NREL Publishes Interim Progress Report on Fuel Cell Learning Demonstration
07 August 2007
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| Composite view of fuel cell efficiency from all participating OEMs. Click to enlarge. |
The US Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) published an Interim Progress Report summarizing results from the first two years of the Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project.
The report includes 30 composite data products that show the project’s technical results without identifying individual companies. It includes information on fuel cell efficiency, projected fuel cell durability, fuel economy, driving range, and refueling rates. Results to date indicate that the fuel cell vehicles are performing at levels close to DOE baseline targets. The results also highlight the ongoing need for better hydrogen storage solutions.
The project is designed to monitor fuel cell vehicles and hydrogen fueling infrastructure performance in demonstration fleets throughout the US. The 5-year project will assess technology readiness and provide data on the status of hydrogen research and development. The industry teams consist of automotive and energy company pairs, including Chevron/Hyundai-Kia, DaimlerChrysler/BP, Ford/BP, and GM/Shell.
NREL will evaluate overall industry and vehicle progress when second-generation fuel cell systems are introduced in 2007 and 2008.
Fuel cell system efficiency. Vehicle chassis dynamometer tests confirm that hydrogen fuel cell systems for vehicles can achieve very high conversion efficiency. The system efficiencies at 25% ranged from 52.5% to 58.1% from the four teams, very close to DOE’s long-term target of 60%.
Projected fuel cell durability. Fuel cell stacks will need to last approximately 5,000 hours to enter the market for light-duty vehicles. For this demonstration project, DOE established targets of 1,000 hours in 2006 and 2,000 hours in 2009. The ultimate goal is to develop fuel cell stacks that last at least 5,000 hours.
Vehicles in the project have not yet achieved 1,000 hours of operation, so NREL made projections based on the slope of the voltage degradation. The projections suggest that the time to 10% fuel cell stack voltage degradation averaged over 700 hours.
One team achieved a time to 10% degradation that was more than 1,250 hours, exceeding the 1,000 hour DOE target. The second-generation stacks introduced beginning in late 2007 will be compared to the 2,000 hour target for 2009. Other tests within the DOE hydrogen program have validated 5,000 hour life in the laboratory. This suggests that more durable materials are still making their way from the laboratories to the demonstration projects.
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| The graph compares the fuel economy of hydrogen vehicles on a dynamometer, window-sticker fuel economy, and on-road fuel economy for fuel cell vehicles. Click to enlarge. |
Vehicle fuel economy. NREL measured vehicle fuel economy from city and highway drive-cycle tests on a chassis dynamometer. The dynamometer fuel economy displays a range from 50 miles per kilogram of hydrogen to 65 miles per kilogram of hydrogen.
These raw test results were then adjusted according to US Environmental Protection Agency (EPA) methods to create the “window-sticker” fuel economy similar to what consumers see when they purchase conventional vehicles. This resulted in an adjusted fuel-economy range of 42 to 56.5 miles/kg hydrogen for the four teams.
The on-road fuel economy shows a range of 30 miles per kilogram of hydrogen to 45 miles per kilogram of hydrogen.
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| Driving range. Click to enlarge. |
Vehicle driving range. NREL calculated vehicle driving range using the fuel economy results multiplied by the usable hydrogen stored onboard each vehicle. Using the EPA-adjusted fuel economy resulted in a range of 100 to 190 miles from the four teams. The second-generation vehicles will strive to increase the range to 250 miles—the 2009 DOE target.
Refueling rates. Consumers will require hydrogen vehicle refueling that is as similar as possible to conventional vehicle refueling. NREL analyzed more than 3,700 refueling events, and quantified the amount, time, and rate.
Refueling took an average of 4.19 minutes with 78% of the refueling events taking less than 5 minutes. The average amount per fill was 2.15 kg, reflecting both the limited storage capacity of these vehicles (~4 kg max) and nervousness about letting the fuel gauge get close to empty.
DOE’s target refueling rate is 1 kg/minute, and these Learning Demonstration results indicate an average of 0.71 kg/min and a median of 0.75 kg/min. Twenty percent of the refueling events exceeded 1 kg/minute.
From the results NREL concluded that hydrogen refueling times and rates close to being acceptable. The challenge, however, is to put enough high-pressure hydrogen onboard the vehicle to provide adequate range. Researchers are also looking for advanced hydrogen storage materials that can replace the need for high-pressure tanks.
Resources:
Learning Demonstration Interim Progress Report – Summer 2007 (NREL/TP-560-41848) July 2007
Fuel cell durability and life have a long way to go before they meet the 5000 hour target life. I think fuel cells hold great promise, but I find it hypocritical that automobile companies dismiss PHEV's until they claim to have the perfect battery, but are willing to spend billions on fuel cells that are perhaps decades away from being commercially viable. While this report states one fuel cell achieving a 10% loss after 1250 hours, I have read in another report that actual fuel cell life for most fuel cell vehicles has been dismally low. Unfortunately, I read the low fuel cell life article a couple of months ago and have not been able to find it since. Perhaps there is someone else reading this blog can chime in refuting or collaborating this claim.
Posted by: James White | 07 August 2007 at 07:24 PM
I'm not even that impressed with the long term potential of hydrogen as a fuel, much less the dismal performance being displayed so far. Even IF they were able to deal with all of the problems discussed here, we would still need a mammoth investment in distribution technology, not to mention a clean and economical source of hydrogen. The whole thing strikes me as an ideologically-driven fraud.
Posted by: George | 07 August 2007 at 08:06 PM
An acquaintance of mine at Ballard indicated that they would get significantly better durability (3 to 4 times) from the membrane if the fuel cell were run at a steady state. If a fuel cell was used as a range extender for a PHEV then it could operate under optimal conditions.
Posted by: Neil | 07 August 2007 at 09:10 PM
"on road fuel economy of 30-45 miles per kg H2"
It takes 60 kWh of primary electricity to make and compress 1 kg of H2. So these vehicles are managing a whopping 0.5 - 0.75 miles per kWh, when a BEV or PHEV can easily manage 4-5 miles per kWh.
More alarmingly, if you take the average amount of CO2 released to produce a kWh of electriticy as 700 g in the USA, these vehicles are indirectly releasing 930-1400 g CO2 per mile (if H2 made by electrolysis).
A Prius emits only 167 g CO2 per mile, and a hummer 566 g/mile, so these FCVs could emit more than twice the amount of CO2 as a hummer!
Posted by: clett | 08 August 2007 at 04:54 AM
Bingo, clett. The question is not whether we can find a way to make, distribute, dispense, and use hydrogen in vehicles, it's whether we can do so in a way that can compete with other options.
I've yet to see any evidence that hydrogen can compete, even if you make some really generous assumptions about breakthroughs in fuel cells and most parts of the hydrogen food chain.
Posted by: Lou Grinzo | 08 August 2007 at 06:48 AM
Despite all of the challenges associated with H2, I'd be willing to bet that we haven't heard the end of it by a long shot. I don't see any other way for the oil companies to maintain their dominance in transportation fuels without it. They'll keep piling money into it until either they overcome the market by shear strength of money or electrics take over.
Anyone ever see a comparison of the money invested in FC research vs. that invested in battery research? I'd be really curious.
Posted by: Neil | 08 August 2007 at 07:18 AM
Look its simple. Using 2012 deadline goals as a guide you get a car that used 2x the energy as an ev car WHEN using h2 as in when going more then 20-40 miles a day and thus depleting the battery.
Later goals will drop that cost from 2x to 1,5x down to as little as 1.2x or less.
And even todays h2 systems can manage 300 mile ranges with alot less weight then pure ev can.
And h2 is the only fuel getting CHEAPER.
And unlike alot of other things you dont have to need to be in the right climate with rainfall and blah blah blah you dont need to worry about climate change you dont need to worry about food vs fuel and you dont have to lug 2x the weight to go 2x the distance.
The simple reason h2 is ging along is they think they can get it not just ok for cars but GREAT. They think they can get the cost down to 3.60 a kilo. They think they can get the storage more compact and less energy costly. They think they can get a fuelcell much cheaper and they think they can get the cost for h2 over ev to be a small fraction of the total energy instead of most of it as it currently is. And so far they seem to be right.
Posted by: wintermane | 08 August 2007 at 11:34 AM
I often see people complain that the entire efficiency of a fuel process is low. Fuel efficiency is important inside a vehicle where the store of energy is limited. When you talk about the cost of electricity to produce a given quantity of hydrogen, the efficiency is much less of a concern. We get all the energy we ever need from the sun. Efficiency in producing hydrogen for mass distribution is not all that critical. I think if you could get 30% - 50% efficiency in producing hydrogen that would be good enough. Now if the US would get serious about generating renewable electricity there would be enough electrical power to provide for a "hydrogen" economy and wean itself off of dirty coal. The US has the vast unused land areas in the south west and mid west that are perfectly suited to solar power on a massive scale. There's also nobody to mind wind generation stations either. Geo-Thermal energy also may be useful. Germany (20% renewable before 2020 if memory serves) and the Netherlands (among others) have set a good example. Perhaps the US could follow this for a change?
I acknowledge hydrogen fuel cells have some serious drawbacks that need to be over come. I'm tired of people citing the efficiency of the hydrogen production as one of the reasons for abandoning the concept of using hydrogen fuel cells for transportation. Hopefully in 50 years or so we'll have fusion power anyway which will make the efficiency of hydrogen production a moot point.
Posted by: KS | 08 August 2007 at 01:11 PM
Efficientcy of production is already factored into the cost of the h2 at the pump. Thats WHY combined with the equipment getting cheaper h2 costs far less then ever before and is getting cheaper.
As long as they can make it cheaper and can get the energy cleanly enough to make it it doesnt matter.
As for the other end the fuelcell and tanks....
Ford chopped the size weigh and as a result cost of its fuelcell in HALF in just one generation and it dropped the cpst upped eff and upsed power output from 50 kw to 80 kw in the generation before that. AND these generations arnt 20 years apart they are 2-3 years apart.
2012 gives enough time for 2-3 more generations of fuel cell and newer better tanks.. the last gen of tank dropped the cost ans greatly improved the capacity...
Finaly we have the blazingly obvious fact that as co2 per km becomes more important and batteries stay spendy and ill capable of handling lux cars and suvs... h2 has a v ery solid market segment to itself.. a VERY valued one were almost ALL the car makers profits sit and one where fuel providers can reap rewards too... THAT is what drives h2 MONEY and wealthy people.
Posted by: wintermane | 08 August 2007 at 06:53 PM
Welcome back, Wintermane.
Hydrogen is the most efficient fuel that mankind can synthesize from renewable energy or nuclear energy right now, using the high-temp electrolysis or thermochemical idodine cycle.
High temp electrolysis will double the electrical efficiency of room-temp electrolysis. 1 kg of H2 contains 36 kwh of energy. At 70% efficiency at room temp, it takes 51kwh of electrical energy. At 800 degrees C, it will take only 26 kwh of electrical input (solar or wind electricity) to generate 1kg of H2 containing 36kwh of energy!
A BEV capable of 250wh/mi running on grid electricity made at ~33% efficiency from fossil fuel will actually consumes 750 wh/mi of primary fossil fuel energy.
A H2-V at 50 mpkg of H2 consumes 36 kwh/50mi = 720 wh/mi. A Honda FCX with proven efficiency of 70 mpkg of H2 consumes 36/70= 500wh/mi. If H2 is made from coal or NG at 70-80% efficiency, then 500wh/mi / .80= 640wh/mi of primary fossil energy. If the H2 is made from high-temp electrolysis at 140% efficiency, then the efficiency will be 500wh/mi / 1.4= 357 wh/mi of primary renewable electricity.
A BEV, even if running on solar or wind electricity must suffer from the lost of energy in battery charging and discharging ~90% for Li-ion or 80% for NiMh, so 250wh/mi / .8= 312 wh/mi. This loss is variable, depending on the rate and depth of discharge of the battery, and also on the rate of discharge of the battery. Lead-footed driver will cause higher current drain in the battery and motor winding in the form of ohmic resistance, hence higher wh/mi consumption.
Now, the real kicker is that for $2000 USD, you can store about ~140 kwh of H2 energy. Let's say that your BEV with battery to wheel efficiency of 75% vs. the Honda FCX at 60% efficiency tank-to-wheel, meaning that 140kwh of H2 is equivalent to 140kwh x 60/75 = 112kwh of battery-equivalent energy. At $500 /kwh of battery cost, let's see how much a 112 kwh Li-ion battery will cost? 112kwh x $500= $56,000 USD. Wow. Current A123 battery is listed at $2000 USD/kwh, bringing the price to ~$200,000 USD if you wanna choose current A123 nanotech lithium that may last for the life of your car. At $500/kwh cost, your Li-ion battery pack will last but 3-5 years the most, or 300 charges.
Posted by: Roger Pham | 08 August 2007 at 09:53 PM
Glad to be back had connection issues for awhile there...
I expect they will both get the fuel below 5 bucks a kilo and get the avergae fuel cell CAR up around 90 mpk with fuelcell suvs and trucks being in the 40 range. That should help thinks alot as far as h2 use.
Posted by: wintermane | 09 August 2007 at 02:10 PM
"Let a thousand flowers bloom..." was a genuine cynical statement by a genocidal killer of the 20th century. He neglected to mention that the rest of his statement is " ...before we cut them all down like a scythe..."
But the sentiment to allow lots of diferent approaches proliferate and the best answers will emerge.
I stand open-minded.
Personally, I think this is a dead-end technology. There are othe ranswers that will work. If nothing else emerges, this may be the only alternative, but I doubt it. But there will be some applications for it. I don't think ground transport is it but ...
Does anyone have any conception of how hot 800 degrees C really is? It is well beyond the operating temperature of most steels. Common steel would be glowing red-white hot. It is the temperatures to be found in the heart of turbine jet engines. Preheating steam to those temperatures to raise the efficiency of H2O electrolysis is pretty tough. As an engineeer, I can assure you that steam boiler codes don't run to within 500 degrees Farenheit of those temperatures.
Doing this on a small laboratory scale is one thing; doing it to generate the prodigious quantities of H2 needed is quite ANOTHER THING.
You are speaking very casually of running massive operations containing the pressure of steam 500-700 degrees beyond the temperatures industry is familiar.
The future sources of electricity will provide abundant electricity but this idea still sounds imaginary. Long before this gets practical I suspect that BEVs PHEVs wil have swept the field.
But I could be wrong... So "...Let a thousand flowers bloom..."
Posted by: Stan Peterson | 12 August 2007 at 07:19 PM
Thanks, Stan, for bringing up the technical issue regarding 800-degree temp.
Solid Oxide cells are ceramics that can withstand thousans of degrees C, so heat is no problem. Steam boiler can't get very hot because the pressure of steam in a boiler will build up exponentially with rise in temperature and not linearly. So, the boiler stays at much lower temp than 800 degrees, but the steam can be super-heated to 800 degrees C at a more comfortable pressure after leaving the boiler. Turbojet engine core runs at 1100 degrees C for older design, up to 1400 degrees C for hollow, internally-cooled blades, or for crystal blades.
Yes, steel will melt around 1400 degrees C, and will get soften at 800 degrees C, but, the steel liner can be cooled with steam that will be fed to a steam turbine to recycle the high heat involved. Cooling is the same reason your car engine with peak combustion temperature of ~2500 degrees C can operate in an aluminum engine which melts at ~600 Degrees C.
"Let a thousand flowers bloom" is from Mao Zhe Dong, a cult-like leader who made a mess in China with huge famine than killed tens of millions, and economic collapse.
His successor, Deng Xiao Peng, was a much more pragmatic man who started China's massive economic reform, but only allows a few flowers bloomed at a time! His famous statement was: "It doesn't matter whether a cat is white or black, as long as it catches mice!" Same here, it matters not what technology used, as long it produces results, in the most timely manner.
Posted by: Roger Pham | 13 August 2007 at 03:12 PM
@Roger Pham
"Hydrogen is the most efficient fuel that mankind can synthesize from renewable energy or nuclear energy right now, using the high-temp electrolysis or thermochemical idodine cycle."
Hydrogen is not really a fuel as such, but more an energy carrier, nor is it the most efficient. Electricity is produced much more efficiently.
To produce H2 from nuclear energy, only electrolysis is currently available as high temperature nuclear is not yet possible. Now, the maximum efficiency is 33-35% for nuclear to electricity, 75% electrolyser (high-end), 85% on LHV for compression to 800 bar (for 700bar storage on vehicles). This gives an overal efficieny of H2 production of 25%.
"High temp electrolysis will double the electrical efficiency of room-temp electrolysis. 1 kg of H2 contains 36 kwh of energy. At 70% efficiency at room temp, it takes 51kwh of electrical energy."
Whereas high temp electrolysis will indeed increase efficiency by a few percent due to less activation overpotential, it is especially the high pressure electrolysers that have much more potential. These operate at 400-750bar so that the compression stage of H2 can mostly be avoided and replaced by a pumping stage at the H20 side (up to 10% won in efficiency.
"At 800 degrees C, it will take only 26 kwh of electrical input (solar or wind electricity) to generate 1kg of H2 containing 36kwh of energy!"
Now this is completely impossible (2nd Law of Thermodynamics). You can't take more energy out of a process, than you put in it.
"A BEV capable of 250wh/mi running on grid electricity made at ~33% efficiency from fossil fuel will actually consumes 750 wh/mi of primary fossil fuel energy."
If you're producing H2 from NG or coal, than please also you current technology for electricity production. For electricity from NG it is 55% and from coal 45-50% for ultra super critical plants. So at about 50% eff that would be 500wh/mi.
"A H2-V at 50 mpkg of H2 consumes 36 kwh/50mi = 720 wh/mi. A Honda FCX with proven efficiency of 70 mpkg of H2 consumes 36/70= 500wh/mi. If H2 is made from coal or NG at 70-80% efficiency, then 500wh/mi / .80= 640wh/mi of primary fossil energy. If the H2 is made from high-temp electrolysis at 140% efficiency, then the efficiency will be 500wh/mi / 1.4= 357 wh/mi of primary renewable electricity."
140% efficiency is NOT possible. Efficiency is always lower than 100% on a Higher Heating Value (HHV=> condensing the watervapour to liquid in the exhaust). on a LHV this would be about 118%. So if the H2 would be made from electrolysis at 86% (almost highest theoretical value) this would be 581Wh/mi. Plus you have to make your electricity, if you assume this as a 'given' for renewables, than the same goes for the previous paragraph and comparing the 500Wh/mi vs the 581Wh/mi, the electric car still wins.
"A BEV, even if running on solar or wind electricity must suffer from the lost of energy in battery charging and discharging ~90% for Li-ion or 80% for NiMh, so 250wh/mi / .8= 312 wh/mi. This loss is variable, depending on the rate and depth of discharge of the battery, and also on the rate of discharge of the battery. Lead-footed driver will cause higher current drain in the battery and motor winding in the form of ohmic resistance, hence higher wh/mi consumption."
Completely true, but we also didn't count the energy losses in transporting the H2 through pipelines (6x more energy cost than Natural Gas) or about 10% energy loss on a LHV of H2.
"Now, the real kicker is that for $2000 USD, you can store about ~140 kwh of H2 energy. Let's say that your BEV with battery to wheel efficiency of 75% vs. the Honda FCX at 60% efficiency tank-to-wheel, meaning that 140kwh of H2 is equivalent to 140kwh x 60/75 = 112kwh of battery-equivalent energy."
For $2200-3300 you can currently store about 1kg H2 = 33kWh. Battery to wheel efficiency is about 95% electronic converter and 90% electric motor= 85%.
taking the current maximum efficiency of a fuel cell (SOFC hybrid GT fuel cell 53% - PEMFC are typically at 42-45%) 53%*95%*90%= 45%. The electronic converter is needed for control of the electric motor torque and speed. So it would be 33kwh*45/85=17.45kwh of battery equivalent. using you quoted numbers 17.45*500=$8735
Which is still alot, but these where about the prices for a123 systems for the GM Volt and Tesla Roadster's
"At $500 /kwh of battery cost, let's see how much a 112 kwh Li-ion battery will cost? 112kwh x $500= $56,000 USD. Wow. Current A123 battery is listed at $2000 USD/kwh, bringing the price to ~$200,000 USD if you wanna choose current A123 nanotech lithium that may last for the life of your car. At $500/kwh cost, your Li-ion battery pack will last but 3-5 years the most, or 300 charges."
The A123 battery price you're quoting is for individual cells bought from A123 in the form of a developpers kit. The former price you quoted is much more accurate for a decent size batch.
Small note about the figures I used: these came from the International Energy Agency's rapport of "Prospects for Hydrogen and Fuel Cells" 2005. Which in itself is quite biased towards fuel cells.
Posted by: Steven | 19 September 2007 at 08:01 AM
Fuel cells and Hydrogen are such bogus frauds.
No one mentions the BIG problem, that to make the stack last, you need technical grade O2 as well as H2. Operating a fuel cell car in the midst of auto exhaust from IC cars is a death sentence for the fuel cell stack.
There are hundreds of EVs left in the hands of loving owners, which are about two orders of magnitude cheaper than fuel cell cars, don't need constant servicing, have a ready fuel supply (electric is everywhere), and last a long, long time, even though Toyota doesn't support them any more.
So why fool around with the DEAD END of fuel cells? Why not use proven EVs?
Because the auto companies are just using Fuel Cells as a sort of chimera, a totem, an article of faith, even though they've made essentially ZERO "progress" changing the laws of nature, which would be required to achieve practical results.
A big fraud and a lie, promoted by Big Oil. Wake up and break up Chevron and the rest of Standard Oil, and stop their stranglehold on our economy.
Posted by: Doug Korthof | 15 April 2008 at 12:47 AM