High cost, lack of use shutter Thunder Bay Generating Station: Investment in repairs for ailing plant 'unjustifiable,' says power authority.

• Author: Kelly, Lindsay
• Position: ENVIRONMENT

Citing expensive repairs and the ongoing high cost of operation, Ontario Power Generation (OPG) announced on July 27 it would permanently shut down the 55-year-old Thunder Bay Generating Station.

In a news release, the OPG said "significant corrosion damage" was found at the generating station's boiler in May, rendering the plant non-operational, and it's been idle ever since. The province estimated repairs would cost $5 million.

"Because of the high capital repair costs, high operational costs and limited time remaining on the IESO contract for Thunder Bay Generating Station, OPG and IESO (Independent Electricity System Operator) determined that shutting down the station now is in the best interests of electricity customers," the news release said.

The OPG emphasized that none of the plant's 70 employees would lose their jobs as a result of the closure, although some will be redeployed to other facilities.

The Thunder Bay Generating Station is known as a "peaking plant," meaning it's only used during peak times of energy use, when the provincial grid needs additional power to meet demand.

Brayden Akers, a spokesperson with OPG, said since 2014, the plant has only run 10 days in total.

"The IESO is responsible for system planning and capacity," he noted, "but there is a significant overcapacity in the northwest, and that's why this plant was called upon so little. It was never really on."

Should the boiler be repaired, the province said that, based on an historical annual average of operational days, it would only be used for about two and a half days per year.

Meanwhile, the repairs would take about six months, leaving just one year remaining on the supply contract with the IESO, which expires in 2020.

Located within city limits, next to the Lakehead Region Conservation Authority's Mission Island Marsh, the station was first placed into service in 1963 as a coal-burning facility, producing 326 megawatts (MW) of power.

It was the oldest of OPG's thermal electricity-generating stations and the last in the province to burn coal.

Following the Liberal government's vow in 2013 to phase out all of the province's coal-fired plants, the Thunder Bay Generating Station was shut down and, by 2015, had been converted to a biomass-fired facility, with the capacity to produce up to 306 MW of power, at a cost of $5 million.

Before the boiler failure, the plant was burning torrefied wood pellets imported from the Norwegian company Arbaflame.

As the plant...