Driving the Future of Sustainable Mobility
In the sustainable mobility space, there is no shortage of innovation. And as the old barriers begin to fall, we must navigate the choices—with a clear eye on the road ahead. For real direction, not detours, we look to the leaders in research.
For 30 years, the Center for Sustainable Systems (CSS) at SEAS has focused on sustainability assessments of products and emerging technologies, and transportation has been a critical part of that research since its inception. CSS led life-cycle analysis research for the U.S. Council for Automotive Research, U.S.-China Clean Energy Research Center Clean Vehicle Consortium, and Lightweight Innovations for Tomorrow (LIFT).
Recent CSS transportation research includes studies of Electric Vehicles (EVs), Connected and Automated Vehicles (CAVs), Vertical Takeoff and Landing Aircraft (VTOLs), vehicle lightweighting, road and charging infrastructure, and automobile circular economy, to name but a few. Among the latest papers published, CSS researchers addressed EV battery degradation and charging strategies, stationary and dynamic wireless charging technology, last-mile parcel delivery by automated vehicles and robots, shared mobility and taxi fleets—as well as the greenhouse gas (GHG) emissions for natural gas vehicles and hydrogen fuel-cell vehicles in China.
So, what are the most viable solutions? CSS Director Dr. Greg Keoleian emphasizes that sustainable mobility solutions must address time, comfort, convenience, safety, cost, and importantly, equity and access.
We asked Keoleian for a quick take on where we’re headed—and which routes are on the fast track to get us there.
Electric Vehicles (EVs)
Keoleian finds that EVs provide the greatest opportunity for improving vehicle efficiency and decarbonizing mobility by shifting the fuel mix of the grid to renewable sources. While EVs represent only 3% of new vehicle sales today, this number could reach 50% by 2030, an aspirational goal of the auto industry. “We need to accelerate the EV transition, and there is over 100 years of inertia and powerful interests behind petroleum and gasoline engines to overcome,” says Keoleian. “That will require scaled-up production of EVs, additional charging infrastructure, and rapid decarbonization of the grid with wind and solar deployment.” He adds that making EVs accessible to low-income households and communities is a critical energy justice challenge to address.
Keoleian relates that battery materials and technology are a key determinant of EV costs, adoption rates, and environmental impacts, and notes that CSS automotive battery studies have ranged from analyzing global lithium supply to developing green principles for responsible battery management. Keoleian adds that dealerships need EV training too, based on his recent experience purchasing a new plug-in hybrid electric vehicle.
Connected and Automated Vehicles (CAVs)
While some of the CAV technology is being applied to vehicles today, such as lane-keeping systems and automatic emergency braking, Keoleian doesn’t expect to see widespread deployment of fully automated vehicles in the next decade. “At CSS, we have found that the sustainability benefits of CAVs from ecodriving, platooning, and intersection connectivity are offset by increasing loads from CAV equipment and computing power,” says Keoleian.
An unintended consequence of CAVs is known as the “rebound effect.” In their 2019 study, SEAS professors, Drs. Ming Xu and Sam Stolper, explored the possibility that automation could lead to a net rise in energy use, especially in higher income groups. This is because automation could change our patterns of where we live relative to where we work, and lead to sprawl. “You may be willing to add commuter miles because you can read the paper or take a nap during your trip,” says Keoleian.
“There are many challenges ahead,” Keoleian notes. “A rapid response to the climate crisis that would meet IPCC 1.5°C GHG emissions reduction trajectories will require perfect alignment of sustainable technologies, markets, policy incentives, and behavior change. All of us will need to play a role, and I am especially encouraged by our alumni working to advance sustainable mobility solutions in the private and public sectors including Ford, GM, Fiat Chrysler Automobiles, Tesla, U.S. EPA National Vehicle and Fuel Emissions Lab, Argonne National Lab, National Renewable Energy Lab, Rocky Mountain Institute, City of Detroit, City of Ann Arbor, and the Biden administration, as well as faculty such as Alissa Kendall (MS ‘04, PhD’ 07) and Hua Cai (PhD ‘15).”
Parth Vaishnav’s POINT OF VIEW
Dr. Parth Vaishnav is a new assistant professor at the Center for Sustainable Systems at SEAS. His research aims to understand how technology can help solve social problems, and he is particularly interested in finding ways to make both mitigation and adaptation equitable.
Vaishnav shares a few thoughts on sustainability issues—from freight to flight, and raises questions of equity and justice.
JUST BETTER VEHICLES
“Electric motors are incredibly durable, and the lifetime of electric batteries is continuously increasing. An electric drivetrain needs less maintenance (e.g., no oil changes). And because you don’t have engine noise or vibration, the ride is more comfortable, and quiet. EVs are also safer—the heavy battery keeps the center of gravity low, with less risk of toppling. The absence of an engine block could improve crash performance. So, beyond the sustainability aspect, I think people are going to conclude that EVs are just better vehicles. And in four to five years’ time, they will also be cheaper.”
ACCESS AND ENERGY JUSTICE
“We have to make sure that the new technology becomes available to everyone, and that we don’t effectively create a regressive subsidy. On its face, the $7,500 federal tax credit on the purchase of some EV models is great. But today, the person who buys an EV is probably relatively well-off, and can wait for that benefit. A more accessible solution might be giving cash rebates at the point of sale, or the option of a substantial rebate on an E-bike, instead.”
“Ultimately, to achieve sustainable mobility, there’s much more to think about than just replacing all the gas-fueled cars with electric cars. We must improve public transit, increase ridership, and further develop the infrastructure for biking. We also must encourage and support people in transitioning to those alternatives.”
“In electrifying a semi-truck with a range comparable to diesel truck, you end up with a very large battery carrying a small amount of freight. Another issue is charging: plugging in a 500-kilowatt hour battery and trying to charge it in half an hour puts the same amount of stress on the grid as plugging in 60 or 70 houses. So, for freight, we’re going to have to be creative. Maybe we do hydrogen; maybe we don’t use batteries at all. Or we build catenaries, where trucks operate like trams once did.”
“For small planes on short hops, I think there is a path to electrification, but beyond that, I don’t know how you do it. The National Academies concluded in a 2016 report that over a 20-year time frame, they didn’t see how you could do it either. Of course, technical progress has a way of making fools of everyone, so you never know. Meanwhile, we should be more circumspect about how we fly. Weekend getaways 3,000 miles away are just decadent. But we must be careful about how we reduce air travel—and remember that a lot of the world does not fly at all, right? So, by saying that ‘we’ should fly less, are we saying that I should fly less to conferences, but someone in India or Indonesia should never fly?”
"I used to live in the Netherlands, which is where Shell is headquartered. Across Europe, Shell is buying electric charging companies because it knows that if it wants to be in the business of fueling cars, it’s going to have to own and operate electric charging stations. Shell has stated that its goal is to be the world’s largest electricity company. BP aims to cut its Scope 1 and 2 emissions to zero by 2050. Even Exxon says it supports the goals of the Paris Accord. In large part, I think that industry, including the auto manufacturers, has seen the writing on the wall."
JIM GAWRON (BSE ’10, MSE ’11, MBA/MS ’19)
Electric Vehicle Ecosystem Manager in the Ford Business Leader Program at Ford Motor Company
While pursuing dual degrees at SEAS and the Ross School of Business, Sustainable Systems graduate Jim Gawron produced research on CAVs as well as published work on Vertical Takeoff and Landing Aircraft (VTOLs), also known as “flying cars.”
“I see the best path toward sustainable mobility as a feedback loop involving intentional urban planning and smart infrastructure, coordinated deployment of new mobility technology, and behavior change. Sustainable mobility must start with the design of our cities to foster a ‘walk or bike first’ mindset and convenient access to home, work, and play locations. New technology such as electric vehicles and shared autonomous shuttles can then integrate with robust public transit to fill in the use cases for longer distance travel. Underpinning this all is consumer behavior change to embrace these multi-modal forms of travel. Overall, sustainable mobility can be achieved through the orchestration of these complex systems leveraging data, connectivity, and new platforms tailored for regional differences. The result will be an efficient ecosystem that allows for the freedom of movement to drive continued societal progress.”
MARYAM ARBABZADEH (PhD ’18)
Postdoctoral Associate at the MIT Energy Initiative
Dr. Maryam Arbabzadeh develops models and tools to assess the sustainability implications of energy systems, employing computational programming, power system modeling, and life cycle assessment to provide industry stakeholders and policy-makers robust guidance for improvement. Her work is problem-focused, often relying on interdisciplinary partnerships to more effectively address challenging environmental problems.
“Currently, I think EVs and batteries are the main promising technologies. However, it is very critical to acknowledge that the environmental impact of EV use in terms of emissions reduction would have temporal and regional variations. We should avoid providing general statements about their environmental benefits without considering these changes.”