fuel cells versus batteries

[gloo]

From what i understand, the only thing that makes using fuel cells in cars versus lithium batties less desirable, is the cost of hydrogen.

If hydrogen can be produced extremely cheaply, assuming the same standards for compressing and transporting and storage of hydrogen, would it be better to invest in the fuel cell industry, or in the car battery industries.

The assumption that it is made really cheaply, abundantly and has NO CARBON EMISSIONS in the process.

[russ_watters]

No, it isn't just the cost of the hydrogen, it is also the cost of the fuel cell itself as well as the storage density of hydrogen. Hydrogen is made from water using electrolysis and that makes it a storage medium conceptually similar to batteries. Albeit a much less efficient one (that would be where the cost of the hydrogen comes in). Fuel cells are made using exotic metals and that makes them expensive. And since hydrogen isn't stored as a liquid, the storage density is much lower than gasoline.

[mgb_phys]

And that a fuel cell is primary power source (fuel in -> power out) unlike a battery you can't (easily) refill the fuel cell when braking - so a fuel cell vehicle would probably need batteries as well.

Fuel cells are a bit more practical for bikes, they are much lighter than a battery and because you lose most of the power to wind drag on a bike there isn't as much scope for regenerative braking.

[gloo]

so doesn't that mean the fuel cell industry is doomed in terms of it's use for cars?
I don't know what metals are in fuel cells, but lithium is only abundantly found in a few places on earth isn't it? I thought car batteries were really expensive as well and would pose problems when it needs to be replaced.

So the answer is that batteries are better economically even in light of cheap cheap hydrogen? What about just a pure hydrogen powered car then? I know the tank has to be bigger, but isn't that still a good tradeoff over the cost of replacing batteries and the future environmental problems of that?

[mgb_phys]

Lithium is currently only mined commercially in a few places but it isn't that rare, as demand goes up new sources will be worth extracting.
Most current fuel cells use rather more exotic materials, Platinum, Silver, Palladium etc - these aren't going to get cheaper. There are fuel cell technologies that use cheap polymers being developed.

Current lithium-ion batteries are expensive, they will get cheaper as production ramps up but they will always be fairly large, heavy and expensive.

The main problem with hydrogen (other than you can't fit much in a tank) is where do you get the hydrogen? Main sources at the moment are either from natural gas - in a rather nasty process that involves carbon dioxide and high temperature/pressure. Or by splitting water which requires a huge amount of energy.

If you have nuclear reactors then making hydrogen from water migth be practical. Another source is countries with an abundance of cheap power, (solar/geothermal/wind) which might make H2 locally and ship it the customers.

[gloo]

Lithium is currently only mined commercially in a few places but it isn't that rare, as demand goes up new sources will be worth extracting.
Most current fuel cells use rather more exotic materials, Platinum, Silver, Palladium etc - these aren't going to get cheaper. There are fuel cell technologies that use cheap polymers being developed.

Current lithium-ion batteries are expensive, they will get cheaper as production ramps up but they will always be fairly large, heavy and expensive.

The main problem with hydrogen (other than you can't fit much in a tank) is where do you get the hydrogen? Main sources at the moment are either from natural gas - in a rather nasty process that involves carbon monoxide at high temperature/pressure. Or by splitting water which requires a huge amount of energy.

If you have nuclear reactors then making hydrogen from water migth be practical. Another source is countries with an abundance of cheap power, (solar/geothermal/wind) which might make H2 locally and ship it the customers.

Yes, i understand the ramifications of our current technology to extract hydrogen, that was why i tried to take that out of the equation by assuming that away. Russ, says that the elements to make fuel cells are really expensive so I buttled that with the cost of replacing a lithium battery and the environmental cost of dead battery storage. From what I understand, fuel cells don't have limited life spans that batteries do, so, with the assumed world of cheap cheap, easily made, carbon less production of hydrogen, is the fuel cell a clear winner over lithium batteries, or even yet, a pure hydrogen combustion car?

[Q_Goest]

... with the assumed world of cheap cheap, easily made, carbon less production of hydrogen, is the fuel cell a clear winner over lithium batteries, or even yet, a pure hydrogen combustion car?
I think it is. If we look at the market today, we see batteries being replaced by fuel cells in the material handling market (ie: forklifts). Warehouse operations commonly employ dozens or even hundreds of battery operated fork lifts.
Each of those forklifts has a 2000-pound lead-acid battery. In fact, each forklift has two huge batteries – one in use and one being recharged. A battery charge only lasts about 7 hours. That means that every one of those forklifts needs a 2000-pound battery changed for every shift. That’s 14,000 battery changes in a year, totaling about 4000 labor hours.
Ref: http://blog.wholefoodsmarket.com/2009/11/hydrogen-fuel-cell-powered-forklifts/

Recharging a 5000 psi hydrogen cylinder on the other hand, only takes a few minutes. There are a number of fuel cell companies now making drop in replacement systems for batteries used in fork lifts. These replacement systems consist of a fuel cell, a cylinder for the hydrogen, and of course controls. They also include weight because they're much lighter than the battery and the fork lift needs the weight to operate properly.

It's this material handling market which may eventually give birth to fuel cell vehicles as described here: http://www.nuvera.com/blog/?p=203
I believe that not only is the fuel cell forklift market interesting from a business standpoint, but this is also an early market that can accelerate the adoption of fuel cell cars.

To make the case for my hypothesis, consider the following. As shown in the graph below, a typical forklift drive cycle is very similar to an urban drive cycle that a fuel cell car would encounter. Because of this similarity, the fuel cell technology and system design between the forklift and the car will, by necessity, be similar (the car having more power, of course).

In a given year, a fuel cell forklift will operate for approximately 5,800 hours. If these hours are integrated into an automotive drive cycle, a year of forklift operation effectively simulates approximately 125,000 miles of driving. In this sense, you can consider the forklift operation as an accelerated durability test for a fuel cell car. During this year of operation, the forklift will need to be refilled about 700 times, and it will consume about 1000 kg of hydrogen.

Get a few thousand fuel cell forklifts in operation and the numbers start to add up. Very quickly you will have a lot of field data that can be directly translated to the automotive fuel cell market. Before the first fuel cell car ever “hits the streets” we could have millions of equivalent miles of data and operation in the forklift market. Further, the hydrogen dispensing experience would directly translate so that by the time fuel cell cars come about, the hydrogen dispensers will have been in operation for several years, performing hundreds of thousands of successful refueling events.

Early market applications like the fuel cell forklift market will help develop the technology and supply chain required for successful fuel cell cars, and educate customers to the advantages of fuel cells and hydrogen. Without a doubt, this will help accelerate the future of clean transportation.
I would agree with all this. Note that hydrogen may be made primarily from natural gas today, but what about electricity? For the most part, it's made from coal and other fossil fuels too. Hydrogen is only an energy carrier, not a fuel source. There are many efforts today that are focused on how to make hydrogen in the 'greenest' way possible. The accusation that it is dirty doesn't make sense.

[cepheus]

Fuel cells are more expensive than batteries, hydrogen is more expensive than electricity, hydrogen is more expensive to transport than electricity.

The only economic way of producing hydrogen is via steam reforming from natural gas so unless you sequester the CO2 it doesn't even reduce greenhouse gases. At least electricity can be sourced from nuclear and renewables for all their problems. So what's the point?

To me the hydrogen fuel cell has been a diversion, I am almost tempted to say a conspiracy to convince the public that an environmentally acceptable fossil fuel replacement solution exists.

This is the finest critique of Hydrogen

http://www.oilcrisis.com/hydrogen/crea.htm

If your interested in real world tests of fuel cells v Diesel read this

http://www.dpi.wa.gov.au/mediaFiles/alt_CUTEreport.pdf

See Fig 4.12, greenhouse gases are about 3 times greater than diesel when using steam reforming using latest bus design! And these buses cost a milllion quid each!

[mheslep]

Yes, i understand the ramifications of our current technology to extract hydrogen, that was why i tried to take that out of the equation by assuming that away. Russ, says that the elements to make fuel cells are really expensive so I buttled that with the cost of replacing a lithium battery and the environmental cost of dead battery storage. Lithium batteries are not classified as hazzardous waste. They can go in the so called universal waste stream. They won't though, they'll be recycled.

From what I understand, fuel cells don't have limited life spans that batteries do,Fuel cells do have limited life spans in relation to vehicle life. The membranes degrade over time. Google 'fuel cell stack poisoning'.

[mheslep]

I think it is. If we look at the market today, we see batteries being replaced by fuel cells in the material handling market (ie: forklifts). Warehouse operations commonly employ dozens or even hundreds of battery operated fork lifts.

Ref: http://blog.wholefoodsmarket.com/2009/11/hydrogen-fuel-cell-powered-forklifts/

Recharging a 5000 psi hydrogen cylinder on the other hand, only takes a few minutes. There are a number of fuel cell companies now making drop in replacement systems for batteries used in fork lifts. These replacement systems consist of a fuel cell, a cylinder for the hydrogen, and of course controls. They also include weight because they're much lighter than the battery and the fork lift needs the weight to operate properly.

It's this material handling market which may eventually give birth to fuel cell vehicles as described here: http://www.nuvera.com/blog/?p=203

I'm not persuaded. These links refer to one-off pilot projects or blogs, not any major move in the material handling market. (The other similar area is airport ground equipment). Batteries can (http://www.youtube.com/watch?v=5b0T5NUHyxs) be switched in 2-3 minutes, even if this particular facility's equipment is slower. And 2000 lbs of lead acid can be replaced with 400 lbs of lithium ion these days. How many labor hours are required to handle the receiving and storage and removal of H2 bottles for such an operation? There are no H2 pipelines. What's the life cycle cost of those fuel cells?

[Topher925]

The only economic way of producing hydrogen is via steam reforming from natural gas so unless you sequester the CO2 it doesn't even reduce greenhouse gases. At least electricity can be sourced from nuclear and renewables for all their problems. So what's the point?

No it isn't. Electrolysis is a very common process, and while more expensive than steam reforming, it is still very economical. It is also extremely likely that future nuclear power plants will abandon the rankin cycle and operate using thermochemical cycles which produce hydrogen directly. Future technologies such as photochemical and photovoltaic electrolysis are good candidates for hydrogen generation as well.

On another note, no way does a diesel powered bus produce less pollutants than one that is H2 powered. That article may state that, but I've read half a dozen more that state the opposite. I'll try and find some of them later.

Fuel cells do have limited life spans in relation to vehicle life. The membranes degrade over time. Google 'fuel cell stack poisoning'.

Membrane degradation is really no longer an issue with FCs. There's a variety of flavors of Nafion that easily exceed DOE targets. Poisoning isn't a real big issue anymore either assuming the hydrogen is relatively pure. The only real poisons that need to be considered are sulfur based compounds commonly generated by diesel engines, i.e. H2S. Right now, the most dominant PEMFC degradation mechanism is the cathode catalyst layer which suffers from Pt particle agglomeration and dissolution.

How many labor hours are required to handle the receiving and storage and removal of H2 bottles for such an operation?

I don't understand? Why would you ever remove a H2 tank from a vehicle unless its being serviced? It only takes a few minutes to fill a 4kg H2 tank from empty to full in a FC vehicle (I've witnessed it first hand).


Back to the OP question,
From what i understand, the only thing that makes using fuel cells in cars versus lithium batties less desirable, is the cost of hydrogen.

It's actually much more than this. The #1 advantage of using PEM fuel cells for vehicles is it allows for a completely closed chemical cycle. There is no other technology that can do that although some bio-diesel schemes aren't to far away from it. The other distinct advantage over batteries is that FCs are engines, not energy storage devices. Transportation requires an energy scheme which allows a vehicle to be able to travel from point A to point B with little to no downtime, aka charging a battery. You can however just swap a battery out and replace it with a charged one but then you create a logistics nightmare which would most likely come with severe cost penalties. Another aspect is that hydrogen is an incredibly versatile fuel. It can be made efficiently in a variety of ways and on any scale. Theres no reason you can't economically generate H2 from solar panels at home and still be able to fill up at fuel station if your taking a road trip.

So now for the real question, why aren't we driving FC vehicles today? In a nutshell its because of the scarcity of platinum which is the primary material used for the anode and cathode catalyst of PEMFCs. If Pt was cheap and plentiful, we would all be driving fuel cell powered cars today. About 75% of the cost of a FC stack (batch production) comes from the price of Pt, and its only getting more expensive. In order to solve this problem there is an enormous scientific effort to discover new catalyst materials in order to reduce costs and at the same time increase durability. A lot of scientists are looking at materials that are N or Fe based complexes to replace Pt, but so far most materials provide to low of an activity. But the prospects are looking pretty good and its very likely better catalyst materials will be discovered in the next few upcoming years. Toyota, Honda, GM, and I believe Nissan are all planning on releasing FCVs for commercial sale before 2015. Germany, Japan, and Iceland are already developing hydrogen infrastructures to support this new technology.

[cepheus]

And 2000 lbs of lead acid can be replaced with 400 lbs of lithium ion these days

At what cost?

No it isn't. Electrolysis is a very common process, and while more expensive than steam reforming, it is still very economical.

I would like to see some evidence of this, do you mean economical for producing hydrogen? I recall seeing actual figures during the CUTE bus project I linked, which used local electroysis stations and the economics both in terms of energy and money was appalling!

[Q_Goest]

Hi mheslep,
How many labor hours are required to handle the receiving and storage and removal of H2 bottles for such an operation? There are no H2 pipelines.
As Topher also mentions, the hydrogen cylinders are refueled not replaced. The refueling station looks a lot like a conventional gas station, with an interface display on the dispencer just like at a gas station, and a hose that connects to your vehicle. The dispencer purges the connection with helium automatically and pressurizes the cylinder in a few minutes. It even has safety features built in that detect leakage, fire, tow away, etc...

Regarding supply, stations are presently being supplied in a variety of ways depending on customer requirements. The most common means of supply are:
- Electrolysis
- Gasseous delivery
- Liquid delivery
- Portable refueling stations

Regarding cost, like anything - costs are dictated by technology, quantities and infrastructure. Right now, hydrogen is only manufactured in large quantities at a few locations around the US, so shipping costs are relatively high. It isn't unusual to see hydrogen being shipped over a thousand miles for a demonstration project. There's probably a few hundred miles of pipeline but they're mostly around the gulf coast and used by refineries.

Also, the technology for producing hydrogen from renewables hasn't gotten off the ground yet; but that doesn't mean it won't. Comparing the cost of hydrogen to fossil fuels right now means nothing. It's like comparing the cost of a transistor radio to the cost of a vacuum tube radio in 1961. Making those kinds of comparisons simply shows a misunderstanding and lack of foresight for the technology.

[cepheus]

Regarding cost, like anything - costs are dictated by technology, quantities and infrastructure. Right now, hydrogen is only manufactured in large quantities at a few locations around the US, so shipping costs are relatively high. It isn't unusual to see hydrogen being shipped over a thousand miles for a demonstration project. There's probably a few hundred miles of pipeline but they're mostly around the gulf coast and used by refineries.

Also, the technology for producing hydrogen from renewables hasn't gotten off the ground yet; but that doesn't mean it won't. Comparing the cost of hydrogen to fossil fuels right now means nothing. It's like comparing the cost of a transistor radio to the cost of a vacuum tube radio in 1961. Making those kinds of comparisons simply shows a misunderstanding and lack of foresight for the technology.

Well true, but there are just so many inefficiencies along the route to producing power, even before transport, storage then use in the fuel cell:

The energy efficiency of water electrolysis varies widely with the numbers cited below on the optimistic side. Some report 50–80%.[10][11] These values refer only to the efficiency of converting electrical energy into hydrogen's chemical energy. The energy lost in generating the electricity is not included. For instance, when considering a power plant that converts the heat of nuclear reactions into hydrogen via electrolysis, the total efficiency may be closer to 30–45%.[12]

I recall assessing a proposal for a hydrogen powered fuel cell tram! why not just use the electricity directly?

[Borek]

That’s 14,000 battery changes in a year, totaling about 4000 labor hours.

Strange. That means 17 minutes per change. I have seen large batteries changed in much shorter time, thery were just rolled out, rolled in. 2 minutes max, including cigarette break.

I am not stating batteries are better than fuel cells, I just don't like numbers presented.

[Topher925]

I would like to see some evidence of this, do you mean economical for producing hydrogen? I recall seeing actual figures during the CUTE bus project I linked, which used local electroysis stations and the economics both in terms of energy and money was appalling!

http://www.popularmechanics.com/science/research/4212844.html

Right now you can buy H2 at 5kpsi for about $3.25 a kilogram depending on where you live. This is the typical cost when you get it by reforming a hydrocarbon on an industrial scale. The link I posted to above is an electrolyzer that GE developed which claims that they can make H2 for about $3 at pressure. I've personally never seen real numbers this low but I have seen H2 at 5kpsi for about $5 a kg generated by electrolysis.

Also, the technology for producing hydrogen from renewables hasn't gotten off the ground yet; but that doesn't mean it won't. Comparing the cost of hydrogen to fossil fuels right now means nothing. It's like comparing the cost of a transistor radio to the cost of a vacuum tube radio in 1961. Making those kinds of comparisons simply shows a misunderstanding and lack of foresight for the technology.

I concur, you can't make direct comparisons, but I would like to add that as far as the cost of fuel is concerned, it is cheaper to drive a fuel cell powered car 250 miles than a similar ICE powered car.

For example (using local prices near me),
Honda FCX Clarity - 250 miles - 60mpkg - 4.2 kg of H2 @ $3.25/kg - Total Cost $13.65
Honda Civic - 250 miles - 35mpg - 7.14gllns of gas @ $2.75/glln - Total Cost $19.635

[cepheus]

Strange. That means 17 minutes per change. I have seen large batteries changed in much shorter time, thery were just rolled out, rolled in. 2 minutes max, including cigarette break.

I am not stating batteries are better than fuel cells, I just don't like numbers presented.

I suggest that power units should be standardised with respect to the fixture points, and module based (battery pack or hybrid). The position of the module is defined relative to the wheels and ramp so the module replacement can be largely automatic and shouldn't take longer than normal refuelling. Of course the advantage of a module is that you can effectively swap your battery for a IC engine generator for the occasions you travel long distances.

http://www.entrans.co.uk/entransmainreport2/index38.html

[mheslep]

Strange. That means 17 minutes per change. I have seen large batteries changed in much shorter time, thery were just rolled out, rolled in. 2 minutes max, including cigarette break...Agreed. I provided a 90sec switch film link above, 250kg, 25kWh battery

[mheslep]

I don't understand? Why would you ever remove a H2 tank from a vehicle unless its being serviced? It only takes a few minutes to fill a 4kg H2 tank from empty to full in a FC vehicle (I've witnessed it first hand). I wasn't referring to switching H2 in the fork lifts. The blog link was adding up man hours for everything in the process. I was referring to fact that the H2 has arrive at the warehouse somehow. In most of the cases today for a warehouse this will be done periodically via pressurized H2 bottles brought by truck: receiving, storing, and shipping out H2 bottles at the warehouse takes time and space. There's no such overhead with electricity - it comes in over the wire.

[pantaz]

I concur, you can't make direct comparisons, but I would like to add that as far as the cost of fuel is concerned, it is cheaper to drive a fuel cell powered car 250 miles than a similar ICE powered car.

For example (using local prices near me),
Honda FCX Clarity - 250 miles - 60mpkg - 4.2 kg of H2 @ $3.25/kg - Total Cost $13.65
Honda Civic - 250 miles - 35mpg - 7.14gllns of gas @ $2.75/glln - Total Cost $19.635

Are there any figures available for comparing lifetime costs? I know many people with well over 100,000 miles on their Honda Civics and Accords, with quite reasonable maintenance costs. How long does a H2 fuel cell actually last? Are they recyclable?

[Topher925]

Are there any figures available for comparing lifetime costs? I know many people with well over 100,000 miles on their Honda Civics and Accords, with quite reasonable maintenance costs. How long does a H2 fuel cell actually last? Are they recyclable?

Not really, and if there are they probably aren't very reliable. Fuel cells are a new technology, and it takes a long time to put 100k on a car under practical operating conditions. The lifetime of most modern fuel cells isn't even that well known since most technology is highly proprietary. But I would like to point out, that fuel cells require very little to no maintenance over their lifespan since the entire system has only a few moving parts (pumps/blowers). Most FCs are also mostly constructed out of carbon based materials which makes them relatively easy to recycle.

[mheslep]

Right now you can buy H2 at 5kpsi for about $3.25 a kilogram depending on where you live. This is the typical cost when you get it by reforming a hydrocarbon on an industrial scale.[...] Right now? Odd, I thought we'd been through this before. I forget what supplier our chem/bio lab uses now, but my retail price exceeds $100 / kg DELIVERED.

Airgas (http://www.airgas.com/browse/product_list.aspx?catID=195&WT.svl=195) List Price Quote this month ($5B industrial supplier):
Cylinder fill/swap (300 cu ft cylinder, actual 261 cu ft = 0.62kg H2) at 2200 PSI on site:$62
Delivery + hazmat fee: $39
Delivery Fuel surcharge: $11

Total: $118/kg plus $78 cylinder lease.


Break out of total costs from a study:
http://i48.tinypic.com/21m51l0.jpg
http://198.173.87.9/PDF/Doty_H2Price.pdf

[Q_Goest]

Right now? Odd, I thought we'd been through this before. I forget what supplier our chem/bio lab uses now, but my retail price exceeds $100 / kg DELIVERED.

Airgas (http://www.airgas.com/browse/product_list.aspx?catID=195&WT.svl=195) List Price Quote this month ($5B industrial supplier):
Cylinder fill/swap (300 cu ft cylinder, actual 261 cu ft = 0.62kg H2) at 2200 PSI on site:$62
Delivery + hazmat fee: $39
Delivery Fuel surcharge: $11

Total: $118/kg plus $78 cylinder lease.
But mheslep, you're quoting prices on cylinders... You can purchase it that way, but I can assure you, the price you're paying is all labor and various overhead costs. It has nothing to do with the value of the hydrogen. Customers that buy in bulk, such as 13,000 gallons of liquid hydrogen at a shot don't pay anything like that. It's on the order of $4/kg when purchased in quantity. So for a typical customer that has a liquid hydrogen tank, even with the cost of leasing the tank, dispencers, and compression equipment, the cost only goes up an additional few dollars per kg. These are not unusual customers either, they may have 50 or more forklifts at a warehouse. You could similarly imagine a hydrogen refueling station on your street corner that could refill one car every 5 minutes (288 fills/day) located near a hydrogen plant. Such a refueling station could sell hydrogen to a typical drive up customer at $4 to $5 /kg and still make a substantial profit.

[mheslep]

But mheslep, you're quoting prices on cylinders... You can purchase it that way,I know, I labelled the information as a retail list price for cylinders.

but I can assure you, the price you're paying is all labor That's part of the nature of distributing H2. It's 99.9% truck and driver.

and various overhead costs. It has nothing to do with the value of the hydrogen. Customers that buy in bulk, such as 13,000 gallons of liquid hydrogen at a shot don't pay anything like that. It's on the order of $4/kg when purchased in quantity. Total cost, as it goes into the tank in the fork lift, or other vehicle? I think you are mistaken. Certainly the price comes down, but not that low, delivered, and including storage. As shown in my previous post the cost of LNG and reforming to H2 is ~3-4/kg, but the distribution and storage H2 is expensive compared to gasoline. I see here (http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/liquefaction_comp_pres_praxair.pdf) (pg 8) the cost of electric energy alone for liquification, no capital costs or anything else, is $1.2 to $1.50 /kg of H2.

In the future that price may come down, but I was challenging the assertion of a given price "right now".

So for a typical customer that has a liquid hydrogen tank, even with the cost of leasing the tank, dispencers, and compression equipment, the cost only goes up an additional few dollars per kg. [...]Source for any of this?

You could similarly imagine a hydrogen refueling station on your street corner that could refill one car every 5 minutes (288 fills/day) located near a hydrogen plant. Such a refueling station could sell hydrogen to a typical drive up customer at $4 to $5 /kg and still make a substantial profit.If you want an H2 plant close by, then to be fair in comparison to gasoline you need include a prorate of the H2 plant in the refueling station cost. My current gallon of gasoline was probably refined a 1000 miles away in Louisiana, and I still pay $2.80 for it.
__________________

[Q_Goest]

Hi mheslep,
Source for any of this?
Regarding costs I've quoted, I work as an engineer developing compression equipment for the hydrogen energy market. The costs I've quoted are what I've seen as being 'in the ballpark' of what is typically paid for hydrogen in bulk and for the ancillary equipment. I've tried to be as accurate as possible and I've checked the costs I'm posting.
If you want an H2 plant close by, then to be fair in comparison to gasoline you need include a prorate of the H2 plant in the refueling station cost. My current gallon of gasoline was probably refined a 1000 miles away in Louisiana, and I still pay $2.80 for it.
Yes, good point. But there are pipelines for petroleum products all over the US (unlike hydrogen). The cost of transportation for these products is minimal. In essence, you ARE very close to a source of petroleum. I live in PA and there's a pipeline from the gulf coast that extends up to where I'm at. Hurricane Katrina for example, knocked out pipelines up the east coast that caused a dramatic increase in the cost of gas before those pipelines could be repaired. Here are some maps of various petroleum pipelines in the US:
http://www.rextagstrategies.com/downloads

[mheslep]

Hi mheslep,

Regarding costs I've quoted, I work as an engineer developing compression equipment for the hydrogen energy market. The costs I've quoted are what I've seen as being 'in the ballpark' of what is typically paid for hydrogen in bulk and for the ancillary equipment. I've tried to be as accurate as possible and I've checked the costs I'm posting. Yes I recall you mentioning background, that's why I'm particularly interested what detailed information you might provide, e.g. 300 kg H2 tube trailer cost, hazmat delivery costs, onsite storage costs, onsite energy costs for liquification or compression, etc.

Yes, good point. But there are pipelines for petroleum products all over the US (unlike hydrogen). The cost of transportation for these products is minimal. In essence, you ARE very close to a source of petroleum. I live in PA and there's a pipeline from the gulf coast that extends up to where I'm at. Hurricane Katrina for example, knocked out pipelines up the east coast that caused a dramatic increase in the cost of gas before those pipelines could be repaired. Here are some maps of various petroleum pipelines in the US:
http://www.rextagstrategies.com/downloadsExactly so. No doubt you are familiar with the economic difficulties of attempting the same with an H2 pipeline - expensive to maintain, more pipe section to push the same number of joules as CNG, etc. The US has some one million miles of hydrocarbon pipeline, only ~300 some miles of H2 pipe, and most of that is in that one Louisiana - Texas pipeline.(5) (http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/liquefaction_comp_pres_praxair.pdf)

[Q_Goest]

Yes I recall you mentioning background, that's why I'm particularly interested what detailed information you might provide, e.g. 300 kg H2 tube trailer cost, hazmat delivery costs, onsite storage costs, onsite energy costs for liquification or compression, etc.
Cost depends on a number of factors including shipping charges and whether or not the customer is looking for just a single delivery or has a long term contract. For what it's worth, hydrogen gas in tube trailer form is much more expensive than liquid. Costs for tube trailer hydrogen are in the ball park of $14/kg with significant adders for trucking and single deliveries.
Exactly so. No doubt you are familiar with the economic difficulties of attempting the same with an H2 pipeline - expensive to maintain, more pipe section to push the same number of joules as CNG, etc. The US has some one million miles of hydrocarbon pipeline, only ~300 some miles of H2 pipe, and most of that is in that one Louisiana - Texas pipeline.(5) (http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/liquefaction_comp_pres_praxair.pdf)
I'm reasonably familiar with the pipeline but I guess the point I'd like to make is that the costs for hydrogen right now are not what they could be if various other sources were to be developed. There are ways of producing hydrogen from water or bio sources for example, that might not be cost effective today because they're still in the research phase. In the future, the hope is that these technologies will be able to produce "green" hydrogen at a cost equal to or less than the cost of hydrogen today.

[mheslep]

... such as 13,000 gallons of liquid hydrogen at a shot don't pay anything like that. It's on the order of $4/kg when purchased in quantity. ...
Backing up here. So the common US 18-wheel gasoline tanker truck carries 9000 gallons. I'm curious as to how the 13,000 gallons of liquid H2 you referenced is delivered? Multiple tankers of what capacity? The end user, the large warehouse in our example case, must have a similarly sized storage facility.

[Q_Goest]

13,000 gallons is a typical LH2 trailer load. That's 1 trailer. Gasoline tankers are smaller no doubt because gas is much heavier per gallon than LH2.

[Topher925]

Right now? Odd, I thought we'd been through this before. I forget what supplier our chem/bio lab uses now, but my retail price exceeds $100 / kg DELIVERED.


I'm sorry to hear that mheslep. But the fact is, most people that drive FCVs pay only about $3.50 a kg for their H2 when bought at a fueling station.

http://www.fuelcells.org/info/library/QuestionsandAnswers062404.pdf

[mheslep]

I'm sorry to hear that mheslep. But the fact is, most people that drive FCVs pay only about $3.50 a kg for their H2 when bought at a fueling station.

http://www.fuelcells.org/info/library/QuestionsandAnswers062404.pdfI see no facts presented here, just an assertion referenced to an environmental activist (http://www.harrywalker.com/speaker/Robert-Rose.cfm?Spea_ID=632) and fuel cell association executive.

[dr dodge]

back to some basics, here
hydrogens molecule is very small vs most other products shipped in pipelines. We use He for measurement purposes, and its ability to leak as compared to nitrogen is significant. products can be "completely sealed" on n2 and leak badly on He. my suspicion is that, with hydrogens small size, the same problems will occur. pipelines would all need to be of a new construction to not leak (vs existing pipelines). all the support systems and refueling rigs would also be "potentially leak prone" after a few years of service, given the same level of maintainence that our local gas stations do. Slight leaks in the vehicle, pipelines, and support tools would not show up easily (vs gasoline) because there is no real smell, or fluid to leak, but would be very dangerous (more that gasoline).
Would the high pressure hydrogen cause hydrogen embrittlement in steel vessels?

dr

[Borek]

We use He for measurement purposes, and its ability to leak as compared to nitrogen is significant. products can be "completely sealed" on n2 and leak badly on He. my suspicion is that, with hydrogens small size, the same problems will occur.

Could be you are right, but from what I remember helium is absolutely unique in its "penetrativeness". I always thought it is not just a matter of size, but also of perfect symmetry and inertness, which make helium interactions with every material much weaker than those of other gases.

[dr dodge]

many gases when pressurized to high levels have a highly natural solvent ability.
I am unsure what the threashold pressure of hydrogen is.

dr

[Topher925]

back to some basics, here
hydrogens molecule is very small vs most other products shipped in pipelines. We use He for measurement purposes, and its ability to leak as compared to nitrogen is significant. products can be "completely sealed" on n2 and leak badly on He. my suspicion is that, with hydrogens small size, the same problems will occur. pipelines would all need to be of a new construction to not leak (vs existing pipelines). all the support systems and refueling rigs would also be "potentially leak prone" after a few years of service, given the same level of maintainence that our local gas stations do. Slight leaks in the vehicle, pipelines, and support tools would not show up easily (vs gasoline) because there is no real smell, or fluid to leak, but would be very dangerous (more that gasoline).
Would the high pressure hydrogen cause hydrogen embrittlement in steel vessels?


Some of the assumptions are correct. Hydrogen does penetrate most materials more easily than other materials. Natural gas pipelines that currently exist would nee to be modified/replaced if they were to carry hydrogen. High pressure hydrogen will cause embrittlement in steel vessels if they are not lined. Hydrogen pipes and storage vessels are usually lined with a polymer to prevent things like embrittlement and material penetration.

As for a hydrogen leak being more dangerous than gasoline, that is not necessarily true. Its a very different kind of fuel that is safer in some aspects, but also more dangerous than others. Hydrogen disperses and diffuses very quickly, and requires a 4% concentration with air before it even becomes possible to ignite. However, at that 4% and even well above it hydrogen can be extremely difficult to ignite unless very high temperatures are present. Because of this most hydrogen fires can be prevented by simply keeping H2 tanks outside or have a building with good ventilation. Gasoline on the other hand will pool in one location and the vapor forms locally in high concentrations, making it easier to ignite. Also, the flame from hydrogen isn't entirely invisible, but it is more difficult to see. It also has low thermal radiation making it more difficult to detect.

Another thing about H2 is that its non-toxic. In other words you can be in a room with relatively high concentrations of it and not get sick. The same can not be said for gasoline.

http://polymer.matscieng.sunysb.edu/msds/hydrogen.pdf

http://www.hydrogen-fc.com/wp-content/uploads/2007/01/hydrogen_gasoline.jpg
Yes, I know this picture doesn't really prove anything but I just think it looks cool.

[dr dodge]

my point about the leak was more that it is generally "undetectable" vs gasoline
gas vapors hang next to the ground, and will tend to concentrate their. Hydrogen being lighter than air would mix better, and could accumulate inside of sealed places. gasoline also has a much lower vapor point, so colder weather would decrease its evaporization.

The big thing I see though is the added costs to upgrade the pipelines and added systems. Those will be passed along to the consumer.

dr

[mheslep]

back to some basics, here
hydrogens molecule is very small vs most other products shipped in pipelines. We use He for measurement purposes, and its ability to leak as compared to nitrogen is significant. products can be "completely sealed" on n2 and leak badly on He. my suspicion is that, with hydrogens small size, the same problems will occur. pipelines would all need to be of a new construction to not leak (vs existing pipelines).That's correct, H2 requires more elaborate mechanisms to transport or store than hydrocarbon molecules, in part because of the small size of the H2 molecule.

all the support systems and refueling rigs would also be "potentially leak prone" after a few years of service, given the same level of maintainence that our local gas stations do. Perhaps. The small amount of existing H2 pipelines require high levels of maintenance in comparison to natural gas pipelines.

Slight leaks in the vehicle, pipelines, and support tools would not show up easily (vs gasoline) because there is no real smell, or fluid to leak, but would be very dangerous (more that gasoline). Probably not. It is more difficult to achieve an H2/air mix that will ignite and explode than gasoline/air. H2 also burns much cooler than gasoline.

Would the high pressure hydrogen cause hydrogen embrittlement in steel vessels? Yes over time, that's why inner liners of polymer are typically used.

Edit: I see Topher scooped me; I agree with Topher's post.

[Q_Goest]

In 2008, ASME came out with a new piping code specifically for hydrogen in anticipation of the rapidly expanding hydrogen energy market. That piping code is ASME B31.12. It covers such things as materials and hydrogen embrittlement. It's understood that many steels are susceptible to hydrogen embrittlement, especially the higher strength steels. But the penetration or leakage through steels used for piping and components isn't significant. You certainly wouldn't be able to detect it using something like a bubble fluid. The penetration of hydrogen through steel isn't even sufficient to measure inside the vacuum space of vacuum jacketed lines. Note that helium is used to determine leak points using a mass spec, which is much more sensitive than bubble fluid.* In other words, there is no measurable hydrogen leakage through steel unless perhaps there are flaws in the material such as found in castings.
Hydrogen pipes and storage vessels are usually lined with a polymer to prevent things like embrittlement and material penetration.
Where have you seen this? We use steel hydrogen vessels up to 7000 psi and there's no liner. I can't imagine polymers doing any good anyway, they're much more easily penetrated by hydrogen than steel. I've discussed this with people who have tested polymer lined vessels but they were relative novices and the linings failed to make any significant improvement. Take flexible plastic hoses for example, they leak through the wall at a rate that's measurable using a pressure gage. Steel on the other hand, won't leak at all.

*Edit: Point being that properly sealed, helium is impossible to detect using a mass spec, and helium is a small molecule (atom) just like hydrogen. The fact it isn't detectable for a properly sealed system should give an indication of the low permeability of these systems.

[mheslep]

gasoline
gas vapors hang next to the ground,Yes, tend to.

and will tend to concentrate their.

Hydrogen being lighter than air would mix better,
No, because it is lighter than air it tends to diffuse rapidly and falls quickly below explosive concentration.

and could accumulate inside of sealed places.Sealed? As can any gas. I think you me confined spaces, in which case heavier than air vapors are much more dangerous. Heavier than air gas is especially dangerous on e.g,, marine vessels because they concentrate in the holds.

[mheslep]

Where have you seen this? We use steel hydrogen vessels up to 7000 psi and there's no liner. Edit: The issue would be with what gauge steel. One could theoretically contain any PSI with enough gauge, but that doesn't mean its the most economic method.

I can't imagine polymers doing any good anyway, they're much more easily penetrated by hydrogen than steel. I've discussed this with people who have tested polymer lined vessels but they were relative novices and the linings failed to make any significant improvement. Take flexible plastic hoses for example, they leak through the wall at a rate that's measurable using a pressure gage. Steel on the other hand, won't leak at all.

Low Permeation Liner for Hydrogen Gas Storage Tanks (http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/iiia5_lessing.pdf)

[dr dodge]

the sealed areas are trunks and compartments in the vehicles, being as modern technology has made the modern car very leak proof. hydrogen "diffusing" into air is going to provide the oxygen needed to explode

With the permeability problem, how are you going to deal with flexible lines? no O-rings, it would need metal seals in many places.

There also will be very few "smell additives" that will not foul of inhibit the fuel cells abilities.

and I don't know where the idea that hydrogen is hard to burn/ignite comes from. A small static spark is adequete to ignite it. Takes a heck of a static spark to blow gasoline. We use it here to work quartz tubing and the grounding on the semi trailer outside is almost silly (theres so many of them)
We had to install ground rods, etc.

dr

[Q_Goest]

Low Permeation Liner for Hydrogen Gas Storage Tanks (http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/iiia5_lessing.pdf)
Thanks for the link mheslep, but that's for a polymer lined composite vessel, not a polymer lined steel one. Composites are highly permeable, which is why they needed something to reduce leakage rates. I've also seen aluminum used as the liner for composite vessels, which is probably a much better solution IMO. Hydrogen will diffuse through a polymer relatively quickly compared to a metal, which is why I don't think a polymer is going to help much on a steel vessel.

[Q_Goest]

the sealed areas are trunks and compartments in the vehicles, being as modern technology has made the modern car very leak proof. hydrogen "diffusing" into air is going to provide the oxygen needed to explode

With the permeability problem, how are you going to deal with flexible lines? no O-rings, it would need metal seals in many places.
In my experience, hydrogen diffusion through a metal isn't signficant enough to measure. Diffusion through a plastic hose or similar polymer is relatively significant, though still very low and difficult to measure. Diffusion through an O-ring or other elastomeric seal is less than a hose because of the smaller cross sectional area. For these kinds of seals, the diffusion rate is insignificant.

There also will be very few "smell additives" that will not foul of inhibit the fuel cells abilities.
I've heard this brought up a number of times, but to date, there are no additives that can be used.

and I don't know where the idea that hydrogen is hard to burn/ignite comes from. A small static spark is adequete to ignite it. Takes a heck of a static spark to blow gasoline. We use it here to work quartz tubing and the grounding on the semi trailer outside is almost silly (theres so many of them)
We had to install ground rods, etc.

dr
Agreed. Hydrogen is extremely easy to ignite.

[mheslep]

Agreed. Hydrogen is extremely easy to ignite.
Ok, details details. Yes, H2 has a low energy of detonation compared to hydrocarbons.

H2 energy of detonation is 14x less than natural gas, but
H2 detonation requires 4x3x higher concentration than gasoline vapor (http://www.engineeringtoolbox.com/explosive-concentration-limits-d_423.html), and as discussed above H2 isn't prone to concentration.
H2 14x lighter than air
H2 4x more diffusive than natural gas, 12x more than gasoline fumes
H2 combustion emits 1/10 the radiant heat of an hydrocarbon fire and burns 7% cooler than gasoline, emits no CO2 or smoke.
H2 explosive power 22x weaker per STP unit volume vs gasoline fumes.

So pick your poison.

[Q_Goest]

Ok, details details. Yes, H2 has a low energy of detonation compared to hydrocarbons.

H2 energy of detonation is 14x less than natural gas, but
H2 detonation requires 4x3x higher concentration than gasoline vapor (http://www.engineeringtoolbox.com/explosive-concentration-limits-d_423.html), and as discussed above H2 isn't prone to concentration.
H2 14x lighter than air
H2 4x more diffusive than natural gas, 12x more than gasoline fumes
H2 combustion emits 1/10 the radiant heat of an hydrocarbon fire and burns 7% cooler than gasoline, emits no CO2 or smoke.
H2 explosive power 22x weaker per STP unit volume vs gasoline fumes.

So pick your poison.
<clappin' for mheslep> couldn't agree more. Really is a pick/poison decision. The only really significant difference I see is in the means of storage. For H2, the product is commonly stored (today) at high pressure, so there has to be a large number of special precautions to ensure the 350 barg product goes into a cylinder and stays there. I wouldn't trust my mom to refuel a hydrogen vehicle with that much pressure. It isn't the flammability, it's just pure pressure I worry about.

[Topher925]

It isn't the flammability, it's just pure pressure I worry about.

Same here. I don't really feel all that comfortable with a 10kpsi tank in the trunk of my car but it isn't necessarily any worse than driving around with a thin steel walled tank of a nearly liquid explosive either. But I've seen FCV's refueled before and its actually very safe. Safe enough that I wouldn't get worried if someone was smoking right next to the car they were filling up. The refueling process is entirely computer monitored with several safety precautions in place. You can't really say that about filling up a gasoline fueled car.

[mheslep]

<clappin' for mheslep> couldn't agree more. Really is a pick/poison decision. The only really significant difference I see is in the means of storage. For H2, the product is commonly stored (today) at high pressure, so there has to be a large number of special precautions to ensure the 350 barg product goes into a cylinder and stays there. I wouldn't trust my mom to refuel a hydrogen vehicle with that much pressure. It isn't the flammability, it's just pure pressure I worry about.On that note, has anybody proposed a mechanical automated tank switch in lieu user tank fills? Not that I believe vehicle tank switching would be easy or problem free, but there are tank switch precedents with lab cylinders and the common propane residential cylinder. Mechanical battery switching is about to go into beta test in Israel and Denmark (not for safety but fast fill up reasons).

[Q_Goest]

On that note, has anybody proposed a mechanical automated tank switch in lieu user tank fills? Mechanical battery switching is about to go into beta test in Israel and Denmark (not for safety but fast fill up reasons).
Fills are completely automated. The user hooks up a nozzle and fliks a lever on the nozzle to lock it in place. Then it's just press some buttons. It pressurizes up to a given level automatically and shuts off. The purging (done with helium) and leak detection is also automated.

Ok, I might trust my mom to do it if someone gave her instructions and walked her through it. Right now, people that do this have been given training to do so. Not exactly a self service station.

There's a video of someone doing this on this page (http://blog.wholefoodsmarket.com/2009/11/hydrogen-fuel-cell-powered-forklifts/), about half way down:

[mheslep]

Fills are completely automated. The user hooks up a nozzle and fliks a lever on the nozzle to lock it in place. Then it's just press some buttons. It pressurizes up to a given level automatically and shuts off. The purging (done with helium) and leak detection is also automated.Well that's similarly true of modern gasoline fill ups except for leak detection.

Edit: So I viewed the video and have a couple observations. Outside that's a tube trailer parked on site (Air Products makes a version) i.e. compressed H2 not liquid. The $4/kg price quoted above was for 13,000 gallon loads of liquid H2. I expect the gas tube deliveries to be considerably more expensive to move the same amount of joules around. Also outside we have what appears to be a fixed compressor and manifold installation, and inside a very nice dispenser and meter hookup. My question, not answered in the text: what's the cost of that H2 installation installation, the delivered H2 per kg, plus the fuel cells on the lifts. All of that versus the traditional battery switch mechanism and extra battery costs in all electric system?

[Q_Goest]

So I viewed the video and have a couple observations. Outside that's a tube trailer parked on site (Air Products makes a version) i.e. compressed H2 not liquid. The $4/kg price quoted above was for 13,000 gallon loads of liquid H2. I expect the gas tube deliveries to be considerably more expensive to move the same amount of joules around. Also outside we have what appears to be a fixed compressor and manifold installation, and inside a very nice dispenser and meter hookup. My question, not answered in the text: what's the cost of that H2 installation installation, the delivered H2 per kg, plus the fuel cells on the lifts. All of that versus the traditional battery switch mechanism and extra battery costs in all electric system?
Wow! You sure ask a lot of question... are you trying to set up a hydrogen refueling station?

On the flik, you ponted out all the bits and pieces. Tube trailer, compressor, dispencer. The one shown in the flik is an older style with electric hook ups. (forgot to mention that) The new ones have an infrared connection on the dispencer nozzle so you don't have to hook those wires up anymore.

Yea, the tube trailer is going to cost a LOT more for a kg of hydrogen. As mentioned before, it's about 3 to 4 times the cost, primarily because of all that extra metal that has to be dragged around. In that case, it won't make much sense to go with a hydrogen powered fuel cell from what I've seen - unless perhaps Uncle Sam is footing the bill. Demo projects are often subsidized. Regarding cost, our company doesn't sell the equipment. The capital cost and maintenance is more like a monthly lease. The customer pays X amount per month to cover eqiupment and all maintenance.

[mheslep]

Wow! You sure ask a lot of question... are you trying to set up a hydrogen refueling station? I don't mean to burden you individually with Q&A sessions. You did suggest the H2 economics were such in post 7 that they could tip over the material handling business, a substantial claim given a existing $2-4 billion business using batteries or petroleum power. But maybe so. I've been through the National Academy reports on H2, etc but they admit to many estimates that are difficult to check. Here we have a case we can check. How? By modelling with as much detail as possible and crunching the numbers. We're engineers, that's what we do.

On the flik, you ponted out all the bits and pieces. Tube trailer, compressor, dispencer. The one shown in the flik is an older style with electric hook ups. (forgot to mention that) The new ones have an infrared connection on the dispencer nozzle so you don't have to hook those wires up anymore.

Yea, the tube trailer is going to cost a LOT more for a kg of hydrogen. As mentioned before, it's about 3 to 4 times the cost, primarily because of all that extra metal that has to be dragged around. ...That makes sense, yet the WholeFoods warehouse went with compressed gas and not liquid storage. Thus I assume they found the on site liquid storage costs to be prohibitive, even given the cheaper transportation via liquid H2 trucks.

[mheslep]

Here's a new pricing data point on the fuel cell end. The well funded startup Bloom Energy finally went public with their product - a 100kW high temperature ceramic fuel cell. No noble metals, no reformer, runs on various hydrocarbon gasses, 50% efficient. Fuel cell price is ~$7500/kW (before subsidies), they expect $3000/kW. At least for the moment they are far short of the $100/kW for an ICE or an electric motor.

http://www.luxresearchinc.com/blog/2010/02/is-bloom-energy-a-better-place-redux/
Wired and 60 minutes also did pieces on them yesterday and Sunday.

[Topher925]

Here's a new pricing data point on the fuel cell end. The well funded startup Bloom Energy finally went public with their product - a 100kW high temperature ceramic fuel cell. No noble metals, no reformer, runs on various hydrocarbon gasses, 50% efficient. Fuel cell price is ~$7500/kW (before subsidies), they expect $3000/kW. At least for the moment they are far short of the $100/kW for an ICE or an electric motor.

Just an FYI, all modern SOFCs contain no noble metals. Bloom's is no different than anything else out there other than its very inefficient (most SOFCs are ~65-70% efficient).

On another note, there is no way to realistically compare a SOFC to an ICE designed for a car. Two very different technologies, for two very different applications. Those prices also don't include the cost savings of fuel over the life of the system since SOFCs require about 3 times less fuel than your ordinary ICE and about 4 times as less than your a turbine engine. SOFCs also typically require significantly less maintenance.

And $3k/kW is outrageously expensive after including subsidies. You can go out and buy a PEM cell with the same efficiency for $3k/kW with no subsidies what so ever and even thats on the expensive side.

http://www.horizonfuelcell.com/store/h5000.htm

[mgb_phys]

On another note, there is no way to realistically compare a SOFC to an ICE designed for a car.
At current efficencies if you ultimately want rotary motion you are probably better off with an ICE than a FC+Electric motor.

[mheslep]

Bloom's is no different than anything else out there other than its very inefficient (most SOFCs are ~65-70% efficient). We're talking about an in production FC here, not a lab prototype. Bloom makes numerous claims other than efficiency about its fuel cell. Are saying you have reviewed all the salient claims, compared them to actual SOFC products available and found them no different? Who has an SOFC product on the market at 65%?

On another note, there is no way to realistically compare a SOFC to an ICE designed for a car. Two very different technologies, for two very different applications. Those prices also don't include the cost savings of fuel over the life of the system since SOFCs require about 3 times less fuel than your ordinary ICE and about 4 times as less than your a turbine engine.I didn't claim lifecycle costs, I stated the upfront kW cost only, as reported in the reference. How do you get FC eff * E-motor eff (~92%) = 3 X 25% ICE eff?
SOFCs also typically require significantly less maintenance. Than what? A diesel backup/load levelling generator?

And $3k/kW is outrageously expensive after including subsidies. You can go out and buy a PEM cell with the same efficiency for $3k/kW with no subsidies what so ever and even thats on the expensive side.

http://www.horizonfuelcell.com/store/h5000.htmYes $3k/kw is expensive, but that PEM is not comparable. No reformer to run off natural gas. No three phase high power AC inverter. No packaging for outdoor operation. Ten percent less efficient.

[Topher925]

At current efficencies if you ultimately want rotary motion you are probably better off with an ICE than a FC+Electric motor.

How do you figure? FC coupled with traction motors are significantly more efficient than any ICE engine available.

We're talking about an in production FC here, not a lab prototype.

No, I'm talking on the market commercialized SOFCs. SOFCs are very popular in applications where reliable steady state power is required. Heres an example of some manufacturers but many more can be found with a simple search.
http://www.fuelcellmarkets.com/fuel_cell_markets/products_and_services/2,1,1,17.html?q=Systems,Solid_Oxide_Fuel_Cell_Syst ems


I didn't claim lifecycle costs, I stated the upfront kW cost only, as reported in the reference. How do you get FC eff * E-motor eff (~92%) = 3 X 25% ICE eff?

SOFCs like the ones Bloom has made can only be used for stationary applications and APUs. In these applications you go from fuel to electricity in with a FC. ICEs require you go from fuel to generator to electricity. However, if you do consider a transportation application, SOFC+Motor:65% x 95% >> ICE:25%.

Than what? A diesel backup/load levelling generator?

Yes.

[mheslep]

No, I'm talking on the market commercialized SOFCs. SOFCs are very popular in applications where reliable steady state power is required. Heres an example of some manufacturers but many more can be found with a simple search.
http://www.fuelcellmarkets.com/fuel_cell_markets/products_and_services/2,1,1,17.html?q=Systems,Solid_Oxide_Fuel_Cell_Syst emsYes I'm aware there are SOFC's companies, though it is not clear any of them are are past pilot projects and into production. But that was not my question. I was asking for a reference to your claim that most "SOFCs are ~65-70% efficient" - products not research prototypes - , and that "Bloom's [SOFC] is no different than anything else out there." I can't find anything that exceeds 60%, and even that is only at a specific power operating point less than full load. BTW, Bloom's exact spec is ">50% (http://www.bloomenergy.com/products/data-sheet/)"

Yes.Having designed one (diesel electric APU) in to a commercial building, and having reviewed the FC reliability comments from the National Academy report, I doubt that is true. More reliable than gasoline-generators maybe, not diesel APUs. I expect the reliability comparison is a wash.

[russ_watters]

Those prices also don't include the cost savings of fuel over the life of the system since SOFCs require about 3 times less fuel than your ordinary ICE and about 4 times as less than your a turbine engine. SOFCs also typically require significantly less maintenance. Where do you get the cost savings over a turbine? A commercial gas turbine is around 30% efficient, so a 60% efficient fuel cell would use half, not 1/4 the fuel.

In the US, for commercial use, a GTE would almost certainly include heat recovery to provide all hot water and heating in addition to electricity, so the all-up efficiency may end up being better than a fuel cell.

How does a fuel cell perform at part load?

GTEs are somewhat of a niche market right now, but one very good niche is sewage treatment plants, which use megawatts of electricity (to run massive pumps) and tons of heat (to keep their vats of crap warm) while producing lots of methane. Traditionally, they'd take grid power to run the pumps and capture some of the methane for heat (maybe 25-50%), flaring (burning off) the rest. A GTE can provide both the electricity and heating.

[Topher925]

can't find anything that exceeds 60%, and even that is only at a specific power operating point less than full load.

I believe that 60% is total power conversion, including transformers and/or converter. I have lots of info about SOFCs that can operate at those efficiencies, unfortunately none of it I can share on the internet. I'll try to find some other sources later.

You may be right about diesel and SOFC reliability being a wash, I really have no info about diesel generators but for SOFCs the only components that ever really need maintenance are pumps.

Where do you get the cost savings over a turbine?

http://www.netl.doe.gov/publications/proceedings/03/seca/daviddaggett.pdf (slide 15)

In the US, for commercial use, a GTE would almost certainly include heat recovery to provide all hot water and heating in addition to electricity, so the all-up efficiency may end up being better than a fuel cell.

Not gonna happen. SOFCs (and all high temp FCs) produce high quality heat just like turbines except they produce a little more of it and are often used for co-generation as well.

http://www.greencarcongress.com/2009/12/tmc-sofc-20091218.html
http://www.energy.siemens.com/hq/en/power-generation/fuel-cells/sofc-commercialization.htm

Combustion of gases in turbines causes dissociation of products reducing temperature and the amount of heat that could have been used for co-generation. This is something that can be avoided with SOFCs.

How does a fuel cell perform at part load?

Depends on the design, but usually just fine. Although FC efficiency is directly proportional with overpotential. SOFCs usually don't care at what load they operate at as long as its enough to stay warm. What does matter however, is the rate at which that load changes. Like almost all energy conversion and storage devices, SOFCs like to operate at a steady state constant load. If the load operates with large transients, you've got problems.

A GTE can provide both the electricity and heating.

See above.

[russ_watters]

http://www.netl.doe.gov/publications/proceedings/03/seca/daviddaggett.pdf (slide 15) Did you see slide 14? Your data point is for a case where the jet APU operates far outside its design range, but doesn't say exactly what that range is. It is unreasonable to assume 15% efficiency from a GTE would be typical. Slide 14 shows that in normal operating conditions, the difference is only 45%. Not gonna happen. SOFCs (and all high temp FCs) produce high quality heat just like turbines except they produce a little more of it and are often used for co-generation as well. If they do heat recovery, fine, but that means the all-up efficiency would end up being about the same.

But you do have that first part backwards: since fuel cells are more efficient, the waste heat is lower than in a GTE (generally a good thing, I'm just pointing it out for clarity).
http://www.greencarcongress.com/2009/12/tmc-sofc-20091218.html
http://www.energy.siemens.com/hq/en/power-generation/fuel-cells/sofc-commercialization.htm Your second link claims an all-up efficiency of 80%, which is exactly the same as a GTE operating at the lower heating value*. http://www.capstoneturbine.com/prodsol/solutions/chp.asp

Since the chemistry is exactly the same, this isn't surprising that they both hit the exact LHV efficiency that is typically possible in any fuel fired heating application (such as your home boiler or furnace). Not sure why they can't condense the water out and go for the HHV, though.... Combustion of gases in turbines causes dissociation of products reducing temperature and the amount of heat that could have been used for co-generation. This is something that can be avoided with SOFCs. I'm not following. The chemistry of these things is is exactly the same:

[CH4 + 2 O2 => 2 H2O + CO2 + E]

They do the same thing: they both burn methane in air.

*Edit: Actually, in the literature I linked, they are switching back and forth between the HHV and LHV, which is a little misleading: what they are really claiming is 80% of the LHV efficiency, or 75% of the HHV. Your first link shows both for a fuel cell: 85% HHV, 77% LHV.

[mheslep]

How does a fuel cell perform at part load?


This Australian SOFC model reaches peak efficiency at about 80% rated load, falls off slightly at 100%, and falls off drastically at below ~40% load.

http://www.fuelcellmarkets.com/images/articles/443/graph.gif
http://www.fuelcellmarkets.com/images/articles/443/graph.gif

It's not clear it this company is actually in production mode yet.

[russ_watters]

Thanks. Put another way, at 25% ouptut, the efficiency drops by 40%. For the turbine I linked above, the efficiency drops by 30% at 25% load. The curves are not the same shape, though, and it looks like their curves cross somewhere around 10% load (ie, below 10%, the fuel cell isn't losing as much of its peak efficiency).

[mheslep]

..
Your second link claims an all-up efficiency of 80%, which is exactly the same as a GTE operating at the lower heating value*. http://www.capstoneturbine.com/prodsol/solutions/chp.aspAlso, one can actually buy a micro CHP from Capstone and obviously larger scale co-generation has long been available. That Siemen's SOFC on the other hand is not in production.

The chemistry of these things is is exactly the same:

[CH4 + 2 O2 => 2 H2O + CO2 + E]

They do the same thing: they both burn methane in air.Not quite. Don't forget the combustion side reactions due to high temperature in the presence of Oxygen which, in addition to their resultant pollution, consume energy. E.g.
O2 + 2 C + E => 2 CO
Same for NOx, etc.

[Topher925]

Did you see slide 14?

Yes I did. I didn't include it because slide 14 refers to electrical power generation while the engine is driving the plane. In other words, the engine isn't only working to produce electricity, its producing thrust and electricity. This will give a value of apparent efficiency making it not comparable to electrical or co-generation only power generation.

But you do have that first part backwards: since fuel cells are more efficient, the waste heat is lower than in a GTE

I think I got it forwards, this is a good characteristic to have. In most applications its always more favorable to produce more electricity than heat since electricity is a very versatile form of power and heat (especially at lower temperatures) is not.

The chemistry of these things is is exactly the same:

[CH4 + 2 O2 => 2 H2O + CO2 + E]

They do the same thing: they both burn methane in air.


The chemistry is most definitely not the same. SOFCs don't "burn" anything. What you posted is the IDEAL global reaction and not what you would find in a real application.

For a SOFC, a more realistic equation would look something like this,

CH4 + 2 (O2 + 3.72 N2) => 2H2O + CO2 + 7.52 N2

For a GTE, especially a higher efficiency one (higher temp), it would look something more like this,

CH4 + a (O2 + 3.75 N2) => b H20 + c CO2 + d N2 + d CO + e NO + f NO2 + g H2 + etc.

http://en.wikipedia.org/wiki/Dissociation_%28chemistry%29

[mheslep]

http://en.wikipedia.org/wiki/Dissociation_%28chemistry%29As I recall and the Wiki indicates Dissociation refers to ionic bonds, not the covalent bonds broken and made in combustion.

[russ_watters]

Not quite. Don't forget the combustion side reactions due to high temperature in the presence of Oxygen which, in addition to their resultant pollution, consume energy. E.g.
O2 + 2 C + E => 2 CO
Same for NOx, etc. [and for Topher]

Granted, but just how much are we talking about? According to GE, all of those are in the PPM range, with a total of all of them of less than 1 part in 1000, so the efficiency hit you take is several significant digits away from the decimal point in the efficiency calculation. It isn't enough to be relevant.

[russ_watters]

Yes I did. I didn't include it because slide 14 refers to electrical power generation while the engine is driving the plane. In other words, the engine isn't only working to produce electricity, its producing thrust and electricity. This will give a value of apparent efficiency making it not comparable to electrical or co-generation only power generation. The efficiency number does not include the propulsion of the plane. It says that explicitly on the slide: ""40-45% Jet-A to electrical efficiency"

If that bothers you, just drop this special case and compare the fuel cell to a similar product such the capstone turbine I linked. 15% is not a fair/realistic efficiency for a typical commercial gas turbine generator. I think I got it forwards, this is a good characteristic to have. In most applications its always more favorable to produce more electricity than heat since electricity is a very versatile form of power and heat (especially at lower temperatures) is not. No, I was referring specifically to your claim that more waste heat is available with a fuel cell. This is simply wrong.
The chemistry is most definitely not the same. From the post above: when the difference in the chemistry is on the order of hudredths or thousandths of a percent, it isn't useful to call it different (at least when efficiency is what you are comparing).

As far as what to call what a fuel cell does, different sources say different things. Some sources say any reaction that involves oxidation and releases energy (such as rust) is a combustion reaction. Some say it must happen fast and/or involve heat and light as the energy released. Whatever. I'm less concerned with the label than I am about the similarity between the chemistries.

[mheslep]

[and for Topher]

Granted, but just how much are we talking about? According to GE, all of those are in the PPM range, with a total of all of them of less than 1 part in 1000, so the efficiency hit you take is several significant digits away from the decimal point in the efficiency calculation. It isn't enough to be relevant.Yep, that makes sense, should be small.

[Topher925]

If that bothers you, just drop this special case and compare the fuel cell to a similar product such the capstone turbine I linked.

Ok.


No, I was referring specifically to your claim that more waste heat is available with a fuel cell. This is simply wrong.

Sorry, I should have been more clear. What I meant was that the amount of energy that can be utilized per unit of fuel is greater. This is ultimately because you are not forming products which are generated by an endothermic reaction removing usable energy nor do you have to deal with them after your process.


From the post above: when the difference in the chemistry is on the order of hudredths or thousandths of a percent, it isn't useful to call it different (at least when efficiency is what you are comparing).

I'll agree that the amount of heat lost isn't significant but in many cases dissociation can drop an ambient flame temperature by a hundred degrees or so. Granted this isn't a big deal for turbines as flame temperatures are usually as high as alloys can take but the pollutants should be considered. After all, things such as catalytic converters on cars do reduce engine efficiency (and increase cost).

As far as what to call what a fuel cell does, different sources say different things.

Fair enough. I'm not concerned about semantics.

[russ_watters]

Sorry, I should have been more clear. What I meant was that the amount of energy that can be utilized per unit of fuel is greater. Ok, fine. This is ultimately because you are not forming products which are generated by an endothermic reaction removing usable energy nor do you have to deal with them after your process. No, as I pointed out, the differences in the chemical reaction are less than one part in a thousand. Essentially all of the difference in efficiency is due to the thermodynamics of a brayton cycle heat engine vs direct electrical conversion of a fuel cell.