By Ashwini Sakharkar 6 Nov, 2024
Collected at: https://www.techexplorist.com/transforming-electric-bus-depots-profitable-energy-hubs/91997/
Transportation is undergoing rapid electrification, with electric buses at the forefront of public transport. In the fight against climate change, electric buses offer multiple advantages – they promote energy-efficient urban population density, reduce the number of polluting vehicles on the road, and produce no tailpipe emissions.
However, the rising popularity of this solution creates its own difficulties – cities can roll out electric buses more quickly than their power grids can accommodate the increased energy demand.
Xiaoyue Cathy Liu, an engineering professor at the University of Utah, is taking this challenge as an opportunity—not only to address the pressing issue of grid stability but also to fundamentally rethink the integration of public transportation systems with other elements of civic infrastructure.
“Integrating onsite solar power generation and energy storage at bus depots introduces a brand new renewable energy production and management mode,” Liu said, “transforming a public transport depot into an energy hub that produces more electricity than it consumes.”
In a new study, Professor Liu, in collaboration with experts from Beihang University in China, Chalmers University of Technology in Sweden, and the Fraunhofer Institute for Systems and Innovation Research ISI in Germany, has revealed the potential benefits of integrating solar power into Beijing’s electric bus system.
Beijing’s extensive fleet of 27,000 buses not only represents the largest public transportation system globally but also showcases over 90% of its vehicles as low- or no-emission by 2022. These electric buses are charged at a network of more than 700 depots, covering an area of 6,500 square miles, which serves as a significant piece of infrastructure that operates alongside the region’s electrical grid.
Due to the high power requirements of the buses, these depots significantly burden the grid, increasing the risk of localized brownouts or other interruptions.
Utilizing advanced data science techniques, Liu and her team are investigating whether solar power generated locally could adequately offset this demand. Importantly, they are also analyzing the complex economic factors that will influence the feasibility of this approach.
“More than meeting demand, our simulations show that these depots could net out to be energy producers, further stabilizing the grid,” Liu said.
The research utilizes a sophisticated computer model of the Beijing bus network, integrating real-world data concerning air temperature and solar radiation at each depot collected throughout 2020.
By combining this information with the rooftop area at each depot, the researchers could forecast the energy production from potential solar panel installations. The model addresses the variations among depots regarding energy supply and demand. Busier depots with a higher number of buses can maximize their solar energy intake on sunny days, while more remote depots face the challenge of storing or redistributing excess electricity to prevent waste and increase efficiency.
“We found energy storage to be the most expensive factor in the model, so smarter and strategic charging schedules would need to be implemented,” Liu said. “That responsiveness is critical, as variable energy pricing schemes have such a large impact on the overall economics.”
The researchers plan to refine their model further to offer other countries a robust framework for evaluating the return on investment in transforming bus depots and similar civic infrastructures into sustainable energy hubs.
Journal reference:
- Xiaohan Liu, Patrick Plötz, Sonia Yeh, Zhengke Liu, Xiaoyue Cathy Liu & Xiaolei Ma. Transforming public transport depots into profitable energy hubs. Nature Energy, 2024; DOI: 10.1038/s41560-024-01580-0
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