The Grand River Dam Authority (GRDA) has completed a $525 million natural-gas power project in Oklahoma, bringing a new 426-megawatt generating unit into service at its Grand River Energy Center.
GRDA formally dedicated Unit 4 on September 9, 2026, marking the latest expansion of the utility’s generation portfolio as electricity demand and grid conditions continue to change across the Southwest Power Pool region.
The new facility uses a 426-MW Mitsubishi Power M501JAC combustion turbine operating in a simple-cycle configuration. Mitsubishi Power says the project is the first M501JAC unit in the United States to operate in simple-cycle mode.
The turbine also has hydrogen-firing capability, giving GRDA additional flexibility as fuel technologies develop.
New 426-MW Unit Targets Fast-Start Power
Unlike combined-cycle plants, which use both a gas turbine and a steam turbine to generate electricity, GREC Unit 4 relies on a single combustion-turbine configuration.
That setup allows the unit to start quickly when the grid needs additional generation.
The capability matters in the Southwest Power Pool, where wind generation has become a significant part of the regional electricity mix. A fast-start unit can help utilities respond when renewable output changes or demand rises.
GRDA can therefore use Unit 4 as a dispatchable resource alongside its other generation assets.
The project also gives the utility an option to incorporate hydrogen into its fuel mix. However, the current project is a natural-gas generation facility, and the announcement does not indicate that hydrogen will provide its primary fuel.
Construction Started in 2024
GRDA and Black & Veatch formally moved the project forward with a signing ceremony on October 2, 2023.
Construction followed with a groundbreaking on May 16, 2024. The unit reached commercial operation in 2026, ahead of its formal dedication on September 9.
Black & Veatch provided engineering, procurement support and construction leadership for Unit 4. Mitsubishi Power supplied the M501JAC combustion turbine generator.
The companies have previously worked with GRDA on another major generating project at the energy center.
Black & Veatch served as owner’s engineer for GREC Unit 3, a combined-cycle generating unit that entered service in 2017. GRDA describes that project as the first unit of its type deployed in the Western Hemisphere.
Unit 4 has also received an Award of Merit in the Energy/Industrial category of Engineering News-Record’s 2026 Texas & Louisiana Best Projects Awards.
$525M Investment Adds Generation Capacity
The completion of Unit 4 gives GRDA another large dispatchable power resource at a time when utilities across the United States are investing in generation to meet changing electricity demand.
For GRDA, the project adds 426 MW without relying on the longer operating cycle of a combined-cycle plant. Its simple-cycle design instead focuses on rapid response and operational flexibility.
The utility is Oklahoma’s largest public power electric utility and finances its operations through electricity and water sales rather than taxes.
With Unit 4 now operating, the Grand River Energy Center has added another major generation asset to GRDA’s system. The project also demonstrates the utility’s continued investment in advanced natural-gas turbine technology while it manages a grid that increasingly includes variable renewable generation.
GRDA’s investment comes as utilities and developers across the United States look for new ways to meet rising electricity demand from large industrial and digital loads. In Louisiana, ONE Nuclear is pursuing a different but related approach through a planned 5 GW portfolio combining natural-gas generation, battery storage, advanced nuclear power and data-center infrastructure. The development is outlined in our report on ONE Nuclear Pushes 5 GW of Gas, Battery and Nuclear Projects Into Louisiana’s Data-Center Corridor.
Factsheet: Grand River Energy Center Unit 4
- Project: Grand River Energy Center Unit 4
- Owner/Developer: Grand River Dam Authority (GRDA)
- Location: Oklahoma, USA
- Project cost: $525 million
- Generation capacity: 426 MW
- Fuel: Natural gas
- Turbine: Mitsubishi Power M501JAC combustion turbine
- Configuration: Simple cycle
- Technology: Advanced-class, fast-start combustion turbine
- Hydrogen capability: Yes
- Engineering, procurement support and construction lead: Black & Veatch
- Turbine OEM: Mitsubishi Power
- Project signing: October 2, 2023
- Groundbreaking: May 16, 2024
- Commercial operation: 2026
- Formal dedication: September 9, 2026
- Grid region: Southwest Power Pool (SPP)
- Recognition: 2026 ENR Texas & Louisiana Best Projects Awards — Award of Merit, Energy/Industrial category
- Project status: Completed and operational
Leave a Reply