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Is a TOU tariff right for your home?

Compare usage times, Peak/Off-peak periods and meter-change costs.

Edited by SolarKrasibUpdated 22 September 2026Read5 min

The answer first

TOU may suit homes that can shift substantial use to off-peak hours. Compare bills before and after solar, including meter-change costs. High daytime use does not always make TOU cheaper.

Low-voltage residential rates in the calculator

Peak: 5.7982 THB/kWh; Off-peak: 2.6369 THB/kWh; service charge: 24.62 THB/month, excluding Ft and VAT. Peak is generally 09:00–22:00 on working days as defined by the utility.

Not every holiday is off-peak

Tariff definitions contain exceptions for substitute holidays and Royal Ploughing Ceremony Day. Use the utility’s calendar for the relevant year. This calculator uses an average off-peak-day share, not an exact daily calendar.

Use the same basis for comparison

The calculator compares solar and no solar under the same selected tariff. To compare normal vs TOU, create two plans and include meter-change costs in installation or upfront fees. Check minimum tariff-use periods before changing back.

Supporting sources

  1. PEA — Electricity tariff effective September 2026 ↗

General information for questions and preliminary estimates. Site and contract conditions need individual verification. International sources explain principles, not Thai law.

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