More Solar, More Wind, But What Keeps the Grid Stable?
- August 20, 2026
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In June, the Department of Energy (DOE) said that the certification of 13 renewable energy (RE) projects worth a combined ₱344.62 billion under the government’s Green Lane initiative underscored the Philippines’ accelerating transition toward cleaner energy.
The Green Lane initiative is a government program designed to fast-track permits and other regulatory approvals for strategically important investments, helping reduce delays in the development and implementation of major projects, including those in RE.
“RE is not a side story in our economic growth; it is the headline,” DOE Secretary Sharon Garin stated.
However, the current experience in the Visayas offers a glimpse of the challenge ahead. Recurring red and yellow alerts since May have raised concerns over the grid’s ability to keep pace with the rapid expansion of renewable capacity. The alerts have persisted through the rainy season, typically a period of softer electricity demand, and as economic growth slowed to a six-month low of 2.6%.
The alerts underscore a broader challenge for the country’s energy transition: as intermittent RE takes on a larger role, the grid must become more capable of managing swings in supply and demand. For energy experts, the question now is how to build a power system that can absorb more renewables without compromising stability and reliability.
(Also read: Philippines Advances Nuclear Power Plants With Seven Potential Sites)
Why a Renewable Grid Still Needs Baseload
The country’s recurring grid alerts point to a more fundamental problem: insufficient dependable generation.
National Grid Corporation (NGCP) data shows that 235 of the 240 red alerts recorded from 2016 to 2025, or 96.7%, were linked to generation-related supply issues.
“We need more baseload supply. Otherwise, red alerts will continue to be a regular occurrence,” highlighted NGCP CEO Anthony Almeda. “The incoming solar capacity is a welcome addition to our pool of energy sources. But, as the sun begins to set, and solar power harvest starts waning, the system again loses much-needed capacity.”
Baseload refers to generation that can provide a steady supply of electricity over extended periods, forming a dependable foundation for the power system. Depending on the system, this can include coal, nuclear, geothermal and some forms of hydropower.
The DOE reported 4,046 megawatts (MW) of new installed capacity, including 3,544 MW from solar and 502 MW from wind. Yet if the country is adding thousands of megawatts of renewable capacity, why do supply concerns persist?
To put the issue in perspective, one can look at power plant performance through two key measures: the availability factor, or the share of a plant’s capacity that is ready to operate, and the capacity factor, which gauges its actual electricity output against its maximum potential generation.
In Visayas, in particular, the numbers reveal a stark difference in reliability. Solar posted availability and capacity factors of just 18%-19% in 2024-2025, while wind averaged 22%-23%. Coal-fired plants, by contrast, delivered far more consistent output, with availability factors of 86%-88% and capacity factors of 61%-64% during the same period.
Simply put, the data show that solar and wind output is more variable, while conventional baseload plants tend to deliver more consistent generation.
The International Energy Agency (IEA) also acknowledges that coal continues to play a role in Southeast Asia’s power systems as countries balance decarbonization with energy security. It noted that the region’s relatively young coal fleet can still provide flexibility and backup capacity, particularly during supply disruptions. “Alongside renewables, greater use of domestic resources – including hydropower, geothermal and existing fossil fuel production – can also support diversification,” it stated.
Harnessing Technology for a More Flexible Grid
As RE takes on a larger share of the power mix, the grid will need generation that can respond just as quickly as conditions change.
Engine-based power plants can play a role. Unlike conventional plants designed primarily for continuous operation, flexible engines can ramp up quickly when additional electricity is needed and scale back when renewable generation increases. Some engine technologies can reach full output within minutes and synchronize with the grid in seconds, allowing them to respond to short-term changes without having to operate continuously.
As solar and wind penetration rises, balancing plants may spend more time ramping up and down rather than operating at full capacity around the clock. Engine-based generation is designed for this operating pattern, maintaining relatively high efficiency even when running below maximum output.
Depending on the technology and configuration, engines can operate on natural gas, liquefied natural gas (LNG), liquid fuels, biogas, and hydrogen blends. For the Philippines, where LNG infrastructure remains uneven, this flexibility could provide a practical transition path: plants could initially use available liquid fuels, shift to LNG as infrastructure expands, and eventually incorporate lower-carbon fuels as they become commercially viable.
Another technology that could help carry the RE transition forward is pumped-storage hydropower (PSH), particularly as grids grapple with the limits of short-duration battery storage.
Lithium-ion batteries can absorb excess RE and respond quickly to changes in demand, making them useful for daily balancing and peak periods. But most utility-scale battery systems are designed to discharge for only four hours. When renewable output remains low for longer periods, the grid needs storage capable of delivering power over extended durations.
Pumped hydro can fill that role. Often described as a giant water battery, PSH stores electricity by using surplus power to pump water from a lower reservoir to an elevated one. When electricity demand rises, or renewable generation falls, the stored water is released through turbines to generate power. This allows PSH to shift large amounts of electricity across hours and help smooth the variability of solar and wind.
The technology is already the dominant form of long-duration energy storage worldwide. The International Hydropower Association (IHA) estimates that pumped storage has nearly 200 gigawatts (GW) of installed capacity, representing around 90% of global long-duration storage.
China is leading the expansion. It accounts for roughly 40% of global pumped-storage capacity, with more than 50 GW installed. Its Fengning pumped-storage facility in Hebei, completed in 2024, is the world’s largest, with 3.6 GW of capacity.
Europe is also investing heavily in the technology. Spain’s Aguayo II expansion, for instance, is expected to add 1.4 GW of pumped-storage capacity using underground infrastructure and reversible turbines.
However, these technologies also underscore the hidden cost of a renewable-heavy power system. Solar and wind do not simply replace conventional generation; because their output is variable, the grid must also invest in a second layer of capacity to step in when the sun is not shining or the wind is not blowing. In effect, the country is not building just one system to generate electricity, but two: renewable capacity to produce clean power when conditions allow, and backup generation or long-duration storage to keep the lights on when they do not. That makes the transition not only a question of adding more megawatts, but also of financing the additional infrastructure needed to make those megawatts reliable.
(Also read: Power Push: DOE Eyes 121.3 GW Capacity By 2040)
Making the Energy Transition Work
The Philippines’ shift toward RE is necessary, but the path to a cleaner power system will not be straightforward. The red and yellow alerts across Luzon and the Visayas in May are already an early warning that the country cannot simply add renewable capacity without simultaneously strengthening the system that supports it.
Former Energy Regulatory Commission (ERC) Chairperson Monalisa Dimalanta argued that recent grid incidents and successive alerts should catalyze deeper reforms in the power sector. As the generation mix evolves, she pointed to the need for upgrades in transmission and changes in system operations to accommodate a more distributed and variable supply of RE.
“…the grid remains a highly centralized network designed to operate with large power
generation units,” she wrote. “…given the direction the DoE has taken on increasing supply from RE and indigenous resources to wean us away from dependence on imported fuels, what revisions are needed in: a.) the grid’s design to most efficiently serve variably-sized RE plants located in multiple far-flung sites, and b.) the operation of a power system with high-and-dispersed RE penetration?”
That is the real challenge of the energy transition: not simply building more renewable plants, but building a power system capable of making use of them without sacrificing reliability. The economic stakes are high, as the Philippine Chamber of Commerce and Industry (PCCI) warned. “Energy instability is not just a regional issue; it is a national economic risk,” the group said. “…prolonged brownouts will further weaken productivity, investor confidence, and household welfare.”
The country therefore needs a pragmatic transition, one that recognizes the value of renewables while ensuring that firm generation, flexible technologies, storage, and transmission develop alongside them.
The warning signs are already here. Without the right foundation, the country’s push to go green could leave the grid in the red.
Sources:
https://www.pna.gov.ph/articles/1277082
https://mb.com.ph/2026/08/10/doe-still-has-no-clear-fix-to-power-supply-problems
https://newsinfo.inquirer.net/2234978/ngcp-clarifies-we-can-only-transmit-power-if-its-available
https://bworldonline.com/the-nation/2026/05/26/752123/ngcp-blames-plant-shutdowns-for-grid-alerts/
https://www.philstar.com/business/2026/06/01/2531859/its-available-baseload-stupid
https://opinion.inquirer.net/192970/the-critical-deficit-of-baseload-power-in-visayas
https://www.iea.org/reports/southeast-asia-energy-outlook-2026/executive-summary
https://www.energy.gov/cmei/water/pumped-storage-hydropower
https://www.ess-news.com/2026/02/03/spain-secures-major-eu-grant-for-1-gw-pumped-storage-project/
https://www.bworldonline.com/opinion/2026/05/22/751239/all-about-that-grid
