2022-10-12
Antonio Garcia, Mechanical Engineer. May 2023.
Recently, the Center for Information Technology Research in the Interest of Society (CITRIS) and the Banatao Institute hosted University of California, Merced professor, recipient of a F3 Challenge Grant, and CITRIS Seed Fund Ricardo de Castro. On October 12, 2022, he discussed his newest endeavor: “Electric Propulsion in Agriculture Vehicles: Opportunities and Challenges.” Dr. de Castro dove into the pressing issue of the emission rates of diesel tractors.
As an undergraduate studying mechanical engineering, I have studied the emission rates and the overall inefficiencies within the diesel cycle. Seeing what I study being applied to real world scenarios was not only motivating but made me question personal career choices. CITRIS is a fully functioning research unit with the University of California, Merced with heavy student driven initiatives. CITRIS here at UC Merced addresses California’s most pressing societal and environmental problems by leveraging cutting-edge technologies, developing novel research, and conducting inspiring outreach. These research exchange events gave Dr. de Castro a platform to show all the challenging work he has done on advancing electric propulsion within agriculture.
In his talk, Dr. de Castro discusses how an electric powertrain has efficiencies greater than 90% while its diesel counterpart sits anywhere from 35-45% efficient. As explained by the automobile company, Kia, a powertrain is “an assembly of every component that pushes your vehicle forward.” Most inefficiency stems from friction and the heat generated during operations. Additionally, Electric powertrains also provide a quieter operation environment while the diesel powertrains are loud enough that the CDC says, “if an individual exposed to such an environment for even five minutes. The said individual is susceptible to permanent hearing damage and loss.” Dr. de Castro elaborated on maintenance between the two powertrains and the electric option comes out on top as the cheaper alternative. With all these overwhelming stats it poses the question; why are not all tractors electric already? Dr. de Castro explains that there are a few major limitations with electric.
Diesel powertrains are overall more efficient when it comes to harder and longer days whereas electric is only most viable in light work scenarios. This is in part to the size of battery, the cost of recharging, and the cost of a battery replacement. There is a limit of how big the battery can be because if it is too large the tractor could have a gross weight large enough that damages the soil because of the pressure induced by the tractor. As it stands currently, farms also do not have the infrastructure to support the charging of batteries.
However, Dr. de Castro gave multiple options and scenarios to combat the challenges of electric farm vehicles. Cutting the standard operation time down from eight hours to just four hours a day would make electric more viable – primarily since the load of a four-hour day is much less than that of an eight-hour day. Farmers are already looking for ways to reduce operation times to help lower fuel costs. Dr. de Castro adds that the cost to recharge these batteries is getting cheaper. Soon the price difference between gas and electricity will be cost effective enough to start utilizing electric tractors. In my opinion, the most important development is that only 0.5% of the crop area here in California needs to be covered in solar panels to produce enough power to support all the tractors here in California.
Dr. Castro acknowledges that these new concepts and technology are challenging to implement. However, he has been developing comparison matrixes with simulations that will help the everyday farmer pick the right tractor fleet. Whether that is diesel, electric or even a hybrid.
For those interested, Dr. de Castro’s presentation is uploaded to the CITRIS YouTube channel for everyone to see.