OXNARD, Calif. — It’s been more than a year since the ribbon cutting on Gills Onions’ Oxnard, Calif., processing plant with the world’s first anaerobic digestor to turn onion waste into methane fuel. The company, however, still considers itself in a start-up phase with the technology.

Gills Onions strives for efficiency with biodigestor

Ashley Bentley

The biodigestor at Gills Onions is saving the company more than $450,000 per year it used to spend on labor and fuel to get rid of onion waste.


“We’re still in the process of understanding exactly how it works,” said Nikki Rodoni, director of sustainability. “When we started, it was going to work one way, and now it’s working a little different.”

The biodigestor the company built is basically a large working prototype. The technology was developed in a 1-liter experiment at the University of California-Davis.

Steven Gill, partner, led groups of foodservice buyers through the facility before the Produce Marketing Association’s foodservice conference in Monterey at the end of July. The groups saw how onions destined for customers including McDonald’s and A&W of Canada made it from whole onions in the field to the very specified end product.

“With this (biodigestor) it was kind of go big or go home,” Gill said. “There was no point in building a very expensive prototype. We just had to build the whole thing.”

What the company soon realized is that the onion waste made methane much quicker than anticipated.

“It is working better than we had planned, but being the first in the world to do exactly what it does, some adjustments still need to be made,” Rodoni said.

A few million dollars later, and the biodigestor was sitting outside the Oxnard plant. Despite the high price tag, the biodigestor is saving the company more than $450,000 per year that it was spending on labor and fuel to get rid of its onion waste. Without a better outlet for its waste, Gills Onions was not going to be able to grow the way its owners had planned.

Gills specializes in fresh-cut and value-added onion products, including peeled whole onions and a variety of slices and dices. Peeled yellow onions make up 75% of its business.

The company is collecting and reporting 2009 emissions and will have a measurable idea of the biodigestor’s performance when that is finished, Rodoni said.

While it continues to tinker with the digestor and its optimal fuel composition, Gills Onions has plenty to boast about, including beating out the Dallas Cowboys for an engineering award just this year.

Gills went head-to-head with the Cowboys’ new stadium in April for recognition from the American Council of Engineering Companies. It took home the national Grand Conceptor Award, as well as the state award, the 2010 Golden State Engineering Excellence Award.

In 2010, it has also received the Green Summit Award in the waste management category from the California Energy Commission.

Gills awaits a different kind of recognition before the end of the year. After a visit from host Mike Rowe and the crew from The Discovery Channel’s “Dirty Jobs,” the company anticipates the airing of its episode this fall.

Gill and Rodoni, along with Arturo Coronado, head of engineering and also the designer of the company’s proprietary equipment, and Fernando Luna, plant manager, all made appearances on camera.