Onion Waste Turned Into Electricity

All photos courtesy of Gills Onions.

Onions – one of nature’s superfoods; and, as far as I am concerned, one of the holy trinity of cooking – onions, garlic and ginger!!


A lot of waste products have been turned into biogas (most well-known being manure). However, this is the first time I have heard of onion waste being used for biogas production.

Gills Onions, the largest processor of fresh onions in the USA, has just debuted an anaerobic digester system at its Oxnard, CA location. This digester will turn 100% of the plant’s onion waste and juice into electricity, heat and cattle feed.
feed:


In a win-win situation both Gills Onions and the environment come out as winners. The environment wins because 300,000 lbs. of onion waste is utilized each day to produce enough electricity to power 460 average homes. This also removes 300,000 lbs. of onion waste from being landfilled daily. It is estimated that 30,000 tons per year of greenhouse gases will prevented from entering the atmosphere.

Gills Onions wins because they get a warm, fuzzy feeling for doing something so environmentally significant; and, it saves them $700,000 per year in electricity cost. Furthermore, by installing the system Gills Onions is eligible to receive $2.7 million from Southern California Gas Company as part of a state program to encourage on-site electrical generation for businesses.


This a flowchart of anaerobic digestion:

Photo courtesy Blue Planet Energy.

Here's a couple videos on the making of biogas.




Design of a floating drum biogas digester for an Ecovillage at the Children's Youth Empowerment Centre in Nyeri, Kenya.