About
Alectra Utilities has retained WSP Canada Inc. (WSP) to prepare a Class Environmental Assessment (EA) study for a proposed 230 kiloVolt (kV) Municipal Transformer Station (Vaughan MTS #6) in Vaughan with the capacity of 170 Mega Volt Ampere (MVA), which will connect to an existing 230 kV transmission line. The new Vaughan MTS #6 will transform the high voltage (230 kV) to distribution voltage (27.6 kV) and provide capacity to an Alectra customer’s new facility with a maximum demand of 108 MVA with a planned operation in 2027.
Purpose
An undisclosed customer has proposed a 108 MVA data center in the Langstaff Road/Hwy 27 area in Vaughan. Alectra does not have capacity in the current system to meet the forecasted customer demand beyond 2026. In order to meet the forecast capacity deficiency, additional transformation and feeder capacity needs to be operational by Q4 2026.
The customer’s maximum demand is forecasted to be 108 MVA and will require ten (10) 27.6 kV feeders to meet 100% redundant supply needs. It is proposed that a Bermondsey type transformer station is required to meet the customer’s long-term needs. A typical Bermondsey type transformer station has two 125 MVA transformers, twelve 27.6 kV feeders, and 170 MVA capacity. Figure 1 below is an example of a typical transformer station.
The proposed site is located at the northeast corner of Line Drive and Langstaff Road. The line connection will involve the installation of 230 kV cables in an underground duct bank to connect the station to the existing Hydro One 230 kV transmission line and towers located west of the study area (Figure 2 above). The proposed underground 230 kV cables, which will be approximately 425 metres (m) long, will convey electricity from the existing Hydro One tower located southwest of the study area to a new municipal transformer station in Vaughan, and then a 27.6 kV underground duct bank line will convey electricity to the future data facility.
The Process
The Study is subject to the Class EA for Minor Transmission Facilities (Class EA for MTF) in accordance with the Ontario Environmental Assessment Act. The Class EA for MTF is a streamlined process for planning transmission projects that have a predictable range of environmental effects and feasible mitigation measures that can be applied (www.hydroone.com/ClassEA). The Class EA process includes public and agency consultation, Indigenous community engagement, an assessment of the potential effects of the proposed project, and the identification of mitigation measures.
Within the Class EA for MTF there are two tiers of assessment corresponding to project scale and potential for environmental effects. These include:
- Screening Process, and
- Full Class EA Process.
The Screening Process is a streamlined process for smaller scale projects with minimal environmental effects (confirmed upon satisfying 16 screening criteria). Based on completing the consultation activities and fulfillment of the 16 screening criteria, this Study will follow the Screening Process.
In the months ahead, we will collect environmental and technical data to assess the study area. We will also gather input on the proposed project from residents, Indigenous communities, local businesses, government agencies, and interest groups. Once the Class EA process is successfully completed, construction could commence as early as May 2025, and be completed by the end of 2026.
