The majority of U.S. school buses today are diesel, emitting pollutants harmful to the environment and to kids. Highland Electric Fleets is behind the largest electric school bus project in America, and its founder and CEO says the buses are healthier, quieter, and a cost savings over time. But upgrading is complicated and costly, and uptake is slow. How CEO Duncan McIntyre is trying to make school buses greener, and what's standing in the way.

• Plus: Axios reporters Jael Holzman and Nathan Bomey provide context and a look at what's next.

Guests: Duncan McIntyre, CEO and founder at Highland Electric Fleets; Jael Holzman, Axios energy and climate reporter; Nathan Bomey, Axios business reporter

Credits: 1 big thing is produced by Niala Boodhoo, Alexandra Botti, and Jay Cowit. Music is composed by Alex Sugiura and Jay Cowit. You can reach us at [email protected]. You can send questions, comments and story ideas as a text or voice memo to Niala at 202-918-4893.