Evacuees take shelter at an evacuation centre during a blackout

Japanese utility companies forced to introduce rolling blackouts

Utility companies have been forced to introduce rolling blackouts after energy shortages caused by the Japanese earthquake.

The country’s largest utility, Tokyo Electric Power Company (Tepco), has seen its capacity heavily hit and has introduced rolling blackouts of three hours at a time.

It estimates it will face an electricity demand of around 37 GWe against an available supply of 33 GWe.

The energy shortage means that the country is relying more on its remaining nuclear reactors as it has few natural energy resources, although eleven out of 54 nuclear plants are currently out of action.

Some reactors, including three at the malfunctioning Fukushima Daiichi plant, the two units at Hokuriku's Shika plant, Chubu's Hamaoka 3 and Tohuku's Higashidori 1 were already offline for routine outages when the earthquake struck.

This means that some 13,360 MWe of Japan's installed nuclear capacity of just over 47,500 MWe is out of action – nearly 30 per cent of its capacity. 

Although nuclear energy supplies around 30 per cent of Japan's electricity, the country generates around twice as much power from fossil fuel power stations, relying on imported liquefied natural gas (LNG), oil and coal. Hydroelectricity also provides around 7.5 per cent of its annual generation.

Japan's Ministry of Economy, Trade and Industry (Meti) said it would take steps to suppress power demand from industry.

Soon after the earthquake Tepco reported that 12 of its thermal power units and 22 hydroelectric plants had ceased operations because of the earthquake, leading to about 2.4 million households in its service area deprived of power.

Although all the hydroelectric plants were back online two days after the quake, nine thermal units totalling about 6750 MWe of capacity remained out of service from the company's total thermal capacity of just over 38,000 MWe. 260,000 households were still without power.

The Niigata-Chuetsu-Oki earthquake of 2007, which saw Tepco's Kashiwazaki Kariwa nuclear power plant taken offline for two years, resulted in an estimated cost of $5.62 billion to the company.

Increased fuel costs to replace the 8000 MWe of lost capacity accounted for an estimated 75 per cent of that total.  

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