DeCordova Energy Storage System
DeCordova Energy Storage Facility / GranburyTX
How do you build the largest energy storage facility in the state of Texas?

Vistra and Mortenson successfully completed the DeCordova Energy Storage Facility, bringing 260 MW/260 MWh battery energy storage to Texas. The facility is now operational, storing and distributing electricity to the grid across the region.


Mortenson was chosen as the EPC contractor for the DeCordova Energy Storage system for Sungrow and Vistra in Granbury, Texas. At energization, the DeCordova project is the largest energy storage project in the state. The project strengthens the grid in Texas by providing resiliency services by being co-located on the Luminant (a subsidiary of Vistra) DeCordova gas power plant. The project is the second of seven new renewable energy projects that Vistra is bringing online over the next few years as part of growing Vistra Zero portfolio which includes nearly $1 billion in capital investment in Texas.


The project can store enough energy to power approximately 130,000 average Texas residences and provides dispatchable, instant-start, and emission free power to the ERCOT grid. The batteries charge from the grid during low-demand times, primarily overnight, and release power during periods of high demand. The adjacent natural gas fueled power plant provides an additional layer of resiliency to their customers.

Mortenson was the engineering, procurement and construction contractor for the facility, which consists of 260MW/260MWh of battery energy storage using lithium iron phosphate (LFP) technology and full integration of the energy management system. Interconnecting the battery storage system to the power grid is a 138kV substation that Mortenson built and tied in to the existing plant substation. Sungrow provided the battery enclosures and inverters.

The DeCordova project consists of more than 22,000 batteries in 86 enclosures. Construction commenced in February of 2021 and completed in April of 2022.

Facts And Figures



260MW / 260MWh

Standalone Energy Storage


Delivery Methods

Engineer, Procure, Construct

The Team