United Parcel Service Inc. (NYSE: UPS) has announced it has placed an order for 125 Tesla all-electric semi-trucks. UPS chief information and engineering officer Juan Perez called the trucks “groundbreaking.” The UPS order is the largest known order for the big rig so far, with an order valuation of about $25 million.

Scott Phillippi, UPS senior director for automotive maintenance and engineering for international operations, said the 125 trucks will allow UPS to conduct a proper test of their abilities. He said, “As with any introductory technology for our fleet, we want to make sure it’s in a position to succeed.” Phillippi said the semis will primarily be used in the United States.

Tesla unveiled its semi last month, describing it as an affordable electric big rig comparable in range and cargo capacity with the diesel trucks currently in use. The Tesla trucks will cost around $200,000 each, with the cheapest model expected to cost $150,000 and have a 300-mile range. Conventional big rigs run at about $120,000. Tesla hasn’t talked about freight capacity, but federal law says a fully loaded truck can’t weigh more than 80,000 pounds.

The Telsa truck’s operating costs are estimated to be substantially below those of current diesel trucks. Tesla claims a Tesla Semi owner could save $200,000 in net fuel costs over the vehicle’s lifetime. Current-generation semis get around 6 to 8 miles to the gallon.

Tesla is trying to convince the trucking community to take a chance on its semis. Roughly 940,000 heavy-duty semi trucks are sold around the world each year, 238,000 of them in the United States. Trucks haul 70 percent of the freight in the U.S. and long-haul truckers often travel more than 600 miles a day.

Tesla has received at least 410 pre-orders from companies such as Walmart, Sysco Corp., PepsiCo, and J.B. Hunt Transport Services, according to a Reuters tally. Tesla expects the truck to be in production by 2019. The reservation fees are set at $20,000 a piece.

According to UPS, data on how its trucks function on their real-world routes has been provided to Tesla. Tesla will provide the company with consultation and support on charging infrastructure. The company is planning solar-powered “megachargers” that could get the trucks recharged after charging for only 30 minutes.

UPS previously laid out its plans to expand its fleet of alternative-fuel vehicles. The package delivery company already has an alternative fuel fleet that includes trucks that use electricity, natural gas, propane, and other non-traditional fuels.

Tesla will soon have competition in the electric semi space. Salt Lake City-based Nikola is building a fuel-cell electric semi that is expected to hit the market around the same time as the Tesla truck. Navistar International Corp and Volkswagen AG also plan to launch an electric medium-duty truck by late 2019.