Foothill will also be building off of the success of the full electrification of Route 291, currently serving more than approximately 700,000 annual riders.

The proposed facility, to be located in the San Gabriel Valley, is expected to be operational by the fourth quarter of 2015 and will create more than 70 new local jobs. During the grant term, Proterra plans to manufacture an estimated 424 buses , resulting in a reduction of 900 million pounds of CO₂ over the lifetime of those vehicles. Proterra was the only bus provider selected for CEC funding.

Proterra selected the San Gabriel Valley as an optimal location to serve existing and future transit customers throughout California. The manufacturing facility will benefit economically distressed communities throughout the San Gabriel Valley. Proterra suggests that implementing the California Zero-Emission Public Transit Bus Manufacturing Project will help further lower production costs, reduce the upfront cost of zero-emission buses and accelerate widespread deployment and adoption. The project will bring in $5,411,352 in private investment to match the $3,000,000 Energy Commission investment, for a total project budget of $8,411,352.

Matt Horton, Proterra’s Vice President of Sales and Marketing, said that the construction of the second plant will help ease the current 18-month backlog Proterra is in its Greenville facility.

Proterra refers to its Catalyst bus as a platform for the electrification of transit systems. This is currently manifested with the two configurable versions on sale: the original FC version, designed for fast charging with a shorter range, and the new XR version with a different battery pack for extended range.

• Proterra’s TerraVolt FC fast charge battery options (lithium titanate, LTO chemistry) allows for maximum run time with minimum dwell time. This system can be recharged on-route in less than ten minutes with a 500kW charge rate. Fast charge configured buses can also be charged in-depot to take advantage of off-peak charging times. Proterra has demonstrated that this option can travel more than 700 miles in 24-hour period.

• The new Catalyst XR Extended Range product uses an NMC higher energy density pack, said Horton, allowing flexibility in the deployment of electric buses on routes of all types. The XR is compatible with the fast charging equipment (although the charge will not be as quick as with the FC); full charge recovery can be accomplished in less than 90 minutes.

With these options, customers now have the ability to carry between 53 kWh to 321 kWh of energy storage, and the option to charge on-route or in-depot. Once customized, operators can easily reconfigure battery packs to meet evolving service needs.

Proterra uses industry-standard modules which it assembles into packs for the bus. All the batteries are underneath the body of the bus, which is the same bus, except for the battery type. With the design of the Catalyst, operators could theoretically switch out battery packs, converting an FC Proterra bus to an XR version, based on their needs, Horton said.

Proterra’s TerraFlex Energy System features configurations of 4-10 battery packs with plug-and-play interoperability between battery types. With this system, the Catalyst buses are upgradeable to leverage advances in battery technology, and offer great flexibility in fleet deployment based on route needs. Click to enlarge.

We can really maximize the configuration for a given customer. We can find the right balance of onboard energy storage versus charging opportunities; no more batteries than needed. This is a mind-expanding exercise for a lot of our customers. They are not used to the number of options.

Today, from the battery packs that we’ve developed, we can already serve 85% of the transit routes out there. What we have really focused on is not maximizing range, but smart range: the optimum mix between putting energy storage on the bus and taking enroute charging. There are a lot of customers who unfortunately tend to want to overload vehicles with too many batteries. A lot of what my team does is to work with customers to plan out they best way to serve their routes with EVs. There is a continuum. On one hand, you can put almost no energy storage on board and use a 500 kW fast charge to charge at a very, very high rate for a short duration, then on the other hand a more traditional model with big battery packs where you load up over night with all the energy for day. For most customers, neither of those extremes is the most efficient, it’s somewhere in the middle.

—Matt Horton

Proterra has developed an in house capability with simulation models to take data inputs from customers and then project with very high fidelity how differently configured vehicles would perform on routes. An online configurator begins the process.

Horton said that Proterra has had a very strong first quarter in terms of orders, logging more during those three months than in all of 2014. The transit agencies with which he speaks largely are on board with electrification, he said; the question comes down to timing and funding. Although Proterra has had customers purchasing buses using local funds only, most take advantage of FTA (Federal Transit Administration) funding. (The FTA funds pretty close to 80% of most capital purchases for buses across the country, Horton noted.)