Three Sisters

The Three Sisters Plant is one of TransAlta’s smallest power plants, with a generating capacity of three megawatts. Its primary function is to control the release of water from the Spray Lakes reservoir. The Three Sisters Plant generates an average of 4,200 megawatt hours annually.

The Three Sisters Plant is one of three TransAlta plants on the Spray System, which is part of the Bow River Electric System in Alberta. The plant uses the Spray Lakes Storage Reservoir which is created by the Canyon Dam to the south, and the Three Sisters Dam to the north. The plant is located at the base of the Three Sisters Dam.

The Three Sisters Plant is named for three mountain peaks on a ridge south of Canmore that resemble each other.

TransAlta’s hydroelectric plants primarily provide electricity during periods of peak electrical demand and ensure system stability. Their operating flexibility means they can start quickly to introduce hydro power within minutes, balancing out shortages due to unexpected outages, or providing power at times of high demand.

Environmental Highlights

Protection of the environment is an important part of our hydro power business, as is responsible water use. We continually work with environmental and community groups to ensure habitats are protected, and that all users’ needs are heard.

We are also working to enhance the environmental component of our Environment, Health & Safety Management System to meet ISO 14001 standards (ISO 14001 is an international standard setting the framework for a holistic and strategic approach to environmental policy, plans and actions).

Three Sisters

Facts & Figures

  • Location: Canmore, AB
  • Fuel: Hydro
  • Capacity (MW): 3
  • Ownership: 100%
  • Operator: Yes
  • First on-stream: 1951
  • Revenue Source: Alberta PPA
  • Builder: Yes
  • Contract Expiry: 2020