Great River Energy analyzes future of unique transmission system

The announcement that Great River Energy will close the Coal Creek Station power plant in the last half of 2022 led to in-depth analysis of how the cooperative’s high-voltage, direct-current (HVDC) transmission system will be used after the plant closes.

The HVDC system, which is made up of a 436-mile transmission line and two converter stations at either end of the line, delivers all the power from Coal Creek Station to Minnesota now, but it could be used in a variety of ways in the future.

“We have long known this system is a highly valuable asset not only to our member-owners, but also to the state of North Dakota and the market, regardless of what kind of generation is at the end of the line,” said Great River Energy’s Vice President and Chief Transmission Officer Priti Patel.

She said Great River Energy fully expects the HVDC system to remain an important asset for the efficient, reliable operation of the Midcontinent Independent System Operator (MISO) market after the closure of Coal Creek Station.

The HVDC system is made up of a 436-mile transmission line and two converter stations at either end of the line to deliver power from Coal Creek Station to Minnesota.

Patel also addressed a misunderstanding that is circulating.

“There are some in North Dakota who are hoping to keep the plant open by claiming that without it, we will not be able to use the HVDC system. That is not accurate and any efforts to dismantle this critical system could deter other utilities and developers,” she said.

Coal Creek Station and the HVDC system were permitted separately in 1978 as required by the North Dakota Public Service Commission. The use of the HVDC system is not dependent on the existence and use of Coal Creek Station.

Patel said there are many ways the HVDC system can be used and there are teams of Great River Energy employees who are working with MISO to analyze the options. Both selling the system and continued Great River Energy ownership are being considered.

“North Dakota is rich in a variety of generation resource fuels. One or more generators may want to use the system to deliver electricity to the Twin Cities,” Patel said. “The system does not need to be dedicated to just one source like it is now.”

Another option is turning control of the HVDC system over to MISO to use in the same way

they use Great River Energy’s other transmission assets. Or, Great River Energy could sell Coal Creek Station and its interconnection rights which, in today’s environment, are very valuable. Interconnection rights allow generators to use the transmission system to deliver the electricity they generate.

“While we do not know exactly how the system will be used in the future, it is inconceivable to me it would not be used in some way. North Dakota has a desire to continue to be an exporter of energy and this line helps facilitate that. It is capable of moving a tremendous amount of electricity. In a transmission-constrained world, it would be very rare not to use it,” Patel said.

The HVDC system plays a key role in economic development in North Dakota. It alone provides good jobs and tax income. And, if new power generation is sited near the line, it would result in added tax revenue, jobs and economic activity in the state.

The teams analyzing options for the future of the system plan to have determined a path forward by the end of the year.