Read: Electric School Bus Financing: Making Fleet Transitions Operationally Sustainable for the Long Haul
Now Made in America: Proterra Turns to U.S.-Built EV Batteries
Proterra announced a new U.S.-sourced battery cell option for its Onyx platform, boosting domestic content by more than 600% and strengthening EV supply chain resilience for commercial vehicle OEMs.

The announcement comes as Proterra invests in localizing and de-risking battery materials and components, it said.
Proterra
Proterra's Onyx battery platform will soon be available with a U.S. cell option, with shipments beginning in Q1 2027. The move reflects the company's commitment to American manufacturing and helps position partners for supply chain resilience and regulatory compliance.
This update also increases domestic content sourcing to support evolving customer, regulatory, and end-market requirements.
“The market is asking for greater supply chain certainty and stronger domestic content. We’re answering," said Chris Bailey, CEO, Proterra. "This investment ensures we can deliver both while continuing to lead in performance and safety.”
Proterra’s decision to expand the Onyx platform to include a U.S. cell option addresses growing OEM demand for battery solutions with stronger domestic content and supply assurance. As procurement requirements, customer preferences, and regulatory frameworks evolve, Proterra is strengthening a U.S.-anchored supply chain through investments like the U.S. cell option and other strategic sourcing initiatives.
According to the announcement, Proterra is investing in onshore and nearshore critical battery pack and module components, as well as other major internal subsystems. This strategy is designed to reduce disruption risk, diversify geographic dependency, and support scalable production, delivering supply continuity, greater cost stability, and long-term reliability for OEM partners and their customers.
Taking orders now, with availability in Q1 2027, Proterra’s broader onshoring effort, anchored by U.S. cell, will increase American content by over 600%. This significant milestone builds directly on the company’s U.S. footprint, including its technology center in Burlingame, California, and battery manufacturing facility in Greer, South Carolina.
The move aligns with Buy America and Build America, Buy America (BABA) requirements.
Check out our interview with Proterra from this year's ACT Expo:
Proterra’s Onyx modular battery platform is used by heavy-duty equipment OEMs, offering high energy density, durability, and an advanced safety architecture. Its batteries are used in Thomas Built Buses' Jouley and Wattson.
More Alternative Fuels

Bipartisan Bill Seeks to Extend Clean School Bus Program Through 2031
The proposed legislation would renew federal support for cleaner school buses as districts navigate funding uncertainty, rising fuel and infrastructure costs, and fleet replacement needs.
Read More →
Alt-Fuel Moves: Electric Bus Rollouts, Bidirectional Charging & Propane Growth
See which fleets are adding electric and propane school buses as districts and operators invest in charging infrastructure, bidirectional technology, and alternative-fuel expansion.
Read More →
Nobody Told Diesel Prices They Were Supposed to Come Down
With diesel prices surging, school bus fleets have new reason to stress-test fuel costs, consider diversification, and calculate what each route really costs to operate.
Read More →
Why Gasoline School Buses Are Making a Comeback
Gasoline is gaining ground in full-size school buses. See how today’s options stack up against diesel on cost, maintenance, emissions, performance, and more.
Read More →
EPA Opens $180M DERA Funding Round for Diesel Upgrades
The 2026 Diesel Emissions Reduction Act program seeks applications from eligible organizations to accelerate the retirement of legacy diesel vehicles.
Read More →
The Secret Life of an Electric School Bus Battery
Batteries change throughout years of daily routes, but degradation doesn’t necessarily mean the end. Here’s what operators should know about performance, safety, and second life.
Read More →
CALSTART and Forth Combine to Form Catalyst Mobility
The new name represents a renewed vision for the nonprofit focused on advancing clean, equitable, and affordable transportation solutions that move people and goods.
Read More →
Alt-Fuel Moves: New Buses, Charging Hubs & Real-World EV Testing
Propane and electric school bus deployments continue to grow as districts add new vehicles, expand charging infrastructure, and gather more real-world operating data.
Read More →
Fewer Electric School Bus Models Reshape the U.S. Market
WRI’s latest buyer’s guide points to a consolidating electric school bus market, but fewer options may reflect a maturing industry rather than fewer meaningful choices for school bus operators.
Read More →
The Fuel Budget You Can Actually Predict: How Propane Autogas Keeps Money in the Classroom
Learn how propane autogas helps school districts manage fuel costs with predictable pricing, lower maintenance, and reduced emissions from former transportation director Joel Stutheit.
Read More →
