Uprating and Refurbishments

Uprating involves replacing older components of generating equipment with new, more efficient components. The result is that the generator can produce more electricity with the same amount of water. Refurbishments are major overhauls of existing facilities where many pieces of equipment are reaching end of life.



KGS Group completed an uprate study in 2016 that considered options for uprating one or both of the older Aishihik hydro units. A similar study is being done by Hatch for the Whitehorse hydro units and is expected to be finished by early 2017. For the purposes of our work to date we have estimated costs and benefits of the Whitehorse unit uprates.

KGS also looked at four options for the future of the original Mayo hydro facility that included refurbishing the hydro station, replacing it, abandoning it, or removing it.

Technical and Financial Findings

Annual Energy Firm Energy Installed Capacity Dependable Capacity Levelized Cost of Energy Levelized Cost of Capacity Project Life In-service Lead Time
GWh/yr GWh/yr MW MW $/kWh $/kW yr Years Years

Option #1

Mayo Hydro

15.77 15.77 2.3 2.3 $0.08 $481 65 5

Option #2

Whitehorse Hydro

11.12 11.12 1.7 1.7 $0.04 $201 40 3

Option #3

Aishihik Hydro

2.74 2.74 1.3 1.3 $0.09 $178 40 3




Aquatic environment Most favourable
Terrestrial environment Most favourable
Air quality Most favourable
First Nation lands Most favourable
Traditional lifestyle Most favourable
Heritage resources Most favourable
Tourism/recreation/other land uses Most favourable
Cultural/community well-being Somewhat favourable
Local economic benefits Least favourable
Climate change risk Most favourable
  •  Most favourable
  •  Somewhat favourable
  •  Least favourable


The Aishihik study found that by uprating both older hydro units, the plant efficiency could increase by four percent.

In terms of the original Mayo hydro plant, the evaluation found that refurbishing the facility was the most economical option.

Whitehorse uprating is expected to increase efficiency by four percent.

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Initial key findings


Least expensive energy option

Relatively inexpensive capacity option

 Little, if any, environmental impact