In just over two years, Amazon has installed more than 17,000 chargers at about 120 warehouses around the United States, making the retail giant the largest operator of private electrical vehicle charging infrastructure in the country, Bloomberg reports.

Amazon has backed Rivian with a massive investment and an order for 100,000 custom-built delivery vans—13,500 of which have been delivered to date. The company has suggested it can eliminate much of the emissions associated with its last-mile delivery business.

According to an October post from Amazon, the Rivian-built vans were making deliveries in more than 1,800 cities in the United States, including Austin, Boston, New York, Philadelphia, and Seattle. The post stated that the vans incorporate “First-of-its-kind embedded technology that fully integrates the delivery workflow with the vehicle, enabling seamless access to routing, navigation, driver support, and more.”

To build its charger network, “Amazon had to learn how to pick up the phone and call the power company. Electric utilities, which to that point primarily dealt with electric vehicles through powering the odd home car charging setup, encountered a new type of customer in Amazon. Government electricity use estimates show a 100,000-square-foot warehouse tucked in an industrial area might be powered by about 50 kilowatts, mainly for lighting and air circulation. Setting up 100 chargers in the parking lot could require 10 to 20 times as much power,” according to Bloomberg.

The Bloomberg article notes that UPS and FedEx have also rolled out their own ambitious electric vehicle targets. Amazon itself had to back away from a vow to make half of all deliveries with zero carbon pollution by 2030.

Read more lessons learned in the full article from Bloomberg.