When Tesla first showed the Semi in November 2017, many critics doubted that the all-electric Class 8 heavy-duty truck could stick to the payload estimates when reaching production stage.
Fast forward to 2021, and it appears that the Tesla Semi’s payload will be comparable to a Class 8 diesel truck, according to the company’s Impact Report 2020.
There are two main reasons for that: Tesla has made significant advancements in battery technology since 2017, and US and EU regulators have since approved higher weight allowances for heavy-duty electric trucks.
Starting with the latter, Tesla’s Impact Report 2020 states that in the European Union, electric semi trucks are allowed to be 2 tonnes (4,400 lbs) heavier than diesel equivalents, while in the US the allowance is 0.9 tonnes (2,000 lbs).
“With both the US and EU having approved higher weight allowance for electric heavy-duty trucks, we expect the payload to be at least as high as it would be for a diesel truck.”
As for the battery tech, many analysts and experts estimated in 2017 that Tesla would need a 600 kWh to 1,000 kWh battery pack to produce the Semi’s 300-mile (483-km) and 500-mile (805-km) variants. Since a 600 kWh pack weighs about 8,000 pounds (3,629 kg), it would eat into payload as Class 8 trucks have a total weight capacity limit of 80,000 pounds (36,287 kg).
However, Tesla argues it has made notable advancements in battery tech since the Semi’s unveiling, including the introduction of the 4680 battery cells. Since these cells are lighter but have a higher energy density, they could reduce the Semi’s weight, therefore making higher payloads possible.
“When fully loaded, the Tesla Semi should be able to achieve over 500 miles of range, achieved through aerodynamics and highly efficient motors. This truck will be able to reach an efficiency of over 0.5 miles per kWh.”
In the report, Tesla also says it is in the process of developing a Megacharger network at trucking rest stops across the US and Europe where each Semi will be able to top up its range.