pressure - for example as a result of damage to the tank - and lets-off excess hydrogen safely under controlled conditions. Notably, in the event of an accident the risk of burning fuel spreading along the ground doesn't even present itself in the H7, since hydrogen rises and evaporates into the air, rather than accumulates on the ground like petrol. Most reassuring of all, the Hydrogen 7 goes far beyond previous hydrogen demonstration models and qualifies for full homologation approval according to EU standards. The Hydrogen 7 represents an impressive achievement for BMW. By creating a standard production car platform that safely employs potentially-sustainable hydrogen as a fuel source, the carmaker has started a lively debate about how to create a global infrastructure for hydrogen power. And the timing couldn't be better. As worries over rising oil prices and global warming continue, BMW's proactive 'build it and they will come' ethos shows how carmakers, rather than lawmakers, are taking the lead in developing a sustainable energy infrastructure for motoring. AT A GLANCE: BMW Hydrogen 7 What drives it? A 260 brake horsepower six-litre V12 bi-fuel hydrogen/petrol engine linked to a five-speed manual gearbox. How fast is it? It hits 100km/h in 9.5 seconds, with a top speed electronically limited at 230km/h. How safe is it? As safe as any 7-Series BMW. It has dual, side and curtain airbags, ABS with electronic brake-force distribution, ESP, steering stability, impact bars, parking sensors and an immobiliser. How thirsty is it? It drinks 8kg of liquid hydrogen per 200km. Hong Kong friendly? No emissions other than water vapour in hydrogen mode. Where from? Industry experts predict that commercial hydrogen cars won't appear on forecourts for five to eight years.