No longer just a means of getting from point A to point B, subways and electric buses can also be used with battery storage to actively contribute to the reliability of the power grid. The IESO is investing $4.3 million, and the Toronto Transit Commission (TTC), City of Toronto and PowerON are investing $10.3 million in two projects that will explore innovative ways that large batteries can help subways and electric buses reduce peak demands and strain on the electricity system.

The IESO forecasts that electrification of Ontario’s transportation sector is expected to grow an average of 20 per cent a year for the foreseeable future. For local utilities and the IESO, this presents a challenge of meeting increased electricity demand – as well as the opportunity to use new technologies to create dynamic solutions to meet long-term energy needs.

Batteries can store energy during periods of low demand and then supply it during on-peak hours, reducing electricity costs and potentially deferring grid infrastructure upgrades. The IESO’s Grid Innovation Fund is investing in pilot projects such as these ones to enable local forms of supply to contribute to the resiliency, sustainability and affordability of the power grid. 

The learnings from these projects have the potential to promote transportation electrification, reduce greenhouse gas emissions and support local community sustainability goals. The TTC already has the largest fleet of battery-electric buses in North America, and will transition its fleet in line with the City of Toronto’s TransformTO target of achieving net zero emissions by 2040. 

IESO President and CEO Lesley Gallinger announcing the funding for the TTC and PowerON pilor projects. (L to R): Associate Minister of Transportation Stan Cho, Toronto Councillor and Chair of the Environment and Infrastructure Committee Jennifer McKelvie, IESO President and CEO Lesley Gallinger, Toronto Councillor and TTC Chair Jaye Robinson, PowerON Energy Solutions Managing Director Keegan Tully, His Worship Toronto Mayor John Tory.  

The two projects are: 

• Complementing electric buses with battery storage – PowerON will deploy a smart charging management system and batteries to minimize how much the battery-electric buses charge from the grid at peak at TTC’s Birchmount and Malvern garages. The batteries will also demonstrate how they can provide grid services such as energy, operating reserve and capacity to the provincial electricity market. Partners: PowerON Energy Solutions LP, Toronto Transit Commission, City of Toronto’s Environment and Energy Division. 
• Maximizing regenerative braking on TTC subway trains – The pilot project will store excess energy from the subway system’s existing regenerative braking system for later use. Currently, TTC trains use the regenerative braking system to capture a portion of the kinetic energy generated from braking and transfer that energy to other trains that use it to accelerate. The energy storage system will allow the TTC to use energy that would otherwise be burned off as heat. Partners: Toronto Transit Commission, City of Toronto’s Environment and Energy Division, PowerON. 

Since its inception in 2005, the IESO's Grid Innovation Fund has supported more than 260 projects, taking innovative ideas from the sector that can enhance reliability, sustainability and resiliency of the provincial electricity system. A third-party analysis of 27 past innovation projects showed that if those technologies were adopted more widely across the province, they could reduce system and customer costs by half a billion dollars.