Nissan’s Solid Oxide Fuel Cell system, and what the fuss is all about

June 15, 2016 |

Fuel cells are important technology. You may remember them from the space program. They show up in the drama of Apollo 13, for example. Many car companies have investigated their potential — but here’s a breakthrough that addresses the major barriers for fuel-cell adoption.

Earlier this week, we reported that Nissan is researching and developing a Solid Oxide Fuel-Cell system that runs on ethanol-based electric power.

As part of our 4G Tech series this week, looking at the future of ethanol and first-gen ethanol plants in the US, Brazil and elsewhere — let’s look at the implications of this shift in ethanol’s potential.

We’re going to need ‘em. As Jeremy Martin of the Union of Concerned Scientists observed earlier this year in “Fueling a Clean Transportation Future: Smart Fuel Choices for a Warming World.”:

Major studies have found that a large-scale transition to EVs powered by batteries or fuel cells is required to achieve the deep emissions reductions necessary by mid-century to avoid the worst effects of climate change (Williams et al. 2014; Yang et al. 2014; NRC 2013). 

And Hyundai’s Scott Nargar told The Digest last year:

“There are great things about gasoline internal combustion engines and electrics — fuel cell vehicle combines the best of both worlds. They have long-range, quick refueling, and the technology is scalable and long-range. With our partners — all manufacturers are looking at fuel cell vehicles. Research began 15 years ago, and the next-gen is on the way, ready in 2018, for the US, Europe and Australia. It is right hand drive in the next-gen, gets 800 KM on a tank. Power getting out of the motors is increasing.”

What is a Fuel Cell, anyway?

The e-Bio Fuel Cell generates electricity through the SOFC (power generator) using bio-ethanol stored in the vehicle. The e-Bio Fuel-Cell utilizes hydrogen transformed from fuel via a reformer and atmospheric oxygen, with the subsequent electrochemical reaction producing electricity to power the vehicle.

Here’s a diagram.

Screen Shot 2016-06-15 at 3.40.56 AM

In the long-term, the advantage of molecules over electrons is that they store more energy with less weight than traditional electrical battery systems. The longer the trip, the more that the cost of transporting the energy along with the vehicle becomes a factor.  Electric batteries are really, really heavy. And, the amount of time that it takes to recharge an electric battery becomes a source of aggravation. That’s why long-range marine, heavy-duty trucks and aviation have been especially fertile areas for biofuels and traditional fossil fuels. And why light-duty, local transportation has been the best fit so far for electric vehicles.

Screen Shot 2016-06-15 at 3.41.13 AM

The promise, of course, is an end to EV range anxiety, endless battery re-charges, and the infrastructure cost of electric vehicles. While, at the same time, enjoying the acceleration, the quiet operation, and the eco-friendliness of electric vehicles.

Why isn’t everyone driving fuel cell vehicles, already?

In a word, hydrogen.

As a fuel, nothing wrong with hydrogen. It has pop. But, there’s little infrastructure to deliver it to passenger vehicles. Storage of compressed hydrogen is an iffy proposition in many consumer’s minds — they have images of the burning Hindenburg airship in their minds. And, hydrogen is not exactly cheap to source and generally is made from fossil fuels – typically, steam reformation of methane.

Toyota has been struggling through some of those issues with its spectacular hydrogen vehicle — and they are focused on the California market where there is a friendly state government to assist with an infrastructure build-out.

So, what’s different about Nissan?

In a word, ethanol.

SOFC is a fuel cell that produces its hydrogen from ethanol, on the fly. The e-Bio Fuel-Cell utilizes hydrogen transformed from fuel via a reformer and atmospheric oxygen, with the subsequent electrochemical reaction producing electricity to power the vehicle.

Unlike conventional systems, e-Bio Fuel-Cell features SOFC as its power source, affording greater power efficiency to give the vehicle cruising ranges similar to gasoline-powered cars (more than 600km). In addition, the e-Bio Fuel-Cell car’s distinct electric-drive features—including silent drive, linear start-up and brisk acceleration—allow users to enjoy the joys and comfort of a pure electric vehicle.

Are hydrogen fuel cell EVs as energy-efficient as battery electric cars, or gasoline-powered cars?

In a word, no. Jeremy Martin at the Union of Concerned Scientists writes:

“While EVs offer the convenience of home recharging and allow the use of existing electricity infrastructure, hydrogen fuel cell EVs allow fast central refueling similar to that of current gasoline-powered vehicles, once the necessary infrastructure is in place. Fuel cell vehicles are much more efficient than internal combustion engines, but not quite as efficient as battery EVs. CARB computed an energy economy ratio for hydrogen fuel cell powered passenger cars as 2.5, which means they can go 2.5 times as far as gasoline-powered cars on the same amount of energy, while battery EVs have an energy economy ratio of 3.4. However, hydrogen fuel cells offer the highest energy storage capacity for electric drive, facilitating scalability to larger and heavier vehicles.”

Is FCV more eco-friendly?

Abso-freakin’-lutely. They will beat, hands down, conventional electric vehicles, which source their energy mostly from fossil fuels, because the electric grid is not greened in most locations, including California. That goes for hydrogen too: in this case, no fossil fuels as the ultimate energy source. Compared to most biofuels options, the ability to use the more energy-efficient electric motor (vs the conventional internal combustion engine) is a winner.

Does the process emit ethanol when fuel cells are in operation?

Yes, but the CO2 is ultimately provided to the underlying plant from the atmosphere, so the CO2 is recycled. New CO2 is not used except where fossil fuels are used for farm equipment, power for the bioconversion site, and so on.

Costs?

Running costs, say Nissan, will be remarkably low—on par with today’s EVs, ultimately benefitting the public as well as businesses, because the e-Bio Fuel-Cell is an ideal fit for wider customer needs because of the short refueling time and ample power supply that can support a range of services such as refrigerated delivery.

What about re-fueling infrastructure?

The good news is that re-fueling is easy and fast. But that doesn’t mean that E100 is widely available. A round of certification would likely be required, for example, to utilize E85 pumps to deliver E100. Still, the problem of converting one pump in a station to E100 is a no-brainer compared to establishing electric re-charging stations or hydrogen fuel outlets.

If Nissan FCVs had wide adoption, what would it mean for ethanol production?

The FCVs use less energy to go the same distance, so cars that go 20 miles per gallon on ethanol would likely travel up to 50 miles per gallon on a fuel cell. That’s good news for costs, of course. Overall, a switch to a Nissan FCV uses about 4X the ethanol, per fuel-up, as an E10 car. No gasoline at all, of course.

So it would be big news for ethanol producers — getting them comprehensively and effortlessly past the E10 saturation point.

Since ethanol is pricing somewhat lower than straight gasoline, the savings per fuel up would be somewhere around 50 percent. If you’re paying $30 today for a tank full that takes you 360 miles, you’d pay something like $24 for a tank full that would take you 600 miles. That’s more or less — ethanol and gasoline aren’t always in complete price synch. But you get the idea — vastly improved fuel efficiency. As well as very friendly to the environment.

Nissan’s Quest for a Zero-Emission Society

The e-Bio Fuel-Cell will realize the concept of “Nissan Intelligent Power,” promoting greater efficiency and electrification of cars and the joys of driving, alongside battery EVs, such as the “Nissan Leaf”, “Nissan e-NV200,” and “e-Power,” which is equipped with an engine housing an exclusive large-capacity motor and power generator.

Further readings

Union of Concerned Scientists (UCS). 2015. Fulfilling the potential of fuel cell electric vehicles.

Union of Concerned Scientists (UCS). 2014. How clean are hydrogen fuel cell electric vehicles?

Union of Concerned Scientists (UCS). 2014. The importance of both battery electric and hydrogen fuel cell electric vehicles. Cambridge, MA. November. Online at , accessed October 16, 2015.

 

More on the story

The Digest’s Multi-Slide Guide to Nissan fuel cell tech

 

 

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