The plan to retire the last coal-fired units at a power plant in Colorado has moved a step closer to completion, with the announcement that Colorado Springs Utilities (CSU) has chosen General Electric (GE) technology to keep the plant operating at least temporarily as a gas-fired facility.
GE on Feb. 10 announced that six of the company’s advanced 34-MW LM2500XPRESS aeroderivative gas turbine packages will be deployed at the 208-MW Martin Drake plant in downtown Colorado Springs, one of the last operating urban coal-fired plants in the U.S. It’s the first time GE will install the technology in North America.
CSU’s ‘Energy Vision’
The board of Colorado Springs Utilities in June 2020 voted to end coal-fired generation at Martin Drake and replace the facility’s remaining two operating coal units with natural gas-fired generators, saying they were looking for technology that could later be moved offsite.
The board also last summer voted to retire the utility’s other coal-fired plant, the 207-MW Ray Nixon facility, located in Fountain, south of Colorado Springs, by 2030. The utility as part of its “Energy Vision” plan wants to reduce carbon emissions from its power generation by at least 80% by 2030, compared to 2005 levels. The plan to retire the Drake and Nixon facilities aligns with Colorado officials’ goals to reduce statewide greenhouse gas emissions from electricity production, transportation, and other sectors.
The last two coal units at Drake are scheduled to be retired by year-end 2022, 12 years earlier than originally planned. The new gas units will enable the plant to continue producing electricity for Colorado Springs until a new transmission line into the area is completed, a project expected to come online in 2025.
“The LM2500XPRESS units were purchased to provide safe, affordable and reliable generation to support the increased use of renewable solar and wind power,” CSU CEO Aram Benyamin said Wednesday. “These natural gas units will help us better integrate renewable energy sources, further reduce CO2 emissions, and accelerate the retirement of the Martin Drake Power Plant.”
The board has said CSU will integrate more cost-effective renewable energy and non-carbon resources, such as wind and energy storage, into its portfolio to replace the coal-fired generation capacity. Board members worked with CSU staff in recent years to develop the utility’s new energy plan, designed to serve the city for the next 30 years.
Recent closure announcements by other Colorado utilities mean that Xcel Energy, the state’s largest electricity provider, will be the only utility in the state with operating coal-fired units after 2030. The 505-MW Pawnee Generation Station in Brush is scheduled to operate until 2041. The 750-MW Unit 3 at the Comanche plant in Pueblo is slated to run through 2069.
Aeroderivative Gas Turbines Offer Flexibility
The GE turbines set for use at the Drake plant are 95% factory-assembled into simplified modules, enabling easier and faster installation onsite, according to GE. The units also are mobile and can be relocated if needed. GE said the aeroderivative technology “will help Colorado Springs Utilities ensure reliable and flexible power to enhance grid stability and renewables growth.”
GE said the LM2500XPRESS units at the Colorado Springs site “are expected to start commercial operation by the summer of 2022.” GE said the units can be moved on trailers, and “will eventually be relocated to other sites in the Colorado Springs area.”
“GE is proud to work with Colorado Springs Utilities and to provide our technology for its customers,” said Eric Gray, CEO of GE Gas Power for the Americas. Gray told POWER, “We are dedicated to their success and to helping deliver more efficient, affordable, and reliable electricity for Colorado Springs’ homes and businesses. This project with Colorado Springs Utilities is a great example of how gas can play a meaningful and critical role in the future of energy and drive decarbonization.”
Gray said, “GE is committed to a decade of action for industry-wide decarbonization through the strategic and accelerated deployment of complementary gas and renewable energy technologies. We are pleased to help Colorado Springs Utilities achieve a faster path toward decarbonization using GE’s LM2500XPRESS units. The flexible concept of this breakthrough technology made it Springs Utilities’ ideal choice with a quick installation, small footprint, and the ability to easily relocate the equipment in the future.”
GE said the LM2500XPRESS generators “provide a ‘plug and play’ concept that can be installed in less than three weeks. This makes the units ideal to bring fast power to the grid when needed.” Each power block includes an aeroderivative gas turbine modular package, gas compressor, and emissions control system. A black-start diesel generator is included to provide start-up capability in case of grid events.
The units also have dual-fuel capability, primarily burning natural gas but with the ability to use other liquid fuels. GE said the units’ “advanced emissions control system uses a dry low emissions [DLE] combustion system that cuts down on water use, and an oxidation catalyst to reduce emissions from these units.”
GE said the LM2500XPRESS technology “is available in both simple and combined-cycle configuration, for 50 and 60 Hz utility providers. In simple cycle configuration, it delivers 34 MW and achieves up to 39.5% of efficiency. In a combined cycle configuration, it delivers up to 47 MW with up to 54.4% of efficiency.”
Colorado Coal Fleet Fades
The end of coal-fired generation at the CSU plants is part of a statewide move away from coal by utilities operating in Colorado. Xcel in January said it would close the 441-MW coal-fired Hayden Generating Station in Hayden, west of Steamboat Springs, ahead of schedule. The plant’s 44-year-old Unit 2 will close by year-end 2027, and Unit 1, which came online in 1965, will be shuttered by the end of 2028. The Hayden units originally were slated to close in 2030 and 2036.
Xcel’s move is the latest of several earlier closure announcements in the state, from four different utilities. In addition to Xcel’s units, and the two power plants in Colorado Springs, the Platte River Power Authority last year said it will close its 280-MW, coal-fired Rawhide plant north of Fort Collins by 2030, 16 years ahead of schedule.
Tri-State Generation and Transmission Association, a power wholesaler supplying 43 rural electric cooperatives, including 17 in Colorado, last summer announced the early closure of two coal-fired units at the 1,285-MW Craig Station in northwest Colorado by 2030. A third Craig unit was already scheduled to close by 2025.
—Darrell Proctor is associate editor for POWER (@POWERmagazine).