John Plaza is one of those entrepreneurs who truly believes what he's selling will change the world.

On a recent day, though, the West Seattle man faced a more mundane challenge: a disgruntled customer. "Can't I get more?" groused a driver who pulled a tanker truck up to Plaza's loading dock along the Duwamish waterway in South Seattle.

Plaza shook his head, amused at his fledgling industry. He's been open only two months and his product is perpetually sold out.

"I haven't done a minute of sales or marketing, and people are buying this stuff as fast as we can make it," he says.

"It" is biodiesel, the latest rage in the alternative energy world. It's a fuel made from vegetable oil that can be used in most any car, truck, bus or boat that has a diesel engine.

Cleaner-burning and more energy-efficient than petroleum, it's being hailed as a way to literally grow our way out of dependence on foreign oil.

Plaza has built the Northwest's first large biodiesel factory. I visited to get a sense of whether the fuel that smells like French fries is a fad or the real deal.

It's not a new idea. The guy who invented the diesel engine more than a hundred years ago, Rudolph Diesel, powered his with peanut oil.

For years, enthusiasts have microbrewed plant-based diesel fuels in backyard stills.

It started to go mainstream around 2002, when the price of a barrel of petroleum oil began its surge from $20 to $60 today. Now biodiesel is used by governments, to run ferries and buses, and by several thousand Puget Sound drivers.

Enter Plaza, 39, a commercial jet pilot who built Seattle Biodiesel for $1 million. It looks like a beer brewery, complete with tanks salvaged from the old Rainier plant.

From here Plaza hopes to refashion the industry, mimicking the hugely successful model of the organic-food business.

Today the raw materials for biodiesel come from the Midwest. The idea is to make them here instead, by growing canola seed in Eastern Washington and crushing it into oil there. Then, the oil can be combined with ethanol made from local wheat to make biodiesel.

The result: a locally grown, locally made, sun-powered fuel.

Plaza's big hope is that he can make it for the same price as petroleum diesel, without subsidies. Today biodiesel is heavily subsidized and costs 50 to 75 cents more per gallon.

He just bought two seed crushers to try to prove that making vegetable oil here can bring down biodiesel's price.

"We should be relying on ourselves for our own fuel," he says. "That's not sexy, but it's a world-changing idea."

I have been leery of biodiesel, as it seems it will require huge taxpayer subsidies, à la the ethanol program.

It's a watershed, though, that people such as Plaza are vowing to compete with the likes of Exxon Mobil. And that their plan to do it is the opposite of outsourcing.

Biodiesel may not change the world. But it's already changing this country's stale energy debate.

Danny Westneat's column appears Wednesday and Friday. Reach him at 206-464-2086 or dwestneat@seattletimes.com.