Energy Minister Supattanapong Punmeechaow has defended the government's power development plan, saying it does not just benefit energy businesses as alleged by the opposition.
Mr Supattanapong was speaking during the censure debate against the government after the opposition took aim at its plan to ramp up rates.
The opposition further said that the electricity production capacity, if maintained at an excessively high level, will result in a greater financial burden for consumers.
Mr Supattanapong insisted the figures used by the ministry to calculate the power production capacity are correct and differ from those provided by the opposition.
According to the ministry's calculation, the excess capacity currently exceeds 35%, not 54% as claimed by the opposition.
"Currently, the total electricity production capacity is more than 50,000 megawatts, which may sound huge.
"But a breakdown of the figures shows the production comes from various sources, such as solar cells, wind, or biomass. Power from these sources cannot be generated all the time, and depends on factors such as the season, time of day and weather," he said.
Stable production capacity should be maintained at 35%, he added.
He admitted the 35% level exceeds the threshold of 15% suggested by the opposition.
"But we had to plan several years in advance and we drew on information from several agencies and advisers that have assessed the demand for electricity for decades.
"Due to the [Covid-19 and economic] crises over the past two years, the demand for electricity has declined so we had to plan the investment in production capacity in advance," the minister said.
Under the new power development plan for 2022, production capacity has been reduced by more than 3,000 megawatts, he said, adding that demand for power is also expected to increase for electric vehicles in the future.
Mr Supattanapong said the production capacity is expected to return to 15-20% in the next 5-7 years, adding it must be increased to replenish the existing electricity supplies which will be used up over time.
Regarding a planned hike in the fuel tariff (FT), he said this reflects the change in fuel costs, which have been revised for several years.
According to media reports, the Energy Regulatory Commission (ERC) is considering increasing the FT used to calculate electricity bills, which would cause bills to rise to five baht per unit.
Mr Supattanapong said the commission is expected to conclude how much the power tariff, made up of a base tariff and the FT, will be increased by within this month.