OC Transpo installing gas generators for e-bus charging

Two large natural gas generators are being installed at OC Transpo's garage on St-Laurent Boulevard to support the city's growing fleet of electric buses — a move that raises questions about how fossil fuels fit into a zero-emission strategy.

Each four-megawatt generator costs around $14 million. The pair will serve two main purposes: provide backup power so buses can keep charging during grid outages, and reduce electricity costs during peak-demand periods — which the city estimates happens about 30 days a year.

The retrofit addresses a real infrastructure problem. With around 111 e-buses currently in the fleet and a goal of 350 by the end of 2027, the garage needs major upgrades: a 13.8-kilovolt substation, new Hydro Ottawa distribution lines, and massive charging capacity. The electrical grid alone can't handle that load without strain.

"If a local grid outage were to occur, this project would require a power-generation source large enough to provide charging to the e-bus fleet, potentially for multi-day operation," Daniel Villeneuve, manager of the zero-emission bus program, said in a statement.

The generators are expected to be ready in September. City estimates suggest they'll run about 120 hours a year for peak-demand management — not a daily thing, but enough to take pressure off the grid when the whole city is drawing power. It's a practical answer to a problem bigger than transit itself.