What Is the Ft Charge? The Fuel Adjustment Charge — May–Aug 2026 Period
The Ft is an automatic variable electricity charge added on top of the base tariff on every Thai electricity bill. The Energy Regulatory Commission (ERC) sets and adjusts it every four months. This page explains what Ft is, who sets it, how it's calculated, its current value, and how it affects your factory bill — plus an FAQ.
Quick Answer — What Is Ft, and What Is It Now?
The Ft (variable energy charge, or Fuel Adjustment Charge) is the part of your electricity price that rises and falls with changing fuel costs and power-purchase costs — added on top of the "base tariff." The Energy Regulatory Commission (ERC) announces and reviews the Ft every four months (three periods a year). The current Ft for the May–Aug 2026 period is 0.1623 THB per unit (kWh). It applies to all customer types under both PEA and MEA, and is before 7% VAT. (This is the current-period ERC figure — the next period may differ; see the tariff page for the live value.)
Current Ft at a Glance
- Current Ft value
- 0.1623 THB/unit (kWh)
- Period
- May–Aug 2026 (พ.ค.–ส.ค. 2569)
- Set by
- Energy Regulatory Commission (ERC / กกพ.)
- Adjustment frequency
- Every 4 months (3 periods/yr: Jan–Apr, May–Aug, Sep–Dec)
- Applies to
- All customer types (home, business, factory) — PEA & MEA
Note: the Ft is before 7% VAT and is billed as THB-per-unit multiplied by the units you consume.
1. What Is Ft — and How It Differs from the Base Tariff
The price you pay per unit of electricity has two main parts: (1) the base tariff, which reflects long-run generation, transmission and distribution costs, and (2) the Ft (Fuel Adjustment Charge / variable energy charge), a short-run "adjuster" reflecting how fuel costs (mainly natural gas and LNG), power-purchase costs and exchange rates have moved away from the assumptions baked into the base tariff. So when fuel prices rise, the Ft tends to be positive and bills go up; when fuel prices fall, the Ft can shrink or even turn negative. "Ft" comes from the automatic tariff-adjustment formula (the fuel-adjustment charge at a given time).
2. Who Sets the Ft and How It's Calculated
The Ft is set by the Energy Regulatory Commission (ERC / กกพ.), Thailand's energy-sector regulator. The Electricity Generating Authority (EGAT), the Provincial Electricity Authority (PEA) and the Metropolitan Electricity Authority (MEA) then apply the ERC-announced Ft on the bills they issue. The ERC reviews and announces the Ft every four months (three periods a year), based on actual and forecast fuel costs, power purchased from independent producers and neighbouring countries, exchange rates, and any carried-over balance from prior periods. Before each announcement, the ERC typically opens a public consultation and proposes several options before finalising the figure that is actually billed.
3. Current Ft Value 2026 — How Many Baht per Unit
The current Ft announced by the ERC for the May–Aug 2026 period is 0.1623 THB per unit (kWh). It applies equally to all customer types under both PEA and MEA, and is before 7% VAT. Combined with the base tariff, the average residential electricity price works out to roughly 3.95 THB/unit (before VAT) for this period. The next period's Ft may change when the ERC next reviews it — check the latest value and full rate tables on the Thailand electricity tariff page.
See the Thailand electricity rate tables + latest Ft4. How Ft Affects Your Factory Bill (Worked Example)
The Ft is billed as THB-per-unit multiplied by the units you consume, so the more electricity a factory uses, the larger the Ft impact in absolute terms. Example for a factory using 200,000 units/month:
- Units consumed / month
- 200,000 units (kWh)
- Current Ft
- 0.1623 THB/unit
- Ft portion of the bill (before VAT)
- 200,000 × 0.1623 = 32,460 THB/month
If the ERC raised the Ft by just 0.20 THB/unit in a future period, the same factory's Ft portion would rise to 200,000 × 0.20 = 40,000 THB/month — about 7,540 THB/month more for using exactly the same electricity. That is why factories should watch every Ft announcement and consider "locking in" their power cost with on-site solar self-consumption, which cuts both the units bought from the grid and the exposure to a volatile Ft. (Illustrative figure; the next-period Ft is set by the ERC.)
5. The Ft Trend — Why It Moves Up and Down
The Ft has been high during periods of surging global energy prices (for example the 2022–2023 energy crisis, when imported gas and LNG prices spiked) and has eased as fuel costs cooled and carried-over balances from earlier periods were unwound. Because Thai electricity relies heavily on natural gas and LNG, the Ft is sensitive to global gas prices, the baht exchange rate, and international energy-supply events. We do not list per-period historical Ft figures on this page to avoid imprecise data — the actual figure for each period is per the ERC's own announcement.
A Volatile Ft — How Solar Reduces the Risk
Every unit a factory generates and consumes from its own rooftop solar is a unit it does not buy from the grid — so it pays neither the base tariff nor the Ft on that unit. When the ERC raises the Ft, a factory with high solar self-consumption is less exposed, because part of its power cost is "locked in" at solar's fixed cost over the system's life.
About the Author
This article is prepared by Frank Lee, Founder of CapSolar, which has delivered 80+ MWp of commercial & industrial solar across 150+ projects for 100+ clients. We help factories understand their electricity cost structure — including the Ft — and design solar systems that cut energy costs in concrete terms.
Reviewed by: CapSolar Research Team | Updated: Jun 2026
Frequently Asked Questions
Sources
- Energy Regulatory Commission (ERC / กกพ.) — Fuel Adjustment Charge (Ft) announcement for May–Aug 2026: 0.1623 THB/unit (each period's actual value is per the ERC's own announcement).
- Provincial Electricity Authority (PEA) and Metropolitan Electricity Authority (MEA) — apply the ERC-announced Ft on issued bills; Electricity Generating Authority of Thailand (EGAT) as principal generator/off-taker.
- CapSolar's Thailand electricity tariff page — TOU / customer-type rate tables + current-period Ft (3.95 THB/unit average including Ft 0.1623, May–Aug 2026).
Is the Ft Pushing Your Factory Bill Up? Lock in Your Cost
CapSolar has delivered 80+ MWp of commercial solar across 150+ projects. We analyse your bill, quantify the Ft impact, and design a solar system that cuts both grid units and Ft exposure — free consultation.