MADISON, Wis. -- About 100 visitors toured a new biodiesel plant in DeForest as part of a "Green and Growing" tour aiming to keep Wisconsin at the forefront of biofuel production.

While ethanol production didn't exist in Wisconsin six years ago, the state currently produces 200 million gallons a year.

Visitors who toured the Sanimax Biodiesel Plant learned what goes into each gallon of renewable fuel.

"Our plant, the (United Wisconsin Grain Producers) plant in Friesland, is one of the plants we're visiting. I just wanted to see what's happening in the bioenergy field and what some other people are doing," said Bob Lange, co-founder of United Wisconsin Grain Producers, LLC.

About 100 people tour the Sanimax plant and three others, including an ethanol plant in Friesland.

Using renewable sources, like animal fat or corn to make fuel is the wave of the future for some, WISC-TV reported.

"Biofuels are not a flash in the pan. They are going to be here forever. They are the wave of the future," said Russ Read, manager at the Sanimax Biodiesel plant

Earlier this year, state officials pledged $80 million in grants and loans to biofuel businesses.

Experts said that kind of financial commitment is needed to make Wisconsin a national leader in renewable fuels.

"If we can start producing larger and larger portions of what we use, we keep the dollars, we keep the jobs (and) we keep the opportunities here in Wisconsin," said Rod Nilsestuen, Wisconsin secretary of agriculture.

But biofuel also has it critics. Auto expert Matt Joseph said that more oil is used than saved to convert corn to ethanol.

"The technological miracle is selling the American people on the concept of ethanol. There isn't enough land mass to plant what we would need. It's supposed to help farmers; it hasn't to date," Joseph said.

Despite critics, biofuel production continues to grow.

"Whether it's jobs, a little bit better price for the farmers, fuel for people who are driving, it's all staying in the state. I think that's the big advantage," Lange said.

Sanimax, the largest biodiesel plant in Wisconsin, is capable of generating 20 million gallons per year.

The plant started production in January, WISC-TV reported.