Roger Highfield, the Telegraph's science editor, reports on the use of solar power by the Weizman Institute to generate hydrogen

The institute, working with colleagues in Switzerland, France and Sweden on the EU-backed project, used sunlight to heat a metal ore, such as zinc oxide, to about 1,200° Celsius in the presence of charcoal. This split the ore, releasing oxygen and creating gaseous zinc, which was then condensed to a powder. The powder was later allowed to react with water, yielding hydrogen to be used as fuel and zinc oxide, which was recycled in the solar plant.

The significance of the development lies in the use of renewable, non-polluting energy to produce hydrogen. Critics of the hydrogen economy point out that most hydrogen is produced by expensive processes involving the use of polluting fossil fuels. Some have suggested that only nuclear energy can produce 'clean' hydrogen, and although the nuclear option is winning support, it is still far from popular among many environmentalists. Some of them regard the hydrogen economy as a distraction from what they see as the need to cut down on growth, transport, and other energy-using activities.

The construction of commercial plants using the new process could come in six to eight years. It fits squarely with the recent US-led initiative to co-operate in developing technology to reduce emissions and dependence on fossil fuels. The recent G8 communiqué promised development of hydrogen-powered vehicles.

The new process may make only a small contribution, but it is a good indicator, and there will undoubtedly be others. The supply of some natural resources may be limited, but human ingenuity seems unbounded.