For a glimpse into what automobiles will be like 20 years from now, contributing editor Stuart F. Brown conducted a group interview with executives at General Motors, Tesla Motors and Toyota and also spoke separately with a program manager at the Electric Power Research Institute. The interviewees, whose comments have been edited for length, foresee increased communication among cars and a combination of vehicle types. Some, like Tesla’s current sports cars, will draw their energy from a battery pack. Others, in common with today’s Toyota’s Prius and the 2010 Chevy Volt, will be hybrid designs, relying on both electric motors and small internal-combustion engines. Many forthcoming hybrids will charge batteries by plugging into the electric grid, and hydrogen fuel cells might be a reality. But that is not all that the participants see. Read on.
—The Editors

Larry D. Burns
Vice President, Research and Development and Strategic Planning, General Motors*
(*Burns retired in October, after participating in the interview recorded here.)

Bill Reinert
National Manager, Advanced Technology Vehicles, Toyota Motor Sales USA

Mark S. Duvall
Director, Electric Transportation and Energy Storage, Electric Power Research Institute

JB Straubel
Chief Technical Officer, Tesla Motors

SCIENTIFIC AMERICAN: Let’s start by talking about the transportation fuels we can expect to see in the years leading up to 2030.

REINERT: Through the middle of the next decade, gasoline prices should remain fairly low. I think for at least the next five years and probably the next 10 the predominant number of cars will have internal-combustion engines. You will see six- to eight-speed automatic transmissions, continuously variable transmissions, low-loss lubricants and maybe even new ceramic bearings to reduce friction. And we’ve got a lot of stuff in near to midterm development to really make major improvements in how the internal-combustion engine functions.

Yet if we look out to 2020–2025, you’ll see the gasoline engine and the diesel engine starting to grow together, becoming very similar to each other. You’re going to see ethanol die out, as I think it should. But it will be replaced by biogasoline and second- and third-generation biofuels that are compatible with older cars. Biomass, probably from algae, maybe from municipal solid waste, will be used to produce synthetic gasoline and synthetic diesel.

By this time we may see a developed battery, a replacement for lithium technology that allows full, no-compromise electric cars. But they would still be a niche. And I think that you’ll probably start to see low-carbon hydrogen [Editor’s note: not derived from natural gas] that has been developed to supply fuel cells. So you will see niche battery electric vehicles coming and that market starting to mature more in the later years. Plug-in hybrids and major range-extended hybrids will be a subset of the market. There will be a lot of internal-combustion-type hybrids and then fuel cells starting to come onto the market.

At 2030 we still have an internal-combustion-type component, strong hybrids, probably range-extended electric vehicles and small electric vehicles, and fuel cells are starting to make bigger inroads.

SA: Wireless communication is exploding all around us. How will it affect vehicles?

BURNS: Connected vehicles is another important transformational technology. The fact is that we are now beginning to have vehicles that can communicate with each other. We have the opportunity to have more and more of the driving task be done autonomously by the vehicle. Our road maps for all of the enabling technology for autonomously driven vehicles, and for vehicles that don’t crash, will be coming together in the next five to 10 years.

REINERT: I’d like to talk about how vehicle communication might affect urban vehicles. I think that not only is peer-to-peer vehicle communication critical as we start to platoon cars for congestion mitigation, but it also is important from a social-networking angle as you start to get the millennium generation coming in, people who have always been networked. And you start to have computational clouds that follow the people around. You aren’t attached to a computer anymore, and your car becomes part of a computing platform.

BURNS: I have an 18-year-old daughter. When I grew up, my rite of passage was my first car. For my daughter, I think it was her first cell phone. Today she has an iPhone, and she has a Saturn Vue. If I asked her which one she would give up if she had to, I think she would give up the car before she would give up the social networking associated with that iPhone. This social-networking point that you raise is enormously important. It’s such a powerful behavioral force. And when you have this convergence of an inexperienced driver who wants to text-message, that’s a formula for real concern. I think that as technologists, we have solutions within our grasp so that these young drivers can have both.

REINERT: Absolutely. If we can’t make these cars a social-networking tool just like the iPhone, we’ll lose the customers younger than Larry’s daughter. They just won’t want to get into the cars if they lose their social-networking cloud. I would guess that the automobile companies sooner or later will have connectivity partners to help us through. I would guess that partnerships will be the new thing that will start to emerge out of all of this.

SA: Batteries are essential to many of the ad­vanced vehicles now under development. Are they good enough yet?

DUVALL: In the near term we’re absolutely right in trying to deliver as long a battery life a possible. Carmakers are going to baby the batteries at the beginning at the expense of slightly higher cost. Later, costs will come down and batteries will get worked harder. We have seen this in hybrids already, which enables them to get better miles per gallon.

BURNS: The Chevy Volt will have a 16- kilowatt-hour battery, and we’ll use only half of that energy to run the car. We will learn and discover, and we will improve for sure, but we’ve got to get out there and start doing it.

Our industry in normal times builds 70 million cars and trucks per year. So for any battery-based solution to matter, you’re going to have to get into tens of millions of units per year, and I think we’ve got a ways to go before [durability and cost issues are solved enough to allow that kind of scale].

As a manufacturer, if you have to replace the battery one or two times in a vehicle with a 150,000-mile lifetime you are in trouble. I do believe there will be continuous improvement with lithium-ion batteries, but I think we’re going to need some invention and breakthrough to get the cost per kilowatt-hour down to where we need it to be.

We’ve got to have some breakthroughs here on chemistry. There’s a big difference between using these batteries in your recording devices and cell phones and in an automobile in terms of the temperature extremes and [changing demands for power] and the need to cool the cells uniformly and manage their state of charge uniformly. We’re going to be discovering a whole lot of that as we get out with these early-generation applications of lithium-ion.

REINERT: To a certain extent, the battery longevity is going to shape the applications for a while. So Toyota, and I assume other manufacturers, is going to be very cautious about how we cycle the batteries, about the charge-sustaining and charge-depleting modes we operate them in, and about the actual size of the battery, with an eye toward warranty costs. Lithium-ion batteries still are not available with the 150,000-mile durability you have with an internal-combustion engine. So that’s going to limit the penetration of the battery-powered cars to either niche markets, urban cars, plug-in hybrids with very small batteries, or range-extended cars with moderate-size batteries.

STRAUBEL: I would suggest maybe another way to look at this is to think about the cost per mile. We can talk about a minimum durability re­­quired, but it’s a little bit different with the case of a replaceable battery pack. You have to consider the cost of operating the vehicle per mile, along with the associated replacement cost, if there is one, of changing the battery pack. On those metrics, we’re close, possibly over a threshold in some cases, where it’s actually cheaper to operate and own an electric vehicle than a gasoline car. That’s not the case necessarily with $2 per gallon gasoline, but it absolutely is the case with $3.50 or $4 gasoline in most parts of Europe. And especially if there are any political incentives or tax credits involved.

DUVALL: Many utilities might be willing to help with the costs of your home infrastructure because they are really interested in off-peak charging. And in turn you would enroll in a rate program that would cause your vehicle to charge predominantly off peak. Which really means that your vehicle wouldn’t charge during the six hottest months of the year from, say, 2 p.m. to 9 p.m.

SA: Is it practical to use plugged-in electric vehicles to fill in low-demand times on the grid?

DUVALL: That’s where the utilities’ interests lie. In the short run, we agree with the automakers that we need to reach certain objectives with the vehicles, including lifetime batteries. Then we can start talking about doing other stuff. To us, smart charging [where electric cars and the grid can schedule lowest-cost battery recharging] is a daunting enough task for the present.

I think you will probably see the utilities go to what’s called time-of-use pricing for most of their customers—meaning you will pay more for the loads on your house at the peak hours and less at night. So vehicle chargers or clothes dryers that turn on automatically at 3 a.m. would cost less than running at the peak time. And occasionally if car owners want to hit a button that says, “charge now,” they will just pay more when they’re doing that. But their default behavior will be charging off peak.

SA:  We have heard a lot about fuel cells during the past decade. How do their prospects look today?

DUVALL: I would say the biggest challenges with fuel cells may not be the vehicles themselves but the infrastructure to provide the hydrogen. And when it comes down to it, we can either make hydrogen from re-forming fossil fuels or make it from electricity by electrolyzing water. If we are making the hydrogen with electricity, electric vehicles are a more efficient use of that energy. And the infrastructure is much less costly.

So I think if you were designing the U.S. energy network from the ground up today, you would have an easier time creating a role for hydrogen. You could put in place a hydrogen infrastructure such as advanced electrolysis. But right now unless hydrogen vehicles can provide an absolute sea change in efficiencies, electricity as a transportation fuel is pretty tough to beat on efficiency. And it will come from the same sources as hydrogen.

STRAUBEL: I definitely think that fuel cells are going to have a struggle to make sense in any time frame. I think the physics around the energy efficiency of that fuel cycle is going to be one of the thorniest issues to solve. I don’t see fuel cells as the Holy Grail in the long term.

REINERT: But right now Daimler, GM, Honda and Toyota have very well developed fuel cells, mostly waiting on fuel-cell infrastructure, which should come into play some time around the year 2025. I think that you’re going to see a more segmented usage pattern, and the idea that we’re going to have a 400-mile range for every car in the fleet may not be as important in 10 years as it is to customers today. It may be enough to have an adequate range to get yourself through your day plus [another half day], for example, and that you have services such as Zipcars that allow you to buy the exact car usage you need and no more.

SA: The fuel efficiency, exhaust emissions and safety of vehicles all have to meet standards. What are your thoughts about future regulation?

STRAUBEL: We really need to focus these policy decisions on things that can be economic in order to scale up. If we put policy in place to implement something that won’t be economic for two decades, it’s useless. It’s not going to affect any issues related to CO2 reduction or energy security or anything else.

BURNS: The reason I get worried about trying to pick the winner [for future transportation] is that it can induce policy makers to take options out of play, and it’s way too early to take some of those options out of play, in my judgment. We’ve been doing some really interesting work where we looked at this not as an “or” question: that it’s either batteries or fuel cells or biofuels, but we’ve looked at it as an “and” question. What if we had all of them in play? Whether it’s  electricity or renewables or whether it’s hydrogen, none of them by themselves can displace the amount of petroleum and CO2 that we’re talking about. Don’t dismiss any of these, put them all in play together and see where the world heads with that.

All this technology will matter only if we can get it to high volume. Because you’re not going to have impacts on energy, environment, safety and congestion if you only sell specialized niche products. I just find so many regulators and politicians and other people weighing in on this debate who don’t have a clue about what’s required to get to high-volume commercialization of a technology.

DUVALL: Let’s be very careful before we adopt very expensive alternatives that try to create a one-size-fits-all technology. We need to avoid the silver bullet approach—it’s always proved to be generally more expensive and have less of a chance of success.