Net Metering & Net Billing Thailand 2026 Complete Guide: Residential vs Factory
Everything you need to know about selling solar electricity in Thailand 2026 — 2.20 THB/kWh buyback, 500 MW Solar Prachachon, factory self-consumption rules, Direct PPA, Royal Decree 805 tax deduction, factory license exemption — all in one guide
Published 2026-05-15 · Last updated 2026-05-15 · CapSolar Research Team
Table of Contents
Net Metering vs Net Billing: What's the Difference?
Net metering is a system where excess solar electricity is sent to the grid and offsets your consumption at the full retail rate on a kWh-for-kWh basis. Think of it as "depositing electricity" with the utility and withdrawing it at night — you only pay for the net difference.
Net billing differs in that excess power is not offset kWh-for-kWh but as a financial credit at a wholesale buy-back rate — much lower than the retail rate. In Thailand, the buy-back rate is 2.20 THB/kWh while the retail rate is 3.95 THB/kWh (May-Aug 2026).
| Feature | Net Metering | Net Billing (Thailand) |
|---|---|---|
| Offset method | kWh-for-kWh | Financial credit (฿) |
| Export rate | = Retail rate (3.95 THB) | 2.20 THB/kWh |
| Spread | 0 THB (balanced) | −1.75 THB per exported kWh |
| Status in Thailand | Not adopted (on hold) | Currently active |
| Key implication | Self-use = export = equal value | Self-use > export (always) |
Offset method
Export rate
Spread
Status in Thailand
Key implication
The critical takeaway: Thailand adopted net billing, not net metering. This means self-consumption is always more valuable than exporting — every kWh you use saves 3.95 THB, but exporting earns only 2.20 THB. Designing for maximum self-consumption is the key to higher ROI.
Thailand's Current System: Net Billing (Solar Prachachon Program)
The Solar Prachachon ("Solar for the People") program is a government initiative allowing residential users (Type 1 meter) to install rooftop solar up to 10 kWp and sell excess electricity back to the utility at 2.20 THB/kWh on a 10-year contract.
The program started with a 90 MW quota that filled up rapidly. In 2026, the National Energy Policy Council (NEPC) approved an expansion to 500 MW to meet growing public demand for rooftop solar.
Eligible: Residential (Type 1) only · Up to 10 kWp · 10-year contract · Buy-back rate 2.20 THB/kWh
Application Steps
01Study requirements & design system
Evaluate roof orientation, available area, and average electricity consumption to determine optimal system size (1-2 weeks).
02Prepare documents & submit application
ID card copy, house registration, past electricity bills, house plan, installer quotation (1 week).
03Register online via MEA or PEA portal
Bangkok, Nonthaburi, Samut Prakan → MEA (myenergy.mea.or.th) / Other provinces → PEA (ppim.pea.co.th)
04Await review and approval
Utility reviews documents, inspects home electrical system, evaluates grid connection conditions (30-45 days).
05Install system & schedule inspection
Certified installer mounts solar panels, inverter, and protection equipment, then schedules utility inspection (2-4 weeks).
06Digital meter installation & commercial operation (COD)
Swap to bi-directional meter that measures both consumption and export. Credits start accruing (1-2 weeks).
Total estimated timeline: 3-6 months
The 2.20 THB/kWh Buy-Back Rate — Is It Worth It?
Many ask: is selling at 2.20 THB worthwhile? The answer requires comparing against your purchase rate (3.95 THB/kWh as of May-Aug 2026). Every kWh you use yourself saves 3.95 THB, but exporting earns only 2.20 THB — self-consumption is worth 1.75 THB more per unit.
Conclusion: Self-consumption is always more valuable, but net billing is still better than nothing — instead of wasting excess power, you still earn 2.20 THB/kWh from exports.
Factories & Commercial Users: Self-Consumption Only (No Grid Export)
Many factory owners ask: "Can factories sell excess solar power back to the grid?" The answer is clear: No. Under current regulations, commercial and industrial users (Type 3-7 meters) cannot export excess electricity to the grid. Factories must design for 100% self-consumption.
Factories CANNOT export — but every self-consumed kWh = 3.95+ THB ≫ 2.20 THB (export) — factory solar ROI actually beats residential net billing
But this is actually an advantage: every kWh your solar produces is self-consumed at the full retail rate (3.95+ THB/kWh) — no export at a discounted 2.20 THB. Combined with TOU rates where solar generates during peak hours, the per-kWh value for factories is higher than residential net billing.
Payback Comparison
Home 5 kWp + Net Billing
7-9 years
Factory 100 kWp Self-Consumption
4-5 years
Factory 1 MWp + BOI
3-4 years
Direct PPA: The New Framework (2026-2027)
The Direct PPA (Direct Power Purchase Agreement) framework from the Energy Regulatory Commission (ERC) allows private power producers to sell electricity directly to buyers via state transmission lines (Third-Party Access — TPA) — opening new opportunities for large consumers.
In the pilot phase, Direct PPA is ring-fenced for BOI-promoted hyper-scale data centers with a total allocation of 2,000 MW. Broader access for general large industrial users is expected from 2027 onward.
What this means for factories: Direct PPA will let large factories buy electricity directly from external solar farms at below-grid prices — but general industrial access is not expected until 2027+.
Royal Decree 805: Solar Tax Deduction (March 2026)
Royal Decree 805 (effective 3 March 2026) allows individuals (not companies) to deduct up to 200,000 THB (including VAT) from personal income tax for grid-connected solar installations up to 10 kWp by a certified installer.
Factory License Exemption (Dec 2024): Install Solar Without รง.4
Ministerial Regulation No. 3 (B.E. 2567), announced 27 December 2024, eliminates the requirement for factories outside industrial estates to obtain a รง.4 factory license before installing rooftop solar — regardless of system capacity.
This is a major change. Previously, factories needed a รง.4 license that took 45-90 days and added cost and complexity. Now only a PEA/MEA grid connection permit for self-consumption is needed.
Since Dec 2024: Whether 100 kWp or 5 MWp — no รง.4 factory license required (for factories outside industrial estates)
Community Solar (1,500 MW): What It Means for You
NEPC approved a 1,500 MW community solar framework featuring ground-mounted solar with local community benefit-sharing mechanisms — distinct from the rooftop net billing program discussed above.
The program aims to reduce electricity costs at the community level, potentially lowering rates for nearby consumers. Application details and timelines are expected to be announced through 2026.
Decision Matrix: Which Solar Path Is Right for You?
The table below summarizes all four solar paths so you can see the big picture before deciding.
Residential + Net Billing | Small Commercial + Self-Consumption | Large Factory + EPC | Large Factory + PPA | |
|---|---|---|---|---|
| Investment | 150,000-350,000 THB | 1-5M THB | 25-35M THB/MW | 0 THB (zero investment) |
| Payback period | 7-9 years | 5-7 years | 4-5 years | Day 1 (15-30% discount) |
| Grid export | Yes — 2.20 THB/kWh | No | No | No |
| Tax incentive | R.D. 805 ≤ 200,000 THB | BOI Section 7.1 | BOI 8yr CIT exempt | No BOI (no investment) |
| Est. ROI range | 10-15% | 15-20% | 22-30%+ | N/A (no investment) |
Frequently Asked Questions
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