Improving batteries so that they can carry large loads for long distances is a challenge. Heavy batteries can take a toll on efficiency, as they have to draw on their own power to move themselves, as well as the vehicle.

Tesla plans on cutting its teeth on this issue by launching its electric semi-truck in September, although experts have questioned how they will achieve this. According to a paper published this year by academics at Carnegie Mellon University, a battery powerful enough to drive a semi-truck 600 miles would require a battery that weighs more than the cargo, due to federal regulations limiting the gross weight of trucks to 40 tons.