N.L. Hydro extends life expectancy of Holyrood plant by another year as Muskrat delays continue

Newfoundland and Labrador Hydro confirmed it will delay the decommissioning date of the thermal power generating station at Holyrood by at least another year in order to ensure customer reliability early on in the Muskrat Falls era.

The decision is linked to the ongoing struggle by GE Canada to perfect the computer software required to operate the high-voltage transmission line from Labrador to Newfoundland's Avalon Peninsula, and growing questions about the ability of the line — known as the Labrador-Island Link, or LIL — to withstand extreme weather events such as freezing rain storms.

In a letter to the province's utility regulator on Friday, Hydro said it will commit to operating the half-century-old Holyrood plant until at least the spring of 2024. That's a year longer than planned, but is just the latest extension for Holyrood as the completion schedule for Muskrat Falls continues to be hit with setbacks.

The Holyrood station is rated at nearly 500 megawatts of electricity, and is a key source of power for the Avalon Peninsula, home to about half the province's population.

But Holyrood relies on expensive and polluting diesel fuel, and being able to replace those emissions with non-emitting hydro power from Labrador, and save money on fuel, was one of the key arguments for moving forward with Muskrat Falls.

Now there's a possibility that the Holyrood station might be around much longer.

Hydro president and CEO Jennifer Williams could not provide a cost estimate for the Holyrood life extension, saying a staffing and maintenance strategy is being developed. 

She said it's common for new utility infrastructure like Muskrat Falls to encounter what she called growing pains, and said it was always the plan to keep Holyrood as a back-up for two winters after Muskrat Falls was commissioned.

"So if you do have a bump in the early in-service years, on the LIL or the [generating station at Muskrat Falls], Holyrood will be there to help the reliability concerns that could cause," said Williams.

"Just because of the current schedule of the LIL software, we wanted to add on that extra year to make sure we have two full winters where we would plan for that extra level of reliability."

Williams said Hydro is preparing a series of recommendations about reliability to the PUB, which are due by late summer. Among the options on the table? Maintaining Holyrood in stand-by mode for an indefinite period, and upgrading some vulnerable sections of the newly built LIL.

The LIL comprises some 3,200 towers, 2,300 kilometres of conductor wire, the 30-kilometre subsea cable across the Strait of Belle Isle, and is projected to cost some $3.7 billion when complete.

Williams said the province has to strike the right balance between cost and reliability.

"Do we do some upgrades to what we currently have? Do we invest in actual backup, and if we do, do we back it up fully? Do it back it up partially? All of these are questions that we're going through with the regulator right now," said Williams.