Delta Energy Center

The Delta Energy Center CCS project is a large-scale post-combustion carbon capture retrofit developed for Calpine’s 857 MW natural gas combined cycle power plant in Pittsburg, California. Led by ION Clean Energy under a U.S. Department of Energy NETL cooperative agreement, the project is designed to capture CO₂ from the full flue gas stream of the facility using ION’s proprietary low-water amine solvent technology. The capture system is configured with two parallel 50 percent trains to provide operational flexibility and redundancy, targeting a 95 percent capture rate and enabling capture of approximately 2.4 million tonnes of CO₂ per year at expected operating conditions. The design integrates steam extraction from the existing steam turbine, dedicated heat rejection systems, and flue gas tie-ins to the HRSG stacks, allowing full-scale carbon capture while maintaining grid reliability and plant performance. The Front-End Engineering and Design study advanced the project to AACE Class 3 maturity and confirmed technical feasibility, constructability, and system integration across the power island and balance-of-plant. Final FEED results estimated total capital costs of approximately $1.5 billion with annual operating costs of about $61.6 million. Techno-economic analysis showed the design achieved a 27 percent reduction in capital cost, 12 percent reduction in operating cost, and a 28 percent lower cost of capture compared to DOE NGCC reference Case 31B, demonstrating meaningful cost improvements over conventional capture designs. Engineering studies also verified steam sourcing options, cooling water availability using reclaimed water and process blowdown, and successful integration with existing plant infrastructure. The project brings together a consortium of major industrial and engineering partners. ION Clean Energy served as the capture technology provider and overall project lead, Calpine acted as the host site owner and operational partner, and Sargent & Lundy led balance-of-plant engineering and cost estimating. Equipment and integration support was provided by Koch Engineered Solutions for absorber systems, Siemens Energy for CO₂ compression and heat integration, Toshiba for steam turbine integration, Deltak for HRSG tie-ins, and Kiewit as owner’s engineer supporting constructability and technical review