Electric bus maker Proterra is fresh off an important $140 million investment round to expand production and yet, it just announced another (Series 6) $55 million investment round.

Investors include Al Gore’s Generation Investment Management and BMW’s venture capital arm, BMW i Ventures.

Proterra says that they already delivered 380 buses, but the backlog of orders keeps growing.

They will use the money to increase production capacity:

“Proterra will utilize the $55 million to increase production at its manufacturing facilities in South Carolina and Los Angeles, while also bolstering research and development efforts at the company’s headquarters in Silicon Valley. Currently, the company has sold more than 400 vehicles to some of the country’s most innovative cities and communities, including Seattle, Dallas, Nashville, San Jose, Philadelphia and Reno. In addition to its commitment to nationwide growth, Proterra remains focused on attracting the best engineering, design and electric vehicle technology talent from across the country. This dedication to workforce development has helped the company achieve multiple innovation firsts, including its recent launch of the industry’s first autonomous bus development program with the University of Nevada, Reno.”

The company recently hired Tesla’s former Vice President of Manufacturing to lead a production expansion at their facility in Greenville, South Carolina, and their new factory in Los Angeles County in order to satisfy the increasing demand.

Earlier this year, as their latest round of financing was oversubscribed, Proterra disclosed to investors that they were aiming for an IPO within the next year.

Like Tesla, it will be interesting to have a look at the financials of another company solely dedicated to the electrification of transport. Ryan Popple, CEO of Proterra, recently said that electric buses are now cheaper than diesel/CNG and could dominate the market within 10 years. Depending on what we learn when they go public, it could prove an interesting investment. What do you think? Let us know in the comment section below.