TAIPEI (REUTERS/BLOOMBERG) - A man was killed and his elderly mother injured when candles caused a fire in their home during a massive power blackout across Taiwan on Tuesday night (Aug 15), reported Taiwanese media.

No other deaths or injuries were reported.

State-owned CPC Corp, the island's biggest gasoline supplier, said on Wednesday at a news briefing that ​a flawed power supply replacement process caused Tuesday's massive power blackout.

The power outage was caused by a human technical error at state-owned gas supplier CPC that affected the operations of a state-owned Taiwan Power Co power plant in north-western Taoyuan, the two companies said at a news conference on Tuesday evening.

Taiwan Power Co's outage at its Taoyuan plant caused six generators to stop working, resulting in a massive blackout across Taiwan, the company said.

CPC said it accepted responsibility for the outage and was investigating the cause. The blackout was the island's most severe since the 1999 Jiji earthquake, Taiwan Power Co said.

The massive blackout came as a combination of factors: an unusually hot spell, damage to infrastructure from recent typhoons and a push by the Tsai Ing-wen administration to abandon nuclear power that has left Taiwan barely able to supply sufficient electricity to residential and business users.

That balance gave way just before 5pm on Tuesday when a plant in northern Taiwan stopped generating power after workers accidentally shut off its supply of natural gas. Electricity had been restored by 10pm on Tuesday, and by Wednesday morning, power had been fully restored across the island.

An article occupying the entire front page of Wednesday's China Times newspaper questioned the competence of Ms Tsai's administration for allowing the situation to deteriorate so badly and her insistence on phasing out nuclear power.

There had been multiple warnings about Taiwan's electricity supply before the blackouts.

A week earlier, state-run utility Taiwan Power Co issued a red alert as the operating reserve margin, the difference between power produced and consumed, fell to the second lowest on record.

Business associations, including the Chinese National Federation of Industries, had also called for slowing the pace at which nuclear plants were being phased out.

Ms Tsai has shown no indication of abandoning her position, which formed a key component of a campaign that swept her into office more than a year ago. Taiwan has already mothballed one of its four nuclear power stations, and of the six remaining reactors available, three are currently shut down for maintenance.

She apologised on her Facebook page for the blackout, describing electricity supply as a national security issue.

Relevant government departments needed to quickly explain why a single event could cause such large damage across Taiwan's electricity system, she said.

"We must reform the system. I will make this an important point for thorough inspection reforms in the future."

Her Facebook post included a reiteration of her determination to push forward with phasing out nuclear power in favour of renewable energy.

"The government is promoting distributed green energy to avoid the situation where an incident at a single power station can affect the power supply for the whole country," Ms Tsai wrote. "We will not change course. Today's incident only makes us more determined."

Taiwan's Minister of Economics Affairs Lee Chih-kung had offered to resign over the incident, which was accepted by Premier Lin Chuan, the government said. The Taiwan government said on Wednesday (Aug 16) that Mr Lee will be replaced by his deputy as acting minister.

Mr Shen Jong-chin, the administrative deputy minister, will assume the duties temporarily, the government said at a news briefing.

Tuesday's night outage affected more than 6.68 million households across Taiwan. It also hit offices and factories on the island of nearly 24 million people, but appeared to have a limited impact on businesses, including some of the world's leading technology manufacturers.

Taiwan Semiconductor Manufacturing, the world's largest contract chipmaker and a major supplier to Apple, said its operations were not affected, as did electronics manufacturer Pegatron.

ChipMOS Technologies said the outage had not had a big impact on its operations. Its shares fell 2 per cent in early trade, lagging a flat broader market.

Residents complained as temperatures hovered around 32 deg C, while the blackout caused havoc as restaurants and small businesses were left without power, traffic lights stopped working and elevators stalled.

Several department stores and shopping malls in Taipei, Taoyuan and Taichung, such as Pacific SOGO Department Store, Shin-Kong Mitsukoshi Department Store and Far Eastern Department Store, had to evacuate their customers soon after the outage occurred.

The island's tallest building, Taipei 101, also had to evacuate people from the building when the outage took place.

The government said that the public transportation system was largely unaffected by the outage.