Fuel of the future may come from pond algae

Think twice before you fill in that back garden water feature, pond slime could become the fuel of the future. Under the correct conditions, algae can produce large quantities of hydrogen gas, a valuable fuel that could power vehicles and produce electricity.

"It could completely replace fossil fuels if you got the production right," stated Dr Stuart Ruffle of Exeter University.

He told the Festival of Science yesterday about research into algae as a source of hydrogen. "The production of hydrogen gas is actually quite efficient by the algae," he said.

He described work being done at the University of California, Berkeley by Prof Tasios Melis, who was developing systems for collecting useable amounts of hydrogen gas from growing algae. The object was to produce as much hydrogen as possible for the least cost.

The current cost of producing a kilowatt of algae energy was 70 cent, Dr Ruffle said. If this was reduced to about seven cent, it would become economically viable, and this did not represent a major challenge, he added.

It was an ideal fuel source because it was virtually non- polluting.

"The advantages are it is clean and when you combine it with oxygen all you get is water."

His own work involves a "nuts and bolts" examination of photosynthesis, the process used by plants to turn sunlight and carbon dioxide into food for growth. His model for this is the green algae, Chlanydomas.

It was an ideal model because of its size and short life span, he said. While oaks might make a more majestic subject for study, the work would be very slow.

Harnessing photosynthesis opened up a great many opportunities, Dr Ruffle said. "The reason photosynthesis is so important is because it is almost an unlimited source of energy. The irony of photosynthesis is it is damaged by light. How plants respond to that damage is important."

Life on earth would be very different without plants if it could exist at all, according to Prof John Bowyer of Royal Halloway, who also presented research during a session entitled "Plant Power".

"Without the evolution of plants early on, there would be no oxygen," he said yesterday. The oxygen supply that keeps us alive today was built up by algae and more advanced plants over millions of years. It also provided the oxygen needed as ozone to help protect life on earth from solar radiation. "Without photosynthesis, there would be nothing to eat," he added.