Electricity bills are set to rise throughout 2017 because of rising natural gas and oil prices, says the Energy Regulatory Commission (ERC).
ERC commissioner and spokesman Veeraphol Jirapraditkul said natural gas accounts for almost 70% of Thailand's power-generating resources, and normally price rises lag six to nine months behind global oil prices.
Gas prices will start to affect power bills from the second period (May to August). Gas prices rose by 9.35 baht per million British thermal units (BTU) or 4% from the previous January-April period, to 244.58 baht per BTU.
As a result, a fuel tariff (Ft) rate hike for May to August was approved by the ERC, rising by 12.52 satang per kilowatt-hour (kWh), Mr Veeraphol said.
Power bills were set to increase by 17.83 satang per kWh, but the ERC said the rise in the Ft was offset by a drop in gas prices during the facilities shutdown for maintenance during the previous period, keeping the hike at 12.53 satang per kWh.
"The Ft rate is rising and will continue to increase gradually until early next year," he said.
The new Ft rate combined with a base factor for May-August means an average increase for all categories of power users (business, residence and public service) of 3.508 baht per kWh, up from 3.38 baht in the first period.
The average monthly power bill in the residential sector will increase by 3.7% or 16.50 baht for consumption of 124 kWh, some 477 baht. Residential users make up almost 90% of power users.
In related news, Mr Veeraphol said the ERC is conducting a study on the possibility of delaying the commercial operation date of National Power Supply Co's (NPS) coal-fired power plant with a combined capacity of 540 megawatts in Chachoengsao province.
NPS is wholly owned by a large pulp and paper maker, Advance Agro Plc (AA). AA won an auction in 2007 to be an independent power producer, allowing operation of a coal-fired power plant. But after the licence was granted, a new constitution was implemented in 2007 with a law requiring environmental and health impact assessments (EHIA) before operations could begin.
Approvals of EHIA by the Office of Natural Resources and Environmental Policy and Planning have sometimes taken more than a decade, and there is still no clear signal on when AA will receive approval.
It still has also not signed a power purchasing agreement with the Electricity Generating Authority of Thailand.