7 Best: Metering PV Law Explained
Navigating the legal landscape of solar energy in the Philippines is like navigating EDSA: crowded, rule-heavy, and prone to sudden stops. But if you know the lanes, you can get where you need to go much faster than everyone else.
For most Filipino home and business owners, the term "Net Metering" is thrown around loosely. You hear it from sales agents, you see it on Facebook ads, and you might even see it on your Meralco bill. But the actual law—Republic Act 9513 (The Renewable Energy Act of 2008)—and the subsequent ERC resolutions are more complex than just "selling power to the grid."
Understanding the nuances of these metering laws is the difference between a 4-year ROI and a 7-year administrative headache.
Whether you are a homeowner with a 3kW system or a factory owner eyeing a 500kW rooftop array, here are the 7 Best Aspects, Strategies, and Provisions of Philippine PV Metering Law that you need to master in 2025.
1. The 100kW "Sweet Spot" (Standard Net Metering)
The most important number in Philippine solar law is 100kW.
Under the Amended Net Metering Rules (ERC Resolution No. 06, Series of 2019, and recent 2025 updates), any system sized 100kW AC or below is eligible for the standard Net Metering program.
Why This Is The "Best" Path
If you stay under 100kW, the law treats you as a "Qualified End-User" (QE). This status grants you specific rights that larger generators do not easily get:
Automatic Export Rights: You have the legal right to export excess power to the grid. The Distribution Utility (DU) like Meralco or VECO must accept it, provided you pass the technical safety standards.
Simplified Permitting: While still bureaucratic, the process for <100kW is significantly streamlined compared to building a power plant. You don't need a full "Certificate of Compliance" from the ERC in the same way a commercial generator does; you largely deal with your DU and the local building official.
The Strategy
For many commercial buildings that have a load of, say, 120kW, we often advise sizing the inverter strictly to 99.9kW. By staying just one kilowatt under the legal cap, you remain in the "Net Metering" lane and avoid the complex regulatory mud of the "Generation Company" lane.
For a deeper dive into how this specific cap works, read our breakdown of ERC Net Metering policies.
2. The "Zero Export" Provision (For Systems >100kW)
What happens if you need more than 100kW? This is where the law gets tricky, and where the "Zero Export" (or "Own-Use") strategy becomes your best friend.
Strictly speaking, RA 9513 limits Net Metering to 100kW. If you install 200kW, you cannot simply apply for Net Metering. In the past, this meant you had to register as a full-blown power generation company—a nightmare of paperwork involving the WESM (Wholesale Electricity Spot Market).
However, the industry and regulators have adopted a practical workaround: The Zero Export / Own-Use Scheme.
How It Works
You install a system larger than 100kW, but you install a smart limiting device (often integrated into the inverter) that throttles your solar production to match your building's real-time demand.
If your factory is using 150kW, the solar produces 150kW.
If your factory slows down and uses only 50kW, the inverters instantly throttle down to 50kW.
Result: 0.00kW touches the Meralco grid.
Why It’s a Legal "Best"
From a regulatory standpoint, if you do not export, you are not "disturbing" the grid. This often allows for a much faster approval process called a "Non-Net Metering" interconnection. You are essentially telling the utility, "I am generating my own power, and I promise none of it will leak into your lines."
This is the preferred route for malls, cold storage facilities, and factories that have high daytime loads and don't care about selling scraps back to the utility.
Learn more about the technical side in our Zero Export overview.
3. The Distributed Energy Resources (DER) Rules
For years, there was a "dead zone" between 100kW (Net Metering) and massive solar farms. Business owners asked, "What if I have a 200kW roof and I want to export?"
Enter the Distributed Energy Resources (DER) Rules (ERC Resolution No. 11, Series of 2022, effectively rolling out in 2023-2024).
This legal framework creates a middle ground for systems between 100kW and 1MW.
The 30% Export Cap
The "Best" feature of the DER rules is that it finally allows larger commercial systems to export power, but with a catch: you can typically export only up to 30% of your nameplate capacity.
Example: You have a 200kW system. You can export a maximum of 60kW at any given moment.
Why It Matters
This is a game-changer for businesses that operate 6 days a week. On Sundays, when the factory is closed, a Zero Export system would just shut off and waste potential energy. A DER-compliant system can stay active and sell that Sunday power to the grid (up to the 30% limit), turning a dead day into a revenue day.
It is more complex than standard Net Metering—requiring a more rigorous System Impact Study (SIS)—but for the right business profile, it unlocks value that was previously illegal to capture.
4. The "Blended Generation" Compensation Rate
One of the most misunderstood aspects of the law is the price you get for your exported power. Understanding this is the "best" financial shield you can have.
Many people assume: "If I buy electricity at ₱12/kWh, I should sell it back at ₱12/kWh."
The Law says: No.
Under the Net Metering Rules, you are compensated based on the "Blended Generation Cost". This is the average cost the utility pays to its huge power suppliers (coal plants, hydro, WESM).
The Math
Retail Rate (What you pay): ~₱11.00 - ₱12.00 / kWh (Includes generation, transmission, distribution, taxes, universal charges).
Export Rate (What you get): ~₱4.50 - ₱6.00 / kWh (Generation charge only).
The Strategy
Because the law dictates this lower compensation rate, the "best" metering strategy is Self-Consumption. You should design your system to cover your daytime usage, not to oversell. Every kWh you use yourself saves you ₱12.00. Every kWh you sell earns you only ₱5.00.
Do not build a massive solar roof hoping to get rich selling power to Meralco. The law is designed to help you offset costs, not become a utility.
Check our detailed guide on credit calculation and savings to see the real numbers.
5. Infinite Credit Banking (The 2025 Update)
A massive win for consumers in the updated rules (reinforced by recent ERC advisories in 2025) is the clarification on Credit Banking.
In the past, there was confusion about whether credits "expired" or if they could be cashed out. The current legal framework establishes that Net Metering credits are non-expiring.
How It Works
Summer (March-May): You produce massive solar power. Your ACs are running, but you still have excess. You accumulate ₱5,000 worth of credits.
Rainy Season (July-Sept): Solar production drops by 30-40%.
The Benefit: The law allows you to use that "banked" ₱5,000 from summer to pay for your electricity bills in the rainy season.
The credits roll over indefinitely. While you generally cannot ask for a check (cash) unless you close your account, this banking mechanism effectively turns the grid into a "virtual battery" for your financial savings. You store value in the grid during sunny months and withdraw it during cloudy ones.
6. The Bi-Directional Meter Requirement
The law mandates a specific piece of hardware for all grid-tied setups: the Bi-Directional Meter.
Why It’s Critical
Standard digital meters are often "dumb." If you push solar power back into the grid through a standard meter, many of them will read that flow as consumption.
The Nightmare Scenario: You generate 500kWh of solar and send it to the grid. A standard meter reads this as you using 500kWh. You get billed for your own solar power!
The Legal Mandate
The Net Metering rules require the DU to replace your existing meter with a Bi-Directional one. This meter has two registers:
Import (kWh you buy): Moves forward when you pull from the grid.
Export (kWh you sell): Moves forward (or logs separately) when you push to the grid.
Additionally, a second meter (often called the REC Meter or Renewable Energy Certificate meter) is installed near the inverter to measure total solar production. This is technically for the utility's data and compliance, but the Bi-Directional meter is the one that determines your bill.
Never, ever turn on a grid-tie system permanently until this legal metering swap has occurred.
For a step-by-step look at how to get this meter installed, refer to our Net Metering application guide.
7. Transferability of Credits (Asset Protection)
This is a newer "best" provision that protects your investment.
Solar systems last 25+ years. But you might sell your house in 5 years. What happens to the accumulated credits sitting in your account?
Recent amendments and ERC guidelines have clarified the Transferability of Net Metering Credits. If you sell your property, the credits sitting in the account don't necessarily vanish. They can be transferred to the new owner of the property, provided the account name is updated correctly.
Why This Matters
This legally cements the solar system and its accrued value as a real estate asset. When you sell your home, you are selling a house that comes with:
Lower future bills.
A "bank account" of energy credits that the new owner can inherit.
This provision is crucial for real estate developers and house flippers. It ensures that the value generated by the solar system stays attached to the property's lifecycle.
Summary: Which Lane Are You In?
The Philippine "Metering PV Law" isn't one single rule; it's a collection of pathways. Choosing the "best" one depends on your profile:
Profile | Best Legal Pathway | Key Limitation |
Homeowner | Net Metering (<100kW) | Must export at low rates. |
Factory (High Load) | Zero Export / Own-Use | Cannot sell excess; wasted potential on Sundays. |
Factory (Med Load) | DER (100kW-1MW) | Capped at 30% export; complex permitting. |
Large Corp | GEOP | Buying RE, not just generating it. |
Practical Next Steps
If you are planning a system in 2025, do not ignore the legal side. The "fly-by-night" installers will tell you to "just hook it up and don't tell Meralco." This is illegal and dangerous. It risks your safety, your fire insurance, and penalties from the ERC.
Check your load: Are you under or over 100kW capacity?
Run the numbers: Use the Net Metering credit logic to forecast savings, not just production.
Hire a pro: Ensure your installer knows the difference between a Net Metering application and a Zero Export scheme.
The law is actually on your side—if you read the fine print. By leveraging these 7 aspects of the metering regulations, you turn compliance into a competitive advantage.
Need help navigating the Meralco application? Check our full guide on Philippine Net Metering Rules.