By Jericho Rajninger and Megan Bergeron
Electric vehicles (EVs) are more than just a means of transportation: they’re mobile batteries that store large amounts of power on the road. Because EV batteries are often underutilized by drivers, some of the energy stored in these batteries can be pushed back into the electrical grid through a process known as vehicle-to-grid integration. Vehicle-to-grid integration involves creating EV batteries that are capable of bidirectional charging, meaning they can both receive electricity from and return electricity to the power grid. If electric vehicles were to be adopted on a large scale, they could help supply renewable energy to buildings and homes.
Smart Charging and Renewable Energy:
EV owners often charge their vehicles during hours of peak energy demand — for instance, in the evening after they arrive home from work. But charging at these times puts additional strain on the power grid, and because the power grid at higher usage includes more power from polluting sources, such as natural gas-fired power plants, this reduces the greenhouse gas benefits of electric vehicles.
Smart charging systems look to maximize renewable energy use by charging EVs when surpluses of renewable energy are available — for example, at noon on a sunny day. When the power grid cannot store all of the energy generated by renewable sources at a given time, this energy may be “curtailed” – a circumstance in which power generators are actually paid not to generate power. But if EVs were integrated with the existing power grid, they could improve the flexibility of the grid by storing clean energy during periods of low electricity demand (noon on a sunny day). Then, during periods of high demand (in the early evening), energy providers could purchase clean energy back from EV owners and use it to power homes and buildings. This process is known as Demand Response.
Autonomous vehicles, such as cars, trucks, and drones, rely on artificial intelligence to operate with varying degrees of human input. By computing billions of data points each second from an array of sensors, cameras, and radar systems, AVs can effectively see the road and respond to changing conditions or navigate obstacles. Automation technology, vehicle connectivity technology, and big data could reduce congestion, keep travelers safe, protect the environment, respond to climate change, connect underserved communities, and support economic vitality. The United States has committed to significant carbon emissions reductions in order to avert the worst impacts of climate change. In light of these commitments, it is critical to examine the development of automation technology and self-driving vehicles through the lens of climate change.
On its own, autonomous vehicle technology will not affect carbon emissions from light-duty vehicles; however, the application of the technology will herald changes in how Americans, particularly in urban areas, travel from one place to another. Whether AVs mitigate or worsen carbon pollution from light-duty vehicles in the transportation sector will depend on three key factors: their effect on the total vehicle-miles traveled in the United States; their impacts on congestion; and their fuel efficiency and fossil fuel consumption. Whether AVs will add new classes of drivers to the road, remove cars from the road through car-sharing, encourage people to commute from farther distances, or make vehicle-based transportation more efficient are still being determined.
Challenges and Limitations:
In order for vehicle-to-grid integration to become both economically and environmentally viable, there must be many more electric vehicles on the road than there are today. But electric vehicles are often more expensive to buy and produce than gas-powered cars, and while California is home to more electric vehicles (about 600,000) than any other state, EVs still represent only a small share of total vehicles. By 2030, California aims to have 5 million EVs on the road.
Most importantly, the technology that would allow for bidirectional charging is still in early stages of development. More research is required to understand the efficacy of this technology and the effect it might have on EV batteries. Needed, too, is a robust charging infrastructure that can accommodate an expansive network of electric vehicles.
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Electric Vehicles with Scott Moura (extended edition)
Ethan: Welcome to Climate Break, bringing you stories about innovative climate solutions being developed at UC Berkeley and around the world shared by the experts themselves. I’m your host, Ethan Elkind, from the Center for Law, Energy and the Environment at Berkeley Law. We’re talking today about electric vehicle charging systems and how we can make them better. Most of us have probably seen or even used today’s typical EV chargers. They basically function like gas pumps. You hook up your vehicle and start funneling power into it. But what if we could make chargers smarter and along the way improve vehicle battery life and reduce greenhouse gas emissions? To learn more, I spoke with Dr. Scott Moura, who is an Associate Professor of Civil and Environmental Engineering here at UC Berkeley. Through his lab, he’s working on just such a pilot project. It’s called SlrpEV, or the Smart Learning Research Pilot for Electric Vehicles. He told me how it works.show more
Prof. Moura: So you drive up. On the box, there’s a QR code, you scan with your phone. It takes you to a web app. And then after you’ve registered, it provides you with two charging options. Regular, scheduled. Regular is just like your normal charging experience. You plug in, it starts charging immediately, and then it’s done when your vehicle tops out before you leave and there’s a price per hour rate for that. The slightly more interesting one is scheduled. Scheduled you indicate, when you plan to depart and how much added miles you want. And you can set default so you don’t have to pick out every time. That now gives us flexibility to optimize how we charge the vehicle, and it optimizes the charge schedules such that you’re guaranteed to have those added miles when you plan to depart.
Ethan: These two charging options are key to Moura’s research SlrpEV uses statistical models based on a wide array of variables to analyze driver choice. Maura says this attention to the preferences and needs of drivers sets his pilot apart from others.
Prof. Moura: Consumer behavior. That is what’s definitively different here, is we’re now taking the behavior of people in terms of do they prefer regular or scheduled? And it is now part of our model, It’s part of our system. And we’re trying to really more deeply understand that so that we can present this menu of choices to options that better reflects how different people value EV charging and how do you price that and schedule charging in an optimal way, given a model of human behavior.
Ethan: Power grids can often be energy inefficient, wasting renewable energy when it’s available or failing to store it for future use. Optimizing charging schedules can lower costs for drivers and help reduce strain on the power grid, leading to fewer blackouts and cheaper electricity prices.
Prof. Moura: If we can better understand when people are flexible with their EV charging, it now becomes a flexible resource that we can use to lower emissions by aligning EV charging in moments that there are lower carbon electricity generation resources on the grid.
Ethan: Moura is alluding to a process known as Vehicle-to-Grid integration, with smart charging EV batteries can be charged when renewable energy is abundant and energy demand is low, say at noon on a sunny day. Then in times of high demand, energy stored in these batteries can be funneled back into the grid. The result is clean, renewable energy on demand. This concept may seem simple, but significant hurdles remain. Technology is certainly one hurdle. Policy is another. Lawmakers can often be slow to respond to changes requiring swift reforms. Moura says that for his research to be put into practice, changes in policy must be made.
Prof. Moura: There’s a specific policy that I think we need to overcome, and that is in many cities, to get a permit to install EV charging, you need to have sufficient electric capacity to support all the chargers running at full power. Now, with software controls, that is unnecessary and quite expensive, because it means you may have to do a large infrastructure upgrade. So what I would like to see is cities adopting a policy where with software, if you can ensure that the maximum power is within the electrical charging infrastructure, that would dramatically lower the infrastructure costs. Dramatically. Which would help proliferate EV charging in these public and workplace settings.
Ethan: Charging aside, battery performance represents another opportunity to encourage EV proliferation. Batteries represent the most expensive part of an electric vehicle, which are otherwise often cheaper than gas cars when you factor in long term savings on fuels and maintenance. Moura says EVs could become more cost competitive with gas cars sooner if the capacity and lifespan of their batteries improve.
Prof. Moura: Batteries are electrochemical systems. And so the key to what we’re doing is we’re embedding mathematical models into electrochemistry, into the control system. What that does is it means you can better see inside what’s happening with the battery and operate it closer to its performance limits because you’re now using knowledge of the electrochemistry so that you can charge them faster, get more energy without degrading it.
Ethan: Under certain conditions, EV Batteries may perform poorly or even get damaged. At E-Cal, Moura is developing techniques to monitor, manage and improve these systems.
Prof. Moura: Right now the way we operate batteries is – do imagine a little old lady, but not the little old lady from Pasadena, who is very good and fast driver, but someone who’s very conservative driving, to like a racecar driver who has a super accurate model in their mind of how the vehicle, of the vehicle dynamics and its limits and they can operate at right at its performance limits. So that’s the paradigm that we’re moving to with battery controls.
Ethan: In addition to developing smart charging and improved battery performance, Moura’s lab is working with ARPA-E, an agency funding research and energy technology to make vehicles more energy efficient on the road. The project uses a framework called Infrastructure to vehicle communication.
Prof. Moura: So imagine a world where traffic lights broadcast to your vehicle, their schedule for when they’re red or green. Now you can think about your own commuting and there’s probably roads that you drive down fairly often, and you’ve got a good sense of the timing, right? And you probably think about that when you drive, how fast you go, when you get out of a traffic light and you know, to try to catch the green wave. So how do you actually embed that into an automated vehicle? If you can do that right, then you can avoid stopping.
Ethan: By minimizing braking and accelerating, vehicles don’t have to switch gears as often or as quickly. This increases fuel economy and reduces emissions, including toxic air pollution and greenhouse gasses.
Prof. Moura: We also focus a lot on tailpipe emissions, but a lot of the emissions also come from the road in the tires and the brakes. So if you can reduce the amount of braking, and also if you’re doing this with electrified vehicles, with this regenerative braking, you also eliminate emissions that come from the brake pads and in the tires from that perspective, which have health impacts that we’re only beginning to understand in science. So it’s not just tailpipe emissions, it’s brake and tire emissions as well, which are non-trivial. They, in fact, are a significant part.
Ethan: Recently, we’ve unfortunately seen that extreme weather, rising sea levels and other phenomena caused by climate change disproportionately affect low income communities and communities of color. Before our conversation closed, Moura emphasized the importance of including marginalized groups in climate discussions and solutions.
Prof. Moura: All of us in UC Berkeley are really trying to think about climate equity also, and the fact that those who suffer from climate change are often those who don’t have resources to address it and more for those who have creative ideas and solutions and the best understanding of these problems often come from nontraditional backgrounds. So it’s absolutely tremendous to get involved with these groups and make it an institutional part of what we do day to day.
Ethan: For more interviews with climate experts discussing groundbreaking research, you can visit our website at climatebreak.org. We’ve gathered resources there to help you remain up to date on the latest climate change solutions. I’m your host, Ethan Elkind. See you next time on Climate Break.show less
EV Charging Vehicle-to-Grid Integration with Scott Moura
Ethan: How can electric vehicle charging become smarter? This is Ethan Elkind of Climate Break. I spoke to UC Berkeley engineering professor Scott Moura. He’s working on a new EV charger that lets drivers choose immediate charging, or schedule a charge that favors renewable energy use. Immediate charging is what we are used to. It’s done when your vehicle tops off or you leave.
Prof. Moura: The slightly more interesting one is scheduled. Scheduled, you indicate when you plan to depart and how much added miles you want. That now gives us flexibility to optimize how we charge the vehicle. And it optimizes the charge schedules such that you’re guaranteed to have those added miles when you plan to depart. We can do so in a way that lowers cost for the consumer, lowers energy emissions, and that’s essentially the experience, these two differentiating charging options.
Ethan: Moura’s installing charging boxes on the UC Berkeley campus, and he plans to test the system as soon as construction’s complete.
Prof. Moura: We’re going to present these randomized prices in the charging options and see how people react to them.
Ethan: For more on Moura’s work, and for more climate solutions, go to climatebreak.org or wherever you get your podcasts.
Batteries with Scott Moura
Ethan: How can we get electric vehicle batteries to perform better? Battery cost and range anxiety can deter drivers from purchasing electric vehicles. To learn more about how we can improve EV battery life, I spoke with Scott Moura. He directs the Energy, Controls and Applications Lab at UC Berkeley where he studies battery management systems.
Prof. Moura: We work a lot on the software controls that take existing and future batteries and get more energy, power and longer life out of them. Absolutely critical, especially for electric vehicles to make them economically on par cheaper than internal combustion engines.
Ethan: As an analogy, Moura invites us to compare a very cautious driver with a race car driver.
Prof. Moura: Imagine a little old lady, someone who’s very conservative driving, to a race car driver who has a super accurate model in their mind of vehicle dynamics. So that’s the paradigm that we’re moving to with battery controls.
Ethan: Moura wants to optimize EV battery usage so that all drivers can operate their vehicles at high efficiency.
Prof. Moura: Batteries are electrochemical systems. The key to what we’re doing is we’re embedding mathematical models of the electrochemistry into the control system. What that does is it means you can better see inside what’s happening with the battery and operate it closer to its performance limits.
Ethan: This is Ethan Elkind of Climate Break, bringing you 90 seconds of climate solutions. For further information on Moura’s work at UC Berkeley, and for more climate solutions, go to climatebreak.org or wherever you get your podcasts.
Autonomous Vehicles with Scott Moura
Ethan: Will vehicle automation help make transportation more energy efficient? This is Ethan Elkind of Climate Break. I spoke with Scott Moura, Professor of Civil and Environmental Engineering at UC Berkeley, about the potential impact of infrastructure-to-vehicle communication.
Prof. Moura: Imagine a world where traffic lights broadcast to your vehicle, they’re scheduled for when they’re red or green. Now you can think about your own commuting and there’s probably roads that you drive down fairly often, and you’ve got a good sense of the timing, right? So how do you actually embed that into an automated vehicle? If you can do that right, then you can avoid stopping.
Ethan: When cars don’t have to switch gears as often or as quickly, they maintain higher fuel economy.
Prof. Moura: If you can reduce the amount of braking, you also eliminate emissions that come from the brake pads and the tires from that perspective, which have health impacts that we’re only beginning to understand in science.
Ethan: In the near future, Moura hopes cities across the country will dedicate more urban zones to emissions reduction.
Prof. Moura: I would love to see policy, more policy in that direction to use our cities as innovative test beds and examples to the rest of the world, of how can this be done.
Ethan: For further information on Moura’s work at UC Berkeley, and for more climate solutions go to climatebreak.org or wherever you get your podcasts.