Commercial fleet expansion is driving innovation in charging infrastructure, with speed, volume and reliability as the top goals. Proterra’s next-generation charging system helps transit and fleet operators, big and small, to meet these demands

In the drive to achieve 100% clean transportation, fleet electrification and charging infrastructure presents a complex challenge for many operators.

Proterra’s new line of charging infrastructure features five units: the biggest, which produces 1.5 megawatt (MW) of power, is designed for large-scale fleets and allows for shift charging of up to 40 vehicles and 20 vehicles simultaneously. The four other charging systems are designed to power fleets of up to 10 vehicles, with power output ranging from 75 kilowatt (kW) to 500 kW.

“Cities, states, schools, airports and many more are going all in on zero-emission transportation. Large-scale charging infrastructure will play a vital role in achieving important transportation electrification goals,” said Proterra CEO Jack Allen in announcing the company’s new charging solution. “Proterra is excited to work with Power Electronics to help fuel this transition with our new, next-generation charging systems.”

Reliability and versatility

Proterra’s new systems boil down to two guiding tenets: versatility and reliability.

“Large-scale charging infrastructure will play a vital role in achieving important transportation electrification goals”

Jack Allen, CEO, Proterra

Building on learnings from previous generations of chargers, Proterra says this new line of products is more compact, lower cost, includes higher power options and is designed to achieve 99.5% availability, making it more reliable overall.

The higher power rates result in faster charge times, enabling Proterra’s ZX5 electric transit bus to charge almost 20% faster than with their previous charging systems. Every unit except the single 75kW charger has simultaneous charging capabilities with multiple plug-ins.

The latter underscores the other critical feature of Proterra’s fleet chargers — versatility. The ability to create different charging configurations within the units is baked into the product’s DNA.

With more options, fleet operators have more flexibility. For instance, customers can mix-and-match charging configurations using a combination of plug-in and overhead chargers to deliver up to 1.5MW of power to charge their vehicle fleets.

A 1.5MW system is capable of simultaneously powering 20 vehicles at 75kW each, 10 vehicles at 150kW, or three vehicles at 500kW. Using a combination of simultaneous and sequential charging, the 1.5 MW system could power up to 40 vehicles. Procuring and installing one system can also help bring down the costs of hardware and installation for a more cost-effective solution than buying individual charging units.

Redundancy is also key to the exceptional reliability. The charging systems are designed so that should one power module fail, the others will be able to keep operating.

An eye on “future proofing”

As fleet operators look toward a future of fully electrified vehicle fleets, Proterra’s new charging solutions provides a flexible and scalable solution to help meet transportation electrification needs today and tomorrow.

The scalability of Proterra’s fleet chargers also extends to the number of charging modules within the unit. For instance, a fleet operator doesn’t need to fully stock the whole unit if their fleet doesn’t require that many chargers. Instead they are able to add additional modules to their base order on an as-needed basis, which allows “future proofing” for the customer as they grow their fleets of zero-emission vehicles.

Likewise, the charging system’s DC/DC configuration means it can essentially serve as a central node for solar and energy storage integration.

In addition to having customized system configurations, Proterra’s charging units are equipped with bidirectional vehicle-to-grid (V2G) features to take advantage of additional emerging benefits of EVs. The ability to integrate with renewable energy generation offers the potential for further cost savings.

The 1.5MW fleet charger is also able to tie directly to the grid without the need for a transformer thanks to its “medium voltage” capability — a unique cost-saving feature of the unit and a space saver in already crowded fleet yards.

Full-suite solutions

With fleets starting to go electric on a large scale, flexible and powerful charging solutions like these are essential to helping them meet their goals.

Proterra’s comprehensive offering includes not only these new systems, but also the services of Proterra Energy. With Proterra Energy fleet solutions, the company takes care of designing and building charging infrastructure all the way through to energy management and infrastructure financing.

“Proterra Energy goes beyond just providing a charger,” said Andre Lalljie, Vice President of Energy at Proterra. “It’s a full suite of products and services in-house from Proterra that makes the transition to electric as easy as possible for our customers.”