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Below is the text version of the webinar titled "Introduction to SAE Hydrogen Fueling Standardization," originally presented on September 11, 2014. In addition to this text version of the audio, you can access the presentation slides.
… this webinar is being recorded, so a recording, along with slides, will be posted to our website in about 10 days. I will also be sending out an email once those are posted to our website. So just, you know, be aware that that will be coming within about 10 business days.
Everyone is on mute, so—but we encourage you to ask questions while our presenters are presenting. So please submit your questions via the question box. I have an example here. So if you can just submit your questions as the presenters are presenting, and we will cover those the last 10 to 15 minutes of the webinar. So we definitely encourage you to submit those. Since we have multiple speakers today, please indicate who your question is for when submitting questions, if you can, if you think of it. If not, we'll be able to address the question to the right presenter.
Also, I encourage you to check back to our website for future webinars. We do host these monthly, and we have different topics each month, so I encourage you to check back. I also encourage you to sign up for our newsletter, if you've not done that. We do send those out monthly, and it keeps you up to date on webinars and other things we have going on in the fuel cell technology program.
So on that, I am going to turn it over to Will James. Will is a fuel cell technology manager for the Fuel Cell Technologies Office, managing the Safety, Codes and Standards program. And on that note, I will turn it over to Will.
Thanks, Alli. As Alli mentioned, my name is Will James, and I'm here at the—in the Fuel Cell Technologies Office at DOE, and on behalf of the office, I would like to welcome everyone to today's webinar.
So I just wanted to take a few minutes to say a few words before we proceed. As you know, this webinar is designed to be the first introduction to the new SAE J2601 and J2799 standard related to public refueling of hydrogen fuel cell electric vehicles. So as Alli also mentioned, I'm going to be moderating today's webinar, including the Q&A section, and with that, we're pleased to have two speakers today. The first will be Jesse Schneider from BMW North America, and he will be followed by Steve Mathison from Honda North America.
And Jesse is the manager of the fuel cell electric vehicle development and standards program at BMW USA, which he relocated from the Munich office of BMW several years ago. He's been in charge of the 70 megapascal storage as well as the internal and external standardization of fuel cell electric vehicles. Prior to this, Jesse worked in both U.S. and—excuse me, for both U.S. and Germany automakers in jobs ranging from conventional production of vehicles to electric and fuel cell vehicles testing and system integration. Externally at BMW, Jesse has been leading the hydrogen fueling protocols, SAE J2601 and SAE J2799. He also led the first efforts on establishing emergency response for fuel cell vehicles, developing a hydrogen dispensing test device, and hydrogen qualification specification at the California Fuel Cell Partnership. Jesse has a bachelor's degree in international mechanical engineering from the University of Rhode Island, as well as a diploma in electronics.
Steve is a senior engineer in the energy and environmental research group at Honda North America. He has a bachelor's degree in mechanical engineering from the University of Idaho and a master's degree in engineering mechanics from Virginia Tech. Steve's research focus has recently been in the area of hydrogen refueling, where he has developed a novel approach for controlling the fueling process called the MC method. Steve is actively involved in the work being conducted to bring SAE—that was—sorry, he has been involved in the work that—in the work bringing SAE J2601 to a full standard.
So with that, before we get started, as a reminder, please don't forget to submit your questions. So I want to thank everyone for attending, and I will now turn it over to Jesse.
OK. Thanks, Will, for the introduction. I really want to just say up front—to thank U.S. Department of Energy for hosting this webinar, SAE International, and especially the team that helped make the hydrogen fueling standards, 2601, 2799, possible. So without them, we would not be here.
So with that said, we're here to talk about J2601 and 2799. We're also going to give you an overview of what's coming up next. I would want to—I just want to mention in this slide that I'm actually presenting here on behalf of SAE as a role for the sponsor. So with that said, can we move on to the next slide?
So as just an overview, as we go through the presentation, you'll see this outline coming up. It's a hydrogen fueling standardization presentation that has background. We're also going to get into the steps to get to the hydrogen fueling standardization, and talk about some of the technical details in the 2799 standard, as well as the hydrogen fueling standard, 2601.
In addition, the standard was validated with lab testing and fuel verification, and we'll show you a little bit of that. And also, how the 2601 and where is it implemented, and also some guidance in that regard, and then we'll pass it off to Steve.
OK. So let's get right into it. Hydrogen fueling background.
I was asked from the U.S. Department of Energy, in addition to the standardization, just to provide some perspective on what—where hydrogen fueling is today, and that's what this slide is. You'll see that there are three major areas where hydrogen fueling infrastructure is currently being developed.
You'll see in Japan there's—all of this is focused around the near future, 2016, and the intermediate stuff, around 2025, on this slide. As you see, Japan is planning 100 stations in the first step, and then 1,000 stations in the second step. Germany is—has a number of different demonstration projects as well with the Clean Energy Partnership. They have about 50 stations in process for 2016, total. And there are also 400 privately funded stations that are being put together by a consortium called H2 Mobility there, until 2023.
In addition, close to Germany, there's the Scandinavian countries also put together about 16 stations in the near term, and then 15 planned thereafter, I should say all for 2016. And getting back to where we're—where this is presenting from, in the United States, we have the—California, because of the ZEV mandate, and also the infrastructure being supported by CEC and ARB, there are currently 10 public stations, 45 more in process for 2016, with 100 total being planned and funded by the State of California. And there's also East Coast Hydrogen Highway that's starting up.
So that's it for the overview. Now let’s talk about the status of what's happening in the field, with the automakers, there were recently announced plans for hydrogen fuel cell vehicles. If you see there are seven automakers that have announced plans. A number of them have announced joint plans. In addition, as I mentioned in a previous slide, the State of California mentioned that they were going to fund 100 hydrogen stations, and I understand that 68 of them are in progress right now, and of course, this slide is also for the Department of Energy along with industry, a partnership, excuse me, have created a hydrogen initiative called H2USA, which was recently joined—which recently formed, to coordinate a national hydrogen infrastructure in the United States. And this includes assisting in codes and standards.
And H2USA is really the national organization. They also formed a DOE project called H2FIRST, with two national laboratories, in order to accelerate the technology needed for the fueling infrastructure. So essentially, the practical arm of H2USA in terms of getting some of the R&D done in order to meet a lot of this rollout is with H2FIRST, and below is just a quotation from Mary Nichols supporting both these efforts.
And this is just getting into the background on why is it so important for hydrogen fueling for the success of the electric vehicles. It really is important in order to—in regards to the infrastructure—to establish hydrogen fueling, which has to be within the hydrogen storage system limits regarding temperature and pressure. There's also fueling rate limits and driving range—the resulting driving range from the fueling has to be acceptable also to the customer.
In addition, the vehicles need to fuel at the same as today's rate, and I'd just like to make the statement that the only infrastructure technology that's able to meet the same as today's fueling rates is hydrogen fueling, and equivalent driving range as well.
OK. So this is a—sorry for the detailed slide, but this is actually to compare two SAE standards. The one on the left hand side, with charging, with the BEV vehicle reference, battery electric vehicle, and the right hand side is SAE 2601 with a reference of 70 megapascal fueling, or 10,000 psi. And if you notice, there is a significant difference between the left hand side with the battery electric vehicle having storage capacities between 30, on a reference storage, and 85 kilowatt hours, and on the right hand side, just to keep it on the same playing field or the same level, this is with a 60 percent efficiency of a fuel cell vehicle. You get the equivalent of a average reference storage of 100 kilowatt hours for 5 kilograms of hydrogen, and 200 kilowatt hours for 10 kilograms of hydrogen. So you're looking at a factor of about 2.5 to 3 more storage you can get on a fuel cell vehicle than electrical vehicle today.
And if you look at the difference of fueling time, you're talking about 3 to 8 hours, or 8 to 20 hours, depending on the type of charging you have, to 3 to 15 minutes with reference to a T40/T30 dispenser type. And what we're going to talk about today is this T40 dispenser, which is the most common one used today, which will get you 3 to 5 minutes, as opposed to fast charging at 20 to 60 minutes. And the resulting will be 500 kilometers or 300 miles, as opposed to 100 miles or 160 kilometers.
OK. Let's talk about the standardization, the reason why we're here.
SAE has got a number of standards, actually, to assist in safety and the infrastructure and the interface to the infrastructure. The first one, a lot of people have asked, you know, has the hydrogen world learned the lessons from the electrical vehicle world with regards to connectors? In fact, they have. Both SAE and ISO have gotten together and formed one coupling worldwide based on SAE J2600, and there's also a hydrogen gas quality for the fuel cell vehicles, SAE 2719, as well as an ISO equivalent to that.
And I wanted to mention that in regards to hydrogen fueling, there is no equivalent worldwide. In fact, SAE is the only standardization organization currently that has a fueling standardization, a fueling protocol for standardization as well.
Regarding fueling—those communications between the fuel cell vehicle and station, SAE 2799, as well as SAE 2601, which is light-duty protocol. In addition, very soon to be published as a guideline, or TIR, will be the heavy-duty vehicle, SAE J2601-2, and there's another TIR or guideline that's already published in forklift vehicles, 2601-3, but we're going to focus on the—if you take a look, we're going to focus on 2799 and 2601 today. That's really what's just recently been released, and let's get into it.
I just want to mention there's a long history behind it. There was a guideline published in 2007 for SAE 2799 with a coupling and infrared data communication guideline.
Essentially it's remained the same, almost identical, over seven years of field data and testing, and it was split up into two documents, because originally, it was the receptacle and nozzle geometry, and the infrared data, that ring in the front, and it was split up into two standards, 2600, which is the nozzle hardware, and 2799, which is the communications.
And in 2007, a number of automakers got together with a few industrial gas companies and created a hydrogen fueling protocol Rev A in 2007. That was used in the field successfully, and lessons learned from that were brought to SAE.
In 2010 was the first TIR 2601 guideline for protocol was published, and we've had about actually four years, not three years, of lessons learned, and we've now come to the realization that we're ready for the first level of commercial infrastructure, and we've made it into a standard, 2601, for compressed gas hydrogen fueling.
OK. Let's start talking about the technology and what is actually the content of 2799 and 2601.
So 2799 is, as I mentioned before, a standard that's published, that gives wireless communication of vehicle data from the fuel cell vehicle to the station. It is optional, so you can actually fill without communication.
This gives you vehicle tank information used to improve the fueling and gives you a higher SOC. It gives you a very high—slightly higher range than even light duty vehicles. And there's an optional abort signal as well, to stop the fueling.
I just wanted to mention one last slide on 2799. There are a number of variables that have been used in terms of signals that have been transferred from the vehicle, and this is a list of them. If you're more interested, you need—you're probably going to need to buy the document, 2799, but this is actually a example out of it in terms of where the fueling station infrared receiver is located, and the vehicle infrared emitter, as well as what channels there are and what the limits are. Essentially, the tank volume, the receptacle type, the fill command, pressure, and temperature is what's being transferred.
There's also one last character there called the optional data, which has actually been expanded from the TIR, and that's not being used currently in the table-based protocol, but that's for future protocols that will need more data characters. That's being left there as a placeholder.
So the meat of the presentation we're going to get to right now in the hydrogen fueling standard, J2601.
And just to give an advertising, again, on the capabilities of this standard, it gives you fueling which is consistent with all hydrogen storage and fuel cell vehicles that drive up to a vehicle—excuse me, drive up to the station, and it gives you a very high state of charge, meaning how full the tank will be, without violating the storage system parameters regarding temperature and pressure, mainly.
It also fulfills the U.S. Department of Energy targets by giving a 3-minute fueling, really it's more like 3- to 5-minute fueling, enables 300 miles range, or 500 kilometers. And we're lucky to have this standard, because it's being used as a basis for fueling worldwide, and gives a consistent fueling for the automakers and the customers.
OK. So here we are today, 12 years later, after we started. It was—as we mentioned before, it's being used in applications in these infrastructure projects worldwide, but it was created—I wanted to mention, this is important—it was created with a lot of thought. There was a lot of—years of simulation done, and math modeling, confirmed with real automaker systems testing in both the laboratory, under extreme conditions, and in the field, in three continents.
What does this standard cover? It's light-duty fueling, as mentioned before. There's other applications, or other standards for other applications. And the range of storage is 2 to 10 kilograms for 70 megapascal, and about 2.5 to 6 kilograms for 35 megapascal. So it covers both pressure levels of fills.
And it's important to know that you can fill with or without communications. It defines what limits, and it—for—from safety, it aligns also with SAE 2579, which is the same as the global technical regulation with regard to safety limits. It also gives you performance targets, what the customer would expect.
The standard actually uses a lookup table-based approach, which has been updated and relaxed from the guideline level with data from the field, and we have a very high confidence in the performance of the new table.
There's also new fueling temperature categories, and we'll get into those slides in a minute. In addition, there's a number of new fueling concepts that have been updated from the Technical Information Report, some of them called the fall-back fueling, the top-off fueling, cold dispenser, and in addition, there's a development method that Steve Mathison will get into, called the MC Method, at the end of this presentation.
OK. So I mentioned before about modeling and simulation models. I think it's important to understand that seven automakers got together in SAE and essentially shared the properties of their tank. We got essentially all of the hydrogen suppliers around the table, and they shared what their—thermal capacity and properties of their components were in different countries. And there have been a number of testing and correlation between the models between the automakers.
So after the simulation was done, we actually did some laboratory validation with extreme temperatures and different tank volume sizes, from 2 to 10 kilograms, and we tested with real automaker tanks in the laboratory and real hydrogen station supplier hardware.
So that said, we're also going to show one slide later about the fuel validation that was done, and I just want to mention these were done in public stations, public hydrogen stations, and a number of OEMs participated, and also submitted the data to SAE.
All right. So just getting into some of the limits, it's important to understand the limits of fueling, at least on the storage side, are minus 40 inside the tank to plus 85, and the maximum dispenser pressure is 25 percent above what's called the nominal working pressure, like 70 megapascal, for example. That gives you 87.5 megapascal for 70 megapascal and 43.8 on 35 megapascal.
We also have a maximum flow limit of 60 grams per second. That really is something that's there to protect the valves. And I should say, heavy-duty fueling is almost double that, but this is light-duty fueling in this particular standard.
So we're able to achieve targets for 3 to 5 minutes, we've said now, and we've proven that we get consistently 90 to 100 percent tank filling or SOC.
With communications, we've already talked about that, but it gives you the vehicle tank parameters, and also non-communication—you can get still the tank pressure when you pull up, and you can use that for the fueling tables.
In addition, we have station control key factors. We have the temperature of the hydrogen gas going in, also called pre-cooling, in order to offset the heat of compression. There's also the hydrogen delivery rate, where the station provides an average pressure rise rate as per the tables. And we'll show some examples of that in a few minutes. And in addition, there's also fill termination, where the station determines what the end pressure or target pressure, based on—based on the tables that have been given.
OK. Just a few more overview slides of the content. There are not only—the ability to fill 2 to 10 kilograms, there's actually three different fueling categories to help separate the tables, 2 to 4, 4 to 7, and 7 to 10 kilograms. The customer doesn't need to know this. This is something for the station manufacturer, in order to be able to determine what table to use. In addition, this 35 megapascal has 2 categories, 2 to 4—excuse me, 2.4 to 4.2, and 4.2 to 6 kilograms. And the reason why the numbers are not even numbers on the bottom, or I should say not rounded numbers, is because they're actually the same tanks as above that could possibly also fill—you can fill a 70 megapascal vehicle at a 35 megapascal station, but not the reverse, of course. And with that said, there's also some calculations on water volume on this slide. And we can go to the next one, if we could.
OK. So with regards to the standard in terms of pre-cooling versus the guideline from 2010, there has been a change, an improvement, because the standard actually defines fueling type to dispense without any gaps in it. As essentially before, we had three different fueling categories, including a non-pre-cooling category, and there were gaps between them, and what we didn't realize when we made the guideline was that there were shutdowns if they were out of tolerance. And that could happen in the field, and there's no reason for the customer to see that. So we improved that so that there were no shutdowns, and there's an allowing—if the station is at full capacity, and even goes over capacity, it can go to a warmer pre-cooling rate and do a fall-back fueling, and I'll show you an example of that in a minute.
OK. Just getting a little bit into the theory, it's important to understand how the tables were made. This graph below really shows the bookends of temperature and pressure. So the tank can take [audio glitch] minus 40 to plus 85, and of course, this is—there's a lot more in terms of buffer there, of what it can take, but this is what the limits of fueling are.
And also, in regards to pressure, the stop point is, as I mentioned before, 25 percent above 70 megapascal, or 87.5, and that's essentially the limits of fueling. That's what this over-pressure and over-heating are, on that upper left hand side and that lower right hand side. What that—with the line going across the screen there, it's showing—it's actually called the line of constant density. At a different temperature, you're going to have a different pressure inside the tank because of the properties of hydrogen, but what this shows is that you're going to have 70 megapascal at the standard temperature rating, and then if it gets warmer, it can get all the way up to 87.5.
And what happens is when you're fueling, you're going to have a hot tank, and you're going to end a little bit warmer, and then it's going to cool down and come down to 70 megapascal. But what's important to show on this is actually the line of constant density. Every point along that line is 100 percent SOC, and that's where the tables were based essentially, to make sure that the dispenser control can program the SOC in order to achieve a high fueling rate under any ambient temperature condition.
OK. This is another theory slide, but it's really to show you what happens in terms of temperature development inside the tank and the dispenser control under average pressure ramp rate. So the green line you see there in front of you is actually the vehicle tank temperature, which may be slightly lower than the ambient temperature, depending on how much it's been driven.
But there's actually a few things that happen when you connect to a vehicle. There's a connection pulse, when you actually put the nozzle onto the vehicle, and you may actually have a small amount of hydrogen that goes in because of the pressure differences. And then there's an intentional volume check, which is actually a pressure hold, so to speak, on the control side, and during that time, the temperature rises slightly. And as soon as the temperature starts on that lower part of the ramp rate of pressure, it actually gives you a steady rise in temperature where it actually tapers off towards the end of the—of the ramp rate.
We're going to get into some of the control methodology, and if you look on the left hand side, of course, the dispenser is where the fuel is coming from, and the right hand side is where the fuel is going into a fuel cell vehicle. And you categorize the types of tables and actually the speed of fueling by the pre-cooling rate, and there's three different types of dispensers. There's the T40, the T30, and the T20, which essentially equates to around minus 40C lower limit and minus 30C and minus 20C on the pre-cooling temperature of the hydrogen going in, or the gas temperature going in.
You have vehicle parameters when you pull up in terms of initial gas pressure, and the station, in order to find the lookup table, looks at the ambient temperature, and then it looks at the delivered gas temperature or the rating of the actual dispenser, coupled with the vehicle parameter, and you get a lookup table. And I'll show you after this slide in a minute how that works.
And at the end of this fueling, you get—you have an end pressure and you have an average pressure ramp rate. I should say, at the end of this control strategy, I should say, you use this target pressure and average pressure ramp rise rate to do your fueling, essentially control the ramp rate, and stop fueling at the target pressure.
What this block diagram shows is there's an integrity check with the communications, and when you start fueling, you have the option of non-communications or communications. The station doesn't know what the vehicle wants when it pulls up, so it pulls up, if there's communications, and if for any reason it fails, it—in terms of the communications going across, it simply goes to non-communications. In most cases, it goes all the way to the end of fueling, and this just shows that there is also different start-up routines, and there's also a fueling process, non-communication subroutine. And each one of these checks will determine if you can start fueling and also if you can continue fueling, and when to end.
OK. Here's one example—sorry for the eye chart. We're not going to look at all the different numbers. What I want to do is show you just an example of how simple the communications is once you have a table picked out. You could slide—if you could hit the next key. Thank you, Allison.
If you look here, when a vehicle pulls up and the initial tank pressure of 10 megapascal, meaning the vehicle itself has got 10 megapascal, and the ambient temperature is 20 degrees, with this T—with H70-T40, which means that it's a 70 megapascal with a pre-cooling of a minus 40 C, and this category of 4 to 7 kilograms, what it gives you, if you go—slide to the next one—it gives you a resulting initial tank pressure of—from 10, and tells you all the way to the end pressure of 86.8 megapascals. So the—on the right hand side, you'll see—lower right hand side, you'll see 86.8, which shows you the stop pressure, and then you'll see average pressure ramp rate, or APRR, which shows you to be 21.8 megapascal per minute. What the customer needs to know in this particular case, you're going to get about a 4-minute fueling.
OK. And now here's a—essentially a graphic of the example we just showed, where you see startup time, as I mentioned, as a pressure pulse, and there's the volume check, and then we have the startup fueling, which gives the initial tank pressure of the vehicle pulling up, and the average pressure ramp rate, which was chosen from the table before. And of course, the end of fueling, which is the resulting stop pressure, end pressure, that comes from the table. And if you go to the next one, Allison, you'll see this is the exact example from the previous slide, where you start at 10 megapascal and end at 86.8 megapascal.
And if you notice, there's something right in the middle, which are dips in the pressure, and those are called non-fueling time. In the United States, there's a code called NFPA, and they ask you to stop fueling in the middle of fueling just to do a leak check in the middle, and there's still a way to maintain a pressure ramp rate for the customer to get a reasonable amount of fueling time, and also for the control system to pick up the ramp rate again and continue fueling.
Now I would like to get into what's called the cold dispenser. Now we're anticipating—we've heard from some of the automakers that the fuel cell vehicles are going to start to come out next year, and there's also been station providers that have actually started building these stations, and you've seen the rollout in a previous slide. We're going to see a number of vehicles filling up at these stations. Perhaps the demand may be actually higher in the beginning than we actually anticipate. But either way, the concept of a cold dispenser is multiple fuelings in a row will really cool down the station components such that you can take advantage of this pre-cooling. You don't have to worry about heating up the—excuse me, you don't have to worry about cooling down the station components in order to fill at a prescribed pre-cooling temperature.
In fact, you can—because you know after multiple fuelings that all the fueling hardware with temperature sensors on the hardware itself can actually optionally use a cold dispenser fueling procedure to increase the APRR when all the station components are sufficiently at low temperature. So that means essentially if you have multiple fuelings in a row, you can use the cold dispenser if the station can have a confirmation that the fuel component temperature is the same as what it is below.
So for instance, there's actually two temperatures that are shown here, 0 degrees and minus 10 degrees. So these are tables that are being used very similarly to the standard tables. But what you do is you use these temperature sensors to confirm what the temperature of your components are, and use the results of that to use a new lookup table. And this is an optional—I should have said that in the beginning—this is something that could be used by station providers, or you can use the standard tables as well. And I'll show you the advantage of using this table in the next slide.
OK. So if you look here, this is a table similar to before. It's an H70-T40, or a 70 megapascal fueling with a minus 40 temperature pre-cooling range for a 4 to 7 kilogram lookup table, and the CD, or the cold dispenser, of minus 10, is the temperature of the fueling components that are actually on the—on the dispenser side.
With that said, in the same scenario as before, a vehicle pulls up with 10 megapascal inside the tank at a 20 degree ambient day—this is all Celsius, of course, so that's about 70 degrees Fahrenheit. If you take a look here, when you go to the next one, you'll get a different result. It's about the same end pressure, but the ramp rate is somewhat higher. It goes up to 27.7, and what that equates to the customer is 3-minute fueling. So you can see with this cold dispenser, you can take advantage of this cold energy already in the component, so to speak. You can reduce your fueling time by increasing your ramp rate.
OK. I didn't mean to show only graphs, but I want to make sure it's understood that there's a change from the TIR, or the guideline, to 2601. It's been revised for fueling corridor pressure tolerances, slightly different than the previous guideline. It's essentially with and without intended non-fueling time. And what that means if you have a leak check, you use the table below, and if you don't have a leak check, you use the table above.
And essentially, the ramp rate, which we described, which is this constant average pressure ramp rate, whichever tank within the category pulls up will give you, so to speak, and this is the tolerance, or delta P, the change in pressure on the lower end, 2.5 megapascal, and a change in pressure on the upper end, 7 megapascal. And essentially, it gives you tolerances with and without leak checks.
OK. This is a similar diagram, and I want to introduce a new concept, which is called top-off fueling. And top-off fueling only happens if you have almost a completely empty tank and you have to do a complete fueling. Towards the end, there is an allowance for a top-off, which is essentially a slower ramp rate, and what it gives you is the same state of charge or guarantee of fueling density in the tank, or fueling fill level. And this window allows you to have a variance in top-off, but of course, the fill targets remain the same.
OK. And this is the last graph of the 2601 presentation. I want to mention, this is just to convey the difference between the TIR 2601 and the standard, where if the—and this is not a normal condition. A normal condition under normal capacities, these stations shouldn't go outside their ramp rate. However, it could be that they're—there's significant enough fuelings back to back, and this is an allowance for those stations that may go out of tolerance to, instead of shutting down, they can actually go to a slightly slower fueling time, or ramp rate, and that ramp rate that it goes to is called a fall-back pressure ramp rate, and essentially, you shift from a table with a minus 40 pre-cooling ramp rate to a minus 30 cooling ramp rate, and that's the APRR final shown here in the graph.
And essentially, when you go outside of bounds, it does it instantly, and there's no delay in the—in the ramp rate. So the customer doesn't see anything except maybe an extra minute or two on the fueling.
All right. Let's talk about lab testing and validation thereof to give you confidence that this has been vetted by the industry.
This is actually funded by industry members of the SAE 2601 team, and I wanted to mention that—if you take a look at that laboratory, I'd like to recognize, that's actually the laboratory of Powertech Canada. Powertech in Vancouver, Canada, excuse me.
And the test cell on the left hand side is a simulation of the storage on the hydrogen station side, and the test cell on the right side is the hydrogen storage on the vehicle side. And we wanted to make sure that we had actual components—and I want to mention that this is—all of the different levels of volume and pressure have been tested in 35 and 70 megapascal fueling under extreme temperatures, so extreme ambient temperatures of minus 40 and plus 50 C, and plus 50 C is—well, it's upwards of 120 Fahrenheit, so it's pretty hot.
And it's a—what I'm trying to say is that this is an extreme temperature test. It's something you probably wouldn’t see in the field, but we wanted to validate the tables would never overheat and never have any overpressure in any of these extreme conditions. So we tested actually—we're lucky enough, automakers donated real station—excuse me, real vehicle hardware, and a number of suppliers from Japan, from the U.S., and from Germany also donated real station hardware, and if you see in that—in that window there, we actually use a real filling line, nozzle receptacle, and a breakaway, similar to—the same components you put on any natural gas station would be the same kind of components you'd see on the hydrogen station, of course, with the hydrogen compatibility being the difference in materials.
But these are all real components and a real tank used to simulate this, and then what we did was—go to the next slide—we actually took this to the field. I shouldn't—I didn't mention the graph on the previous slide, but we used—if I go back one slide, sorry—we used this slide to show the window, if you take a look inside of the simulation, and we actually used this lab testing to compare the simulation with actual fueling results, and validate the tables themselves. Thank you.
And then 2601 was actually tested in the field in three continents, in Europe and in the United States as well as in Japan. It was tested with five automakers, two of which are shown in the slide here today. And I should mention that you'll see an example of the fueling validation with communication, and what we wanted to see is it's just like in the laboratory. We wanted to do real fueling with real ambient temperatures and vehicles just pulling up under different starting pressures, and we wanted to make sure that the tables were not only accurate, and we didn't have any issues that we see in the field, and we got very good correlation. If you look at the results, all of the tests were within 90 to 100 percent state of charge or full tank, and all of the fueling times were at 3 to 5 minutes, and we had ambient temperatures between I think 15 and 30, which is for the validation very good. And I should also mention that we also had one oil company also involved, and we had a number of vehicles. It wasn't just one vehicle that actually pulled up.
OK. Let's talk about the implementation.
I just wanted to recognize the organizations helping making this 2601 happen and putting them into the field and participating in the team in Japan. You see the organizations there, HySUT, Fuel Cell Commercialization of Japan, JARI, NEDO. United States—U.S. Department of Energy, H2USA, State of California, CEC, CARB, the Fuel Cell and Hydrogen Energy Association, the California Fuel Cell Partnership, and also the California Hydrogen Business Council has been helping as well.
In the European Union, I wanted to mention that SAE 2601 is also being referenced in the new station standards for hydrogen stations coming out in 2015 called 19880-1, and that standard is being used in Europe, and the organizations supporting there is the European Hydrogen Association, NOW, CEP, H2 Mobility, and H2 Moves.
OK. To wrap up the slides for the presentation, these links actually will bring you to the document, and so they'll be posted later. So the 2601 and 2799 standards are really enablers of fuel cell vehicle commercializations worldwide. They give you the safe fueling, consistent for the fuel cell vehicles, and the standards can be purchased on the SAE website. There are the links below. In addition, all the data, from the laboratory to the vehicle automakers, have been put in the public domain, and published recently this June, and can be also found in the SAE Technical Report, and in addition, one thing I forgot to mention that in addition to the simulation, there was also sensitivity studies that were done in different scenarios, and all that is documented in—from the standard tables, including the MC method, the data is documented in that report which you see up there.
And to conclude or to close—oh, there's one more point, if I could just—thank you. To close, it's a very important point I'd like to make, that at station commissioning, dispensers that use 2601 need to be validated just to confirm that they meet the limits before starting dispensing, and there's an example of a paper that was done in the past with testing apparatus. But what I'd like to mention is that the State of California through ARB and H2FIRST, that work in the United States, along with HySUT in Japan and the CEP in Germany, and their process with implementing what's called a hydrogen dispenser station test apparatus, or STAs, the hydrogen HSTAs, and these apparatuses are essentially tanks that go and fill and confirm the fueling. This is not a unique thing that's done in the field. It's done also in natural gas stations, in weights and measures. That's something that's underway right now to help with the implementation of the infrastructure.
OK. This is Steve Mathison, and I'm going to talk briefly about the MC method, which is a non-normative fueling protocol included in the appendix of the current J2601 standard.
So just to give you a brief background on the MC method, so MC is a representation of the heat capacity of the hydrogen storage system. So the MC method is a way of—analytical method, and it's a way of quantifying how much heat is generated during fueling, and it allows us to calculate the end of fill gas temperature fairly accurately.
So this original MC method was kind of married together with the same approach that was used to develop the lookup tables for J2601, and we've now called that the MC default fill. So that's the actual name of the protocol itself. The philosophy is identical to the lookup tables. A hydrogen station is fully responsible for safe fueling of the vehicle. There's really no—any additional or safety critical information from the vehicle that's used. And worst case boundary conditions, just like the lookup table, are also assumed for the MC fill.
So the key difference of the MC default fill versus the lookup tables is that instead of using the boundary temperature, which Jesse explained there's station categories, for example the T40 category, instead of using a boundary temperature as an input, we use the actual pre-cooling temperature. But all of the other boundary conditions remain the same, and I'll explain this a little bit more on the next slide.
The other key difference is the ramp rate control methodology. So the lookup tables use a static control method, and the MC fill uses a feedback dynamic control method. Next slide.
So as I mentioned, the boundary conditions remain the same. This is kind of a busy slide. I won't go into the details. But if you focus on the center of the slide, you can see there are boundaries for the pre-cooling temperature that it needs to stay within for a given station category. And so the lookup tables use that red line, which is the boundary temperature, as the input to determine the pressure ramp rate, where the MC default fill uses the dashed red line, which is the actual measured temperature, to determine what's the appropriate pressure ramp rate. And this is done also when calculating the pressure targets. So that's really the key difference between the MC default fill and the lookup tables. Next slide.
In regards to confirming the safety of the MC default fill, Jesse mentioned the amount of mathematical modeling that was done in developing the lookup table approach. The same amount of mathematical modeling was also incorporated to both develop and confirm the safety of the MC default fill. So just like the lookup tables, it's designed to ensure that the gas temperature never exceeds the 85 C limit, and that the pressure targets don't overfill. So to confirm this, we conducted 93 simulations with this math model, the same one as the lookup tables, for overheating, and 48 simulations for overfilling.
We—in addition to that, we also conducted bench tests at the same laboratory that was used for the bench tests for the lookup tables, and these results are also included in the SAE paper that Jesse mentioned in his conclusion slide. Next slide, please.
So in addition to the bench testing and simulations, also to validate the MC fill in the real world, we've applied it at our station here at Honda R&D in Torrance, and we are conducting real world fueling, both with a test tank, which we have here, but we also have been cooperating with General Motors and Mercedes-Benz, who bring their vehicles over on a regular basis. So you can see that we now have about 81 fills conducted to date, and the majority of those are the MC default fills, but we've also been conducting J2601 fills to compare the two.
If you focus on the graph, upper right, you can see how the pressure ramp rate, the green line, is not a straight line. So it's varying throughout the fill. And this is the—just kind of demonstrates the dynamic nature of the control for the MC fill. Next slide.
So as I mentioned, the MC default fill is currently a non-normative protocol, which is included in the appendix. It offers many advantages from a customer experience. They get fast fueling times, and also very consistent fueling times. From a station design standpoint, it does offer more flexibility due to the adaptive nature of the protocol. And for the hydrogen infrastructure, it allows slightly better station utilization by allowing more vehicles to be fueled for a given timeframe.
In-field use and validation is currently ongoing, and we've also been working with other dispenser manufacturers to implement the MC default fill. And finally, the SAE Interface Task Force is currently evaluating the data that we've been generating from this real world usage, and they are considering making the MC default fill a normative fueling protocol in a future revision to the J2601 standard.
So that concludes the presentation portion of the webinar, so now we're going to go to the Q&A portion of the webinar. And so I have quite a few questions from the participants online, and so we'll just jump right into it. So I would say the first question would go to Jesse, and then it basically talks about the safety requirements as they exist in NFPA2 and the I Codes. How do you feel that the—are they adequate when it comes to refueling for the construction and maintenance of a refueling station?
Actually, that's an interesting question. NFPA2, which is the latest code that was adopted, and the predecessor to NFPA55, has all of these topics that we mentioned in the presentation with respect to the leak checks in the beginning, and integrity checks during the fueling.
In addition, there is protection with regard to pressure protection on the station for a pressure release valve, and also a listing requirement for the nozzle. So I think that NFPA is actually a very good document that's being used in hydrogen fueling today.
Great. And Jesse, while you're answering the first question, the second question is also for you. Could you clarify the acronyms that you used related to the cold dispenser, where you used APRR and the CHSS?
Oh, yes. I'm sorry. Yeah. Actually, APRR is the average pressure ramp rate, and that is essentially the slope of the curve or the pressure that's constantly rising that fills up the vehicle, and that's actually taken from the table. That's one of the variables that are taken out of the lookup table. CHSS is actually tank—it's compressed hydrogen storage system.
OK. Great. And then one more question for you, Jesse, is the—when the tables were being generated, how is the actual time of fueling being calculated?
Well, the time of fueling really starts after the pressure pulse and the leak check is done. So essentially, you have a lookup table variable called the ramp rate, the average pressure ramp rate, which is in megapascal per minute. And that will give you, with the stop pressure, the amount of time that it's going to take you, and that's explained in the slides.
OK. Great. And then there's a question for Steve. I guess currently, where does the MC method, even though it resides in Appendix H of the current standard, but where is—what's the next step for the MC method in terms of commercial implementation?
Well, in order for the MC method to really be implemented in a commercial environment, it would need to be a normative protocol within the J2601 standard, so that's what we've been working towards. And it was kind of the last point in my conclusion, that the Interface Task Force is currently looking at the data and considering that for a future revision.
OK. Great. So I think I have one more question before we finish the webinar, and I think it is a question that Jesse's probably answered several times, and it's around the 85 degree C and the possible excursions away from 85 degree C. I didn’t know if you wanted to expand a little bit about that issue.
Well, it's not really an issue. What it is, the current document really says to stop around 85 C gas temperature, and essentially the tanks can probably take a lot more than that—it has a lot of margin there. And I think there's a wish in the future to evaluate that and see if that can be moved to material temperature, give you a little faster fueling times, and that's something—something that is not currently on the plate. But we've seen that you can get sufficient fueling times and not exceed any temperatures or pressures by using the 85 C gas. But it is a valid point that the material temperature can take a lot more than that.
Great. Well, once again, I want to thank Jesse and Steve for their time for the webinar. And so with that, I know there were several questions that were not answered. There were also several questions submitted around reports and where they can find some of this information, and so Jesse in his conclusion slide, which will be posted later, there's some of those links available there to guide you to that information.
With regards to the questions that we did not answer, we're going to ask Steve and Jesse to answer those offline, and then we will post the answers to those questions when we post the actual webinar. So with that, I'm going to turn it back over to Alli to finish the webinar, and thank you.
Thank you so much, Steve and Jesse. What a great presentation. Will, thank you for taking the lead on this one. Just to follow up with what Will said, just a reminder, we will be posting a recording of the webinar along with presentation slides in roughly 10 business days. Now keep in mind, these guys are going to be answering questions, and they are doing this out of the kindness of their heart, so we need to give them a few days to answer those questions, and then we'll get that stuff up on the website. So just look out for an email from me, Alli Aman, and I will let you guys know once those are posted. And then just a reminder, we encourage you to sign up for our monthly newsletter as well as check back for our monthly webinar series, because we do have different topics every month.
So on that, I want to thank everybody for your time, especially Jesse and Steve. Thanks so much, everyone.