While I always enjoy looking back at some of the classic motor coaches from the Golden Age of bus transportation, its also good to look forward to see where mass transit may be heading. A few months ago we reviewed current and future trends in bus propulsion technology; CNG, Hydrogen, and Battery Electric. We concluded that battery-electric would likely become the dominant player. Here’s an example supporting that view – the Proterra battery-electric urban transit coach.
Proterra was launched in 2004 and introduced its first 35 ft battery-electric bus in 2008, the Ecoliner BE35. It’s an innovative design, using carbon fiber and other advanced composite materials for a majority of is structure, resulting in a very light curb weight.
Additionally, like some older bus designs, it has its engine, transmission, and other control functions in one power pack unit that can be easily removed and replaced for service and maintenance.
Like every electric vehicle manufacturer from Detroit Electric to Tesla, Proterra had to address the two major hurdles with this type of motive power; battery capacity (as expressed in range) and recharging cycle time. These initial BE35 models have a nominal range of around 146 miles – adequate for shorter lines, but not for a regular urban route which averages around 300 miles in a typical 18 hours of operation. Additionally, recharging requires 3 – 5 hours, which means the bus has to be taken out of service. As a result, initial sales were slow – Foothill Transit of Pomona CA purchased three BE35’s in 2009, ten were sold to five different operators in 2011, nine in 2012, and eleven in 2013.
But things brightened considerably beginning in 2014 – the company hired a new CEO, Ryan Popple, who was previously the Chief Financial Officer for Tesla. Additionally, the company’s R&D efforts began paying dividends – a new 40 foot model was introduced named the Catalyst XR. This model has both an extended range, 258 miles, and a new fast-charging system. In turn, total 2015 sales reached sixty-two coaches to 13 different operators.
In 2016, an updated Catalyst, the E2, was brought out with the longest range of any battery-electric coach – 358 miles on a typical urban transit route. In addition, a further refined fast charging system permits a 26% recharge in only five minutes and a full charge in less than an hour and a half.
In January of this year the company built its 100th bus, and more importantly has another 200 orders on its books. It forecasts that by 2020 every major urban transportation operator will have a portion of its system operating on battery-electric, with 50% of all new bus sales being electric by 2025. Those figures may seem optimistic, but the numbers are compelling; typical real-world MPG for diesel, CNG and hybrid transit buses are, respectively, 3.8, 3.3, and 4.6. A 2016 study of 12 Proterra buses in use by Foothill Transportation of Pomona over 400K miles showed a power usage rate of 2.15kWh per mile which translates to 17.48 mpg equivalent.
Bus prices are coming down also as the manufacturing process becomes more mature and efficient. Early Proterra models were $1 million each – that price has dropped to $800K. Comparable diesel/CNG/hybrid models start at $300K on the low end, up to around $600K. As we’ve mentioned before, the Federal government provides grants that fund about 80% of the cost of new capital purchases – plus additional federal subsidies are given for zero emission models.
BYD K9 Battery-Electric Bus in testing service with MTA of New York
But there are competitors – coach manufacturers in Europe and the US are also pursuing battery-electric models. The Chinese company, BYD, however is on par and in some aspects ahead of everyone else – to date they have built over 4000 battery-electric buses worldwide, and have a new US manufacturing facility in Lancaster CA. They also have a range of sizes that include 35, 40, and a 60 ft articulated version. But while BYD has more models and are less expensive than Proterra’s buses, they lack the range and proprietary fast charging system.
My sense is we’re very likely to be seeing more Proterra buses gliding silently along our streets…