Great River Energy (GRE) is an electric power cooperative serving member-owner distribution cooperatives and customers in Minnesota. In 2022, GRE sought to convert one of its combustion turbines to a dual fuel (natural gas/fuel oil) system at its Cambridge peaking station, which would help keep the station running during periods of low natural gas supply.
Barr’s permitting services for the Cambridge peaking station extend back to 2009, when we helped GRE obtain regulatory approvals for the original facility. These included site permits from the Minnesota Environmental Quality Board and a federal environmental review, as well as air quality and NPDES permits.
For this project, Barr helped GRE modify the peaking station’s air quality operating permit to cover the conversion, and we helped prepare the draft Environmental Assessment Worksheet (EAW) requested by the Minnesota Public Utilities Commission.
Barr helped GRE add diesel fuel firing capability to its combustion turbine. We prepared a preliminary design and cost estimate, which led to our final, detailed design of this facility modification. Our final design and construction drawings encompassed all engineered aspects of the conversion—from structural, electrical, and mechanical needs to civil site, grading, paving, and stormwater plans.
We then assisted with the procurement of major equipment, preparing procurement packages for fuel oil and demineralized water tanks, off-loading and forwarding pumping systems, injection skid enclosures, medium-voltage motor controllers, and other equipment.
We also provided construction support—reviewing shop drawings and developing request for information (RFI) responses, conducting site visits and inspections, and participating in progress meetings.
(Photo above is a stock image)
