Colorado Utility Energy Transition

By 2030, Colorado Springs Utilities is actively working to transition away from coal and toward a new power mix incorporating natural gas, solar, wind, and hydropower. To achieve this, the utility is decommissioning its coal-fired Drake plant and replacing it with six 30 MW simple cycle GE LM2500Xpress aeroderivative gas turbines. These turbines are designed to be reusable, allowing for minor modifications when relocated to decentralized locations in the future. Recently, at PowerGen 2023, Matthew Roling, the Power Generation Practice Lead at Stanley Consultants, delivered a presentation on how this Colorado utility is tackling the technical challenges related to decarbonization during the transition process.

One of the challenges the utility faces is the concentration of its assets in its Martin Drake power plant, wedged into the urban center of downtown Colorado Springs. The company’s 2030 forecasted power mix is net-carbon free, with 43% natural gas, 12% solar, 9% wind, and 8% hydro, respectively. The utility has reviewed market factors, including modernization, syngas/hydrogen compatibility, and improving footprint optimization. Power ratio and transportation factors were included in the power generation mix considerations, including the projected increased use of electric vehicles (EVs) by consumers.

Six GE LM2500Xpress aeroderivative gas turbines running at roughly 164 MW will provide a permanent solution mounted to the ground and capable of over 150 starts per year. However, there are challenges due to the effects of combustion properties at 6,000 feet elevation, which requires reliability, redundancy, and maintenance flexibility. The temporary natural gas (TNG) project will move outside of town after five years to build transmission equipment.

The utility provider acquired a number of valuable lessons from this project. This included the needs of hiring an owner's engineer (independent representative of project owner), doing a front-end engineering (FEED) study, separating the original equipment manufacturer (OEM) and construction firm, and ensuring OEM technical contracts are properly handled. It’s best to make sure all partners in the project are on board and meet at the same table. Hazard and operability analysis (HAZOP) and 3D model walk-ins should be early in the process, as later design adjustments cost significantly more.

He noted that OEMs are becoming more like engineering, procurement, and construction (EPC) entities as modular technology like mobile power solutions become more popular. Finally, the six aeroderivative gas turbines are being built overseas, which increases lead schedules by three months. Commissioning will take two months. The aim is for the project to be completed before summer 2022.