FUEL CELLS FOR TODAY's WORLD
I have taken the time to review my other posts relative to fuel cells. I have once on Stockhouse tried to join all my postings together. After posting it and re-reading it I found it could use a bit of a touch-up. I post my touched up completed version here.
Please note, as I say in my examination, I am not a scientist. (nor am I a writer, a typist, or a linguist) This is not something full of alot of technical data, however I believe the majority of it to be relevant. On this note, I think it represents for a while now the completion of my due diligence. Time to rest and time to look at other stocks now (no, I'm not selling). I need however to clear a few hundred fuel cell bookmarks so that I have some room on my computer for new ones. Comments and opinions (positive and negative are most welcome. If I am in error I ask that you "kindly" correct me. Short of that, happy readin'
Chip
PROLOGE
While 99% of the fuel cell world is focused on companies such as Plug Power and Ballard Power for fuel cell development I thought I would share with you where I believe you will see the practical implementation of fuel cells in mass market applications begin. Rather than viewing it as a race between company A and company B to the mass market, I believe what you will see this evolve to is a race between technology A and technology B:
Technology A - PEM fuel cell (Proton Exchange Membrane fuel cell)
Technology B - SOFC (Solid Oxide Fuel Cell)
Before I discuss the two technologies, perhaps I will share with you a few general points to consider when looking at the two technologies. They are:
1. The world currently already has an existing energy infrastructure / economy based on energy production from hydrocarbon fuels (gasoline, diesel, natural gas, etc.), hydroelectric generation, nuclear power, solar power, wind power, and coal. (these are not placed in order of greatest use to least use).
You cant just say ok, as of January 1, 2000 fossil fuel consumption will be banned world wide. Look at the tobacco industry for example, smoking is bad for you however have they banned cigarettes? No. Do they cause cancer? Yes. Well then, why haven't they banned them? Well, its because there is a whole economy within ours that is based on tobacco. On top of that, there are millions of people around the world who are addicted to tobacco. They can gradually change smoking laws to restrict areas and make it increasingly more difficult to smoke however you would never see an outright ban on tobacco products. The only way you eliminate this is by changing the consumer, and people don't change (or at least not easily). The world is full of people who talk the talk, but do not walk the walk.
2. An increasing need for more power daily. This need is one which cannot be interrupted. Radical changes to the way we satisfy this need will create chaos. There are alot of ways to satisfy this need however if we choose the radical we will end up with chaos. There are alot of articles out there on estimates on how much world power demand will increase in the coming years.
3. An increasing need for cleaner energy to offset the impact we are having on our environment. This need exists today and with the increase in consumption the need will only be magnified.
4. We live in a world based on assumptions. People assume when you turn the handle on your tap in the kitchen that water will come out. Most people (right or wrong) pay little attention to the amount of energy they use. We all "say" we should be more energy efficient but how many really are? If you make the solution to the problem difficult or complex consumers will not buy into it. Take for instance recycling, some may say it is a success, others might say it has all been a total flop. Increases in recycling I believe will come more so as a result of a generation change, rather than through actual changing of the individual.
6. People want change but nobody wants to pay extra for it. You see all these surveys about how so many people say they recognize the need for change and conservation, but how many actually take the steps to implement that change? How many of all these people in these surveys who say they would be willing to pay so much more for cleaner more efficient means of energy actually would? My guess is that most answer what is politically correct, but when push comes to shove they leave the change up to their neighbor. They say yes they are willing to pay more, but turn around and put the owness on others to make the change. If you want an example just look at GM's EV1 vehicle. If you have read alot of the pre-EV1 talk and looked at GM's estimates of how many vehicles they figured they could sell and compare them with the actual numbers they have sold to date the program looks like a complete and utter flop. See the comments under "Buyers shun electric" in this Detroit news article. detnews.com
7. Fear of the unknown. Today's consumers have grown up with pre-conceived ideas on the way things operate. A car for instance runs on gas. When you hit the peddle you expect to hear a "vroom". People have been raised with many of these kinds of conceptions about the world and about technology. Push the consumer too far away from its comfort zone and you are asking for trouble. Look at the self guided vehicles that I believe it is GM or Buick is developing. Listen to the comments of people who have ridden in those vehicles who were never completely comfortable taking their eyes off the road or the steering wheel. People still need to feel like they are in control.
The above is by no means all of the factors in considering what I am about to discuss, however I believe it is generally a pretty rounded out set of factors to consider when considering the choice we make in the evolution of this "New Energy Society".
PEM's
PEM fuel cells are by far the most widely known and talked about fuel cells today. PEM fuel cells in my mind were chosen as the front runner for initial fuel cell mass market development because of one main reason, i.e. the ability to produce power "on demand". As I'm sure you are well aware this would be a very important reason to choose this technology for development. This "on demand" factor, although important to all potential uses, finds it greatest importance relative to the automobile/ transportation industry. We are a society of "get in and go" people, anything that causes us to wait is something people do not accept. Although this technology satisfies the primary mobility need, it falls significantly short in my mind of being a "real world" answer for today's needs. The reason I feel this technology falls short is because all of the technical design problems and infrastructure based hurdles they require. They are:
HYDROGEN
The actually choice of fuels for a PEM fuel cell system is an easy choice to make. The only fuel a PEM fuel cell can operate on is "pure" hydrogen. This fact makes the choice of fuel abundantly clear and easy. The question / debate it stirs up however is on what source this fuel for the cell will come from. There are really only two choices for this fuel storage / delivery system today, tanked hydrogen, or hydrogen supplied through the use of a reformer / refinery to allow hydrogen to be processed from alternate fossil or other fuels along side the cell.
Tanked/ Piped Hydrogen
When I say tanked / piped hydrogen what I refer to is hydrogen supplied to a fuel cell which originates from a remote source. In a transportation application it would come from a tank of hydrogen onboard a vehicle. A tank would have to be re-filled at a filling station. When I refer to piped hydrogen I am speaking more in terms of cogeneration applications for generating power for fixed uses (i.e. homes, business, factories, etc.).
Generation
Firstly before looking at tanked or piped hydrogen one needs to consider hydrogen generation itself without considering its delivery or storage method. Hydrogen's foremost and primary limitation is one that arises from the lack of basic hydrogen generating infrastructure. Generation of hydrogen in itself can be a costly application. Many auto companies advertise that one day all of our energy needs will one day be satisfied through hydrogen derived by water. Although there is much work going into this development for generating hydrogen from such sources as water and sunlight and / or through a method known as electrolysis etc., the fact remains that there is still no clear economical way of producing hydrogen today in the quantities required. Add to this the economic reality that the world currently has billions of dollars invested into a fossil and other alternate fuel infrastructure and no current hydrogen infrastructure and one needs to wonder how it will ever be achieved. I do believe that one day this may be achieved, but I also believe that the way it will be achieved can be summed up in one word SLOWLY. Should the world decide to switch to a hydrogen infrastructure it will need to be done at such pace as that it does not disrupt the world economy as well as our mobility and demand for energy. Switch over too fast, and we will see nothing but economic and mobility chaos. This new energy will make one of the biggest changes in world infrastructure that the world has ever seen. Take for instance internet access. In the beginning the internet started with regular phone line access. The powers that be never choose to wire everyone's houses or all business with fiber optic, they did not initially decide to launch a million satellites to bring internet access wirelessly to every home in the world, rather, they choose what existed in the world at the time. To work with what they had and build from that. Any attempt to make the technological leap too fast would have surely causes excessive economic restrictions on access and we most likely would not live in a world with the internet being what we know it is today. The same I believe can be surmised for the "hydrogen economy", make the leap too fast and it will have a severe impact on economics. In addition to the production and implementation difficulties / realities one must also consider the word "clean". When automakers refer to a 100% clean energy system, I believe they are actually mis-stating this term. Clean perhaps yes as far as the actual vehicle, but is the source of the actual hydrogen "clean"? Could it be a matter where we are only shifting the "dirty" part of the equation to local/ centralized areas (i.e. where the actual hydrogen is being produced)? Another factor in hydrogen storage is items such as parkades and indoor storage. Law does not allow in most areas for instance propane vehicles to park in enclosed parking garages, how then would one park a vehicle with hydrogen in a parkade, especially when the tank "gasses off"? Call some insurance companies and check whether they will insure you if you park a car with a tank of hydrogen in your garage. Ballard Power in Vancouver has to park its hydrogen busses outside for this very reason.
Tanked Hydrogen
The second major hurdle facing the world is an efficient means of storing adequate supplies of hydrogen in a car. Current tank hydrogen fuel cell powered vehicles either have very low / limited driving range or excessively large and heavy tanks to gain any sufficient driving range. Hydrogen by its nature of being a "light gas" with relatively low density present us with some complex storage problems. The only way currently to increase the volume of hydrogen gas per unit area of storage area is through the use of pressure and cold. Current technology dictates that hydrogen be super cooled in order to increase its density in storage. If you fill up a tank in a vehicle with hydrogen currently your choices are "use it or loose it". This use it or loose it comes from the fact that when this super cooled hydrogen gas warms up it expands. This expansion causes added pressure in a tank. A tank can only take so much pressure before some of the gas needs to be vented / evaporated in the atmosphere to help relieve this. Leave a current tanked hydrogen fuel cell powered vehicle sit for more than a few days or a week and come back to it and you will have very little hydrogen left. One solution that is currently being worked on is the storage of hydrogen in something referred to as a nano tube. Essentially I believe this is a system where they take an alternate element and they cause a molecular bond or attraction to two different elements. This bonding enables them to increase the density and change the state of the hydrogen to something more like a solid. As needed, there would be some sort of reaction which causes the hydrogen atom to break the bond with the other agent and release it for use in a fuel cell. Although this may be a solution the mere thought of its complexity leads me to believe it will be something that is a long ways away from being appropriate for actual mass market applications.
Piped Hydrogen
I have heard many people say that it "may" be possible to convert / retrofit existing natural gas pipeline systems to hydrogen systems. Although this may be true, whether it is possible for sure or not I don't know, it lends to questions relative to implementation. We cannot simply turn off the natural gas and turn on the hydrogen. I believe should the world solve the actual hydrogen generating problem the actual implementation of delivering the hydrogen to locations where it will be consumed will at best be slow. Perhaps implementation begins in new area's or communities only. I won't get into this area too much, however it is not hard to understand that it is a logical assumption that should any such switch occur, it will be a costly one, and also be a switch that will occur over many decades. Perhaps the world will see the switch concentrated on the transportation industry first with the supply of hydrogen to a service station type infrastructure.
Reformed Hydrogen
The last and one of the most logical immediate implementation of a system to generate hydrogen for PEM fuel cell powered transportation and fixed power generation / cogeneration applications would be through use of a device to produce hydrogen fuel local to the cell using a device called a reformer. The primary advantage of this system is that it would relieve the burden on the infrastructure somewhat relative to mass hydrogen production as well minimize storage and delivery problems. It would eleviate these problems because rather than having to come up with these other complex solutions, it would allow production of hydrogen at source from fuels such as gasoline, natural gas, methanol, etc. It would allow the world to continue using its predominant infrastructure to continue the fuel production and delivery. When looking at reforming hydrogen however for applications using a PEM fuel cell, it however presents several more problems in development.
Cost
The biggest single factor which will govern the feasibility of using reformers to produce hydrogen for PEM fuel cells is cost. Being that a PEM fuel cell requires ultra "pure" hydrogen the reformers required for this application are extremely costly. A reformer for reforming hydrogen from fossil fuels is complex because it not only needs to gasify the fuels, it needs to separate the actual gasses. PEM fuel cells have little to zero tolerance for "dirty" hydrogen. The actual reformers used to produce the clean hydrogen therefore are considerably larger, heavier, more complex, and more costly. Prices for the actual reformer (although I do not have exact figures) are closer than the actual cost of the cell itself. This is one of the reasons why the Plug Power residential power generation system will be so expensive.
Contaminants
CO (Carbon Monoxide)
A PEM fuel cell cannot tolerate carbon monoxide (a bi -product of reforming). This is another reason for gas separation. The carbon monoxide gets trapped in the cell membrane. Quickly it would clog or kill the PEM fuel cell.
Sulfur
A PEM fuel cell has a very very low tolerance to sulfur contamination. It cannot tolerate more than .5 ppm of sulfur in the fuel stream (hydrogen).
Efficiency
A reformer to produce hydrogen from fossil fuels decreases the efficiency of the overall system. Read this report from the gas research institute <http://electrochem.org/cgi-bin/abs?mtg=196&abs=1525&type=pdf> . Again, because of the complex and "pure" nature of the reforming process for hydrogen to feed PEM fuel cells they become less efficient. Less efficient because of the high temperature required to achieve fuel stream separation. The reformers require energy themselves to achieve this high temperature. No longer are you looking at an efficient low temperature fuel cell system. One must factor in the reforming as part of the system.
Temperature
Because the reformer can only separate the hydrogen from the gas stream at high temperatures it results in a high temperature gas stream. The system must then take the gas and cool it to a suitable temperature before it enters the PEM fuel cell.
Time
As said earlier, one of the primary advantages of using a PEM based fuel cell system for generating power is the "on demand" nature of the operation of a PEM fuel cell. Operation of the system however suddenly changes when one factors in reforming. Because of the increased which is required for reforming the time a fuel cell actually takes to generate electricity changes. With a reformer the time is no longer governed by the fuel cell itself, it is now governed by the time it takes for the reformer to heat up and commence operation. This doesn't necessarily suit the "on demand" nature of the PEM fuel cell choice. In addition to adding the time, it also now would require provisions be built into systems to provide interim power or provisions be built into the reformer to maintain it at stand by temperature. It could be possible that excess reformed hydrogen be stored in a tank however it brings up the same hydrogen storage problems (evaporation, off gassing).
So while we may think that going with reforming as the answer to the PEM fuel cell hydrogen equation we must realize that this answer sheds new problems on the PEM fuel cell. Although it may be from an infrastructure point of view the most logical answer, it open yet a Pandora's box of other problems. No longer do you have a truly "on demand" system. What you have is an increasingly more complex system that has more and more problems and issues.
FREEZING
Another major hurdle yet to be solved by the PEM fuel cell issue is relative to cell freezing. A PEM fuel cell has moisture in the cell membrane. If a PEM fuel cell were to freeze the expansion caused by the moisture in the membrane would damage the membrane and make the cell inoperable. To date companies such as General Motors have announced some advancements in the freezing issue. gm.com This advancement helps the situation but gets nowhere near as close to having the answer for worldwide use. Ballard Power as mentioned before cannot park their busses in the bus barn in Vancouver due to insurance purposes. Because of this, when the weather is cold, them must run hoses and pipe heat into the fuel cell compartments at night to keep the cell's above freezing temperature and avoid their destruction.
COST
Although again I do not have exact figures I am told that just the PEM fuel cell is more expensive to produce. I'm not talking about even adding in the reformer in this. Just the cell in general. They require expensive metal electrodes. Water management systems, extensive heating/ cooling systems to maintain the cell temperature etc.
COGENERATION
The PEM fuel cell system is also not as efficient as the SOFC, alone, or when combined with the reforming process. A cogeneration system using a PEM when used in a CHP (combined heat and power) application is even less efficient than a SOFC based system. Part of the reason for this is because the PEM fuel cell runs at a lower temperature, its "waste" heat is of very low grade. (refer also to the previous gas research institute report). In order to raise the temperature of an 'item', e.g., space heating, you must have a certain amount of BTUs. If the temperature is low, e.g.. 60 deg C., you may never be able to raise the temperature because the loss is greater than the input. It takes a higher temperature or high BTUs per hour to be useful. This would require supplemental heating of water etc. for both hot water needs as well as for space heating needs, and again result in lower system efficiency.
SOFC's
Solid Oxide Fuel Cell has a few major differences from a PEM fuel cell. The first one is that it utilizes a ceramic membrane. The nature of the ceramic membrane allows it to operate a high temperatures. SOFC's operate in the range of 650 degrees Celsius to 1200 degrees Celsius. There are also several advantages and disadvantages of a SOFC power generation system. They are:
FUEL
Similar to a PEM a SOFC operates primarily from hydrogen. The primary difference relative to fuel and a SOFC based fuel cell system is what kinds it may use. SOFC's can run off of pure tanked hydrogen similar to a PEM fuel cell. The biggest difference however comes from the type of reformed fuel that a SOFC can utilize, or better said the quality of the fuel. Unlike the PEM, the SOFC (due to its high operating temperature) can utilize fuel in which does not require gas stream separation. Because the gas stream (hydrogen) separation is the most complex problem in a PEM based reforming system it gives the reforming process required for a SOFC fuel cell alot of simplicity in comparison.
This greater economy is due to the SOFC's ability to deal with other gasses/ substances in the fuel stream. They include but are not limited to the following:
CO (Carbon Monoxide)
A SOFC actually like's carbon monoxide and can generate electricity from it. How does a SOFC produce power from CO? With a SOFC, the oxygen (O) ion travels from the cathode (air side) through the membrane to the anode where it meets with the H ions. The O ion passing through the membrane will be the power path when an external load is connected. Also water is produced at the anode. The same process happens with CO, except that the O ion meets the CO ion and CO2 is produced. Again this additional ion stream produces power with CO2 as the byproduct rather than water. Therefore, no CO is exhausted. This process is unique to SOFCs as opposed to PEMs, because in a PEM, the ion flow is reversed with the H ion traveling from the anode to the cathode where it meets the O ion and water is produced. Therefore, the PEM cannot utilize the CO as fuel and in fact the CO is a poison and must be stripped out. If a PEM system running with a reformer has to extract CO what will it do with it? The cell cant use it, so I would suspect it would be exhausted to the atmosphere, which is not a good thing, it defeats the purpose of cleaner energy.
Sulfur
SOFC can run on fuel that has 10-12 parts of sulfur in it. An SOFC could even run on fuel that has more, however in the interest of the lifespan of the cell values below 12 ppm are the more desirable. The PEM on the other hand cannot run on anything over 1/2 ppm of sulfur. Now one factor one must realize is that this advantage depends on the fuel chosen. Depending on the fuel source decides the amount of sulfur in the fuel stream. For residential gas, there is very little sulfur. This is why mercaptan is added, in other gasses usually found in the field prior to processing, the sulfur is very high. If a PEM runs off reformed gasoline, the cost of reforming is higher, if it runs on methanol it is lower, however still more expensive than the SOFC, and as well with methanol, there is no current distribution system / infrastructure. It would be asking for some significant changes to get methanol everywhere and for what advantage? If reforming slows down the PEM, if it makes it more expensive than a SOFC system, why stick with it? The gas industry is being forced as well to reduce sulfur content in gasoline which is good for both the PEM as well as the SOFC however the PEM requires significantly more sulfur removal than the SOFC. Global Thermoelectric (http://www.globalte.com/) and other SOFC companies use a very simple and proven catalyst such as zinc oxide (there are others) which is very low cost and strips the sulfur from the gas stream. With the SOFC, basic stripping down to under 10 or 12 ppm is more than adequate. When you begin stripping down to 1 or 2 ppm, the units can become very costly. With Global's SOFC, they can simply insert a removable zinc oxide cartridge into the incoming cold gas stream. Depending on the amount of sulfur will depend on how often you change the cartridge. It's like changing a water filter in your home.
Temperature
One of the significant differences which had given the PEM fuel cell an advantage over the SOFC fuel cell was its operating temperature (over 1000 degree's Celsius). This temperature resulted in two things, a longer time for the cell to start and beginning to produce full power and the need for expensive metal alloys to build the cell assembly as well as a greater need for thermal management. These are problems now that have been reduced significantly. With the advent of newer ceramic membrane assemblies cells have been now produced which generate higher power at lower temperatures. See newswire.ca As stated in the release it will result in cells which produce more power at lower temperatures. This will allow cells to be manufactured economically from stainless steel as well as reducing the time required in which the cell takes to achieve full power. When you consider that a PEM fuel cell system which uses a reformers operating/ start up time is governed not now by the cell, rather governed by the time its expensive reformer takes to heat up the systems could be compared on a more even playing field, especially in transportation applications.
How might they address however the issue of "on demand" in a transportation application one may ask? As said the public will not go for a car that you go out and turn on and hop in and drive 20 minutes later. SOFC companies however are developing insulate packages which contain the heat of the cell. It may take 15 or twenty minutes to get a cell to full power (lets say 700 degrees Celsius) from "cold" temperature however they are developing methods to contain the heat when the cell is not in operation. If you turn off the cell and walk away from it what you will find is that you can come back to the car/cell lets say two days later and the cell will still be at maybe 4-500 degrees Celsius). This means that when you restart the cell it may only take one minute to it to reach full power. In the meantime the vehicle can obtain its auxiliary power from battery storage. We are not talking about the mass of batteries that are in battery vehicles here either. The warmer the cell is at start up the faster it reaches full power. By that I mean that the cell may already start its power generation / reaction at the 4 or 500 degree temperature when you come back to it, not full power, but power none the less. This reaction causes heat, which helps the cell start faster. I believe that the time required to say get the cell from room temp to 100c is longer than the time to get it from 100-200, etc.. Therefore if the cell is say still at 50 to 75% or even more of its peak operating temperature 24-48 hours after the cell was last powered up then the time will be relatively short before a) it is producing power (it may start almost immediately if it is still hot enough) and b) until it is at full power. As said, in the mean time batteries would fulfill any interim electrical needs. I emphasize that this scenario would be considered to be in a hybrid vehicle. The type of vehicles we are now hearing about more than fuel cell powered vehicles.
The whole industry is changing as I had mentioned before. In fact it seems to be changing faster than I thought it would. The auto makers have realized that a hydrogen infrastructure will not be available for another 15, 20, more? years and as a result have been quietly working on alternatives. The alternative is the hybrid vehicle. There will be as many variations of hybrids as there are auto makers. All of the auto makers are now beginning to announce their hybrids. Delphi is a leader in SOFC auxiliary power generation because to my knowledge, they are the only ones to have a SOFC as an auxiliary power unit. See newswire.ca and delphiauto.com . No other SOFC company has made the breakthroughs for mobile applications other than Global Thermoelectric. It will come with time though. Many of the companies including Ford have announced hybrids working with modified IC gasoline engines that can accept a small amount of hydrogen. This hydrogen will come from a gasoline reformer. The full output of the reformer will be fed to the engine. The small amount of hydrogen will make the car operate cleaner and more efficient. Other variations will see the engine combined with electric motors and some batteries for dual operation. In one case, the engine will recharge the batteries, in another it may take over the load under heavy loads. This whole new hybrid concept is where Global, Delphi and BMW are going. Maintaining a hydrogen IC engine combined with an auxiliary power unit such as the SOFC and the 42 volt battery system makes sense. The auxiliary power unit that we are developing at Global will fit into almost all hybrid philosophies. Over the past three weeks, it has been evident at the conferences, that the industry is changing to hybrids. APU's have been the talk of the industry. This really has to have Ballard worried or at least thinking. The hybrid is the only alternative to make sense for the next 15 years. The SOFC APU fits perfectly with either a IC engine hybrid or an electric hybrid. When (if) hydrogen ever becomes available, it will operate on it as well which means no obsolescence. How about also this from Ford and BMW ".... Stockhausen said Ford has talked to BMW in the past about their hydrogen engine know-how, and there may be future contacts that could produce "some synergies." A hydrogen i.c. engine will be installed in another P2000 sedan near the end of the year. Initially, the car will be running on gaseous hydrogen. Another point in i.c. technology's favor is hydrogen's purity, the level of reformer technology required, and the related infrastructure issue. A fuel cell needs very pure hydrogen, Bates said, but the i.c. engine "is nowhere as particular." Hydrogen reformed from gasoline, for instance, would be less problematical in an i.c. engine - "a very exciting prospect." Ford's and Mobil's teams are working hard on a less demanding reformer whose products - hydrogen and other residuals - can be fed into an i.c. engine with few, if any, problems...." Ford has also expressed interest in a APU for electrical generation on a vehicle SOFC APU is the only fuel cell that could handle the "hydrogen and other residuals". (I am unsure where that quote came from as someone sent it to me, that would require verification).
Cell Sealing
Another problem that led to the initial choice of PEM development in the past is the problem with sealing of the SOFC fuel cell. SOFC when started up and shut down have a problem with expansion and contraction. Warming a cell slowly and cooling it down slowly is one way to help lower possible sealing problems, but when you rapidly heat or rapidly cool the cell the coefficient of expansion and contraction between the cell materials and its supporting structure etc differs. The difference between the two coefficients cause breaks in the seals of the cell. If you have a fundamental understanding of how a cell works its like this. The anode compartment and the cathode compartment are two different chambers, now when hydrogen enters the hydrogen gas molecules split into protons and electrons. The protons pass through the membrane to react with oxygen in the air (forming water). The electrons, which cannot pass through t |
