Is solar worth it in Thailand?

Yes, if you use power in the daytime: a home using 600 kWh a month with a 5 kW system pays back in about 5.4–9.8 years, saving 1,288 THB on the bill and earning 880 THB from exports each month.

Last updated · Assumes 50% daytime use, PEA area.

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Rooftop solar on a family home
Sergio Martins / Unsplash
Payback (5 kW)
5.4–9.8 years
Monthly benefit
2,168 THB
25-year benefit
650,250 THB
Export rate
2.20 THB/kWh
How rooftop solar works
Panelsmake DC powerInverterconverts to ACYour homecuts the daytime billSmart meterUtility gridsurplus at 2.20 THB/kWh
  1. Panelsmake DC power
  2. Inverterconverts to AC
  3. Your homecuts the daytime bill
  4. Smart meter
  5. Utility gridsurplus at 2.20 THB/kWh

Solar payback calculator

THB
Set higher if you work from home, run a shop or use AC in the daytime

Pays back in about —

Recommended size
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Install cost
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Bill saving
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Export income
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25-year benefit
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Cumulative benefit vs install cost (25 years)
low price high price
Assumptions
    Rates and prices as of 31 Oct 2026

    More daytime use, faster payback

    Solar power is worth more when you use it on the spot: it replaces grid power bought in the expensive tiers. Exported surplus earns only 2.20 THB/kWh.

    Daytime usePayback (5 kW)
    30% (out all day)6.0–11.0 years
    50%5.4–9.8 years
    70% (work from home / shop)4.9–8.9 years

    Payback by monthly electricity bill

    Monthly billSuggested sizeSaving + export/monthPayback
    1,500 THB3 kW1,334 THB6.9–12.5 years
    2,500 THB3 kW1,605 THB5.7–10.4 years
    4,000 THB5 kW2,608 THB4.5–8.1 years
    6,000 THB10 kW4,643 THB4.1–7.2 years
    8,000 THB10 kW5,138 THB3.7–6.5 years

    Assumes 50% daytime use, PEA area, as of 31 Oct 2026.

    When solar may not be worth it

    • Bills under about 1,000 THB a month: most use sits in the cheap tiers.
    • Nobody home in the daytime and no battery.
    • An old roof that needs replacing soon, or heavy shading.
    • Renting, or planning to move within 5 years.

    Installed solar prices by system size

    SizeTypical price (THB)Output / month
    3 kW 110,000–200,000~420 kWh
    5 kW 140,000–255,000~700 kWh
    10 kW 230,000–400,000~1,400 kWh

    Compiled from Thai news and bank guides. Actual quotes depend on panel and inverter brand and on your roof. · As of 31 Oct 2026

    Government incentives

    • Sell surplus power back at 2.20 THB/kWh on a 10-year contract
    • 500 MW national quota
    • Personal income tax deduction up to 200,000 THB (on-grid ≤10 kWp, until 31 Dec 2028)
    • Export is capped at 5 kW per meter
    • People’s Solar subsidy of 50,000 THB per person, registration until 31 Jan 2027 (cannot be combined with the tax exemption)

    As of 31 Oct 2026 · Check the latest MEA/PEA announcement before installing

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    Frequently asked questions

    How many years does home solar take to pay back in Thailand?

    About 5.4–9.8 years for a 5 kW system in a home using 600 kWh a month with half of it in daytime, depending on the installed price.

    Is solar worth it if I mostly use power at night?

    Less so. With only 30% daytime use, a 5 kW system pays back in about 6.0–11.0 years, because most output is exported at 2.20 THB, below what you pay for grid power.

    How long do solar panels last?

    Panels are typically designed for about 25 years; inverters usually need replacing sooner. Our 25-year benefit does not yet subtract panel degradation, because we have not found a source we trust for the rate.

    Does the tax deduction shorten payback?

    Yes. Installation costs are deductible from taxable income up to 200,000 THB. In the 20% bracket that saves up to 40,000 THB. Enter your bracket in the calculator.

    Sources

    1. Khaosod English: Thailand approves electricity bill cuts, boosts rooftop solar
    2. Thairath: Electricity tariff tiers
    3. Thairath: Solar installation cost and tax deduction
    4. Naewna: Output and savings by system size
    5. Thansettakij: 5 kW rooftop solar cost

    Methodology and sources