A University of Utah study explores turning electric bus depots into profitable energy hubs, leveraging solar power to stabilize power grids and reduce emissions.
In a new study, researchers led by the University of Utah have proposed a novel solution to the growing demand on power grids posed by electric buses: transforming bus depots into renewable energy hubs. The study, led by engineering professor Xiaoyue Cathy Liu, suggests that integrating onsite solar power at bus depots could not only meet the increased power demands but also turn these sites into net energy producers.
“Integrating onsite solar power generation and energy storage at bus depots introduces a brand new renewable energy production and management mode, transforming a public transport depot into an energy hub that produces more electricity than it consumes,” Liu said in a news release.
Electric buses offer a trio of environmental benefits: they promote energy-efficient urban density, reduce harmful vehicle emissions and eliminate tailpipe pollution. However, their increasing adoption presents challenges for urban power grids. Cities can quickly roll out electric bus fleets faster than their grids can adapt, risking localized brownouts and other disruptions.
To tackle this issue, Liu and her team examined Beijing’s extensive public transportation system, the largest in the world, with over 27,000 buses. More than 90% of these buses are low- or no-emission vehicles. The researchers used data from 2020, including air temperature and solar irradiance at each of Beijing’s 700 bus depots, to model the potential electric output of solar panels installed on depot rooftops.
“More than meeting demand, our simulations show that these depots could net out to be energy producers, further stabilizing the grid,” Liu added.
The study, recently published in Nature Energy, reveals that bus depots could utilize solar power not only to charge the fleet but also as a means to generate and store surplus electricity. However, the research also highlights the economic complexities involved, particularly regarding the high cost of energy storage solutions.
“We found energy storage to be the most expensive factor in the model, so smarter and strategic charging schedules would need to be implemented,” added Liu. “That responsiveness is critical, as variable energy pricing schemes have such a large impact on the overall economics.”
This innovative approach promises to alleviate the strain on electrical grids, offering a sustainable and economically viable pathway for future public transportation systems worldwide.
The international research collaboration included experts from Beihang University in China, Chalmers University of Technology in Sweden and the Fraunhofer Institute for Systems and Innovation Research ISI in Germany.
As cities worldwide strive to combat climate change, this model presents a scalable solution, enabling other countries to transform their transit infrastructure into self-sustaining energy contributors, setting a precedent for greener urban living.