The world's largest fleet of hydrogen-powered buses will debut at the Winter Olympics in Whistler, B.C., next month amid criticism that the move is environmental window dressing.

The Suzuki Foundation is questioning the 20 buses, meant to showcase the ecological correctness of the Olympic Games.

Ian Bruce, a foundation climate change campaigner, said he did not disagree with B.C. seeking potential clean technologies, but added that the project must be financially viable.

The federal government contributed $45 million and the B.C. government provided $44.5 million for the manufacture of 20 hydrogen buses and to cover the capital and operating expenses of BC Transit until 2014.

Based on those figures, Bruce said, each hydrogen bus costs an average of $2.1 million, or four times that of a diesel-powered bus.

Since the hydrogen will be transported from Quebec because B.C. can't produce enough, the greenhouse gas emission savings would be reduced to 62 per cent from 100 per cent, according to the Suzuki Foundation.

And during the Olympics, bus emissions are expected to increase as BC Transit brings in more than 100 additional diesel buses to handle demand.

Former BC Transit planner Stephen Rees said there are better ways to spend the money.

"If you just wanted zero emission buses, the same money would buy you 40 trolley buses. Or if you wanted to increase transit use, 80 conventional buses," he wrote in his blog on Thursday.

But if the goal is to increase transit use, he said, service must be attractive and reliable, and "we also need to have a land use pattern that makes transit use feasible.

"Outside of Vancouver, there are not many places where that is the case … As long as we are spending billions on widening one freeway and building another one, not much chance of that pattern emerging either," he wrote.

John Tak, president of the Canadian Hydrogen and Fuel Cell Association, defended the project.

"The only thing that is coming out of the tailpipe is water vapour and heat," he said. "So that's where we need to go in terms of transportation in getting rid of pollution and greenhouse gases."

The hydrogen buses will keep rolling after the Olympics, but their fate after 2014 is uncertain.