Stillwater Electric Utility (SEU) is the largest municipal generator and transmission utility in the state of Oklahoma, and the utility has been providing its own electrical generation services since 1903. However, that long history of power generation almost came to an end more than three years ago, if the utility hadn’t adopted a bold and forward-thinking plan to help it provide for its customers well into the future.
For many years, SEU has relied on the Boomer Lake Station to supply the majority of its generation. The 27-megawatt natural gas-fired steam turbine plant was built in the mid-1950s and supplied the entirety of the city’s electrical power until 1967, when the city’s demand exceeded its capacity. The facility was upgraded in the 1990s and was converted into a peaking plant, but by 2012 it became clear that the city would need to begin thinking about other solutions for its power needs. Generation and Transmission Division Manager Loren Smith says the city faced the possibility of shutting down its generation operations along with Boomer Lake Station.
“Three years ago, we found ourselves at a crossroads,” Smith says. “Knowing Boomer Lake Station was quickly reaching the end of its useful life, we had a decision to make: Rebuild Boomer Lake Station, build a new state-of-the-art power plant, or get out of the generation business altogether.”
After reviewing all of the options and thinking about what type of technology would be needed for the energy market of the future, SEU was ready to make a decision.
“We looked at generators that could be brought online quickly, were very efficient and flexible enough to counterbalance the renewables that were being brought into the market,” Smith explains. “After the study was completed, it was determined that it was economically feasible to build a new state-of-the-art power plant using natural gas-fired reciprocating engine technology.”
New Technology
SEU’s new Stillwater Energy Center project will do more than meet the power needs of Stillwater’s residents and businesses now and for the future, Smith says. The new facility will provide a significant cost savings for the city and greater reliability through technology never before seen utilized in the nation’s heartland. “The new plant will be a modern marvel for the state of Oklahoma, if not the Southwest Power Pool (SPP) region,” Smith says. “It will be the first plant [this far inland] in the United States using the large Wartsila engines. At the signing of the contracts, these were the largest natural gas-fired reciprocation engines being produced in the world. Due to the size of the engines, this technology has only been installed in the coastal regions mainly due to the size and shipping.”
The plant will have three of these Italian-made engines, generating more than 56 megawatts. The project involves the power generation building containing the three engines, an operations and administration complex and a new electrical transmission and distribution substation.
Upholding the Commitment
Smith says the new generation facility will put SEU and the city of Stillwater in a great position for the energy market of the future, most significantly when it came to the growing presence of renewables like wind power in the local energy marketplace. “The plant is designed to ‘chase the wind’ or the renewables in the SPP Integrated Marketplace,” Smith says. “The flexibility of the engines/generators is phenomenal. They can be brought online and to full load in 10 minutes, full load to offline in 60 seconds, and be available to restart in six minutes. They are very efficient from 40 percent load to 100 percent, and have a very quick ramp rate to respond to fluctuation in the energy market.”
The efficiency of the new plant is essential for SEU. “Providing low-cost, efficient energy into the market will help to support low-cost power to all of our public power customers in Oklahoma,” Smith says. “With this project, the SEU continues the 114-year commitment to provide low-cost public power to its customers.”
