Intermountain Power

Application: Singleshaft Combined Cycle (CCGT)
Country: USA
Year: 2023
Power: 250MW
Type: 320T

Article lead image — Intermountain Power - by Braddah n8, licensed under CC BY 4.0, 2 off new CCGT sets with old coal fired units to right

Intermountain Power is preparing for the future by replacing its old coal fired units with new highly efficient combined cycle gas turbines that will run on Hydrogen.

The Intermountain Power Renewed (IPP Renewed) project is a transformative redevelopment of a 1,800 MW coal-fired plant in Delta, Utah, scheduled to become operational in 2025 / 26. It replaces coal with two Mitsubishi Power M501JAC combined-cycle gas turbines (840 MW total) capable of burning a 30% green hydrogen mix, with a goal of 100% hydrogen by 2045.

The original power station, built in the 1980s served as a major power source for Southern California (11% of LA's power in 2024). Due to California legislation requiring 100% carbon-free power by 2045, the plant was required to stop burning coal. In 2019, the decision was made to transition the site to a "green hydrogen-ready" combined-cycle gas turbine (CCGT) plant, aimed at extending the facility's life and reducing emissions.

The new installation utilizes existing assets, including high-voltage transmission lines to California, water rights, and access to local natural salt domes for large-scale hydrogen storage.

The route of the HVDC power line, 488 miles from Delta, Utah to Adelanto, California, Image courtesy of Intermountain Power Agency

The Mitsubishi CCGT plant design combines hydrogen-ready technology, high efficiency (>64% thermal efficiency) and high operational flexibility to support renewable intermittency. The single-shaft configuration features a smaller footprint, lower capital cost and high reliability compared to old fashioned multi-shaft designs.

The site will also have 220 MW of electrolysis capacity powered by renewable energy. The project, jointly developed by Chevron New Energies and Mitsubishi Power, delivers utility scale green hydrogen production to support the IPP Renewed Project

Each single-shaft CCGT plant incorporates two SSS Clutches. The size 320T SSS Clutch is mounted between the steam turbine and the generator, allowing the gas turbine to start independently and the steam turbine to automatically engage when there is enough steam provided by the heat recovery steam generator. The size 120T SSS Clutch is part of the turning gear system and automatically turns the turbine system to prevent distortion when it is at low speed.