Idaho Public Utilities Commission

Case No. IPC-E-10-16, -17, -18

June 9, 2010

Contact: Gene Fadness (208) 334-0339, 890-2712




Anaerobic digester projects proposed in Magic Valley


The Idaho Public Utilities Commission is taking public comment through June 23 on a request by Idaho Power Company to enter into power sales agreements with the developer of three Magic Valley anaerobic digester power projects.


The 15-year contracts are all with a Middleton-based developer.  Two of the projects are in Twin Falls County. They are the 4-megawatt Rock Creek Dairy project near Filer and the 2-megawatt Swager Farms Dairy project near Buhl. The 2-megawatt Double B Dairy project is near Murtaugh in Cassia County.


All three projects are qualifying facilities under the provisions of PURPA, the federal Public Utility Regulatory Policies Act of 1978. PURPA requires electric utilities to offer to buy power produced by qualifying small power producers or cogenerators. The rate to be paid PURPA project developers, called an “avoided cost rate,” is determined and published by state commissions. The avoided cost rate is to be equal to the cost the electric utility avoids if it would have had to generate the power itself or purchase it from another source.


For all three of these proposed projects, the rate in the first year is $75.65 per megawatt-hour. The rate gradually increases over the 15 years of the contracts to $128.31 per MWh. That rate is adjusted for heavy- and light-load seasons as well as heavy- and light-load hours. The proposed Rock Creek Dairy project intends to deliver 1,296 megawatt-hours per month, while the Swager Farms and Double B project are anticipating an output of 648 MWh per month.


Anaerobic digestion is a biological process that produces a gas principally composed of methane and carbon dioxide otherwise known as biogas. These gases, produced from organic wastes such as livestock manure and food processing waste, are converted into electric energy.


The commission plans to handle this request in a modified procedure that uses written comments rather than conducting a hearing, unless customer comments can demonstrate a need for a public hearing. Comments are accepted via e-mail through June 23 by accessing the commission’s homepage at and clicking on "Comments & Questions." Fill in the case numbers (IPC-E-10-16. -17 and -18) and enter your comments. Comments can also be mailed to P.O. Box 83720, Boise, ID 83720-0074 or faxed to (208) 334-3762.


A full text of the commission’s order, along with other documents related to this case, is available on the commission’s Web site at Click on “File Room” and then on “Electric Cases” and scroll down to the above case numbers.