The Golden Spread Electric Cooperative today cut the ribbon on its Elk Station power plant near Lubbock, Texas. The 202-MW facility began commercial operation June 12, 2015 and now celebrates the successful validation of all technical metrics.
In recent years, the enormous wind energy potential in West Texas has spurred increasing penetration of renewables in energy portfolios across the state. Elk Station is designed to support this technological evolution by providing power to back-up the intermittent infrastructure.
The project marks the first startup of GE’s 7F.05 air-cooled turbine in the U.S.
“We’re extremely proud of Elk Station because of the performance of the turbine, and because of the success of our customer,” said Monte Atwell, general manager of power generation lifecycle product management at GE Power & Water. “Texas is a unique place; it has a tremendous penetration of renewables. This particular turbine is especially well suited to accommodating this kind of portfolio because it’s so flexible in its operation. When we conceived of the machine and the job it would need to do, we knew that renewables penetration would continue to grow in places like Texas where there’s a lot of wind, and it’s been an ideal fit. What we’re seeing at Elk Station has born this out.”
The GE F-class turbine provides a large amount of power that can be leveraged up and down very quickly. It can be turned down lower than any unit of its type—about 38 percent of its maximum output—while still maintaining emissions compliance. When the wind is not blowing, the turbine can also pick up load very quickly, since it ramps up at a rate of 40 MW per minute. The turbine reaches 75 percent full power in 10 minutes.
In addition to being fast, the turbine is also efficient, reaching nearly 40 percent efficiency levels. Elk Station avoids more than 19 tons of NOx emissions per year, based on 1,200 hours of simple-cycle baseload operation.
The 7F.05 fires at just under 2600°F, right at the line of demarcation between turbine classes. Turbines that fire above this temperature are classified as H-class; below it they are classified as F-class. The 7F.05 uses the latest state-of-the-art compressor—essentially the same compressor that provides the foundation for the H-class gas-fired turbines— which has been fully validated twice at GE’s full-speed, full-load testing facility in Greenville, SC. The turbine also incorporates GE’s most recent hot gas path, representing the latest in F-class technology.
“It’s our state-of-the-art F-class turbine,” said Atwell. “It’s used for a lot of peaking applications in locations where customers are not comfortable going to H-class firing temperatures.“
The project also marks the first time a 7F.05 turbine has operated in combination with GE’s advanced DLN2.6+ combustion system.
“The DLN 2.6+ combustion system has operated extremely well, with very low emissions,” said Atwell. “We love to hear our customers tell such good stories about our equipment. It achieves 4.8 ppm NOx at baseload, which is about a 46 percent reduction in NOx emissions at the current baseload conditions. That’s the first time anyone has achieved that low of a level, which is great. NOx is a regulated emission and something our customers really focus on because their permitting hinges on emissions compliance, and big issues arise if they can’t meet these goals.“
In addition to providing backup power for renewable energy, the Elk Station plant will also provide power for irrigation pumps that supply badly needed water to the state’s arid farmland.
“We need tremendous amounts of energy to run the irrigation pumps,” said J. Jolly Hayden, chief operating officer of Golden Spread. “GE’s 7F.05 really delivers—we affectionately refer to it as “The Beast”. It’s big, and it’s fast.”