Every time Glenn Picard heard or read about climate change, he pondered switching to a cleaner-burning fuel.

The Napa building contractor realized his hacking cough and bronchitis were probably being aggravated by the diesel fumes he was exposed to every workday. But it wasn't until diesel hit $2.28 a gallon, about four years ago, that Picard finally took the plunge into biodiesel.

"Contractors are always looking for a bargain and for a long time diesel was cheap, it was a garbage fuel. Now they're paying premium price for it and they're kind of mad about it," said Picard, who operates Glenn Picard Construction.

Now Picard, 47, relies on biodiesel -- an alternative diesel fuel made from vegetable oils -- to fill up his work truck, his forklift, a tractor and the Volkswagen Jetta driven by his wife, Julie.

Since all those vehicles had diesel engines, none required changes, in theory, though Picard had to put synthetic rubber hoses in his Ford truck because biodiesel burns hotter than diesel and will melt existing natural rubber hoses.

The closest biodiesel pumps to Napa are in Martinez, Santa Rosa, Berkeley and San Francisco, so the Picards rely on deliveries every month or so from Yokayo Biofuels, a manufacturer in Ukiah.

"It's made me a happier person, because all of a sudden I felt healthier," he said.

Picard is one of a growing number of area drivers turning to cleaner-burning fuels -- mainly biodiesel because it's the most readily available. Biodiesel can be used independently or it can be blended, in any ratio, with standard diesel.

Most ethanol -- an alcohol-based fuel made by fermenting starch crops like corn, barley and wheat -- is sold in the Midwest, where it is produced. An ethanol station is planned for construction at the Lawrence Livermore National Laboratory.

While biodiesel is still a fringe fuel, the veggie gas is amassing a following, even at the White House.

On Friday President Bush touted alternative fuels as a clean energy source independent of the foreign oil market.

"I'm very much in favor of promoting the technologies that will enable ethanol and biodiesel to remain competitive, and therefore, affordable," Bush said during his visit to Brazil. The president said he wants to work with Brazil, a pioneer in ethanol production, to push alternative fuel development in Central America and the Caribbean.

Until recently, though, buying alternative fuels was somewhat of an underground endeavor propelled by people committed to using cleaner burning fuel regardless of added costs and inconveniences.

Picard and other Napa biodiesel converts said they stick to biodiesel because it generates less pollution. According to the Environmental Protection Agency, biodiesel emits 67 percent fewer unburned hydrocarbons, 48 percent less carbon monoxide and 47 percent fewer particulates but 10 percent more nitrogen oxides than traditional fuel. Several biodiesel users also expressed a hope to help lessen society's dependence on foreign oil -- Picard mentioned the escalating conflicts in the Middle East.

Production rising

The switch to biodiesel comes with its share of risks and drawbacks.

On average, pure biodiesel costs $1 more a gallon than regular diesel and is harder to get. Using pure biodiesel voids the warranty for vehicles made by most American auto manufacturers -- with the exception of John Deere and New Holland, both agricultural equipment manufacturers.

But with national production of biodiesel on the rise -- from 25 million gallons in 2004 to 225 million gallons in 2006, according to the National Biodiesel Board -- experts predict biodiesel prices will drop.

The recent spike in gas prices, which have reached $2.97 locally, is also good for biodiesel business.

"People are more open to using alternative fuels when they're only 10 to 20 cents more expensive (per gallon) as opposed to 60 cents," said Trevitt Schultz, who shares ownership of Peoples Fuel, a biodiesel cooperative in San Francisco.

An informal survey of several area biodiesel vendors showed prices for a gallon of biodiesel ranging from $3.26 (in bulk) to $4.19 a gallon.

Limited availability is a major barrier for local converts, but a handful of companies deliver biodiesel to homes and businesses where people like Picard keep the fuel stored in 50- to 100-gallon plastic drums.

Besides requiring a large tank of flammable liquid on one's property, there are other quirks to the biodiesel lifestyle, such as signing the "experimental" waiver many sellers require.

Tony Morse, a salesman for Martinez-based Golden Gate Biodiesel, said changing this and other institutional hurdles would be crucial steps if biodiesel is ever to become mainstream.

Morse said he is part of a coalition meeting with the California Air Resources Board to push for auto manufacturers to accept -- without a penalty to car owners -- higher percentages of biodiesel in their vehicles than the current 5 percent.

But losing a warranty isn't a worry for people like Gardner with older diesel vehicles. Gardner seemed won over simply by the fact that biodiesel is more abundant and accessible today than ever.

"I want to do it," said Gardner, who would be switching over several work trucks and vehicles that he uses for his awnings business, PJ's Canvas.

A reliance on biodiesel has worked in other settings, including several area vineyards. David Beckstoffer said most of Beckstoffer Vineyards' tractors and diesel trucks use biodiesel supplied by Napa Valley Petroleum. Come harvest the vineyard operation tends to increase its regular diesel consumption because the tractors they rent from others seldom allow biodiesel use, he said. Other minor hindrances include the fact that biodiesel eats away paint if spilled on a vehicle's surface and that it is not as efficient at generating power as regular diesel.

"You'd probably run into a problem with horsepower if a pickup was hauling a big trailer uphill," he said.

But hauling isn't a concern for biodiesel's converts like Dominic Molinari, a 17-year-old first-time driver.

After learning about climate change and global warming in biology class last year, the Vintage High School junior said he was set on the idea of driving an electric car.

When his parents raised concerns about the small size of most electric vehicles, Molinari kept researching. He then learned about biodiesel while sharing dinner with family friends, Glenn and Julie Picard.

His parents checked out the crash test results for several diesel vehicles -- Jettas, old Mercedes-Benzes, dozens of trucks -- and eventually settled on the 2002 Dodge Ram 2500 TurboDiesel -- a "big truck" as Molinari describes it.

Molinari said his friends were surprised when they first saw him driving the behemoth.

"They asked me, 'Dominic you got that big gas-guzzler I thought you cared about the environment,'" Molinari recalled. "... I'm going to put some stickers on it and let people know. It's the little steps that make a difference."