Philippines Builds World's Largest Solar and Battery Project as Grid and Leadership Challenges Test Rollout

A Giant Power Project Nears Its First Operating Deadline

The Philippines' PHP 200 billion Terra Solar project is approaching a February 26, 2026 deadline for its first phase of commercial operation, bringing a vast solar and battery development closer to supplying electricity to Manila Electric Company, or Meralco. Across Nueva Ecija and Bulacan provinces, approximately 150 kilometers north of Manila, crews are building a facility planned to combine 3.5 gigawatts of solar capacity with 4.5 gigawatt-hours of battery storage.

Terra Solar, also designated MTerra Solar, is intended to become the world's largest integrated solar and battery storage facility. Its 3,500 hectares of land are equivalent to roughly 83,000 basketball courts. When complete, the development is expected to supply enough clean electricity for approximately 2.4 million households.

Construction began in November 2024, with initial operations scheduled for early 2026 and full commissioning targeted for February 2027. As of January 28, 2026, the project is moving from large scale construction toward the more demanding task of coordinating solar panels, batteries and transmission equipment so they can deliver reliable electricity together.

The transition comes with corporate changes and technical concerns. Founder Leandro Leviste resigned from the project company's board in January, while the national grid operator has warned that sudden changes in solar output could strain the Luzon electricity network. A permanent connection point is scheduled much later than the project's own completion.

For the Philippines, the attraction is substantial: electricity generated from a domestic resource, stored for use after daylight fades, and sold under a long contract. The country currently depends on imported coal and natural gas for most electricity generation, leaving consumers exposed to changes in international fuel prices and exchange rates.

What the Solar Panels and Batteries Will Deliver

Terra Solar will eventually operate up to five million solar panels simultaneously. Its estimated annual production is 5 terawatt-hours of electricity, described in the project's projections as enough to meet roughly 12 percent of the Philippines' total electricity demand. The planned 3.5 gigawatts of generating capacity represents the output of several large power stations burning coal combined.

Gigawatts measure how much power a facility can produce at a particular moment. Gigawatt-hours measure an amount of energy produced or stored over time. That difference matters here: the solar panels generate electricity, while the batteries hold some of it for later delivery.

The planned 4.5 gigawatt-hours of storage could discharge 850 megawatts continuously for more than five hours. That would help bridge the gap between daytime solar production and peak demand in the evening, when households still need electricity but sunlight is fading or has disappeared.

Under a power supply agreement lasting 20 years, Terra Solar is to supply 850 megawatts to Meralco. The batteries are central to turning a generation source that varies with sunlight into a dispatchable source, meaning one whose electricity can be delivered when required. The project is intended to provide baseload power, the steady supply needed to meet continuing electricity demand.

Huawei is supplying the battery energy storage system under its largest BESS contract to date. BESS is the abbreviation for battery energy storage system. The equipment uses lithium-ion battery modules housed in containers, with fire suppression systems, climate controls and advanced power conversion technology.

The batteries will store excess electricity generated during periods of lower demand and release it to the grid during peak hours. Their role therefore extends beyond holding energy until evening: they are also part of the project's response to concerns about sudden changes in solar generation.

Building Across Thousands of Hectares

Jacobs Engineering Group has been retained to provide construction management services. It is using drones and advanced digital tools to coordinate logistics across the site, whose scale is also described as 11.5 square miles. Managing deliveries, installation and construction progress across such an extensive area is a major part of bringing the facility into service.

China Energy Engineering Corporation and POWERCHINA are handling engineering, procurement and construction contracts for different phases. Those contracts cover work that includes high voltage transmission infrastructure, needed to carry electricity from the rural provinces toward metropolitan Manila.

By July 2025, crews had completed 54 percent of Phase 1 work within eight months of groundbreaking. They had installed 778 megawatts of solar capacity, a milestone described as already making Terra Solar the Philippines' largest operating solar installation. Construction was advancing ahead of schedule in several respects.

The recent energization of the project's substation operating at 500 kilovolts marked another technical milestone. Energization means bringing electrical equipment into a live condition. It enabled the facility to begin testing grid synchronization procedures, which coordinate a power plant's electrical output with the network receiving it.

Phase 1 is planned to include 2.5 gigawatts of solar capacity and 3.3 gigawatt-hours of storage, with commercial operation scheduled for February 26, 2026. Phase 2 will add the remaining capacity, with full commissioning targeted for February 2027. The construction milestones already reached lead into testing and integration work required before those operating targets.

Billions in Funding and a Changing Ownership Structure

Terra Solar's estimated cost is $3.3 billion to $4 billion, or PHP 200 billion, placing it among Southeast Asia's most expensive renewable energy investments. Its scale requires funding for the generating equipment, batteries, transmission facilities and extensive construction work.

Actis, an infrastructure investor based in the United Kingdom, committed approximately $600 million in September 2024 for a 40 percent equity stake. The investment closed in March 2025, providing funding for development and expansion while bringing international infrastructure expertise to the consortium. It was described as the largest foreign direct investment in a Philippine greenfield infrastructure project, meaning a project developed from the ground up.

Solar Philippines New Energy Corporation, or SPNEC, originally conceived the project with a modest scope of 500 megawatts. The development subsequently expanded eightfold within a year as investor confidence grew and energy policies shifted. Its ownership has also changed substantially since those early plans.

Meralco PowerGen Corporation, known as MGen, now has controlling ownership of SPNEC. MGen is the power generation arm of the Philippines' largest utility and holds more than 55 percent of voting shares through its subsidiary MGreen Renewable Energy Inc.

SPNEC has applied to change its corporate name to MGen Renewable Energy Holdings Inc. Once complete, the facility will operate under the MGreen banner, reflecting its integration into Meralco's renewable energy portfolio.

A Board Change as Commissioning Approaches

Batangas Representative Leandro Leviste, who founded Solar Philippines and originally proposed the development, resigned from the board of Terra Solar Philippines Inc. in January 2026. MGen President and Chief Executive Officer Emmanuel Rubio assumed his seat.

MGen described the change as a natural progression toward operational execution. At this stage, the project must connect decisions made by its board with the practical work of coordinating equipment, completing tests and delivering electricity.

Rubio explained the company's reasoning for strengthening board leadership as commissioning approached:

This transition marks a natural progression for MTerra Solar as it approaches commissioning. Strengthening board leadership at this stage ensures closer alignment between strategic oversight, system integration, and operational execution as we move toward delivering clean, reliable power to the grid.

Leviste's departure occurred amid regulatory scrutiny of his other business interests. The Department of Energy had levied a PHP 24 billion penalty against his holding company for failures involving separate renewable energy service contracts. Those contracts were unrelated to Terra Solar.

Transmission Approval Meets a Long Wait for a Permanent Connection

The Energy Regulatory Commission approved Terra Solar's application in October 2025 to construct PHP 14.25 billion in dedicated transmission facilities connecting the project to the grid. The facilities include a substation operating at 500 kilovolts along the Nagsaag-San Jose transmission line.

Construction of those facilities had reached 90 percent completion as of September 2025. That progress cleared a critical part of the route toward the February 2026 commissioning target for Phase 1. Generating electricity is only part of the task; the facility also needs infrastructure capable of moving that electricity into the wider network.

The permanent connection point at the San Isidro substation, also operating at 500 kilovolts, will not be ready until sometime between 2031 and 2040, according to government infrastructure plans. No more precise completion date was given. Terra Solar must therefore rely in the meantime on temporary connections known as bus-in connections to the existing transmission network.

The National Grid Corporation of the Philippines, or NGCP, has warned that these temporary connections could cause voltage fluctuations and stress equipment in surrounding areas. Voltage is the electrical pressure that drives power through the network; keeping it within suitable limits is part of maintaining a stable electricity supply.

The timing creates a practical challenge. Terra Solar aims to complete both phases by February 2027, while the permanent substation could arrive years later. Temporary grid arrangements will consequently be part of the project's operation while it waits for that infrastructure.

Why Sudden Changes in Sunlight Concern the Grid Operator

NGCP has also raised concerns about frequency stability. Electricity networks must keep generation and consumption in balance, and frequency is a measure of how steadily the network's electrical cycle is running. A sudden loss of a large amount of generation makes that balance harder to maintain.

Weather events affecting the planned facility of 3,500 megawatts could cause output to drop by more than 300 megawatts within seconds, according to the grid operator's concerns. A change of that size would require a rapid response from the electricity system.

Philippine regulations give solar generation priority dispatch, meaning priority in supplying electricity to the network. NGCP worries that rapid fluctuations from such a large facility could destabilize the Luzon grid unless they are carefully managed through battery storage.

Terra Solar's response includes deploying its batteries in phases. Phase 1 incorporates storage intended to sustain output during peak evening demand and provide services that help stabilize the grid. The batteries therefore have two connected jobs: moving solar electricity into the hours when it is needed and helping manage changes in output.

Energy Security, Electricity Costs and Local Benefits

Filipino households pay among the highest electricity rates in Asia. Dependence on imported coal and natural gas exposes electricity costs to international commodity prices and currency fluctuations, with costs rising when global fuel markets spike.

Terra Solar offers a hedge against those swings through solar generation with fixed costs backed by a long term contract. It could help insulate consumers from international fuel price volatility while reducing the national bill for fossil fuel imports.

The Philippines has committed to obtaining 35 percent of its energy from renewable sources by 2030 and 50 percent by 2040. Solar currently represents only 5.5 percent of the country's installed capacity of 28 gigawatts. Terra Solar's planned 3.5 gigawatts would be equivalent to 12.5 percent of that existing installed base, illustrating how large the single development is beside the national total.

The project would also reduce reliance on imported fuels exposed to supply chain disruptions and geopolitical tensions. Its contribution to energy security comes from using sunlight available within the country and batteries that make some of that electricity available outside daylight hours.

By displacing generation from coal, Terra Solar is expected to avoid approximately 4.3 million tons of carbon dioxide emissions annually. The project's environmental estimates describe that benefit as equivalent to removing more than 3 million cars from roads.

Construction has already employed more than 9,500 workers. Ongoing operations are expected to create permanent positions in engineering, maintenance and grid management. Community programs, including workforce training and the installation of solar streetlights, aim to give surrounding municipalities direct benefits from the development.

The Dates That Shape the Rollout

Terra Solar's development has moved through investment, construction and regulatory milestones in a little over a year. The next major target, as of January 28, 2026, is the start of Phase 1 commercial operation on February 26.

• September 2024: Actis committed approximately $600 million for a 40 percent equity stake.
• November 2024: Construction began in Nueva Ecija and Bulacan.
• March 2025: The Actis investment closed.
• July 2025: Phase 1 construction reached 54 percent completion, with 778 megawatts of solar capacity installed.
• September 2025: Construction of the dedicated transmission facilities reached 90 percent completion.
• October 2025: The Energy Regulatory Commission approved PHP 14.25 billion in dedicated transmission facilities.
• January 2026: Leandro Leviste left the project company's board, and Emmanuel Rubio assumed his seat.
• February 26, 2026: Scheduled commercial operation for Phase 1, comprising 2.5 gigawatts of solar and 3.3 gigawatt-hours of storage.
• February 2027: Target for full commissioning after Phase 2 adds the remaining capacity.
• 2031 to 2040: Planned completion window for the permanent San Isidro grid connection.

The operating schedule brings the immediate construction work and the longer wait for grid infrastructure into the same picture. Panels and batteries are advancing toward service, while temporary transmission connections and careful management of electricity output remain central to delivering the promised supply.

The Essentials

• Terra Solar is planned as the world's largest integrated solar and battery facility, combining 3.5 gigawatts of solar with 4.5 gigawatt-hours of storage across 3,500 hectares.
• The PHP 200 billion project is expected to serve approximately 2.4 million households and supply 850 megawatts to Meralco under a contract lasting 20 years.
• Phase 1 commercial operation is scheduled for February 26, 2026, with full commissioning targeted for February 2027.
• MGen controls SPNEC through MGreen, while Actis holds a 40 percent equity stake following an investment of approximately $600 million.
• The regulator approved PHP 14.25 billion in transmission facilities, but the permanent San Isidro connection is planned for 2031 to 2040.
• NGCP has warned about sudden solar output changes, voltage fluctuations and equipment stress. Battery deployment is part of the project's response.
• Leandro Leviste resigned from the board in January 2026, and MGen chief Emmanuel Rubio assumed his seat.
• Huawei supplies battery storage, Jacobs manages construction, and China Energy Engineering Corporation and POWERCHINA handle engineering, procurement and construction work.
• The project estimates annual avoided emissions of 4.3 million tons of carbon dioxide and has already employed more than 9,500 construction workers.