With a long-term Toyota Mirai in our test fleet for a year, we have questions (maybe you have questions, too) about hydrogen and its place in our wheeled future. So we sat down with Toyota senior engineer for fuel cell development Jackie Birdsall—aka The Hydrogen Whisperer—to ask questions about the powertrain and fuel source Toyota is embracing. It was like a seminar for one, a unique opportunity to learn a whole bunch about those little H2 molecules that might or might not be the future of transportation. Toyota says they are. Most other carmakers say pure battery-electric vehicles like the Nissan Leaf, Chevrolet Bolt or Tesla Model 3 will make up our transportation future.

To be sure, Toyota and its luxury Lexus subsidiary have announced plans for pure electrics—particularly in China, where there are numerous advantages and requirements for them— but Toyota has none in the U.S. right now, and plans for Toyota EVs pale in comparison to the company’s hydrogen fuel cell cars. Why is that?

A couple weeks ago, we spoke with Toyota Mirai chief engineer Yoshikazu Tanaka, and he said hydrogen is the perfect storage medium for clean energy. Since the sun doesn’t shine all the time and the wind doesn’t blow every day, you need a way to store clean energy to power fuel cells, and using electrolysis (running electricity through water to break off hydrogen molecules from oxygen) to create hydrogen is an excellent way to do it.

Now we turn to fuel cell expert Birdsall for more details on the universe’s lightest and most common element.

AW: It seems like car companies are either going all-electric, as the majority of them seem to be going, or they’re hedging their bets like Hyundai and Honda and offering everything (fuel cells, PHEVs and BEVs). But Toyota seems to be firmly committed to hydrogen fuel cells. Why?

Jackie Birdsall: First of all, hydrogen is electric. So when you speak of automakers moving to fully electric, hydrogen is also fully electric. It’s just a different way of going about it. We are committed to hydrogen fuel cell vehicles. We just demonstrated that with launching the next-generation Mirai (due out at the end of next year) and we’ve increased our production capabilities (for FCEVs) tenfold. So we are really ready to demonstrate the potential of hydrogen fuel cell vehicles as an electrified option.

That said, we do have a portfolio approach. We are moving toward 25 percent of our sales being hybrids by 2025, and all of our vehicles will have an electrified option by 2025. And that’s going to be a combination of battery electrics, plug-in hybrids and fuel cells.

Our 2019 Toyota Mirai’s fuel cell Tim Sutton

AW: So why hydrogen?

JB: It has several advantages. It takes five minutes to refill a car, and it can go 400 miles on that refill (next year’s Mirai can, anyway), which is a unique attribute of hydrogen. It has higher gravimetric energy density than batteries. And as you look toward longer-range, larger vehicles, that’s really where hydrogen becomes advantageous. That’s something we’ve been able to demonstrate with our heavy-duty trucks. We’ve put two fuel cells in an 18-wheeler, and we can refill that system in equivalent time to a diesel truck.

So the important part is that if we want to move, if we want to achieve our 2050 environmental challenge goals, which is a 90 percent reduction in CO2 emissions, that calls for a huge electrification across our entire portfolio. In order to get there, we need to have solutions that meet the needs of all our customers. While we believe that battery electrics can meet the needs of many of our customers, customers who prefer to charge at home and are capable of leaving their vehicle to charge for 30 minutes to several hours, there’s still the need of the customers who don’t have that capability who need a fast refilling time and who don’t have the ability to recharge at home or at their office. And that’s where the fuel cell electric really fits those customer needs.

It’s not up to us to dictate what the customer chooses. We believe we need to make those options available and then let the customer decide what’s best for their lifestyle.

AW: Reformation of natural gas, which is how most hydrogen is made now, gives off CO2, doesn’t it?

JB: Electrolytic hydrogen production does not; natural gas reformation does.

AW: Right now, we’re in the early stages of fuel cells, so you can’t really complain about the sparse infrastructure we have now, with half the existing fueling stations empty most of the time. Right now, we’re using natural gas reformation to get hydrogen, but Toyota’s plan is to eventually use electrolysis. How do you see building infrastructure with electrolysis?

JB: We’re already at 33 percent renewable (energy) in California. We do have a pathway toward 100 percent renewable.

AW: Toyota has a pathway toward 100 percent renewable?

JB: The hydrogen industry does. The Hydrogen Coalition has a pathway. And there’s SB100 here in California (a law passed in 2018) that’s moving toward 100 percent renewable electricity (by 2045), we have some similar call for hydrogen. So it’s not easy, just as it’s not easy with the grid. We do have a few ways that we’re doing that. One is using that distributed renewable energy that you’re mentioning, as we have this electricity available that’s intermittent, we have to have an energy storage mechanism, of which hydrogen is a perfect application, and the source of that could be either biogas or water.

AW: Biogas is just another word for methane, which gives off CO2 in its reformulation to hydrogen, doesn’t it?

JB: No, no, no, biogas is a renewable methane. It depends on how you define that. Well-to-wheels is an art more than a science. And it does depend on your assumptions. For example, do we call it a CO2 reduction in capturing that CH4 (biogas) that would otherwise be a very potent greenhouse gas being emitted? How do we account for that? Does that get counted if we use biogas in the reformation process; do we count that as a carbon neutrality or even a negative?

AW: Because right now, unused biogas is just going up in the atmosphere.

JB: Correct. As a more potent greenhouse gas.

AW: So by using biogas to create hydrogen you’d reduce the amount of greenhouse gas that would be let off into the atmosphere? Even though some CO2 is released in the process, it’s less harmful than if the biogas wasn’t used at all and just escaped as it is now into the atmosphere?

JB: Exactly. So for us that would be considered a negative CO2. The other would be electrolytic hydrogen.

AW: How much electricity does it take to produce say, a kilogram of hydrogen?

JB: The Department of Energy publishes in their annual merit review numbers around hydrogen production. Last time I checked, I believe electrolyzers were at about 65 percent efficiency. Which means you’ll have that 35 percent loss from the electricity in the creation of hydrogen. Any time you have an energy conversion, you have a loss, right? Electrolyzer companies are moving gung ho on this because they see this huge potential again because of renewable electricity generation.

AW: How far out is 100 percent clean hydrogen?

JB: For California SB100, we’re following the same trajectory for 100 percent renewable electricity generation. The 2030 target is 50 percent renewables—100 percent by 2045 in California. That’s a huge ask. But it’s not insurmountable. The energy’s there.

AW: So many other car manufacturers are talking about an electric future. Apart from Honda and Hyundai, who are covering all their bases, everybody else is electric. Are they all wrong?

JB: No. I think that we do have an electrified future. BMW and Mercedes have also announced their plans for hydrogen fuel cell vehicles. I think all automakers see this trend toward electrification. This (the coming second-gen Mirai) is the most advanced electric vehicle on the market. Toyota is the leader, by far, in fuel cell technology.

AW: But isn’t it an extra step to add fuel cells when the motive power is electricity? For areas of the country that have sun or wind power, wouldn’t it make sense to have both fuel cell and battery electric vehicles?

JB: Yes, that’s a win.

AW: So it’s not just hydrogen?

JB: No, no. We see a portfolio approach that includes BEVSs, plug-ins, traditional hybrids and fuel cell electrics. That’s the beauty of offering all of these options to customers, and they can choose what best suits their lifestyle.

One advantage of fuel cell vehicles and battery electrics is that you have better weight distribution overall, so you get a lower center of gravity overall. And you can have it more aerodynamic based on how you lay out your platform of components because now you don’t have that big chunk of internal combustion engine under the hood anymore and also because you don’t have the dampeners to make up for the vibrations of that engine. You have a more stiff frame. It’s a superior driving experience.

AW: Is a fuel cell vehicle lighter than a battery-electric vehicle?

JB: It depends on the range. With a battery-electric vehicle, the more range, the heavier it gets. So you’re in the intersection at which fuel cell vehicles become lighter per range than battery electrics.

AW: The range for the new Mirai is 400 miles. If you had a BEV that went 400 miles, you’d have to have (I am guessing here) a 130- or 140-kWh battery, and that’d be like 1,500 pounds.

JB: It’d be heavy. Very heavy.

AW: So to have a 300-mile range, it would be lighter to have a fuel cell vehicle.

JB: Correct. And that gets extrapolated more so as you move toward commercial vehicles like the Class 8 semis.

AW: Where would the crossover be where a fuel cell vehicle becomes lighter than a battery vehicle for a given range? Would that be about 300 miles range? 200 miles?

JB: Based on our calculations, it is lower than 300 miles range. And that crossover point’s going to change with technology improvements. Power electronics are moving so quickly. Electric motor advancements are moving so quickly. Batteries, fuel cells, hydrogen storage systems—all of it is a big, synergistic, technological advancement for all of these. And there’s so much componentry that’s shared (between fuel cell vehicles and BEVs). When we launched the first-generation Mirai, the way we were able to bring the cost targets down to where we were able to sell it to the customer was by creating a boost converter that mated the hydrogen fuel cell system to the hybrid synergy drive system. So then we could just choose off-the-shelf components for the hybrid synergy drive system and mate them to the fuel cell system—whereas if you were trying to make dedicated fuel cell, power control unit, motor, battery, inverter and all this stuff, that’s very expensive. So every advancement that we make in any part of this electrified system is a benefit that is shared across our powertrain platform.

AW: How big is the battery in a typical fuel cell vehicle?

JB: Tiny. 1.2 kWh in the first-gen Mirai. The only purpose is to capture regenerative energy and to store any excess energy that’s created from the fuel cell stack. A fuel cell stack can create electricity, but it can’t store it. So we want to have some storage mechanism specifically for regen.

AW: What is the fuel cell stack itself—is it just a series of membranes? And what are those membranes made out of?

JB: They’re called proton exchange membranes, PEMs.

AW: And hydrogen was chosen because it has only one proton? And everything else has more than one proton? Some of them have like 238. So why do you need to have hydrogen in a fuel cell? You don’t want the hydrogen, you want the electron, and everything has electrons. So why not use something easier to get a hold of?

JB: High-temperature fuel cells can be used for reformation, internal reformation, as well, so methane, natural gas, whatever, still we can split off those electrons and make electricity as well.

AW: So why don’t you use that?

JB: Because we want a zero-emission vehicle. Any time we use natural gas, it’s not a zero-emission vehicle. There’s still CO2.

AW: So if you used anything other than hydrogen, it wouldn’t be a zero-emission vehicle. At least zero-tailpipe emissions.

JB: Correct. Still to this day, mobile emitters are the primary factor in smog pollution. Addressing the mobile air quality first is what will help to clean the air. If you make electricity at a natural gas plant, which a lot of electricity comes from natural gas-fired plants, or you make hydrogen from steam methane reformation at a similar natural gas plant, it’s easier to control the emissions at that one plant. You can have scrubbers, you can have all this stuff that if you put onto a vehicle, it starts to make it cost-prohibitive. So to actually manage those emissions at a stationary plant, a big stationary source is kind of easier (to keep clean) and offers more benefits. Coal-fired power plants, we can move away from that—we don’t need that anymore.

Well-to-wheel efficiency has become a really relevant discussion, and people are starting to really delve into what well-to-wheel means. The Department of Energy developed the GREET model (Greenhouse gases, Regulated Emissions and Energy use in Transportation model, which tracks well-to-wheel efficiencies) establishing where you get your energy for BEVs, where you get your energy for FCEVs. We’ve seen that proliferate around the nation as other regulatory authorities are looking into that. And now we’re starting to discuss lifecycle analysis as well. From cradle to grave. So not only the fuel and where it comes from but also where the materials come from, and whether the materials are recyclable. That’s a huge discussion as we start to talk about precious metals, toxicity, recyclability, end-of-life usage of batteries, things like that.

AW: And the solution seems to be less a technological, scientific solution than it is a political solution. There’s a lot of knuckleheads out there, there’s coal rollers, trucks parking in front of Tesla superchargers. It’s a political problem, it’s a human problem, people don’t realize that it’s nice to have clean air.

JB: People generally are a little hesitant to change. So even if you don’t believe in climate change… I drive on the 110 (freeway in Los Angeles), so I get an elevated view of Los Angeles, and on certain days, you can see that haze, just, smog. And in no right mind would you think that that’s OK. And that’s the thing that I don’t understand. Even if you think that climate change is a big conspiracy, how can you look at that air and think, “Yeah that’s OK. We can continue to do that.” Or “We can continue to dump plastic in the ocean.” All of these things, just look.

AW: Indeed. Thank you, Ms. Birdsall!