One-Third of Solar Rooftops in Metro Manila May Be Unregistered. Here's Why That's Everyone's Problem.
Solar power was supposed to be the escape hatch from high electricity bills. For thousands of Filipino homeowners, it still is — but a growing number took a shortcut getting there. And now, Meralco wants to shut that shortcut down.
Published May 19, 2026 by C
A Shadow Solar Market Has Been Growing for Years
Meralco estimates that roughly one in three rooftop solar units within its franchise area is unregistered. The figure, drawn from satellite imaging and grid data cross-referenced with the Institute for Climate and Sustainable Cities (ICSC), was presented at a recent Senate hearing by Meralco VP Lawrence Fernandez. It's a Meralco number, with all the caveats that implies. No one, though, has put forward a competing estimate.
The industry calls these "guerrilla installations." They go up fast and cheap, installed by contractors who skip the paperwork to keep costs down. Meralco currently tracks over 20,000 registered net metering accounts totaling 170 megawatts, plus another 370 megawatts from commercial setups outside the program. Nobody knows how much unregistered capacity sits on top of that.
Why does this market exist? The Philippines has some of the highest electricity rates in Southeast Asia, at ₱13 to ₱14 per kilowatt-hour. A fully compliant solar installation costs ₱200,000 to ₱350,000. Permits move slowly, engineering studies run expensive, and demand is high enough that any household that finds a faster path is going to take it. The guerrilla market is the predictable output of a permitting system that priced and paced itself out of relevance.
This Is a Safety Issue, But Not Only That
The core technical problem lies with the inverters, not the panels.
A properly certified inverter has anti-islanding protection: when the grid goes down, it automatically cuts off your system so electricity doesn't backfeed into power lines. That protects utility workers climbing poles to restore power after an outage. Guerrilla installers often use cheaper, non-certified inverters that skip this feature entirely.
"We have seen that there are installers who do not use inverters that adapt to international standards," Fernandez said at the Senate hearing. Meralco spokesman Joe Zaldarriaga was blunter: "Isang maling instalasyon may result in accidental fire." He confirmed that fire incidents linked to improper installations have already been reported.
The safety argument also has a commercial backdrop. Meralco owns Mspectrum, its own solar subsidiary competing in the same residential and commercial market. The company pushing for stricter standards on independent solar installers also profits when those installers lose business. Critics from the Power for People (P4P) Coalition say existing building codes and Bureau of Fire Protection rules already cover these concerns. They have threatened legal action if any new rules harm consumers.
Meralco's safety case is real. So is the conflict of interest.
Stricter Rules Mean Higher Costs, At Least at First
If new regulations push through, homeowners who went the guerrilla route could be required to regularize their installations. That means inspections, retrofits, and potentially replacing non-compliant inverters at their own expense.
For those planning to go solar, stricter enforcement means the cheaper shortcuts disappear. The formal process becomes the only option: permits, certified installers, and pre-installation coordination with Meralco. That makes solar access harder for lower-income households who can't absorb the full cost of compliance.
Meralco's practical leverage here is significant. They own the grid. If you want your panels to connect to the distribution network and earn net metering credits, you need their technical sign-off. They can't write the regulations themselves, since they have no legal authority over solar installations. But they shape the rules anyway, by showing up at Senate hearings and backing pending legislation.
Legislation Is Moving, But Slowly
Meralco is backing Sen. Sherwin Gatchalian's proposed amendments to the 2008 Renewable Energy Act, which aim to streamline net metering, simplify grid connection permitting, and give the Energy Regulatory Commission broader authority over the program. The stated goal is to make the formal pathway faster and cheaper, so fewer people feel the need to go guerrilla. Whether the final bill actually fixes the underlying permitting friction, or just adds enforcement on top of it, is the question worth watching.
The DILG has also confirmed that a building permit is legally required before any solar installation. The rule has been widely ignored and even more widely unenforced.
Until the legislation passes, homeowners are left navigating an inconsistent landscape. If you're planning to go solar, the practical steps are simple: get your building permit, coordinate with Meralco before installation, and insist on a certified inverter with anti-islanding protection. Ask your installer to explain what that means. If they can't, find another installer.
The sun is free. The equipment that makes it safe to use is not optional, no matter who's doing the asking.
Opinion piece. Reflects the author's interpretation of publicly reported information as of May 19, 2026. Not legal, regulatory, or financial advice — consult primary sources before acting on any specifics.
Sources
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"'Guerrilla' Solar Installations Discovered, Need To Be Controlled, Says Philippine Power Distributor." CleanTechnica, May 4, 2026. https://cleantechnica.com/2026/05/04/guerilla-solar-installations-discovered-need-to-be-controlled-says-philippine-power-distributor/
"Meralco seeks crackdown on guerrilla solar installations." Tribune, May 7, 2026. https://tribune.net.ph/2026/05/07/meralco-seeks-crackdown-on-guerrilla-solar-installations
Umali, Mariz. "Meralco advocates stricter implementation of rules against 'guerilla' solar installations." GMA News Online, May 2026. https://www.gmanetwork.com/news/money/companies/986981/meralco-rules-solar-installations/story/
"Meralco wants stricter regulations on solar panel installations." Unbox.ph, May 2026. https://unbox.ph/news/meralco-solar-panel-installations/
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Lectura, Lenie. "Meralco 'not regulating' use of solar, pushing safety rules." Business Mirror, May 11, 2026. https://businessmirror.com.ph/2026/05/11/meralco-not-regulating-use-of-solar-pushing-safety-rules/
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