Bill Barclay anticipates that one day we will drive their cars on fuel made from algae. He thinks it could help reduce global warming, cut dependence on oil and provide a big payoff on the hundreds of millions of dollars in investment now flowing into algae research.

But Barclay doesn't expect any of this to happen soon. With some of the America’s top algae biofuel experts meeting in San Diego this week, Barclay was one of a number of speakers to caution against expecting speedy results.

He spoke yesterday on the first day of the Algae Biomass Summit, a three-day event at the Marriott hotel downtown where scientists and entrepreneurs are sharing ideas on what has become a fast-growing area of biotech research.

But while money is pouring into the field, Barclay said it could take a decade or more for commercial-scale production to become reality. Before that, scientists will need to identify the best algae strains, optimize production processes and find the best ways to convert bio-oil into usable products.

“We need real commercial learning to be able to develop the production system and all the systems around that,” said Barclay, the chief intellectual property officer at Martek Biosciences, a Colorado company.

“We've got to be careful not to over-promise success.”

This is the third year of the Biomass Summit, and its appearance in San Diego is spotlighting the significant community of companies and researchers in the region who are working on algae.

In recent months, local company Synthetic Genomics landed a deal with Exxon Mobil that could be worth more than $300 million toward development of biofuels from algae.

San Diego's Sapphire Energy produced algae-based diesel last year for a test flight of a commercial jet. And several local research institutes recently joined forces to create the San Diego Center for Algae Biotechnology.

“This really is the crest of what we refer to as the Green Era,” Sapphire CEO Jason Pyle said. “This is going to transform everything we do in our civilization.”

The reason algae represent a potential fuel source is that as they grow, drawing on sunlight and carbon dioxide, they accumulate fats and bio-oils that have molecular structures similar to that of traditional crude oil.

Proponents say the approach has a lot going for it as an alternative to crude oil. Diverting carbon-dioxide emissions to algae production could help with global warming, and the fuel ultimately produced could be processed at existing refineries.

“This is going to be a real industry and make a real difference,” said Stephen Mayfield, an algae scientist at The Scripps Research Institute in La Jolla.

But before that happens, there are a lot of hurdles to overcome. Barclay, whose company uses algae to make food oils, said it took more than a decade to fully develop that technology.

The first obvious step for biofuels is finding the best strains of algae, with several varieties potentially necessary for different seasons and climates.