Project Overview
Mortenson engineered, procured, and constructed the Tierra Seca energy storage project for Spearmint Energy. The system marked the first installation of Sungrow’s PowerTitan 2.0 energy storage technology to enhance grid reliability and flexibility.
Key Takeaways:
- 100 MW / 200 MWh of energy storage
- Mortenson-built 34.5 kV / 138 kV substation
- First installation of Sungrow PowerTitan 2.0 technology
- Added flexible capacity that supports (ERCOT) reliability
- Newly developed greenfield site in Val Verde County, Texas (near Del Rio)
- Completion Date
December 2025
- Delivery Method
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Engineer, Procure, and Construct
- Additional Project Facts
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EMS Provider: Indie Energy, Inc.
Battery Chemistry: Lithium Iron Phosphate (LFP)
Enclosure Supplier: Sungrow Power Supply Co., Ltd
System Integrator: Mortenson/Indie Energy, Inc.
50 Batteries
Interconnecting Utility: AEP
Strengthening Texas’ Grid for a More Reliable Future
Tierra Seca brings 100MW / 200MWh of battery energy storage to a newly developed greenfield site in Val Verde County, Texas, near Del Rio. The region’s growing demand for flexible, large-scale energy infrastructure makes Tierra Seca a strategically placed asset for strengthening grid stability and responsiveness.
Seamless Integration with AEP’s Network
The project interconnects directly with AEP, requiring tight coordination across engineering, protection, and commissioning teams. This collaboration ensured the system could support regional reliability needs while aligning with AEP’s operational standards and long‑term grid planning.
Overcoming Energization Delays with Creative Solutions
Extended delays in utility backfeed and energization posed one of the project’s most significant challenges. To keep commissioning on track, the team deployed temporary generators to supply interim power. This proactive approach allowed critical testing and integration work to continue without impacting the overall schedule.
Community Support Beyond the Project Site
Tierra Seca’s impact extended beyond the project footprint through meaningful local engagement:
- Amistad FC youth sponsorship – The team provided supplies to support the local youth soccer program’s season.
- Roc Solid Foundation playset build – Team members participated in a playset build in San Antonio, creating a positive experience for families facing pediatric cancer