Smart Energy Dollars at Work
Threemile Canyon Farms
NW Natural has partnered with the Bonneville Environmental Foundation and Threemile Canyon Farms to build a first-of-its-kind biodigester. This initial Smart Energy project is being built and will be operated at Threemile Canyon Farms in Boardman, Oregon. Once the biodigester is complete, waste from 1,200 cows - roughly 144,000 lbs. a day, will be used in the biodigester instead of being left on the farm, resulting in a reduction of 1,500 tons of CO2 annually.
The design of the biodigester incorporates a lined and covered lagoon that is filled with discarded automobile tires which trap and retain bacteria from the cow manure. In the treatment process, the retained bacteria break down the manure and convert it into methane-rich biogas, a renewable energy source.
Why have NW Natural, The Climate Trust and The Bonneville Environmental Foundation chosen Threemile Canyon Farms for this project?
Perhaps the primary reason these organizations focused on Threemile Canyon Farms is the farm's commitment to reduce its environmental footprint and be a responsible corporate citizen. Threemile Canyon Farms considers itself a learning lab. Because of its size, it offers the opportunity to test new technologies and practices. A functioning biodigester at this dairy farm can become a model for smaller farms throughout the region.
Threemile Canyon Farms is located on 93,000 acres near Boardman, Oregon. The farm combines crop farming and dairy operations. A 23,000 acre conservation area has been established to protect irreplaceable habitat and the species that depend on it. It employs 300 full-time and up to 400 seasonal workers, with a $10 million payroll and a $250 million annual economic impact in Morrow and Gilliam Counties.
What is a biodigester?
A biodigester is an enclosure that traps methane produced by bacteria which breaks down organic matter (waste). The resulting product, biogas, can be used in place of natural gas or propane for a variety of functions.
How does a biodigester reduce greenhouse gas emissions?
When organic material, like animal manure, decomposes, it emits methane - which is approximately 21 times more potent of the greenhouse gas effect than carbon dioxide. A biodigester speeds up decomposition and captures the methane, protecting the environment.
Are there other benefits to biodigesters?
Yes.
- Biodigesters help farmers deal with troublesome waste management problems. A typical cow produces 120 pounds of waste each day. Dairy farmers work hard to protect water bodies and groundwater from manure. A biodigester can help with this problem.
- Biodigesters create a useful by-product that farmers can sell for fertilizer or mulch, creating organic soil supplements and adding to local farm revenues.
- Biogas created by biodigesters can substitute for fossil fuels. Farmers can use the fuel on site to create electricity or as a substitute for propane for heating or chilling. NW Natural is working with a coalition to set quality standards so that biogas can be integrated into the regional natural gas supply.
How will the biodigester work?
The innovative design overcomes one of the biggest challenges for on-farm anaerobic digester development - namely, cost. Historically, the initial investment to construct a biodigester has been daunting for most dairy farms, especially those using flush systems common among western dairies.
J-U-B's design incorporates a lined and covered lagoon that eliminates the need for the more standard high-priced concrete or steel tanks. The covered lagoon is filled with discarded automobile tires which trap and retain bacteria from the cow manure. In the treatment process, the retained bacteria break down the manure and convert it into methane-rich biogas, a renewable energy source. This process significantly improves the treatment efficiency of the system, making it a more cost-effective design.
How big will the biodigester be, and how much methane will it capture?
The first phase of the biodigester will reduce carbon emissions by 1,500 tons which equals the emissions from the natural gas use of more than 400 homes. While the biogas is to be used on site by Threemile Canyon Farms, it would be enough gas to supply about 102 homes.
What will happen with the biogas?
Threemile Canyon could use it to on site to replace propane or ship it to a neighboring farm that would use it to process food for cattle. It also could be used to generate electricity on site. Another option is to use it in a heat-exchange process. A chiller could cool water used in the farming operation, which otherwise must be retained on site before being discharged into the river.
What's the timeline?
The project is already underway, and is expected to be complete by March 2009.
Will Threemile Canyon Farms develop other biodigesters?
If the first phase of the project shows positive results, Threemile Canyon Farms hopes to capture all methane from manure in biodigesters.
Farm Power
Kevin and Daryl Maas are two Washington state brothers who started a small company, Farm Power, to offer sustainable waste management solutions to farmers in their area. Farm Power invited Harmony Dairy, LLC, and Beaver Marsh Farms, two Washington dairy farms, to participate in a biodigester project. The Climate Trust is purchasing Farm Power's carbon offsets on behalf of Smart Energy customers.
A tank captures the biogas from this project, holding it to produce electricity in an on-site generator. Puget Sound Energy buys the power for distribution to its customers.
The Climate Trust estimates the project will capture more than 2,800 metric tons of methane over 10 years. That's the equivalent of eliminating nearly 60,000 metric tons of carbon dioxide.
