By Jennifer Rose
Successfully using by-products
In 2009, the owners of Corvallis, Oregon-based Stahlbush Island Farms did what they do best: they turned a problem into a solution. Recognizing that they had millions of pounds of fruit and vegetable by-product from their processing activities, they began to investigate ways to turn the calorie-rich material into something useful. The result: the first North American biogas plant to transform fruit and vegetable by-product into electricity.
The plant, which cost 10 million dollars and took fourteen months to complete, is based on “simple innovation,” says Tracy Miedema, National Sales and Marketing Manager at Stahlbush Island Farms. “We simply took the processed food material that we had on hand, designed tanks that were self-mixing, and essentially let nature take its course.” In doing so, the plant’s engineers created just the anaerobic conditions needed to produce biogas, a methane-rich gas that can be used to generate both thermal and electrical energy.
Already, the company’s investment in this technology is paying off. According to Miedema, the biogas plant presently generates enough electricity to power the equivalent of 1,100 homes. Approximately half of this electricity is used to operate the farm, and the other half is sold back to the grid. “From a business standpoint, this is really a fantastic arrangement,” Miedema observes. “Not only do we have enough to power our own operation, we are also able to make money off of the power we produce but don’t use.”
The biogas plant has also helped to reduce Stahlbush Island Farms’ expenditures on farm inputs. Instead of having to pay for manure or other soil amendments, the company is able to apply the material “digested” through the biogas plant to its fields. In this sense, Miedema says, the plant has helped to create a “closed loop” system on the farm. As she explains, “We take energy from the field in terms of the foods we harvest and we return energy to the field using the by-products of the biogas production process, creating a system in which there is little, if any, waste.”
Going forward, Stahlbush Island Farms plans to make improvements to the biogas plant so that it operates with even greater efficiency. As Miedema puts it, “Our goal is to continue to do what we as farmers do best: make the most out of the resources we have and perpetually push the limits to do better.”