FedEx has penned a reservation for 20 Tesla Semi trucks to be used by their FedEx Freight division. FedEx has a track record of striving for efficiency and has made use of alternative energy sources such as natural gas, hybrids and other clean technologies.
https://about.van.fedex.com/newsroom/fedex-reserves-20-tesla-semi-electric-trucks/
https://about.van.fedex.com/newsroom/fedex-reserves-20-tesla-semi-electric-trucks/