Comparative Evaluation of Energy Efficiency and Performance of Electric and Counterpart Diesel Tractors

The objective of this trial was to compare the energy efficiency and performance of battery electric against conventional diesel tractors. Controlled road tests replicating normal operations were conducted using two electric and two diesel day-cab tractors. The test protocol was based on the TMC - Type III RP 1103A and SAE J1526 test procedures. The tests were conducted on a 110 km long route that included a 59 km hilly portion with a maximum altitude difference of 307 m. The tractors were divided into test groups of two vehicles. Trailers and drivers were switched throughout the trial between the tractors in a test group. The tests found that the two electric trucks consumed 61% and 64% less energy than their counterpart diesel trucks, respectively. Considering the production mode of electricity in Canada, the electric trucks emitted on average 82% less GHG emissions than the conventional diesel-powered tractors. The two diesel trucks showed virtually identical fuel consumption and GHG emissions. The difference in electric energy consumption and GHG emissions between the wo electric trucks was 7%. Energy and fuel consumption by route section was determined based on data from the vehicle electronic control modules. The trucks that showed the highest energy efficiency on the complete test route, also demonstrated the highest efficiency on specific sections of the test route. The regenerative braking system of the electric trucks charged the batteries with a regeneration ratio up to 38% on the descending section. Observations from drivers and observers were collected during testing. Generally, drivers would not hesitate to use the electric trucks especially if operability and battery range were improved. The driving experience with electric trucks was rated better than with diesel trucks.