ESTIMATING BATTERY SIZE REQUIREMENTS FOR TRACTOR ELECTRIFICATION OF ROW-CROP PLANTING OPERATIONS.

Power sources such as batteries, used for both on-road and off-road vehicles, are advancing at a rapid pace. Electric batteries are becoming more power dense, thus allowing them to be used as a power source to replace previous diesel or gasoline-powered systems. Efforts are underway to transition off-road agricultural vehicles from Internal Combustion Engine (ICE) vehicles to electric vehicles (EVs); however, the energy requirements of typical agricultural field operations need to be fully understood before such a transition can occur. Theoretical prediction equations available in the American Society of Agricultural and Biological Engineers (ASABE) standards or the use of engine load data from a tractor's Controller Area Network (CAN) bus are two methods for determining the energy demands of implements on tractors. In this study, tractor CAN bus data was collected from multiple no-till corn planting operations to estimate the energy requirements of the planting operation in kWh. The estimated energy requirement was used to determine the equivalent physical mass and volume of a lithium-ion battery needed to power a hypothetical fully electric tractor for comparable planting operations. The estimated battery capacities using the worst-case field-use scenario in this study were 1117 kWh for operating a 16-row planter to plant 68 ha (168 acre) in a day at an average ground speed of 8.6 km h-1 (5.4 mph) for 14 hours, and 2658 kWh for operating a 48-row planter to plant 158 ha (391 acre) in a day at an average ground speed of 8.9 km h-1 (5.6 mph) for 15 hours. Given the current battery energy density requirements, the equivalent battery masses and volumes were found to be 5,319 kg and 3.33 m³, 12,657 kg and 7.93 m³, for 16-row planter and 48-row planter, respectively. These high kWh estimates needed to power future fully-electric tractor power units are based on worst-case scenarios that could be encountered in real field operations that use wide planters over long operating hours. [ABSTRACT FROM AUTHOR]