Greenflash Acquires 200 MW / 400 MWh Rock Rose Battery Storage Project to Expand ERCOT Portfolio
Greenflash Infrastructure, L.P. (“Greenflash”), a leading energy infrastructure investment platform, has announced the acquisition of Rock Rose, a 200 MW / 400 MWh pre-Notice-to-Proceed (NTP) stand-alone battery energy storage system (BESS) project located in Fort Bend County, Texas, from Advanced Power. The addition of Rock Rose strengthens Greenflash’s growing portfolio within the Electric Reliability Council of Texas (ERCOT) market and underscores its commitment to advancing large-scale battery storage capacity that enhances grid reliability and operational flexibility.
The Rock Rose project represents a key component in Greenflash’s broader vision to deploy utility-scale battery storage assets across ERCOT. The project was specifically chosen for its strategic interconnection location, robust transmission access, and its ability to deliver flexible, dispatchable energy to support Texas’s rapidly evolving power system. With battery storage increasingly critical to balancing supply and demand in regions with high renewable energy penetration, Rock Rose positions Greenflash at the forefront of enabling the state’s transition toward a more resilient and cleaner power grid.
“This acquisition adds near-term, execution-ready capacity toward our 5 GW ERCOT buildout,” said Vishal Apte, Managing Partner at Greenflash. “Rock Rose exemplifies our focus on identifying high-quality, ready-to-build storage projects that can rapidly move into construction and operation to help meet Texas’s growing energy and capacity demands.”
The ERCOT market, which covers about 90% of Texas’s electric load, has become one of the most active regions in the U.S. for battery storage development. Driven by increased renewable energy generation, extreme weather events, and the need for fast-responding resources, battery energy storage systems are playing an essential role in enhancing reliability and managing price volatility. Through acquisitions like Rock Rose, Greenflash is accelerating the deployment of advanced storage assets designed to stabilize the grid and ensure continuous power availability, even during periods of peak demand.
Advanced Power, the project’s original developer, expressed confidence in Greenflash’s ability to advance Rock Rose through the next stages of development. “ERCOT, like other major power markets in the U.S., has an urgent need for projects that enhance grid reliability,” said Tom Spang, CEO of Advanced Power. “As a premier developer of thermal, renewable, and now BESS technology, Advanced Power is committed to bringing contemporary power solutions to partners like Greenflash who recognize the region’s growing energy and capacity needs. We look forward to seeing Greenflash successfully carry Rock Rose through construction and long-term operations.”
The Rock Rose project is fully permitted and interconnection-ready, positioning it well for the next phase of development. It is expected to receive Notice to Proceed in 2026, with commercial operations targeted for mid-2027. Once operational, the facility will provide significant storage capacity to the Texas grid, helping to absorb excess renewable generation during periods of low demand and discharge energy when consumption peaks. This operational flexibility is crucial to maintaining stability in a grid increasingly powered by variable renewable resources such as wind and solar.
The acquisition also reflects Greenflash’s broader commitment to investing in energy transition infrastructure across the United States. Backed by H.I.G. Capital, Greenflash has been rapidly expanding its footprint within ERCOT, focusing on battery storage, hybrid renewable projects, and advanced grid solutions. By integrating Rock Rose into its portfolio, Greenflash moves closer to achieving its multi-gigawatt development pipeline and contributing to the reliability and sustainability of the Texas power market.
With the state’s electricity demand projected to grow sharply in the coming years—driven by population growth, data centers, and industrial expansion—battery storage projects like Rock Rose are set to play a pivotal role in maintaining system balance and reducing reliance on fossil-fuel-based peaking plants.
As Greenflash advances Rock Rose toward construction and operation, the project is expected to deliver both economic and environmental benefits, supporting job creation and strengthening the resiliency of Texas’s critical energy infrastructure.
In combining Advanced Power’s proven development expertise with Greenflash’s execution and operational capabilities, the Rock Rose project stands as a model for the kind of collaborative investment needed to accelerate the deployment of clean, reliable, and modern energy infrastructure across ERCOT and beyond.
