By Philip Reed
The Rocky Mountain region is participating in a pilot program designed to meet swings in generation within the Western Area Colorado-Missouri, or WACM, Balancing Authority. The program—a partnership between WAPA and Tri-State Generation and Transmission Association—allows WACM to use Craig Powerplant in Craig, Colorado, as a source of power in the case of system disruption or generation shortfall.
The pilot project is part of the BA Optimization effort, which has the ulti¬mate goal of more efficiently running BAs. If it is successful, similar initia¬tives may be introduced elsewhere in WAPA’s 15-state footprint.
WACM has a significant amount of variable energy sources—a total of 477.31 megawatts of wind and solar—within its BA area. Tri-State contributes the majority of that total with 292 MW of wind power and 26.49 MW of solar power; that’s 318.49 MW from Tri-State in all. What’s more, the utility plans to add another 104 MW of wind power before the end of this year and an additional 345 MW by the end of 2021, with other customers planning to add 52.5 MW.
“With all of that said, it is becoming more challenging to run the BA as ef¬ficiently as possible,” said Supervisory Power System Dispatcher Marc Desmarais.
Desmarais is the reliability opera¬tions supervisor for the dispatchers in Loveland, Colorado. His team man-ages Craig Powerplant’s participation in the pilot.
“As people may or may not know, wind and solar are not a steady, constant source of energy, and the BA has to make up any shortfalls in real time,” Desmarais continued. “The BA has been proactively looking for energy resources to supplement wind and solar resources—their prime mov¬ers—when they are not available.”
Craig Powerplant consists of three coal-fired units. These make up the Yampa Project, which is owned by Tri-State and four other regional utilities. Tri-State owns Unit #3, which is the only unit in this pilot program that may provide energy to WACM BA.
“The other two units are owned by other utilities, and there would be potential to create confusion if those two units were used,” said Desmarais. “Since Tri-State had sole ownership of Unit #3, Unit #3 was the logical choice.”
He explained that the pilot program arose from curiosity regarding Craig Powerplant and what Tri-State’s vision for the future of that plant might be.
“WAPA saw an opportunity to partner with Tri-State and come to a mutual agreement on how we could help each other out,” he said. “Tri-State had capacity to market and WAPA had a need for regulation.”
“Regulation” in this context refers to energy and capacity that WACM has purchased from Tri-State.
The longest part of the process involved the contract discussions, including how WAPA would credit Tri-State for the availability and use of the regulation.
“In the end, WAPA and Tri-State settled on 30 MW of up/down regula¬tion,” he said.
WAPA began utilizing the regula¬tion on July 1, after the organization’s supervisory control and data acquisi¬tion, or SCADA, team helped set up transfers that would give WACM the ability to request regulation from Tri-State. WAPA’s Operations team has already found significant benefit in having the regulation available and ready to use.
Desmarais emphasized the differ¬ence between WACM purchasing regulation from Craig Powerplant and purchasing regulating reserves as defined by the North American Electric Reliability Corporation.
“Regulating reserves as defined by NERC would be responsive to automatic generation control and a BA Area Control Error,” he explained. “That is not what this is. Instead, what WACM purchases from Tri-State is regulation; our operators have to manually input a value into SCADA, which then sends the value to Tri-State to have the utility move the Unit #3 generator in the direction needed.”
As an additional bonus, this ar¬rangement allows TriState to effective¬ly trade energy with WAPA instead of making payments and reduces strain on WAPA’s hydropower.
Unit #3 being available as an extra resource means WACM is able to utilize it before drawing on WAPA’s hydropower resources, which keeps the hydropower free for emergency situations.
“As WAPA continues to encourage markets and renewable resources, and looks to the future to optimize not only our BA but everything we do, I believe that Operations will evolve into even more of a cohesive, efficient working group,” Desmarais said. “By optimiz¬ing ourselves, we in turn optimize our resources, projects and customer costs.”
With Southwest Power Pool’s Western Energy Imbalance Service market launching in early 2021, Desmarais believes we will soon be seeing even more in the way of innovative solutions and planning.
“We have only touched on the tip of the iceberg of partnerships and efficiencies we can achieve when working together,” he concluded.
Reed is a public affairs specialist.