Hyundai ix35 Fuel Cell Offers 365 Miles of Range, and Quick Fill-ups

By · May 01, 2013

Hyundai ix35 Fuel Cell

Hyundai ix35 Fuel Cell

Hyundai joined the London Hydrogen Partnership (LHP) last week. The LHP has initiated more than $66 million worth of hydrogen projects, from buses to scooters and refuelling stations. Hyundai will help by bringing its cars and expertise with the goal of making London a world leader in clean energy.

This comes after the fuel cell version of the Hyundai ix35 (sold as the Tucson in America) was selected last March by the Fuel Cells and Hydrogen Joint Undertaking (FCH-JU) to showcase the benefits of hydrogen and fuel cell technologies to European policymakers.

Hyundai ix35 Fuel Cell

Hyundai ix35 Fuel Cell

There's nothing besides the stickers on the outside to reveal that the Hyundai ix35 Fuel Cell is special. No dramatic differences on the inside either. The speedometer is on the right, and the left dial, which should be a tachometer, has readings going up to 120. That's because it's a power meter showing kilowatts.

Starting the car is conventional, except the absolute quiet says this is no standard automobile. The total lack of noise comes from the use of ambient, instead of compressed air, to feed the fuel stack. Hyundai was the first to develop that technology—it was already present in a 2005 prototype I had a ride in—and it feels superior to all the other systems with noisy compressors. This fuel cell car is silent, just like a battery electric car.

Actually, this Hyundai is very much an EV. It has a battery that can put out a 24-kW current. That is enough for low speed city driving. Some people may then wonder about the usefulness of the fuel cell then. Why not not removing it, enlarging that battery, adding a charger and a plug, to get the same range as the fuel cell gives? The easy answer is that it wouldn't work as well. And, looking further, it's just not doable. This is a compact SUV, but it's still significantly bulkier than a Nissan Leaf. It would take a very large, and very heavy battery to match the range and performance the fuel cell delivers. More than that, according to all the people I talked to—disagree if you like— the fuel cell is cheaper.

Hyundai ix35 Fuel Cell

Hyundai ix35 Fuel Cell

We can debate the cheaper question, but the size and weight issue is easier. The Hyundai ix35 stores 5.64 kg of gaseous hydrogen. This fuel cell car adds weight from the 700-bar tank and the fuel cell itself—but it would take more than 1,000 pounds of the best cells to get the same quantity of energy.

The cost issue is harder to prove, because it's not about the price of a hand-built fuel cell today, but the price in the future when it's built in volume. The average person can't make those calculations, but Hyundai engineers say that fuel cells would not be that expensive if they were put in regular production.

I can't confirm or disprove the claim, but the Hyundai ix35 provides an impressive ride. Suspension and steering could be improved but the propulsion is flawless. The cars I drove was a 2012 model, but Hyundai has already started regular production of an updated ix35 Fuel Cell—gas version should launch as the 2014 model in America—which should correct any remaining small flaws in the model I drove.

Hyundai plans to build a thousand of them before 2015, when the car should be widely available. That is, in the places few and far between where there will be a network of hydrogen stations. Sounds far-fetched, but with a 100-kW fuel cell and a consumption below one kg of hydrogen per 100 kilometers, this car offers 365 miles of range in a fill-up that only takes a few minutes. You have to admit that no battery-electric vehicle can match those characteristics.


· · 5 years ago

Dear Laurent Masson,

I think you got the battery size wrong. It is 24 kW, not 24 kWh. Otherwise your article seems correct. I wish we could step five years ahead when FCEVs have gotten into more general use. Thanks for writing about it.

· · 5 years ago

I've often thought that any sort of hydrogen vehicle should include a complement of batteries to store excess electrical energy produced by the fuel cell or to capture whatever is produced by regenerative braking.

Very interesting article, Laurent. Do you know if it's possible for the driver to select battery-only operation for shorter range city driving? Is it possible to plug in and charge the battery? Or is the fuel cell dependent upon working with the battery on all accounts?

· · 5 years ago

Yay. Fool Cells. If they don't at least add a plug to make this an E-REV, it's dead to me.

@Jonas Blomberg,

kW is a unit of power, kWh is a unit of energy. The Leaf has a 24kWh battery, capable of putting out about 90kW. Are you saying that this battery can only put out 24kW? If the meter goes up to 120kW, that means the other 96kW are from the fuel cell. I thought that fuel cells were high on energy but low in power, hence the reason to supplement it with a battery. 96kW is pretty high on power. And what is the point of the battery then?

· · 5 years ago

@Brian Schwerdt

Agreed, the 24kwh figure seems abit high for being used just for buffering.. .24 kwh or 240wh would be more reasonable, besides I thought Hyundai was using supercapacitors in their hybrids for this function.

I've said it 20 times before but one more time, since GEN3+ Nuke plants aren't going to be built anytime soon due to Fukushima/San Onofre, etc, I don't see any cheap source of Hydrogen anytime soon, and methane derived home refuelers are to my knowledge very expensive, and use a fair amount of gas compared to the amount of H2 Gleened.
Otherwise, if you can find it, I'm assuming H2 is still around $7-8 per gallon.

Someone please explain to me why this is so much superior to Electric Cars. At least EV's are usually cheap to run, for all their other current disadvantages.

· · 5 years ago

Thanks for explaining the kW vs. kWh difference, Brian. The non-engineer in me can never keep this straight . . . and probably still can't on most days. Which begs the question: what IS the kWh rating of this car's battery? Or do we have to know a host of other operating parameters? I found an online kW to kWh convert online, typed "24" into the kW field, typed "1" into the hours field and came up with (surprise!) 24kWh.

As for why you might want a battery in a "fool cell" car, I gave a probable set of reasons above. Keep the hydrogen for the long trips, charge the batteries at home and drive on those cells most of the time around town. That is, of course, if this car can be operated like Volt, but with a fuel cell instead on an ICE.

I'd be amazed to actually see these things in the dealer showrooms by late 2014 and there still is a massive blind spot among hydrogen-friendly OEMs as to where we're going to get all this gas and whose going to pay for the refueling infrastructure. But I'm always interested to read about it.

· · 5 years ago

"Well, according to all the people I talked to—disagree if you like—is because the fuel cell is lighter and cheaper."

Lighter, I could concede. Cheaper than another ~50 kWh of batteries?

If *that* is true, then their engineers are getting nothing short of a Nobel prize when this gets released.

Then you get to consider what happens when you need to refuel. There's another reason for keeping a large battery on board: performance. Usually, pure fuel cell vehicles have crap acceleration because the fuel cell itself can't produce a lot of power. So they have to store it somewhere for the times when you need more instantaneous power. And to do that, usually they use a much smaller battery than 24 kWh.

So if you drive until you need to refuel, then you're going to be waiting a while for the battery to charge before you start moving again.

To me, this doesn't make a lot of sense. I'm going to pin this on you, because more than likely it's because you have the numbers wrong. I could see a 2.4 Kwh battery for starts and regen. But to have a 24 kWh battery PLUS a fuel cell would make the car outrageously expensive. It would be like taking the cost of a Leaf and dropping a $100,000 fuel cell on top of that. Even if they're making the fuel cell "cheaper than 50 kWh of batteries" (which would run a ballpark of $16,000. No less than $10,000, I would expect, and that would be a highly optimistic wholesale rate), that's *still* more expensive than the BEVs we already have on the market. Then after that you still have to pay through the nose for fuel.

And people already say that BEVs are only for people who will throw practicality out the window in exchange for environmentalism. That's why people are tearing fuel cells down as being "fool cells", and I haven't even touched on hydrogen production yet.

· · 5 years ago

@Bill Howland
You forgot to add that we can add about a hundred million EVs charging at night to the fleet spread across the country and only cut the 'cream' off the top of our nighttime baseload that would be wasted emissions anyway. Total, complete, guilt-free driving (except manufacturing/recycling energy).

@Benjamin Nead
To make matters worse, kWh is annoying to any undergrad or physics newbie trying to keep things straight. It's bald-facedly redundant. Power is Energy / Time. kWh is a unit of Energy in that it takes a unit of Power (kW) and *multiplies* by Time (h). The Time cancels out, so you're left with energy.

It does, however make it very easy to guess how long you'll need to charge your car, given the kW of the charger: battery kWh / charging station kW = hours.

Finally, before I go, when converting between kWh and the normal, official, standard, easier energy unit--Joules--I discovered that 1 MegaJoule in most cars will get you exactly 1 mile! 3.6MJ = 1kWh (that's because there are 3600 seconds in an hour), and each kWh gets you as a general rule 3.6 miles of range. You can say your car is pretty tight if it can get 1.1miles/MJ, and is pretty power hungry if it drops below 0.9miles/MJ.

· · 5 years ago


Cool observation about MJ/mile!

Most people are (or should be if you pay for your electricity) familiar with the kWh unit, since that's how utilities measure electricity to homes, and by extension, to EVs. I agree that to a physicist it's redundant. Joules are of course preferred to the physicist.

BTW, for those following along, one Watt is defined as one Joule per second. A kW is 1000 Watts, or 1000 Joules per second. One kWh is 1000 Watts for one hour, or 1000 Joules per second for 3600 seconds. Or simple 3,600,000 Joules. 3.6 Mega Joules.

· · 5 years ago

I've seen the press release for this vehicle before and they do specify a 24kW peak power from the battery. In contrast, the Ford C-Max hybrid has a 1.4 kWh battery with a peak output of 35 kW. That works out to 2.4 minutes of full power before the battery dies. If the Hyundai has the same ratio then that works out to a 960 Wh or maybe a 1 kWh battery. That is just an estimated guess though so don't put too much stock in it. If the battery could keep it's output at 24 kW for 1 hour then it would be rated at 24 kWh. But more than likely it can only keep up that power draw for only a couple minutes.

Also, a fuel cell needs a battery buffer, even though it's rated 100 kW output, because it can't ramp its power output up or down quickly enough compared to a battery or an ICE.

· · 5 years ago

Thanks, Anderian. It became somewhat revelatory to me when I finally got volts X amps = watts under my belt. But, yes, the amp hour thing is counter-intuitive. Glad to know I'm not the only one flustered by it. The Joule equations do make it more understandable.

So, the battery in the Hyundai ends up being fairy small (only about 1kWh?) and is there only to buffer the fuel cell during quick acceleration? I don't know how scalable fuel cell technology is, but the smaller cell with bigger battery scenario still sounds like the way to go to me. Perhaps that's just my plug-in EV bias and the engineers are being market directed to make it more fuel cell than battery.

Still, also, all the same problems with the hydrogen we've talked about before: how to manufacture it without causing environmental issues that neutralize the cleanliness of running it through a fuel cell and the cost of all of it.

· · 5 years ago

And, yes, where's gorr to tell us that the future is here and the rest of us better get on board?
He's uncharacteristically late to this party. :-)

· · 5 years ago

Gorr has been pretty reasonable lately.. He even likes the Chevy Volt!!!! I bet if you had shown him his own statement back in time 2 years, he would have had a heart attack back then!

I have no problem with kilowatt-hours. Its a metric term for those who like metric. To convert to proper British terms, 1 kwh = 3.413 British Thermal Units. A BTU is the amount of heat necessary to heat 1 pound of water 1 degree fahrenheit. How's that for a neat little unit. 970 BTU's will evaporate 1 pound of water at 212 degrees to 1 pound of steam at 212 degrees (in tables they've coined the phrase "FROM AND AT").

1 U.S. gallon (128 oz) of Gasoline has 125,000 BTU. #2 Fuel oil (Diesel) has 140,000.

A pound of H2 is about 60 cents, 48% by natural gas, 30% by oil (and you guys are going to LOVE The next one), 18% by COAL, and 4% by hydrolysis (3 times as expensive). Also the cost goes up 3 times if it has to be liquified for the distributor (likely).

5.64 *2.2 = 12.48 pounds. $7.45 or $22.34 if it is stored at the distributor in liquid form. Not sure how much they charge to compress it. Or whether its refueled as a liquid and it is allowed to boil and build up pressure all on its own, probably the latter.

The Heat value of 1 lb of H2 is 61,000 BTU, but I'm unsure what percentage of that a fuel cell can recover.

So this car goes 365 miles on the heat content of under 6 gallons of gasoline?

Lets assume 95 kwh of electricity for an ev would be required to go 365 miles in this vehicle. So thats 324, 235 btu. 5.7 gal of gas * 125,000 btu would be 712,500 btu. So I guess all these numbers are ball park reasonable.

So, $22.34 doesn't seem too unreasonable to go 365 miles. I'm having trouble finding exactly how much H2 costs at a retail H2 pump. Anyone have any info? My pricing seems a bit too cheap, but honestly this is the first time I've tried to rigorously calculate the cost.

· · 5 years ago

Oops before they yell at me about decimal points again, 3413 btu is 1 kwh

· · 5 years ago

I found out not too long ago that the value for the BTU of natural gas is actually the average of the HHV and LHV values.

LHV-low heating value = 3236 BTU/kWh
HHV-High heating value = 3585 BTU/kWh

Apparently, the government and power companies use the HHV in their reports of annual power generation.

· · 5 years ago

The alleged better efficiency of battery cars over fuel cells is based on making hypotheses favourable to the former.
In fact using present day methods of generating and despatching electricity at the average US efficiency, which is pretty heavy on fossil fuels and the most currently economic way of producing hydrogen by reforming natural gas both use about 1MJ/mile on a well to wheels basis

The supposed lower efficiency of fuel cells comes about by assuming that the energy is first generated into electricity, then electrolysed to hydrogen and back, which obviously entails losses in conversion.

In fact there are umpteen possible pathways including high temperature electrolysis which utilises the otherwise wasted heat of the reaction, and perhaps direct conversion of sunlight to hydrogen etc.

In any case, for those who fancy a high input of renewables, practical plans to do so invariably involve storage, which is always lossy, and storing it as hydrogen is one of the most favoured options.

So IOW the supposed losses are in fact against a resource which would otherwise be thrown away, such as stranded wind (wind is very variable, so at any rate above ~10% of the grid produces excess power on occasion, which is currently dumped)

It doesn't bother me, as I am a nuclear guy, and using nuclear plant it is easier to do all electric, but those who simultaneously advocate a lot of renewables and dislike hydrogen and fuel cells in my view have not done their research, or are indulging in wishful thinking.

· · 5 years ago

Fuel cell cars always use a fair size battery to provide oomph for acceleration, enable regenerative braking and so on.

It is though trivial to increase the battery size to make it a plug in hybrid, unlike the complex engineering needed for the Volt to marry ICE and electric.

You wouldn't lug around 24kwh of battery, but 12-16kwh is perfectly practical, which would mean that everyday running around would be done on battery power, but there would be no hassle at all in longer journeys using the fuel cells.

This immediately knocks out most of the quibbles about fuel cells, and incidentally a great deal of them for battery cars.

If we do set up systems using electrolysis to produce hydrogen and have an efficiency penalty, then for local journeys that is not going to matter, and only the long distances which battery cars are not very good at would be covered by hydrogen, so the alleged poorer efficiency becomes moot.

Far less hydrogen infrastructure would be needed, which knocks out another oft repeated canard about hydrogen.

Conversely the problem of how to wire up the ~50% of cars which are kept by the road, not in a garage, is largely overcome by the flexibility of using hydrogen as well as batteries.
However batter only advocates seek to sweep the problems of charging those cars without a garage under the carpet, this is not a trivial problem.

A fuel cell battery hybrid eliminates the need for around 70kwh or more of batteries to give a battery car respectable range.

Battery only advocates simply like to assume that performance of batteries will increase so greatly, and costs reduce even more, that this can be overcome, whilst of course assuming that fuel cells do not improve hardly at all.

If you ask me how it will pan out, I don't know, and neither does any other serious commentator or organisation, who are pushing ahead developing both batteries and fuel cells.

We don't know and can't know how their progress will compare.

Certainty in the matter is the preserve of guys on blogs.

Dismissing them as 'fool cells' shows the commentator to be something of a fool themselves.

Identical fuel cells already showed themselves to be the most reliable back up power supply in Hurricane Sandy, outperforming both batteries and diesel.

Fuel cells are a vast area of technology, at its very beginnings, and none of us know how great the progress will be, but it is already clear that they will provide an effective solution across whole swathes of technology.

· · 5 years ago

How much does will the vehicle cost? How much will it cost to fill the hydrogen tank(s)? How long will the fuel cell last, and how much will it cost to replace it? Why doesn't it have a plug to charge the battery? What good is the range if there are no hydrogen filling stations? How much energy does it take to make the hydrogen?

I think a small diesel or gasoline genset would be far more practical, and cost a lot less.

Hydrogen powered car = unicorn.


· · 5 years ago


You are right, we don't know with any certainty what the future holds. A "hydrogen economy" sounds great, but today there are major hurdles. By contrast, today the only hurdle to plug-in technology is a slight price premium. And even that often isn't the case when total cost of ownership is considered. I myself am not a purist, at least not in the near-to-mid-term. Technology like the Volt or Energis is the right solution for now. These cars actually solve the problems you mention with battery-only (e.g. no access to garages, quick refuel times), unlike hydrogen, which is not available in most of the US. Gasoline can be purchases in any town in America. No new infrastructure needed. If most charging can be done at home and at work, very little new infrastructure is needed there either.

I am glad people are researching new things, including hydrogen. You never know where it will lead. Einstein once said "If we knew what we were doing, it wouldn't be called research". But I grew weary of hydrogen being dangled in front of me, always just out of reach. Today that kind of thing is a distraction from real technology, selling today in the thousands of cars per month. Keep pressing on with research, but stop pretending that these cars *will* be available N years in the future (or ever).

· · 5 years ago

The price of this car is €128000 or $166000. I seriously doubt the fuel cell is cheaper than a battery, a battery that this car could carry any way.

· · 5 years ago

@DaveMart: If the whole point of hydrogen fuel cell vehicles is environmental, then getting said hydrogen from natural gas defeats that purpose.

As an added aside, on top of the complete lack of any environmental benefit whatsoever, you stack added expense on top of added expense. You have an expensive fuel cell stack. You have an expensive new infrastructure to build. You have the difficulties inherent to storing and transporting hydrogen gas.

And for what? So you can burn natural gas instead of gasoline? Today, you can convert any gas car to use propane or natural gas and take advantage of an already existing infrastructure. It's not tremendously expensive to do so, and the fuel is far less expensive to transport and store. The *only thing* you're saving over a purely electric vehicle is about an hour on the few days a year that you want to drive some significant distance more than normal. Considering the energy that goes into producing hydrogen in the first place, you're better off just burning it to make electricity. It's cheaper that way.

Hydrogen-fueled vehicles are a pipe dream for people who are easily fooled into thinking that it's more environmentally friendly than other, far cheaper alternatives.

· · 5 years ago

@Jesse Gurr.

You're mixing up a few different things here, I think maybe you should reread what you typed. Im sure you didn't mean it as typed. Rather like saying 2 liters is 67.6 oz., it can never change.

The "UHV" (condensing) of natural gas varies, but its around 1022 BTU/ cubic foot.

An electric heater consuming 1000 watts exactly will heat 3413 pounds of water 1 degree rankine after being on for an hour, assuming in a thermos. This can never change. Again, 12" is usually a foot, 5280 feet is usually a mile, etc.

· · 5 years ago

Here is the values for the HHV and LHV for natural gas with the definition of HHV and LHV.

I don't know what UHV is though. Ultra Heating Value? 1022 BTU/ft3, is that LHV or HHV? I always see 3413 BTU/kWh but there is no mention if that is HHV or LHV. So after some research I found that table. Very informative. I was curious because the annual energy efficiency report says it uses HHV values for its calculations. So I had to know what the actual value of the HHV of natural gas was. If you will notice from the table, HHV of natgas is 1089 BTU/ft3.

I'm not saying you are wrong, I just don't know where 3413 BTU/kWh came from.

· · 5 years ago

@Jesse Gurr

Oh ok, what they are talking about in your links is the amount of natural gas heat needed to generate 1 kwh of electricity in california's natural gas fired plants (7855 btu was the latest figure).. If it was 100% efficient it would be 3413. So the latest figure shows the over all efficiency is 43.45 %. Not too shaby.

1089 btu/ cubic foot is interesting, but I'm talking about Standardized Cubic Feet at STP (or 1atm, 20 degrees centigrade) (68 degrees fahrenheit).

Your tables are normallized on 32 degrees fahrenheit, so there's more gas (heavier, more poundage). 1022 is the commonly used industry figure, and it varies slightly since it is a "natural" resource, and the mixture varies slightly from time to time.

If you don't believe me check out the nameplate of any electric heater for sale. It will be proportional to 1000 watts = 3413 BTU.. This can never change.

· · 5 years ago

@Jesse Gurr

Since people are just waiting to pounce, let me correct that to 1000 watts = 3413 BTU/Hour. Obviously a 100 kw heating element would produce 341,300 btu if left on for an hour. IF left on for 20 hours it would produce 6,826,000 Btu.

· · 5 years ago

@Jesse Gurr

You want me to derive the conversion betwee 1kwh and BTU? 1055 joules is 1 btu, therefore 3413 btu is 3,600,715 joules. 1kwh by definition is 3,600,000 joules. Good enough?

· · 5 years ago

Well that's confusing. STP is at 32F but the EPA saw fit to do it differently and make 60F standard just for natural gas. Page 157
Apparently it is 1020 BTU/ft3, you are correct. My bad :P

· · 5 years ago

Oh didn't see those last 2 posts. No I don't need you to derive but thanks anyway. This has been informative.

· · 5 years ago

I have many times provided links to numerous massive studies by the DOE and others which cover all the points you raise.

Ignoring them and continuing to claim that they are unanswered questions is simply being wilfully obtuse.
You don't like the answers they give, and hence you ignore them.

Equally fantastical are ludicrous claims that:
'Hydrogen-fueled vehicles are a pipe dream for people who are easily fooled into thinking that it's more environmentally friendly than other, far cheaper alternatives.'

Amongst those who are not in touch with reality according to this gloss are, as mentioned, the DOE, just about every major car company in the world, and just about every large renewables program including those in Germany and Japan.

We are asked to believe that some guys on blogs who don't happen to fancy hydrogen and have scribbled, invariably inaccurately, on the back of envelopes are the ones really in the know.

As for the notion that using hydrogen invariably means fossil fuels, that is no more true than that producing electricity is only possible using them.

Already in every program there is considerable input of non-fossil fuel sources, and that is not going to stop.

I would link once more to the studies from just about everyone to support what I am saying, but it is clear that the contrary position is not based on data and analysis.

Indeed, zero links are provided to their sweeping claims, and instead the reliance is on entirely false canards such that batteries are far more efficient, which are arrived at by the simple expedient of ignoring well to wheels losses for batteries and/or cherry picked assumptions on future, not present, generating strategies.

· · 5 years ago

My mistake. Hyundai doesn't reveal its battery capacity (in kWh), what it says is that the battery can deliver 24 kW max current, which is enough for low speed city driving, and that the fuel cell, which puts out 100 kW, is needed if the driver asks for more power.

I'm correcting post now.

· · 5 years ago

Try to read ix35 backwards.

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