Energy Fair Interview: Clean Transportation

Perspectives on Changes to Clean Transportation Technology

Reprinted From:  https://www.theenergyfair.org/2019/03/28/perspectives-on-30-years-interview-series/ 

Over the past 30 years, we’ve seen tremendous interest about clean transportation from Energy Fair attendees, and at the 2018 Energy Fair we unveiled a 19 kW Solar Canopy charging station for electric vehicles (PV + EV= Driving on Sunshine)! For some perspective on how approaches to clean transportation, and electric vehicles have changed over the last 30 years we talked with past Energy Fair Keynote, Dr. Ngalula Sandrine Mubenga.

Dr. Ngalula Sandrine Mubenga
Dr. Ngalula Sandrine Mubenga, PE and Assistant Professor at the Engineering Technology Department at the University of Toledo, Ohio, where she received her Bachelor’s (2005), Master’s (2008) and Doctorate (2017) degrees in Electrical Engineering with honors. She was named the 2018 Engineer of the Year by the Institute of Electrical and Electronics Engineers –Toledo section. She was a keynote speaker at The 27th Energy Fair. Sandrine is pictured next to the first 3D printed Car.

MREA: Sandrine, thanks for sitting down with us to provide some perspective on how approaches to clean transportation have changed over the last 30 years. To get started, please tell us a bit about yourself and your work in clean transportation.

Sandrine: I am Dr. Ngalula Sandrine Mubenga, PE and Assistant Professor at the Engineering Technology Department at the University of Toledo, Ohio, where I received the Bachelor’s (2005), Master’s (2008) and Doctorate (2017) degrees in Electrical Engineering with honors. I was named the 2018 Engineer of the Year by the Institute of Electrical and Electronics Engineers –Toledo section.

My research areas include battery management systems, electric vehicles, and renewable energy systems. Our battery research won the 2018 IEEE National Aerospace & Electronics Conference Best Poster Award in the USA, while our hybrid electric vehicle research won the 2008 University of Toledo EECS Dept. Most Outstanding Thesis Award. As far as clean transportation goes, I have made an electric vehicle hybrid, by integrating a fuel cell to it so that the hybrid EV could run off hydrogen gas. This is a clean technology because the only byproduct is water. I also developed a solar powered hydrogen generating station that would decompose water into hydrogen and oxygen so that I could pump the hydrogen into my hybrid EV.

One of the bottlenecks of clean transportation and renewable energy system is battery energy storage. That is why recently I have been focusing my research on battery management systems for Lithium ion (Li-ion). Li-ion batteries are used in clean transportation because they have the highest power density and their cost keeps decreasing. Unfortunately, overtime these batteries are subjected to the weak cell issue, which limits the capacity of the battery pack to that of the weakest cell and increases the risk of fire. We have developed the Bilevel Equalizer, a new energy storage solution to make battery packs in electric vehicles, satellites, planes, and grid stations last longer and cost less. Before the bilevel equalizer, battery makers and automotive manufacturers balanced the cell voltages in a large battery pack using either a passive circuit, which loses more energy, or an active circuit, which is 10 times more expensive. Our new technology called a bilevel equalizer is the first hybrid that combines the high performance of an active equalizer with the low cost of the passive equalizer. Experiments have shown that the bilevel equalizer increases the discharge capacity of lithium ion batteries by about 30%, and the pack lasts longer because the cells are balanced. I am also the founder and CEO of SMIN Power Group, a solar developer operating mainly in the D.R. Congo since 2013.

Recently I founded STEM DRC Initiative, a non-profit organization that promotes Science Technology Engineering and Match in the DRC, USA, and the rest of the world. I was a keynote speaker at The 27th Energy Fair and had a great time meeting a vibrant community of like-minded people.

MREA: Wow! What an impressive list of accomplishments. We really enjoyed your keynote in 2016, your story is truly inspiring. What noteworthy changes have you seen in clean transportation over the last 30 years? What has surprised you the most?

Sandrine: First, there has been more global acceptance of clean transportation as a priority to combat climate change. In the US, about 30% of pollution comes from the transportation sector. Most major car manufacturers have announced that new car models will have electric drivetrain, which is a low carbon option.

Second, the cost of energy storage has been decreasing due to technological advances. The type of batteries used in clean transportation have drastically changed. In the past Lead Acid and NiMH were preferred batteries while, Li-ion batteries were deemed too expensive. Now, because of technological advances, the cost of Li-ion batteries (energy storage) has been decreasing and it seems to be a continuing trend. As a result, more and more clean transportation is using Li-ion batteries to store energy. Another surprise has been the electrification of transportation, even for the heavy duty segment. Companies are looking into cargo trucks and forklifts that are electric or hybrid. In terms of aerospace, when I attended the 2018 National Aerospace conference in Dayton, I was surprised to learn that the military is actively researching and prototyping all-electric airplanes. When I asked them what type batteries have been most promising, they stated that Li-ion batteries are the future of all-electric airplanes.

The third is autonomous vehicles. We now have multiple car companies working on commercially available autonomous vehicles. The degree of autonomy is rated from level 1 through 5. Most commercially available autonomous vehicle are at most a class 2, such as the Tesla S3; there are a lot of policies and work that needs to be done to get to a level 5.

The fourth major change is the type of fuel or biofuel. We started this area with fuel such as ethanol coming from edible crops like corn or sugarcane, then we moved to creating biofuel from non-edible sources. Algae have become an interesting area of research for biofuel mainly because they do not compete with the food supply of humans.

Lastly, the different car sharing programs, such as Uber, have been disruptive. Perhaps in the future, individuals will no longer own their car, but will rather share them. We also notice that transportation is more connected now. Another game changer that we must take note of is 3D printing a vehicle. 3D printing a vehicle allows one to print a vehicle at the site, and at a reduced price depending on the size of the vehicle. It is convenient, on-demand, fast and can be cost effective.

MREA: With all this change, what challenges have we overcome and what challenges remain?

Sandrine: Most people are focused on the electrification of transportation. But what will happen to all these batteries when they reach their end of life? They would most likely end up in the landfill. A few may be recycled but we have a ways to go before Li-ion reach a 90% recycling rate like lead acid. Is there a way to reuse the batteries from the EV and HEV? These are serious challenges that must be solved to manage waste.

When batteries from EV and HEV reach end of life, they can still contain up to 80% of their capacity. So by changing their usage, there is an opportunity to create a market for second life Li-ion batteries. For instance these batteries can be used for energy storage in grid applications or for renewable energy systems. Therefore, because they are second life batteries, they would have a minimal cost compared to new Li-ion batteries.

With the bi-level equalizer, we can take second life batteries from EV and use them to store energy for grid applications for an additional five years or so. Because our technology increases the capacity and longevity of used batteries, the bilevel equalizer can help create a circular economy for used batteries coming from EV and HEV.

MREA: What advice would you give to someone thinking about purchasing an EV?

Sandrine: Go for it! Look for incentives in your state. There is a growing community of EV and HEV owners and it has become easier to buy a used HEV. When I was manager of Electrical Engineering at the University of Toledo, I was in charge of energy management. I upgraded the lighting in 30 buildings on campus with more efficient lights thereby decreasing the energy usage and the carbon footprint of the university. Our project decreased the energy consumption on campus, and Toledo Edison sent us a rebate check because we had increased the energy efficiency on campus. We used funds from the rebate check to purchase a used HEV for the department and student interns, and the rest was used to create a scholarship fund for students interested in studying sustainability. This experience helped me realize how easy it was to purchase an HEV nowadays and their price is competitive with that of internal combustion engine vehicles.

MREA: What role do you see renewable energy playing in the growing transition to clean transportation?

Sandrine: Renewable energy will definitely play an important role in the transition to clean transportation. It can be used to recharge electric vehicles or to generate the fuel for clean transportation. For instance, solar canopies are used to recharge EVs. Solar PV roads that generate electricity and charge the vehicles by induction are already being made in China. Small vertical axis wind turbines are placed along the road and spin based on the traffic flow, these can be seen in Detroit , Michigan.

MREA: And finally, what trends do you see that will influence the future of clean transportation? And what makes you most optimistic about the future of clean transportation?

Sandrine: 1. Autonomous vehicles is a growing trend that will influence clean technology. China is making drone unmanned autonomous vehicle “taxi” that costs around $40,000.

2. Second-life li-ion batteries, with the bi-level equalizer, we can take second life batteries from EV and use them in battery energy storage for grid applications for an additional five years. Because our technology increases the capacity and longevity of used batteries, the bilevel equalizer can help create a circular economy for used batteries coming from EV and HEV. This makes me very optimistic. Another trend is the use of nanotechnology and nanomaterial. Nanomaterial have allowed us to generate hydrogen on board, and therefore Honda, which is a major car manufacturer, is looking into hydrogen cars that can be commercially available. Some people think that in the future people will no longer own cars but would rather share them within a community. Car sharing/car pooling such as Uber will continue to grow in the future as these are preferred means for millenials.

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