The fuel tariff will be raised to 69 satang per unit for the next four months, said Direk Lavansiri, chairman of the Energy Regulatory Commission (ERC).
In fact, the cost increased by 13.94 satang per unit, but the ERC agreed to raise the rate by only 10 satang. The rest of the increase will be absorbed by the Electricity Generating Authority of Thailand (Egat) at 3.94 satang per unit for a total of 2.24 billion baht, said Mr Direk.
The latest fuel tariff, which is adjusted every four months, comes as the price of natural gas surged by 9.11 baht per million standard cubic feet per day to 326 baht. Bunker oil price also rose by 246 million baht to 3.65 billion baht and the exchange rate depreciated to 32.33 baht to the dollar on April 10 from 32.21 baht last November.
"The adjusted power rate will be a record high, and it will rise slightly in the next period as the gas price continues to rise," he said.
The energy regulator held discussions with 11 business sectors in the southern region to cut their power consumption when gas supply from the Malaysia-Thailand Joint Development Area (JDA) is disrupted from June 13 to July 10 for maintenance.
Gas from the JDA accounts for 10% of Thailand's total gas demand. The disruption will affect power plants with a combined capacity of 700 megawatts in the southern region.
Egat governor Soonchai Kamnoonsate said the utility could partially subsidise the cost of the fuel tariff even though it is dealing with trying to upgrade the country's power network.
Egat will try to secure more cheaper fuels such as hydropower and imported coal to reduce the reliance on gas, now accounting for 70% of Thai power generation.
However, the water level at major reservoirs such as Sirikit and Bhumibhol dams is low at only 20% of total capacity.
Yesterday Egat announced a capital expenditure of 240 billion baht from this year to 2019 to upgrade transmission lines and development of power plants.
Mr Soonchai said around 160 billion baht would be used to upgrade high-voltage transmission lines nationwide, with another 80 billion for building new power plants and upgrading existing power generators.
Power transmission lines to be upgraded include those in the southern region linking with provinces in the central plains. Also, the network between eastern and western regions and the northern to northeastern regions would be improved.
Egat also plans to upgrade power generators by retiring those at South Bangkok, Bang Pakong and Mae Moh power plants.
Meanwhile, the price of liquefied petroleum gas (LPG), which is used as cooking gas in the household sector, is expected to increase by another 50 satang per kilogramme from today to 22.63 baht.
The LPG price is projected to increase by 50 satang per kg every month from September of last year from a base price of 18.13 baht until the level reaches 24.82 baht. However, the price of LPG for the transport sector is expected to be maintained at 21.38 baht.