Newfoundland and Labrador Hydro filed applications Friday to build two new sources of power to back up what comes to Newfoundland from Muskrat Falls.

The utility readily admits that the oft-troubled Labrador-Island Link needs that critical backup, and they’ve concluded expansions at Holyrood and Bay d’Espoir are the quickest and cheapest way to provide it.

That said, estimates for both projects — adding an eighth turbine at Bay d’Espoir and another combustion turbine at Holyrood — have climbed from about $1.2 billion last summer, to about $2 billion today, with costs continuing to “go through the roof,” Hydro officials told reporters during a briefing yesterday.

Costs should be mitigated by the fact that, if approved by the Public Utilities Board, the projects are additions to existing facilities as opposed to breaking new ground, said Rob Collett, Hydro’s V-P of Engineering..

Then there’s the lurking issue of how they will be paid for, and affect power bills.

Collett says Hydro is acutely aware of those concerns.

“The good news is that these projects are going to be a few years before they’re in service, not till the end of the decade, so there will be absolutely no rate impact until then,” he said. “After that, we have a commitment from the provincial government about rate mitigation, that rates will be minimized to keep them as low as possible for customers.”

While the new Holyrood turbine would initially run on diesel, the plan is to eventually switch to renewable fuels, pending availability and feasibility.

Hydro hopes to have both projects completed by the end of this decade and early in the next.