The Energy Regulatory Commission (ERC) is gathering public opinion about adjusting the power tariff used to calculate electricity bills between May and August, before deciding whether to maintain the tariff rate at 4.18 baht per kilowatt-hour (unit).
Businesses and households are paying 4.18 baht per unit for electricity from January to April.
Prices for gas, the main fuel used for power generation, are expected to decrease, but this does not always mean power bills will decline as authorities need to allocate part of the bills to reimburse the Electricity Generating Authority of Thailand (Egat), which shouldered huge losses after subsidising electricity prices, according to the ERC.
The new power tariff partially depends on the fuel tariff (Ft), which is determined by various factors, including fuel prices, electricity purchases and other expenses under government policies.
People have three choices for the Ft on the ERC's website during the public consultation from March 8-22.
The input will be considered by the commission, which will approve a new power tariff in April, said Khomgrich Tantravanich, secretary-general of the ERC.
Increasing the Ft to 1.65 baht per unit is the first option, which would cause the power tariff to increase to 5.43 baht per unit. The higher rate would mean Egat could clear its entire loss of 99.7 billion baht by August this year.
The second option is an Ft of 0.55 baht a unit, resulting in a power tariff of 4.34 baht a unit. In this example, Egat's losses would be settled by September next year.
The lowest Ft of 0.39 baht a unit is the final choice, keeping the power tariff unchanged at 4.18 baht a unit. This rate would mean Egat would not clear its loss until September 2026.
The Ft is a separate factor from the cost of imported liquefied natural gas (LNG) people are required to pay Egat and national oil and gas conglomerate PTT Plc.
The expense is not included in the Ft in order to control electricity prices.
Thailand has been buying costlier LNG from overseas after its domestic gas supply decreased.
Mr Khomgrich said the price of Pool Gas, which is the weighted average wellhead price of gas from the Gulf of Thailand, the Malaysia-Thailand Joint Development Area, Myanmar and imported LNG, is expected to decrease by 10% to 300 baht per million British thermal units from May to August.
According to Egat, gas accounts for 60% of fuels used for power generation, followed by coal (15%), renewable energy (10%), and power imports from Laos and Myanmar (10%).
The price of imported coal is expected to fall by 23% to 3,705 baht a tonne, while the domestic lignite price should stay unchanged at 820 baht a tonne, noted the authority.