The southern province power outage last week was no one's fault as it was caused by lightning while most of the power plants were shut down for repair after being overloaded during the summer, said the energy regulator.
Pallapa Ruangrong, a member of the Energy Regulatory Commission (ERC), said the incident last Tuesday could not be helped as several factors happened at the same time.
"We interrogated the responsible parties and found one of two high-voltage transmission lines sending power to the South was under repair from heavy summer use, while the other one was hit by lightning," said Ms Pallapa.
The four other major power plants in the South were not ready to operate at full capacity as a result of overloaded generating systems from the hot summer.
Some 300 megawatts from Malaysia's Tenaga Nasional Berhad should have been available during the emergency, but were also out of order at that time.
The regulator did note all the southern provinces should not have been left in the dark for five hours because state utilities can share the remaining power by switching between provinces during the outage.
"Far less damage and a shorter outage period would have occured if they had managed the situation more wisely," said Ms Pallapa.
Direk Lawansiri, chairman of ERC, said the interrupted rate (IR) will continue to be used to help solve the problem in the short term. The IR is the government's offer of cheap power rates to businesses that allow their power to be cut in an emergency so the state can switch power output to areas affected by an outage.
Only three operators are participating in the IR scheme: Siam City Cement, Thai Asahi and TPI Polene Plc.
Some business leaders said yesterday reports of blackout damage in the manufacturing sector reaching 10 billion baht were outlandish, as unofficial estimates are less than 300 million.
Meanwhile, Peera Pechpanich, chairman of the southern region of the Federation of Thai Industries (FTI), suggested the law concerning operating licence approval should be amended to shorten the approval process.
"Current procedures are slow and redundant," said Mr Peera, proposing a one-stop centre to facilitate 8% annual growth of southern power demand.
The Industry Ministry was accused of stalling the approval process for power plants in the region to receive bribes to shorten the process, said alternative energy firms who asked not to be named.
The problem remains despite a ministry-supervised screening committee set up two years ago to verify licence applications to ensure transparency.
FTI chairman Payungsak Chartsutthipol said he is concerned last week's incident will erode business confidence.
"The new power plants take too long to build and lag behind demand growth. We agree the environment should be taken care of in the process, but nowadays technology can handle this," he said.
The FTI will urge the Energy Ministry to reconsider the country's power development plan to ensure it is in line with economic growth and fuel diversity.