Advanced Search

Please click here to take a brief survey

From Skins of Onions, Farmers Develop Promising Biogas
Article Photo

A large onion processor in California is taking 300,000 pounds of onion waste a day — skins, tails, and tops — and converting much of it into a biogas that he uses to power his operation. Steven Gill, a partner in Gills Onions — which dices, slices, and purees onion for wholesale and retail customers — has worked with Southern California Gas Company to create an energy recovery system that produces 600 kilowatts per day, which meets up to 40 percent of the electricity needs of his processing plant. The onion waste is shredded and pressed to squeeze out the juice, which is then diverted to an anaerobic digester. Workers add microbes that convert the juice into methane gas, which helps power Gill’s facility. Gill used to spread the onion waste on fields but soon ran out of room. Southern California Gas provided $2.7 million in incentives for the $9.5 million energy recovery system. Gill estimates that converting the onion waste to biogas will save him $700,000 a year in electricity costs and $400,000 in waste disposal costs, meaning the plant will pay for itself in about six years. Nearby carrot and wine producers are interested in installing similar systems.

This piece originally appeared in Yale Environment 360

Creative Commons Photo Credit

Related posts:


Bookmark and Share


"600 kilowatts per day" doesn't parse. Did you mean 600 kilowatt-hours?

Posted by: Dave Spicer on 22 Jul 09

Post A Comment

Please note that comments will remain open for only 14 days after the article is posted. While previous comments will remain visible, attempts to post new comments after this period will fail. This helps stop comment spam, so your forebearance is appreciated.

The Worldchanging comments are meant to be used for further exploration and evaluation of the ideas covered in our posts. Please note that, while constructive disagreement is fine, insults and abuse are not, and will result in the comment being deleted and a likely ban from commenting. We will also delete at will and without warning comments we believe are designed to disrupt a conversation rather than contribute to it. In short, we'll kill troll posts.

Finally, please note that comments which simply repost copyrighted works or commercial messages will be summarily deleted.

Yes No







MESSAGE (optional):

Search Worldchanging

Worldchanging Newsletter Get good news for a change —
Click here to sign up!


Website Design by Eben Design | Logo Design by Egg Hosting | Hosted by Amazon AWS | Problems with the site? Send email to tech /at/
Architecture for Humanity - all rights reserved except where otherwise indicated.

Find_us_on_facebook_badge.gif twitter-logo.jpg