Newfoundland and Labrador's Public Utilities Board said today it will launch a formal inquiry into outages in the island's power system, which practically collapsed over the last week.

In a statement, the PUB said it will also hold a public hearing into the matter.

The call comes on the heels of outages that fell in the midst of severe weather, including a blizzard and during brutally cold temperatures.

Almost all of Newfoundland lost electrical power on Saturday when a fire at a substation in Sunnyside triggered a collapse at the Holyrood generating station. The next night, another massive power outage occurred when a breaker at the Holyrood switchyard malfunctioned.

The PUB, which regulates electrical distribution in the province, said it will draft the "process and timelines" for its inquiry over the coming days.

Newfoundland and Labrador Hydro has come in for hefty criticism in the last week, as it disclosed that its aging equipment was not able to generate enough power to meet consumer demand that was significantly higher than expected. Some of the Crown agency's assets were not able to work because of maintenance or faults.

The island-wide outages came in the middle of a series of rolling blackouts that began Jan. 2 and ended Jan. 8. Newfoundland Power, the private company that sells Newfoundland and Labrador's energy to most consumers, was forced to use the rolling blackouts to manage a limited supply that could not not keep up with demand.

This is the third investigation into the collapse of the power system.

On Thursday, Premier Kathy Dunderdale announced the government would launch an independent, external review of the province's energy system, from generation to regulation.

Nalcor Energy, the Crown corporation that runs Newfoundland and Labrador Hydro, has started an internal investigation, and has begun sharing information with the PUB.

Liberals support PUB inquiry

Liberal Leader Dwight Ball says the public must be allowed to express its opinions in any review of the last week's power outages. (CBC) ​Opposition Leader Dwight Ball speaking with CBC News before the PUB's announcement, said Dunderdale should have just let the regulator do its job.

"We believe the Public Utilities Board has the legislative authority to answer all the questions and therefore make orders, allow the public to be involved — there's nothing wrong with that. Why would the premier and this government not want the public hearings in this particular case?" Ball said.

"When you look at the mandate, and what falls within the purview of the PUB, they can do any of this work that the premier is talking about."

Ball is critical that the government review may not allow the public to have a voice.

Dunderdale said she will develop the terms of reference for the government-appointed review within the next six weeks. Ball said it's important that the root causes are found.

"What we're looking for are ways and measures to prevent this from happening again," he said.

NDP Leader Lorraine Michael called for a PUB inquiry earlier this week.

As well, Tom Johnson, Newfoundland and Labrador's consumer advocate, formally asked the PUB to investigate the outages.

Nalcor says confidence needed in system

Meanwhile, Nalcor CEO Ed Martin said he welcomes an independent review of the province's electrical system.

​Martin said he understands the public's confidence has been shaken in the electrical system.

"Our job is to bring back and ensure that people get re-established in their confidence in the system. So, from that perspective, that's why I say I welcome such a review," said Martin.

Martin said an independent review will help Nalcor figure out what worked well and what didn't, so improvements can be made.

"You always want to improve. So, we'll look for the things that went well. We'll look for the things that didn't go well. And once we find those, our job is to take those and fix them and make them better."