Industrial water supply cut in Japan's Aichi causes two coal-fired power plants to shut down

The suspension of industrial water supply in Aichi prefecture of central Japan May 18 is leading to unplanned shutdowns of at least two coal-fired power plants in the Nagoya area amid uncertainty over when supply will resume.

The suspension of supply, which is also leading to a reduction of power output at JERA's 4.1 GW Hekinan coal-fired power plant, comes amid Japan's off-peak power demand season.

Nakayama Nagoya Joint Power Generation, in which Osaka Gas has a 95% stake via a wholly owned subsidiary, was forced to shut the 149 MW No. 1 coal-fired unit at its Nagoya power plant at 1 pm local time (0400 GMT) May 18 following the suspension of industrial water supply, an Osaka Gas spokesperson said.

Nakayama Nagoya Joint Power Generation also plans to shut the 110 MW No. 1 coal-fired unit at its Nagoya Daini power plant at 9pm on May 18 due to the suspension.

It was not immediately clear when Nakayama Nagoya Joint Power Generation will be able to restart the Nagoya coal-fired units amid uncertainty over when the water supply will resume, the spokesperson said.

Supply was suspended May 18 because because of a malfunction at a water intake works, an prefectural official said.

The prefecture is working to install pumps as part of emergency measures in order to resume water intake but the timeline remains unclear , the official said.

JERA, Japan's largest power generation company, said May 18 it would consider cutting power output at its Hekinan thermal power plant in central Japan as part of steps to curb its use of industrial water following the supply stoppage.

JERA stopped receiving industrial water supply at its Hekinan thermal power plant as well as at its Taketoyo thermal power plant in Aichi at around 05:45 am local time May 18, following a request from the prefectural water office.

The 4.1 GW Hekinan thermal power plant has five days of industrial water stocks if all coal-fired units are at maximum output, the company said.

As part of its response, JERA cut output at its 700 MW No. 3 Hekinan unit by 150 MW from 4pm local time May 18 until May 19, when it also plans to cut output by 490 MW from 10 am, the company said in a filing to the Hatsuden Joho Kokai System.

JERA also plans to reduce output at its 700 MW No. 1 unit from 8pm May 18 by 380 MW until May 20, and cut the output by 300 MW from midnight May 21.

The company also plans to reduce output at its 1 GW No. 4 and the 1 GW No. 5 units by 600 MW each at the Hekinan power plant from 8pm May 18, JERA said, without providing timelines for restoring output at the three units.