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Masdar has agreed to purchase a 50% stake in US renewable electricity producer Terra-Gen Power Holdings II LLC, as part of its strategy to expand its presence in the

Terra-Gen LLC has secured approval to build a utility-scale hybrid solar-and-storage project in California. The plan calls for up to 1.4 GW of solar capacity paired with a battery energy storage system rated at 1,000 MW with 8,000 MWh of storage, designed to discharge for roughly eight hours.The project is among the largest solar-plus-storage developments approved in the United States. Terra-Gen will move the project toward construction, using the battery to shift daytime generation to periods of peak demand and lower solar output, supporting grid reliability. The approval underscores California’s continued push to expand renewable energy and storage as it pursues clean-energy and carbon-reduction goals. What does Terra-Gen’s California approval mean for a 1.4 GW solar-plus-1,000 MW storage project? Confirms regulatory and permitting momentum: California’s approval is a green light that can move Terra-Gen from development into the detailed engineering, interconnection work, and construction planning required for a 1.4 GW solar-plus-1,000 MW / 8,000 MWh battery build. Locks in a high-value “dispatchable renewables” capability: pairing large solar capacity with a very large battery rating means the project can provide grid support when sunlight drops—turning variable solar into more controllable power. Enables peak-shaving and load-shifting at scale: with storage sized for about an eight-hour discharge window, the project is positioned to cover late-day and evening demand periods when both electricity prices and system stress often increase. Strengthens reliability for a stressed grid: California’s grid increasingly depends on fast-ramping resources to balance renewables with demand; a 1,000 MW storage block can supply grid services during tight supply conditions. Likely improves the project’s commercial bankability: approvals and progress toward construction can make it easier to finalize offtake arrangements and secure financing by reducing regulatory risk and demonstrating schedule credibility. Elevates the project to “utility-scale standard” rather than pilot status: the size (1.4 GW solar with 8,000 MWh of storage) places it in the category of major grid assets that planners often treat as core capacity for reliability planning, not just demonstration projects. Positions the facility for grid-forming and ancillary-service opportunities: large batteries can typically participate in services such as frequency regulation, reserves, and voltage support—roles that can complement existing generation and transmission constraints. Requires substantial grid-connection coordination: approval means Terra-Gen must still complete the practical steps—interconnection studies, substation upgrades, protection systems, and operational coordination—to deliver power where the grid needs it. Sets expectations for construction and supply-chain logistics: scaling to gigawatt-class solar plus multi-gigawatt-hour batteries typically demands long-lead procurement, contractor mobilization, and phased commissioning—making the path to energization a major milestone. Signals broader market confidence in long-duration storage value: a project at this scale can encourage additional investment by showing that California is willing to clear large hybrid renewables-and-storage proposals through its review process. Helps support state clean-energy trajectories: bringing more solar generation online alongside significant storage capacity can reduce reliance on fossil generation during both everyday operating needs and periods when renewables alone aren’t sufficient.

being constructed there. According To Brian Gorda, vice president of design, Terra-Gen, this project will provide power for "all hours of need". According to

Terra-Gen LLC said its 125-MW Lockhart III solar project in California has reached commercial operations, transitioning from construction to metered electricity. The company said commissioning and interconnection tests are complete, with dispatch and telemetry proven for integration into the CAISO grid.The project will add new daytime power in a state facing tight summer supply conditions despite abundant solar at midday. Terra-Gen said the economics will hinge on sustained performance, including high availability through preventive maintenance, managing soiling, and rapid response to equipment faults. The plant could later be considered for battery storage add-ons as the market shifts toward solar generation that supports needs beyond daylight while California retires fossil capacity. Lockhart III Turns On: CAISO Dispatch, Reliability, and Future Storage Add-Ons? Terra-Gen’s 125-MW Lockhart III solar facility has moved into commercial operations, meaning power is now delivered on a metered basis rather than limited test output. The transition was enabled by completion of commissioning and interconnection activities, including verification that the plant can exchange operational data reliably with the California Independent System Operator (CAISO). CAISO dispatch capability is a key milestone: the plant can follow grid instructions in real time, supporting system operators as they balance load, generation, and ancillary services. Reliability readiness includes proven telemetry performance—critical for operator situational awareness, forecasting accuracy, and faster responses during contingencies or performance deviations. From a grid-planning perspective, additional daytime generation can help relieve tight summer conditions in California, even in a state that already has substantial solar output around midday. Solar additions remain valuable when they reduce the need for more expensive or higher-emissions resources during peak demand windows, particularly during periods when generator availability is constrained. Operating performance will matter beyond initial output: sustained availability and stable generation help CAISO meet reliability requirements, reduce balancing costs, and improve long-term grid confidence. Terra-Gen pointed to maintaining strong availability through preventive maintenance programs that reduce downtime and manage component wear over time. Ongoing performance monitoring and fault-response procedures can also affect how consistently the plant contributes during heat waves and other stress events. Soiling management is a recurring operational challenge for utility-scale PV; managing dust, debris, and seasonal accumulation helps preserve energy production and supports predictable performance. Continued output quality can influence how effectively the plant behaves under grid events, including voltage and frequency conditions that operators require to maintain overall system stability. Lockhart III’s proven integration with CAISO supports wider renewable deployment by demonstrating that new projects can meet technical requirements for control, communications, and operational readiness. Looking ahead, solar-plus-storage strategies could become increasingly attractive as California’s resource mix shifts—retiring dispatchable fossil generation while seeking non-daylight reliability support. Storage add-ons (such as batteries paired with the existing solar site) can extend energy delivery into evening peak hours and potentially reduce curtailment by better matching generation to demand. Any future storage configuration would likely be evaluated on market participation opportunities, capacity value, and how the added duration supports CAISO’s reliability needs. The commercial-operation milestone positions Lockhart III to be considered for incremental upgrades over time, contingent on performance, interconnection capacity, and evolving regulatory and market structures.

and construction of this transformative project," commented Jim Pagano, Terra-Gen's CEO. Mortenson is offering full engineering, purchase and building (EPC)

associates from a four-hour lithium ion battery storage space project that Terra-Gen will create near Barstow in San Bernardino County. The facility, part of a

power producer Terra-Gen and EPC firm Mortenson have completed the Edwards & Sanborn Solar + Energy Storage project, the largest solar + storage project

building, greater than 700 people will be employed on-site at the project. Terra-Gen, LLC, operates over 1.3 GW of wind, solar, as well as geothermal facilities as

renewable energy developer, has successfully acquired a 50% stake in US-based Terra-Gen from Energy Capital Partners (ECP), marking ECP's exit from the company it

Terra-Gen and Mortenson have completed the largest solar + storage project in the US, the Edwards & Sanborn Solar + Energy Storage project. The project spans over 4,600 acres and includes 1.9 million First Solar modules, generating 875 MWDC of solar energy and having 3,287 MWh of energy storage. It supplies power to various entities including the city of San Jose, Southern California Edison, Pacific Gas & Electric Co., Clean Power Alliance, and Starbucks. The project also involved a collaboration with the US Department of Defense and utilizes batteries from LG Chem, Samsung, and BYD. Over 1,000 craftworkers contributed to the project, which received a safety award from the California Association of General Contractors.Brian Gorda, VP of engineering at Terra-Gen, stated that the project is now fully operational and provides resiliency to the grid. Mark Donahue, senior VP at Mortenson, expressed pride in the world-class facility that their team designed, built, and commissioned for Terra-Gen. What is the significance of the Edwards & Sanborn Solar + Energy Storage project in the US? The Edwards & Sanborn Solar + Energy Storage project is the largest solar + storage project in the US. It spans over 4,600 acres and includes 1.9 million First Solar modules. The project generates 875 MWDC of solar energy and has 3,287 MWh of energy storage. It supplies power to various entities including the city of San Jose, Southern California Edison, Pacific Gas & Electric Co., Clean Power Alliance, and Starbucks. The project involved a collaboration with the US Department of Defense. The project utilizes batteries from LG Chem, Samsung, and BYD. Over 1,000 craftworkers contributed to the project. The project received a safety award from the California Association of General Contractors. Brian Gorda, VP of engineering at Terra-Gen, stated that the project is now fully operational and provides resiliency to the grid. Mark Donahue, senior VP at Mortenson, expressed pride in the world-class facility that their team designed, built, and commissioned for Terra-Gen.

project is owned by Terra-Gen, while Mortenson Construction acts as the Engineering, Procurement, and Construction (EPC) service provider for both the solar and

of this range coupled with reducing side battery experience was vital for Terra-Gen, and Mortenson was a natural fit," claimed Brian Gorda, Terra-Gen's

MoU with state power business paves way for applying a $500m integrated PV programme

renewables supplier Terra-Gen has actually finished financing on the first 346MW phase of its Edwards Sanborn solar plus storage space center in California. Funding

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