Nova Scotia Power's ongoing efforts to remove asbestos from its Trenton coal-fired generating station turned into a money pit in 2016, and it could do so again this year.
The asbestos abatement program at the Pictou County, N.S., plant began in 2009.
In 2016, the approved budget was $154,000 — but the utility ended up spending $2 million, according to an NSP filing released by regulators this week.
The company was carrying out a planned maintenance shutdown at Trenton unit five, a 48-year old boiler unit that burns coal to generate electricity, when it found a problem.
"They found some asbestos in some areas where they realised they had to address it immediately," said NSP spokesperson David Rodenhiser.
Persistent asbestos in dust at plant
In a filing to the Nova Scotia Utility and Review Board, the company said crews found persistent asbestos in dust at the area. The asbestos insulation fibres were so widespread that they couldn't identify one single source.
"The infrastructure in that area is prone to considerable vibration, resulting in the spread of the asbestos fibres throughout the area on a daily basis. (i.e. once an area was cleaned up of dust, within hours, more dust/debris containing asbestos fibres appear)," NSP reported.
Its solution was to remove all of the insulation containing asbestos in the area. That added a month to the shutdown, which ended in December.
Rodenhiser said the company expects to spend several hundred thousand dollars removing asbestos from Trenton in 2017, but work plans have not been finalised. In its filing, NSP told regulators asbestos-removal costs could be higher than the normal annual spent due to changes in the way NSP operates the plant.
Is green energy a factor?
Green energy may be aggravating the situation, since to integrate more intermittent wind power onto the grid, Trenton and other plants are being shut down and restarted more frequently, increasing vibrations and the risk of asbestos disturbance.
"As utilization at Trenton continues to change, with more stops/starts concurring, the level of vibrations and potential for asbestos disturbances will increase," NSP said in its filing. It did not explicitly link the operating changes to using wind power.
But Rodenhiser noted that the increased use of electricity generated by wind power — which arrives on the grid intermittently — has affected the entire system.
"All of the plants have been changing their operations as we integrate more wind into the system and that involves turning them down, turning them back up, turning them on, turning them off," Rodenhiser said.
NSP also has asbestos abatement programs at Point Tupper in Richmond County, Tufts Cove in Halifax, and Lingan in Cape Breton.