• Amazon has begun testing electric delivery vans from Rivian on routes in Los Angeles.
• Amazon agreed to buy 100,000 Rivian electric vehicles as part of its pledge to achieve net-zero carbon emissions by 2040.
• Rivian has raised about $8 billion since 2019 from investors including Amazon via its $2 billion Climate Pledge Fund.

Amazon is testing some of the electric delivery vans that it developed with Rivian Automotive on routes in Los Angeles, the companies announced Wednesday.

In September 2019, Amazon announced it would purchase 100,000 electric delivery vehicles from Rivian as part of its aim to achieve net-zero carbon emissions across its operations by 2040. Amazon started a fund, and invested in Rivian through it, as part of this pledge.

The e-commerce titan debuted one version of its delivery vans in October last year. Now, Amazon says it will test the custom electric vehicles in as many as 16 cities in 2021.

In a statement sent to CNBC, Ross Rachey, director of Amazon's global fleet and products, said the electrification effort is a point of pride for the company. It has required Amazon to install thousands of electric-vehicle chargers and change up the electrical design and layout of delivery facilities in North America and Europe.

The company built the test-fleet vehicles for Amazon in Plymouth, Michigan. Each van can drive up to 150 miles on a single charge, the companies said.

The vehicles are still in a test phase, and their design and features could be tweaked ahead of the start of production, which Rivian aims for by the end of 2021.

Rivian is also expected to be among the first companies to bring an all-electric pickup to market later this year.

While it is still privately held, Rivian is shaping up to be a serious challenger to Tesla and has raised about $8 billion since 2019. 

Light-duty trucks including delivery vans are expected to be in demand in the U.S. in coming years, and not just by Amazon. That's in part because President Joe Biden, through his Buy America plan, has committed to replacing the federal government's fleet of internal combustion engine vehicles with cleaner, quieter electrics.

According to data from the General Services Agency, that federal fleet includes more than 400,000 trucks, many of them for use by the U.S. postal service. Daimler, GM,Lion Electric and others are developing, and in some cases already selling, battery-electric light-duty trucks and vans.

Correction: An earlier version of this story misstated the location of Rivian headquarters. The company moved from Michigan to Irvine, California, in 2020.