After nearly two years with the residential solar net billing quota frozen, Thailand reopened applications on July 1, 2026. A new 500 MW round is now accepting submissions through MEA and PEA on a first-come-first-served basis — meaning every solar installation business in the country has a narrow operational window to help customers claim a spot before the allocation fills.

For residential solar installers, this is not just a demand signal. It is a scheduling and documentation challenge. Customers who install a system and then miss the net billing quota get a solar panel that offsets their own consumption but earns nothing on export. Customers who get into the quota lock in a 2.20 baht per kWh buyback rate for ten years. The difference in system economics — and in customer satisfaction — is significant.

The businesses that thrive in this window will be the ones that run applications cleanly, move from first inquiry to PEA/MEA submission without stalling, and manage multiple concurrent enrollments without losing track of any single job.

What Is Net Billing and Why Does It Matter to Your Customers?

Thailand uses net billing, not net metering. The distinction matters when you are explaining system economics to homeowners.

Under net metering (not used in Thailand), exported electricity is credited at the same rate you buy it from the grid — roughly 3.50–4.50 baht per kWh depending on tariff. Under net billing, exported electricity is credited at a fixed government-set rate, currently 2.20 baht per kWh, locked in for 10 years from your commercial operation date.

That 2.20 rate is lower than the retail tariff, which is why good system design prioritizes self-consumption over export. But it is not zero — and for a 5 kWp system that exports two to three kilowatt-hours per day, that 2.20 rate adds up. Over ten years at average Bangkok electricity consumption patterns, the net billing contract contributes meaningfully to payback.

The more important point for your customer conversation: without the net billing contract, exported power earns nothing. A system that produces more than the household consumes during the day simply exports to the grid for free. The net billing quota is what turns that exported power into a ten-year income stream.

What Changed on July 1, 2026?

The previous residential net billing round — 90 MW — filled in late 2024, closing new applications. For over a year, solar installers could only offer systems without grid export revenue.

On July 1, 2026, a new 500 MW residential round opened through MEA and PEA. Key program parameters:

Quota: 500 MW national target, first-come-first-served
Export cap: 5 kW per electricity meter (regardless of installed system size)
Buyback rate: 2.20 baht per kWh, fixed for 10 years from commercial operation
Commercial operation deadline: System must be commissioned and operational by 2027
Eligibility: Residential electricity customers (Type 1 meter), system size up to 10 kWp
PPA signing window: 30 days from receiving the utility’s offer

MEA handles applications in Bangkok, Nonthaburi, and Samut Prakan. PEA handles all 74 other provinces. Both run separate application queues, so a contractor in Chiang Mai does not compete against one in Bangkok for the same MW allocation.

How Does an Installer Submit a Net Billing Application?

The application process sits between your installation work and the customer’s electricity contract. Installers typically handle the submission on the customer’s behalf, using documents the customer provides and engineering data from the installation.

A clean application moves through these stages:

Stage 1 — Pre-application document collection

Before the system goes up, collect: ID card copy, house registration, the most recent 3 months of electricity bills, a basic floor or house plan, and a signed installer quotation. These documents are required by both MEA and PEA and are the most common cause of application delays when they are missing or incorrect. Request them at the contract signing — not after installation is complete.

Stage 2 — System survey and sizing

The 5 kW export cap means that over-sizing a system for the purpose of maximizing export is not the right approach. Design the system to cover the customer’s daytime self-consumption first, then size the export portion. For a household consuming 400–500 kWh per month with a 3–4 kWp load during daytime hours, a 5–6 kWp system typically balances self-consumption with the export cap. The surveying technician should document roof orientation, shading, and meter location — this information feeds directly into the PEA/MEA engineering submission.

Stage 3 — Grid connection application

After physical installation is complete, submit the grid connection application to MEA or PEA with the installation documentation: inverter safety certification, a site plan, and the completed system specification form. As of 2026, the process has been compressed to approximately 30 working days for standard residential applications — faster than the previous 45–90 day window, though congestion during high-demand periods can extend timelines.

Stage 4 — PPA offer and signing

Once the technical study passes, MEA or PEA sends the homeowner a Power Purchase Agreement offer. The customer has 30 days to sign. Miss that window and the application goes back to the queue — potentially losing a slot if the quota tightens. Track this deadline explicitly: it is the single most common point of failure in an otherwise clean enrollment.

Stage 5 — Commercial operation and metering

After the signed PPA is returned, MEA or PEA schedules a meter swap or bi-directional meter installation and confirms the commercial operation date. That date starts the 10-year contract clock and triggers the customer’s ability to export.

What Does a 5 kW Export Cap Mean for System Design?

The 5 kW per meter export cap is a design constraint, not an installation limit. Your customer can install a 10 kWp system — only 5 kW of that capacity can export to the grid at any moment. In practice, for a residential home with meaningful daytime consumption, a well-sized 5–8 kWp system rarely exports more than 4–5 kW continuously anyway.

Where the cap matters most:

Oversized systems without good daytime loads: A 10 kWp system on a home that is empty all day will routinely try to export more than 5 kW. The inverter will throttle the export, and the excess self-consumption benefit disappears. This is not an installation problem — it is a system design conversation you should have at the survey stage.
Commercial-style installations on residential meters: Some homeowners with small businesses run from home push toward larger systems. Confirm the meter type before sizing. If they are on a Type 1 residential meter, the 5 kW cap applies regardless of actual load.

Document your sizing rationale in the survey report. When a customer later asks why you recommended 6 kWp instead of 10 kWp, the answer should already be in their job file.

How Do You Manage Multiple Net Billing Applications at Once?

A solar installation business running 8–15 concurrent jobs in the second half of 2026 will have applications at different stages simultaneously: some waiting for customer documents, some pending PEA technical study, some awaiting PPA signing, some waiting for meter swap.

Without a clear tracking system, the failure modes are predictable:

A PPA offer arrives in your inbox on August 14. The customer’s 30-day signing window closes September 14. If nobody notices the deadline, the application stalls and the customer loses their slot.
A PEA submission was missing the house registration. PEA returns it for correction. The request sits in someone’s email for a week before reaching the relevant technician.
Two jobs submitted on the same day — one is approved, one is held for additional documentation. Without job-level status tracking, both look the same in a LINE group.

OnSiteQ’s scheduling and job management is designed for exactly this kind of multi-stage work: each job has its own record with a stage checklist, document log, and responsible party for each step. When the PPA offer arrives, the job moves to “PPA signing — deadline 14 Sep” in the system, visible to whoever is tracking it, with a clear next action. Nothing depends on someone’s memory or inbox.

FAQ

How quickly is the 500 MW quota likely to fill?

The previous 90 MW round, which was smaller, filled within several months of opening. At 500 MW, the new round provides more runway — but given the combination of the tax deduction incentive running through 2028 and pent-up demand from the freeze period, installers should not assume the window stays open for years. The practical guidance: applications submitted before the end of 2026 have strong probability of being within quota. Applications submitted in late 2027 face more uncertainty.

Can a customer enroll in both the net billing quota and claim the 200,000 baht tax deduction?

Yes. These are separate programs. The 200,000 baht income tax deduction (effective March 2026 to December 2028) covers the installed cost of the solar system. The net billing PPA governs export revenue. A homeowner can benefit from both — the deduction reduces the upfront cost, while the net billing contract generates export income over ten years. The two programs complement each other and both require the same PEA or MEA grid-connection approval.

What happens if the customer’s commercial operation date falls after the 2027 deadline?

Systems that do not achieve commercial operation by the program’s deadline will not receive a net billing contract, even if their application was submitted and accepted. This is why the installation timeline matters: a customer who signs a contract in November 2026 and whose system is not installed and inspected until mid-2027 may find the deadline too tight. Set clear timelines at the quoting stage, and flag the 2027 commercial operation requirement in writing so there are no surprises.

The 500 MW net billing round is a genuine short-term opportunity for residential solar installation businesses in Thailand. Customers who get in are locked into a 10-year export contract at a fixed rate. Installers who move cleanly from inquiry to grid connection — with documents collected upfront, applications submitted promptly, and PPA deadlines tracked — will be the ones their customers recommend.

Solar Net Billing Quota 2026: A Guide for Thai Installers