ICSC: Enable, not constrain, informed solar energy adoption

Institute for Climate and Sustainable Cities
OFFICIAL STATEMENT

Rooftop solar photovoltaic (PV) systems are a critical component of the Philippines’ energy transition, offering a decentralized and increasingly affordable solution to rising electricity demand. Yet a significant portion of these systems—particularly small- to medium-scale installations—remain unregistered and therefore invisible in official energy accounting. This leads to an underestimation of actual renewable energy (RE) capacity and generation, with implications for planning, demand forecasting, and tracking progress toward national RE target share in the power generation mix of 35% by 2030, increasing to 50% by 2040, and over 50% by 2050.

Recently, there have been calls to tighten regulation on unregistered, or so-called “guerrilla” solar installations, which risks framing the issue too narrowly. The challenge is not only about enforcement—it is fundamentally about access, affordability, and transparency in the energy system. As interest in rooftop solar continues to grow among Filipino households and businesses, the response should be to enable informed and responsible adoption, not constrain it. Framing unregistered systems as “guerrilla” overlooks the structural barriers that many users face, including slow and complex net-metering processes, permitting bottlenecks, interconnection delays, and cost constraints.

The Institute for Climate and Sustainable Cities (ICSC) developed the Solar Power Estimation of Capacities and Tracking Using Machine Learning (SPECTRUM) to promote transparency and provide comprehensive data on solar in the Philippines. As a data-driven model and web-based platform, SPECTRUM uses multi-spectrum satellite imagery and machine learning to estimate both installed and potential rooftop solar capacity across the country, and to approximate generation. By making distributed solar more visible, SPECTRUM enables a more accurate and complete understanding of the country’s energy landscape.

Beyond measurement, SPECTRUM also functions as a diagnostic tool. The presence and distribution of unregistered rooftop solar systems can point to policy and regulatory frictions—whether in permitting, interconnection, affordability, or program design. In this context, unregistered systems are not simply a compliance issue; they are also a signal of demand that existing frameworks have yet to fully accommodate.

At the same time, the risks associated with unregistered installations—including safety concerns such as backfeed, voltage fluctuations, and lack of protection coordination—are real and must be addressed. However, enforcement alone is insufficient; there must be a simpler, faster, and more affordable pathway for households and businesses to regularize and integrate their systems into the grid.

ICSC supports the streamlining of solar installation processes and the broader goal of making solar power accessible to all. SPECTRUM was created precisely to inspire action among residents and businesses responding to rising electricity costs. By democratizing access to energy data, it helps democratize access to electricity itself—enabling more Filipinos to participate in the transition to clean energy.

In this light, efforts should focus not only on tighter regulation, but on improving the enabling environment for distributed renewable energy. This includes streamlining net-metering processes, ensuring more competitive and fair compensation for participating households, and reassessing generation sources—including continued reliance on coal and liquefied natural gas (LNG)—that contribute to high electricity prices. A more responsive, transparent, and inclusive energy system will be key to accelerating rooftop solar adoption while ensuring safety, reliability, and long-term sustainability.

Ultimately, SPECTRUM bridges the gap between actual distributed generation and official statistics—supporting better RE accounting, more informed grid operations, and targeted policy reform. The goal is not simply to regulate, but to measure, understand, and safely integrate rooftop solar into the formal energy system, ensuring that the country’s energy transition is inclusive, data-driven, and responsive to the needs of Filipino consumers.