A German safety institute has approved a hydrogen storage system developed by General Motors that could allow fuel cell vehicles to achieve a range of up to 480 kilometres.

The system is the first high-pressure hydrogen storage tank of 700 bar (10,000psi) technology capacity to be certified by Germany's Technical Inspection Association (TUV), an organisation that approves new technology in vehicles.

GM says that until now, hydrogen storage tanks with a maximum of 350 bar had met the TUV's requirements.

For certification, TUV validates high-pressure tanks in accordance with common industry standards in Europe and North America.

The manufacturer said that at 700 bar, significantly more hydrogen can be stored in the same space occupied by a 350 bar tank, extending the range of fuel cell vehicles in between having to fill up.

The European integrated Hydrogen Project (EIHP) has also approved the system.

The manufacturer said: 'The fuel cell technology, showcased in GM's Hydrogen3 fuel cell vehicle, brings GM another step closer to the commercialisation of hydrogen-powered fuel cell vehicles.

'A key challenge to the introduction of fuel cells is to produce an efficient, lightweight onboard storage system with enough capacity for making lengthy drives possible.'

It added that fuel cells are the key technology in GM's drive toward sustainable mobility and its reinvention of the automobile.

It plans to sell one million fuel cells vehicles after their launch by 2010.