DURHAM, N.C.—Jackson Floum, Yingyu Fu, Alexander Yoshizumi and Liyue Zhang (MEM’19) worked together to research an energy challenge in public transportation for their Master’s Project (MP).
They worked with the Environmental Defense Fund and the N.C. Clean Energy Technology Center to assess more sustainable public transportation for North Carolina’s rapidly growing Research Triangle region, where transportation options are largely fossil-fuel powered.
Much of their project focused on working closely with GoTriangle to assess the feasibility of using battery electric buses.
An MP combines the academic rigor of a thesis with the practical experience of an internship.
Working singly or in groups, students apply skills and knowledge they’ve acquired in the classroom to tackle real-world environmental challenges for real clients through a well-formulated and defensible analysis. It is a culminating experience for all Master of Environmental Management (MEM) and Master of Forestry (MF) students at the Nicholas School of the Environment.
Duke Environment recently corresponded with Yoshizumi, who is pursuing his MEM in energy and environment, to discuss the goals and key findings of their MP as well as how the findings could aid further research and conservation efforts.
What is the goal(s) of your MP?
“The overarching objectives of our MP were to assess whether GoTriangle might be a good candidate for battery electric bus implementation and how GoTriangle might best implement battery electric buses. More specifically, we attempted to answer four primary questions:
1. “How will battery electric bus implementation impact the demand for power and grid emissions?
2. “How do battery electric buses compare to diesel buses with regard to well-to-wheel lifetime emissions?
3. “How suitable are each of GoTriangle’s route planning units for battery electric buses?
4. “How might GoTriangle best implement battery electric buses to promote human health and environmental justice in the Triangle?”
What challenges did you encounter with your work?
“For me, a major challenge was creating a Python-based tool that modelled the distribution of emissions based upon time-location data from GPS units on top of the buses. I had worked extensively with ArcGIS, but performing geospatial operations in Python was a new experience and involved learning quite a few new programming packages. I’d like to give a big thank you to John Fay and his Advanced GIS course, which helped me frame my scripting workflow and refine my tool.
“In addition to just creating the tool, it was difficult to define the scope of its operation. I think that is a universal challenge with all of the work that we do at the Nicholas School: accepting limitations of both our data and our methods and learning to make the most from what we do have.”
What are the key findings of your MP?
“In all, GoTriangle appeared to be a fairly good candidate for battery electric bus implementation:
* “Increased demand to the grid would likely be negligible from a transmission point-of-view.
* “In maximum fuel-economy scenarios based upon Duke Energy’s integrated resource plan, it appeared that battery electric buses would contribute less emissions in every category as compared to diesel buses. Though, it should be said that comparatively larger contributions of some air pollutants were observed in electric bus implementation in minimum-fuel-economy scenarios.
* “Many bus route legs – the smallest planning unit used in route optimization – appeared to be good candidates for implementation based on physical characteristics we know would impact energy consumption (elevation change, number of stops, number of intersections, etc.)
* “Route legs located near and around Raleigh were found to be some of the most optimal options based on their physical properties and comparatively greater potential to mitigate human exposure to criteria pollutants.
Are your findings a model or baseline that could be adopted by cities similar to Raleigh or Durham?
“I believe so, yes! I think our methodologies definitely provide a framework for thinking about battery electric bus implementation beyond the Triangle.
“Certainly, the specific techniques that we used would need to be amended slightly for other regions based on data availability and regional variation, but I do believe the methodological approach could be extended to other municipalities.
“As it happens, I am planning to work with EDF’s Office of the Chief Economist this summer to apply some of our research methods towards evaluating the suitability of battery electric bus implementation in Houston, Texas.”