TransAlta asked Alberta regulators for approval to build a 180 MW/360 MWh battery energy storage system on land that is part of the Ghost Hydro-electric facility near Cochrane, Alberta.

The utility said it plans a two-phase approach to construction with Phase 1 constructed, energized and tested by the end of 2023, prior to the construction of Phase 2. The project has an estimated cost of C$120 million ($95 million). The second phase could enter service in 2025.

The final configuration and layout of the battery energy storage system has not yet been finalized and will be determined after a battery manufacturer is selected, TransAlta said.

The battery facility would be charged by electricity produced by the existing Ghost Hydro-electric facility when demand is lower, and discharged to support grid stability during times of higher demand. 

Most of the onsite equipment is expected to be individual battery modules, but will also include medium-voltage step-up transformers, an electrical collection system, switchgear, automation and controls and a connection to the substation. The connection to the existing substation is expected to be through a distribution line at 13.8 kV or 34.5 kV.

The 56 MW Ghost hydro plant is one of four TransAlta hydro plants located on the Bow Mainstream System, which is part of the Bow River Electric System. The Ghost plant created the Ghost Reservoir, which stores water for use in generating electricity. The Ghost plant generates an average of 173,000 MWh each year.