CPS Energy and Ashtrom Renewable Energy have marked the groundbreaking of the 150 MWac El Patrimonio solar project in Bexar County, Texas.
The project is being developed by Ashtrom Renewable Energy and is backed by a Power Purchase Agreement with CPS Energy, the municipally owned electric and gas utility serving San Antonio. Under the agreement, CPS Energy will purchase about 70% of the electricity generated by the project, along with renewable energy credits, over a 20-year term.
El Patrimonio Solar Project – Project Background
The El Patrimonio Solar Facility is a utility-scale solar project located in Bexar County, Texas. Ashtrom Renewable Energy states that the project will span approximately 867 acres and have a projected generation capacity of approximately 150 MWac.
According to Ashtrom Renewable Energy, the project has secured land rights and a grid connection agreement. Construction works are listed as starting in 2025, with the facility expected to become operational in 2027.
Once operational, the project is expected to generate enough electricity to supply approximately 37,000 households. CPS Energy said the project is also expected to reduce carbon emissions by about 193,000 tons annually.
The project forms part of CPS Energy’s broader solar procurement strategy in Texas. CPS Energy described itself as the number one buyer of solar energy in Texas and said renewable energy remains part of its diverse generation plan as San Antonio’s population and electricity demand continue to grow.
PPA Structure and Commercial Arrangement
Under the 20-year Power Purchase Agreement, CPS Energy will purchase about 70% of the electricity produced by El Patrimonio, together with associated renewable energy credits. Ashtrom Renewable Energy states that the remaining electricity is expected to be sold into the Texas open electricity market.
The PPA structure is important because it gives the project a defined revenue pathway while allowing CPS Energy to secure renewable generation without owning the facility directly. For utility-scale solar projects, this type of long-term offtake agreement is often central to project bankability, procurement planning and risk allocation.
The project is also relevant from a grid and market perspective because it will operate in Texas, where solar capacity continues to grow rapidly. As renewable penetration increases, long-term offtake arrangements, market exposure and potential curtailment risks become increasingly important commercial considerations for owners, utilities and contractors.
Construction Partners and Delivery Timing
The official CPS Energy announcement identified SOLV Energy as a project partner, with its role extending from construction through operations. The release did not disclose the construction contract value or specifics.
Construction of El Patrimonio began in 2025 and is expected to be completed in 2027. Ashtrom Renewable Energy’s project page also lists 2027 as the expected operational year for the facility. The milestone is therefore best understood as a formal project groundbreaking and stakeholder event for a project already moving through construction, rather than the initial award of a construction contract.
US Solar Procurement Outlook
The El Patrimonio milestone reflects the continued role of long-term PPAs in moving US renewable energy projects from development into construction. For public utilities and large electricity buyers, the structure allows renewable capacity to be procured through a defined commercial agreement while the developer retains responsibility for project delivery and asset ownership.
Construction Front has covered similar offtake-led renewable energy activity in other markets, including Google’s 250MW wind power PPA with Copenhagen Infrastructure Partners in the Netherlands and Iberdrola and Selex signing a PPA for 1,250 GWh of renewable electricity in Italy. In Australia, the Jinbi Solar Project reached financial close with a long-term PPA linked to Rio Tinto’s Pilbara operations.
The pattern is clear: solar projects are increasingly being advanced through long-term offtake agreements tied to utility, corporate or industrial demand. For contractors, that creates a pipeline of projects where construction readiness depends not only on permits and grid connection, but also on commercial offtake structures that support financing and delivery.
Related Articles and News
- Power Purchase Agreements (PPAs): What They Are and Their Relevance to the Construction Sector
- Yindjibarndi Energy Reaches Financial Close on 75MW Jinbi Solar Project in Western Australia
- Google Partners with CIP for 250MW Wind Power PPA in the Netherlands
- Iberdrola and Selex Sign PPA for 1,250 GWh of Renewable Electricity in Italy
- Curtailment in Renewable Energy Projects: What is it?
Source: CPS Energy
Supporting Source: Ashtrom Renewable Energy
