The first batch of trucks will be tested in Atlanta, Dallas and Los Angeles and based on their performance, the vehicle design will be tweaked ahead of a larger deployment sometime in 2019. "This innovation is the result of Workhorse working closely with UPS over the last four years, refining our electric vehicles with hard fought lessons from millions of road miles and thousands of packages delivered," Workhorse CEO Steve Burns said in a statement. UPS has previously worked with Workhorse on a delivery truck equipped with drones that can take over the last delivery step.

UPS has a number of environmental goals it's aiming to hit in the near future, including a 12 percent reduction of its greenhouse gas emissions within the next seven years. While the company has around 108,000 package cars, vans, tractors and motorcycles on the road, it has over 9,000 alternative fuel vehicles currently in use. Last year, UPS reserved 125 of Tesla's electric semis and began converting 1,500 of its New York-based diesel trucks to all-electric systems.

UPS says it has around 35,000 trucks in its fleet that are comparable to the Workhorse-designed vehicles, meaning a good chunk of its fleet could in theory be replaced by the all-electric trucks. By 2020, it aims for a quarter of its newly purchased vehicles to be advanced technology or run on alternative fuel.