Transmission infrastructure growing in southwestern Ontario

A greenhouse boom in southwestern Ontario is sparking transmission infrastructure construction in the region.

In the most recent manifestation of this trend, the independent system operator that serves Ontario has asked Hydro One to build a new transmission line to meet the growing demand for electricity in the Canadian province's southwestern part.

The 230 kilovolt double circuit line would run between Hydro One’s Lambton transformer station and its Chatham switching station over a route that has yet to be determined. If approved by the Ontario Energy Board, the line would be in service by 2028.

In a March 29 press release, the Independent Electricity System Opertator said the project is necessary because it expects power demand from the agricultural sector in the Windsor-Essex and Chatham areas of Ontario to increase from roughly 500 megawatts today to about 2,000 MW by 2035. Such an increase, it said, is the equivalent of adding a city the size of Ottawa to the grid. Ottawa, Canada’s capital, has a population of around 1 million.

In a “backgrounder” on the project, the IESO attributed the agricultural sector’s increased power demand to “strong indoor agricultural growth, in vegetable greenhouses, as well as in part, cannabis.”

The IESO said it obtained its demand growth forecast for southwestern Ontario from extensive planning, analysis and community engagement. Its work also led it to conclude that the proposed Hydro One transmission line was the most cost-effective next step to meet the anticipated growth. The IESO said it will identify additional steps in studies it plans to release this spring.

The IESO and Hydro One already have taken some steps to address the growing power demand in southwestern Ontario.

Hydro One recently energized two transmission stations in Leamington and is building two other transmission stations in southwestern Ontario. The company also is developing a 230 kV line between Chatham and Lakeshore that will boost available power in southwestern Ontario by 400 megawatts. Hydro One President and CEO Mark Poweska said the line would “allow for more than 40 medium-sized greenhouses to start and grow.”