The North Dakota Public Service Commission has scheduled a March 2 hearing on a recent application by Basin Electric Power Cooperative for a Certificate of Site Compatibility for the Pioneer Generation Station (PGS) Phase III Project.
“The Basin Electric service area in northwestern North Dakota is experiencing a rapid increase in development as a result of the activities associated with oil and gas extraction from the Bakken shale formation, currently concentrated in McKenzie, Mountrail, and Williams Counties,” said the application, filed on Dec. 1. “The development that has already occurred and additional development planned for the future require numerous infrastructure upgrades throughout the region, including an increase in electrical generation capacity and reliability. Through load forecast studies, it has been determined that up to 12 reciprocating internal combustion engines (RICE or gas engines) are needed to serve the needs of northwestern North Dakota by increasing the power generation capacity, increasing voltage support for the electricity transmission system, and enhancing the reliability of the electrical system in the region.”
PGS currently consists of three General Electric LM6000PC natural gas-fired simple-cycle combustion turbines (SCCTs)—Units 1, 2, and 3—each with a nominal generation capacity of 45 MW. PGS Unit 1 started commercial operation in September 2013, Unit 2 started commercial operation in February 2014, and Unit 3 started commercial operation in March 2014.
The existing PGS is located approximately 15 miles northwest of the City of Williston in Hebron Township in Williams County, North Dakota.
Basin Electric proposes, under PGS Phase III, to construct, operate, and maintain up to 12 new RICE or gas engines. The proposed project would have the capability of generating up to 111 MW and would be designed to produce electricity at levels ranging from 3 MW to 111 MW. The new gas engines would themselves occupy approximately 8.2 acres within the energy conversion facility area, which would include all of the existing 120-acre PGS property.
The new RICEs would be installed adjacent to the three existing 45-MW SCCTs located onsite. An approximately 3.7-acre electrical switchyard would also be constructed onsite.
The project is expected to start construction in May 2015 after all the necessary permits have been acquired, with an anticipated commercial operation date of June 2016.
Project would be able to use pipeline, grid infrastructure of existing plant
Each RICE would have a nominal 9.22 MW of capacity. The engines would be turbo-charged, four-stroke, lean-burn (4SLB) engines. They would combust natural gas and, in case of natural gas curtailment, the engines could combust liquefied propane gas (LPG) as a back-up fuel. The project incorporates the design to accommodate LPG tanks and supporting interconnections. This infrastructure would not be installed initially.
Basin Electric currently operates within the Integrated System (IS) with the Western Area Power Administration (Western) and Heartland Power. In fall 2015, Basin Electric will be migrating into the Southwest Power Pool (SPP). If and when the SPP operating criteria require that PGS have a short term secondary fuel supply, the LPG system will be installed. Depending on the criteria, a 20,000-gallon tank would be required for a 4-hour fuel supply, and 120,000 gallon tank would be required for a 24-hr fuel supply. For the purposes of the PSD air permit, the LPG option was incorporated into the application. In the event that LPG is required, the PSD air permit would allow the use of LPG.
Natural gas is supplied to PGS by a WBI Energy Transmission 1,800-foot long, 8-inch diameter pipeline that originates at ONEOK’s Stateline I Gas Processing Plant gas interconnection to the Northern Border Pipeline. ONEOK’s Stateline I Gas Process Plant is located adjacent to PGS. The existing pipeline is large enough to supply the 12 proposed gas engines in addition to the three existing turbines. A 6-inch-diameter pipeline would be required to deliver natural gas from the PGS metering station to the project gas skid. Approximately 711 feet of additional pipeline would be required.
The existing electrical interconnection for the PGS is a 0.5-mile-long, 115-kV transmission line to Mountrail-Williams Electric Cooperative’s (MWEC) Stateline I Substation located adjacent to ONEOK’s Stateline I Gas Processing Plant. As part of the Phase III project, a new electrical switchyard would be constructed adjacent to the proposed gas engines on the site to deliver power from the new engines to the electrical grid. The existing Sheridan Electric Cooperative 115-kV line that interconnects to the Stateline Substation would be re-directed across Basin Electric property at the PGS to the new electrical switchyard. The new configuration of the 115-kV line would cut this existing line and extend one end of the line into the new switchyard. A second line would extend from the new switchyard to connect to the other end of the Sheridan Electric Cooperative line.
Wärtsilä announced in October 2014 that it has been awarded the contract to supply the RICE engines for Pioneer Phase III.