Net-Metering in Thailand 2024 — MEA/PEA Rules, License Process, and Payback Calculation

Why Solar Rooftop is Compelling in Thailand

Industrial electricity in Thailand averages ฿3.8-4.2/kWh (Type 4 demand charge) and commercial buildings ฿4.5-4.8/kWh — 30-50% higher than ASEAN average.

Solar panel pricing (2024-2026): ฿14-22/Wp installed — payback 4-7 years compared to:

• Bank deposit: 1.5-2.5% IRR
• Mutual funds: 4-7% IRR
• Solar self-consumption: 15-25% IRR

But every project requires MEA/PEA + DOEB + ERC permits — 2024 rules changed from 1:1 Net-Metering to Net-Billing with lower export rate.

Net-Metering vs Net-Billing — Critical Distinction

graph LR
    A[Net-Metering 1:1] --> A1[Export 100 kWh = Credit 100 kWh
same rate]
    A --> A2[Used in early Thai pilot 2013-2018
High value, utility not profitable]
    
    B[Net-Billing] --> B1[Export 100 kWh × ฿2.2/kWh = ฿220
Import 100 kWh × ฿4.18 = ฿418]
    B --> B2[Used by MEA/PEA 2020+
Self-consumption preferred]

Math under Net-Billing:

• 100 kWp installed for factory consuming ~500 kWh/day (peak hours)
• Production ~450 kWh/day (annual ~150,000 kWh)
• Self-consume ~380 kWh (84%) × ฿4.18 = ฿1,588/day savings
• Export ~70 kWh (16%) × ฿2.2 = ฿154/day income
• Total: ฿1,742/day = ฿52,260/month
• System cost ~฿1.5-1.7M
• Payback: 2.7-3.3 years (high self-consumption) or 4-5 years (high export)

Key insight: Self-consumption % matters most — design system to peak production matching peak load.

MEA vs PEA Coverage

Both use same Tariff structure (Type 1-5) + similar Net-Billing rules.

License Process — Standard (200-1,000 kWp)

flowchart TD
    Start[Install Decision] --> Survey[1. Site Survey + Load Analysis]
    Survey --> Design[2. Design + Single-Line Diagram]
    Design --> Apply[3. MEA/PEA Application]
    Apply --> Review{MEA/PEA Review
30-45 days}
    Review -->|Approved| DOEB[4. DOEB Permit if > 200 kWp]
    Review -->|Reject| Revise[Revise + re-apply]
    DOEB --> Install[5. Install — 4-8 weeks]
    Install --> Test[6. Commission per IEC 61727]
    Test --> COD[7. Commercial Operation Date]

Required Documents (5 sets per MEA/PEA 2024)

1. Application Form (from MEA/PEA website)
2. Single-Line Diagram — drawn by Licensed Engineer (Phakee Wisawakorn)
3. Technical Specifications:
   • PV module spec (Tier 1 preferred)
   • Inverter spec with IEC 61727 / IEEE 1547 test report
   • Cable + breaker spec
4. DBD Certificate (company registration)
5. Land Ownership Proof or rental contract ≥5 years

Timeline Reality (2024 data)

ROI Calculation Example

Scenario: Plastic factory, 5,000 m², Nonthaburi

Current bill profile:

• Monthly consumption: 80,000 kWh
• Average rate (Type 4): ฿4.05/kWh
• Monthly bill: ฿324,000

Solar system design:

• Size: 350 kWp on rooftop (capacity factor ~16% in Thailand)
• Annual production: 490,000 kWh
• Daily average: ~1,340 kWh

Self-consumption analysis:

• Plant operates 7am-7pm
• Solar peak 10am-3pm matches well
• Estimated self-consumption: 85%

Annual savings:

• Self-consume: 416,500 kWh × ฿4.05 = ฿1,686,825
• Export: 73,500 kWh × ฿2.2 = ฿161,700
• Total: ฿1,848,525/year

Investment: 350 kWp × ฿18,000/kWp = ฿6,300,000

Payback: ฿6.3M / ฿1.85M = 3.4 years

25-year cumulative net: ~฿40.7M (assuming 0.5% annual degradation, no tariff inflation)

IRR: ~22% over 25 years

Common Mistakes

1. Oversize system → low self-consumption → high export at low rate

Wrong: 500 kWp for factory peaking at 200 kW Fix: Match system size to peak daytime load × 0.85

2. Ignoring demand charge

Wrong: Only considering energy charge (฿4.05/kWh), missing demand charge (฿132-350/kW) Fix: Solar + Battery for peak shaving reduces both

3. Inverter without IEC 61727 cert

Wrong: Cheap inverter without certification Fix: Use Tier 1 brands — Sungrow, Huawei, SMA, Fronius, GoodWe

4. Skipping roof load capacity check

Wrong: Installing 12-15 kg/m² panels on weak roof Fix: Civil PE calculate roof load + sign off

5. No shading analysis

Wrong: Installing under shade of building/tree/HVAC chimney Fix: PVsyst or Helioscope simulation + drone survey

Saha Solar Service Tiers

Tier 1: Consultation (฿20-50K)

• Site survey + drone roof image
• 12-month load profile analysis
• Preliminary design (3 options) + 25-yr ROI calc

Tier 2: Design + Permit (฿100-300K)

• Single-line diagram + Licensed Engineer stamp
• MEA/PEA + DOEB submission package
• Project timeline

Tier 3: Turnkey EPC (฿14-18K/kWp)

• Tier 1 procurement + installation + commissioning
• 25-year monitoring service available

Tier 4: Long-term O&M (฿200-400/kWp/year)

• Quarterly cleaning + inspection
• Annual IV-curve test per IEC 61853
• Warranty + insurance support

BOI / Tax Incentives

Summary

• Net-Billing (not Net-Metering) is current MEA/PEA scheme 2024
• Self-consumption % is the most important variable
• License process: Simple (2-4 wk) → Standard (1-3 mo) → ERC (3-6 mo)
• Realistic payback: 3.5-6 years industrial · IRR 15-25% over 25 yr
• 5 documents required: Application + Single-line + Tech spec + DBD + Land proof
• Common mistakes: oversize, ignore demand charge, cheap inverter, no shading analysis

Saha provides design + permit + install + commission packages — contact 02-096-2118 or visit /solar for free TCO calculator.