The investigation is expected to be completed within a month.

Energy minister Takiyuddin Hassan said the investigation would identify the cause and the effects of the outage, and whether power failure comes under Tenaga Nasional’s guaranteed service level.

“That would be used as the basis to determine whether the affected customers are eligible for a rebate or not,” he said.

He said the GSL was fixed by the energy commission to ensure top-quality delivery of electricity supply by TNB. If TNB fails to adhere to GSL, a penalty will be imposed on it in the form of rebates to affected customers.

Around a million customers in several peninsular states were reported to be affected by the power failure, which lasted in places for more than two hours. He said the outage period did not exceed the latest guaranteed service level approved in September 2020.

Yesterday Takiyuddin had been quoted as saying that TNB would give rebates to consumers, especially traders who were affected. He said he would table the detailed information on the rebate in Parliament on Aug 4.