Electric buses are not new. They're not even new to Toronto. The TTC operated electric buses along central Toronto streets briefly in the 1920s and then again continuously from 1947 until 1992.

But those were trolley buses—drawing electricity from overhead wiring like streetcars do.

TTC trolley bus on Bay Street, 1980sTrolley buses on Bay Street, 1980s. Image: John Calnan, Transit Toronto

Batteries power the new generation of electric buses (or "eBuses") and the TTC is in the process of buying them. eBuses, not surprisingly, produce no tailpipe emissions and reduce greenhouse gas emissions by about 149.2 tons of CO2 per bus per year—an annual total of 8,952 tons.

The City of Toronto’s TransformTO Climate Change and Clean Air Action Plan targets reducing greenhouse gases 80 percent by 2050 from 1990 levels.

Supporting the City's commitment, in November, the Toronto Transit Commission—the TTC's board of directors—approved an ambitious target of acquiring only zero-emission buses by 2025. This commitment lines up with the C40 Cities Fossil Fuel Streets Declaration. C40 is a network of the world’s megacities that have committed to addressing climate change. Signatories of the declaration include the mayors of Paris, London, Los Angeles, Toronto, Montreal, Vancouver and 34 other major cities. Several have pledged to operate all-electric buses by 2040, including New York, which has the largest bus fleet in North America. With the TTC buying only zero-emission buses after 2025, Toronto would also have an all emission-free fleet by the end of 2040.

BYD electric bus featuresFeatures of BYD's electric buses, image: BYD, TTC

The board also gave the go-ahead to buying 30 eBuses and the appropriate supporting infrastructure to maintain the buses and recharge their batteries during that November meeting. The board okayed another 30 this month.

In their June 4, 2018 report to the board, staff explain that the TTC has been an early adopter of new technology in the past. It says that some technologies proved more reliable and more cost-efficient than others. That mix of experience has encouraged it to take "measured steps" to limit risk in acquiring eBuses. According to the report, adopting technology too fast can result in decades of poor system reliability, low passenger and operator satisfaction, and a higher cost for maintaining and operating the vehicles.

New Flyer electric bus featuresFeatures of New Flyer's electric buses, image, New Flyer, TTC

However, since the TTC also operates the largest bus fleet in Canada and the third largest in North America, it has a role to play in advancing technologies that promise to significantly improve safety, the environment and vehicle reliability, lower life-cycle costs, and focus on passenger service.

The transit agency is buying eBuses from three different manufacturers to test their performance in regular service conditions on Toronto streets:

  • BYD, a Chinese company with a North American plant in California;
  • Winnipeg-based New Flyer; and
  • Proterra, a US company.

Proterra electric bus featuresFeatures of Proterra's electric buses, image, Proterra, TTC

BYD (BYD stands for "build your dreams") is the world’s largest manufacturer of all-electric buses, having delivered more than 25,000 electric buses worldwide. It is the only eBus manufacturer that develops and produces its own battery technology. The TTC proposes buying BYD's K9M 40-foot (12-metre) model with a 425-kiloWatt-hour battery. The on-board battery uses lithium iron-phosphate chemistry batteries that are 100% recyclable.

BYD’s charging interface differs from other eBus charging equipment in that it converts AC (alternating current) to DC (direct current) on-board the vehicle instead of at the charging point. This feature makes charging possible with little additional infrastructure. The TTC says that using 90 per cent of the 425-kWh battery capacity provides a driving range of 310 kilometres but takes about 4.5 hours to recharge.

Distribution of eBuses to three TTC garagesThe TTC originally planned to store 10 buses of each type at each of three garagesm image, TTC

The New Flyer eBus is the Xcelsior CHARGE XE 40-footer with a 400 kWh battery. The on-board battery is 100% recyclable. Battery packs are in the engine bay area and roof. This translates to about 3.2 hours to charge. The 400-kWh battery offers a driving range of 280 kilometres.

Proterra’s buses differ dramatically from the other two manufacturers. The company has designed them "from the ground up" as electric vehicles. Other makers must work within the constraints of a design for diesel-propulsion systems which requires them to place heavy high-voltage batteries in multiple locations (typically in the engine bay and on the roof). Proterra buses use a lightweight carbon fibre-reinforced composite body with the battery below the floor.

The bus requires a charge time of less than three hours and supplies a driving range of 400 kilometres. The company recently announced that it was producing Catalyst 40-foot buses for the TTC.

Updated distribution of eBuses to three TTC garagesThe TTC has updated its plans to include 20 buses at each site, image, TTC

The electric bus industry does not produce standardized charging ports, charging port locations, plugs or receptacles. BYD, for example, uses a unique system that includes an on-board inverter and a receptacle particular to its buses. Proterra and New Flyer use receptacles that the Society of Automotive Engineers has standardized, with the inverter as part of the external charging station. Lack of standardization between bus manufacturers, and a limit on the number of buses that can be charged at any one garage, led to the TTC allocating each of these buses to three separate garages.

In determining which garages should house the eBuses, TTC staff considered several factors:

  • Physical constraints including indoor ceiling heights and available space for chargers;
  • Other major capital infrastructure projects;
  • Location; and
  • Local staff experience with hybrid electric technology.

The TTC's timeline for buying eBuses after increasing the scope of the project, image, TTC

After reviewing all bus divisions, the TTC decided to send Proterra buses to Mount Dennis (near Eglinton Avenue West and Weston Road), store the New Flyer buses at Arrow Road (Jane / Finch West) and make Eglinton (Eglinton East / Warden) home to BYD. Since the TTC stores 20 percent of its bus outdoors, it will also store and charge solely outdoors four of the 10 eBuses at each division to assess environmental impacts. Each model of bus will operate on local routes from each of the three garages.

This month, the TTC board agreed that staff should work with Toronto Hydro on designing and installing appropriate charging infrastructure—for example, chargers and energy storage systems, revising the project budget from $50 million to an estimated $120 million. Suppliers must deliver all 60 eBuses no later than March 31, 2020 while the Government of Canada's Public Transit Infrastructure Fund (PTIF) is still in effect.

Since November, TTC and Toronto Hydro have worked as a team to strategize and design solutions for expanding the zero-emissions fleet. In this month's staff report to the board, the TTC declared that "Technical solutions not clear to the team only six months ago are now mature and reflect an approach to the charging infrastructure that is modular, resilient, and capable of being scaled up to fleet wide implementation." In November, staff reported that the limit for any one garage was 10 eBuses. The report continues, "However we now understand that with an ESS, the limit can be extended to a maximum of 20". (An ESS is essentially a large battery system to help manage peak loads and spread the charging window without exceeding the operational / infrastructure limit.)

Future-proofing garagesThe TTC wants to "future-proof" all garages to prepare for a variety of "clean" technologies, image, TTC

In partnership with Enbridge, staff are also studying gaseous fuels to determine the cost and time for modifying garages, shop, and stations to accommodate compressed-natural-gas (CNG) -powered buses and or hydrogen fuel cell buses, similar to the hydrail technology Metrolinx is investigating to power GO Transit trains. Later this year, staff will report, recommending courses of action and best practices for the TTC to adopt gaseous fuels to deliver a resilient path from high carbon vehicles to low / zero carbon vehicles.

As the TTC moves towards its 2025 target for zero-emission buses, it's recognizing that continuing to modify garages to accommodate just 20 buses each is inefficient. To stay ahead of its eBus bus purchases and efficiently use resources, it must add electrical capacity by installing substations and back-up generators. The benefits of adding this to the scope of the project now includes the short-term availability of PTIF funding and the fact that the TTC still has to modify all garages starting in 2021 / 2022 regardless whether it uses eBuses or not. Perhaps the most important benefit of expanding the scope is "future-proofing". Whether the future bus fleet consists of all-electric, hydrogen-fuel-cell, CNG, or plug-in hybrid buses—or a mix of these technologies—the transit agency will still require a substation and backup generator.

So the board has also directed staff to further work with Toronto Hydro in modifying one of TTC’s bus garages to accommodate as many as 300 zero-emission (or near zero-emission) buses by supplying a substation and a back-up generator for an estimated project cost of $18 million.

TTC trolley bus on Mount Pleasant Road, 1966TTC trolley bus at Doncliffe Loop, north end of Mount Pleasant Road, in 1966, image, Geoffrey J. Sommers, Transit Toronto

Recognizing that procuring, installing and commissioning a substation requires about two and a half years, staff are to work within the PTIF guidelines to capture as much of the substation procurement cost as possible before the March 31, 2020 deadline. Suppliers must also deliver the back-up generator no later than the deadline to make sure it, too, is eligible for PTIF funding.

Staff are also conducting a garage-by-garage feasibility study at an estimated cost of $2 million to determine total costs, benefits, and potential funding opportunities of the green bus plan, reporting back to the board early next year.

What do you think of the eBuses? You can leave a comment in the space provided on this page, or join in on the conversation in our related Transportation Forum thread.