Eric Parker, Hydrogen Fuel Cell Technologies Office: Okay. Well, hello, everyone, and welcome to another H2IQ Hour, part of our monthly educational webinar series that highlights research and development activities funded by the Department of Energy's Hydrogen and Fuel Cell Technologies Office, or HFTO, within the Office of Energy Efficiency and Renewable Energy. My name is Eric Parker and I am the webinar lead for HFTO.
We also have another special H2IQ Hour coming up very soon I want to mention, so please keep an eye on your inboxes for an e-mail about that very soon.
This WebEx call is being recorded and will be posted to the DOE's website and used internally. All attendees will be on mute.
If you go to the next slide we've got you'll see a Q&A box here that you can use to submit questions throughout the presentation that we will address at the end. I will try to get to as many as possible, so please use that Q&A box as you think of questions, and we will try our best to answer them.
So with that I'll kick it over to Neha Rustagi to tee up today's topic and the speaker. Thanks, Neha.
Neha Rustagi, Hydrogen Fuel Cell Technologies Office: Thanks, Eric. So it's my pleasure to introduce Amgad Elgowainy. Amgad has decades of experience leading hydrogen emissions and infrastructure analysis at Argonne National Laboratory and is also the lead for the Electrification and Infrastructure Group at the lab. Today he'll be giving us an overview of the GREET model.
So GREET has been funded by many DOE offices: ours, the Vehicle Technologies Office, Bioenergy, and many others, and is now used by tens of thousands of stakeholders worldwide to conduct emissions evaluation of hydrogen as well as many other pathways. So Amgad will give us an overview of how GREET works, key perimeters that influence emissions analysis, and then also do a live demo and show some example results.
So without further ado I'll turn it over to Amgad.
Amgad Elgowainy, Argonne National Laboratory: Thank you, Neha, and thank you, Eric, and hello, everyone. Today I will be presenting to you the GREET model for life cycle analysis with a focus on greenhouse gas emissions.
So GREET stands for Greenhouse gases, Regulated Emissions, and Energy use in Technologies. Previously it was transportation-focused, but now it is beyond the transportation. GREET has been supported by several DOE offices, including the Hydrogen Office for the hydrogen pathways along other mainline pathways. GREET has been developed since 1995 and is updated annually, along with documentations. It is available for free download and use using the link you see on the screen. Like Neha mentioned, we have over 50,000 users now, including major automotive, energy companies, and government agencies.
GREET has—for vehicles—has two different scopes, so one system boundary or scope is to evaluate the fuel cycle. Here at the bottom you see from the primary source of energy in nature, I mean whether it is in a well, whether it is in the atmosphere, for example, like wind, or I mean solar, and processing that primary source into the fuel that is required for some NDOs or applications. And then the consumption of that fuel for transportation, it will be a vehicle. So we call that fuel cycle or well-to-wheels. And we cover also the vehicle manufacturing, energy use, and emissions. This becomes recently more important as vehicles target higher efficiency using the lightweight materials, which are in general more energy intensive and carbon intensive compared to conventional materials. There also is electrification, batteries, fuel cells, carbon fiber for hydrogen tank, all play a role into the vehicle manufacturing cycle.
Today I will only focus on fuel cycle and will guide you if you are interested beyond the hydrogen pathway or beyond the fuel cycle, where you will find this information.
So GREET actually, as I mentioned, we have the fuel cycle, we have the vehicle cycle, we have two platforms. So Excel is the original platform, it just expanded so much that we have literally hundreds, actually over 1,000 pathways in GREET, so we developed a .net version. Most of the early users like Excel; most of the new users actually use the .net. We use both to vet against one another before we release.
GREET has many derivatives, so there is a version for the ICAO, for the sustainable aviation fuel, there is a China-GREET version, there is a California-GREET used by ARB for the low-carbon fuel standards, there is AFLEET which uses GREET in the background to look at FLEET for brands. There is the EverBatt in particular, focusing on the manufacturing and recycling of batteries. And there are a really large number of government state agencies, even international governments that use GREET, as you see here on the right.
So what do we evaluate in GREET? The focus is environment. Energy source, for example, is important. Do we use a fossil energy source? I mean fossil energy sources, as you know, we bring the carbon from the ground and put it into the air, so this is actually important to identify with our sources of fossil—source or not. I mean they're renewable sources, there is bio-sources, there is nuclear power. So all of these actually can bisect as the energy supply or the energy embedded in our product. I mean the percentage of the share of the different energy feed spots.
We look at air pollution, that used to be important for light-duty vehicles about with emissions standards, but there really it is now becoming more important for the medium- and heavy-duty vehicles as well as the number of applications, such as marine, for example.
Then greenhouse gases, as you see here in the orange box, this will be the focus of the talk today. So greenhouse gases, we cover a large number of greenhouse gases, but the predominant ones there are the CO2, which is kind of the reference gas; CH4, which has a high global warming potential, this is important for most natural gas derivative fuels and the N2O, which is important in general when we use significant fertilizer that is nitrogen-based. So it is important for the biofuel pathways. And we aggregate these by their global warming potential and then we have also like water consumption and a water footprint brand of deploying the various energy systems.
GREET has different functional units, so we can do per service unit, like miles driven, or ton-miles, or passenger-miles for some transit application. We can do per unit of output, whether it is in units of energy like million Btus, or megajoules, or gasoline gallon equivalent. There's a gallon equivalent for hydrogen, we can do per kilogram, for example. And we can do per unit of resource to understand if you preview a certain amount of fuel, how much of the resources will be needed basically tying up to input through the yield or efficiency.
So very large number of pathways in GREET. I mean we have the petroleum sector. This is our baseline that we cover, for example, for light-duty vehicles. We compare gasoline for medium/heavy-duty vehicles, and some non-road application, like rail we compare against diesel. Aviation we compare against jet fuels, and there are other petroleum delivery fuels. There is also a large number of natural gas derivative fuels, natural gas channels into better electric vehicle through power generation, actually can tightly be compressed, and the port into vehicles for use directly in natural gas engines it would be a source for like since of hydrogen a drop in liquid hydrocarbon that is more of a gasoline-like, or jet-like, or diesel-like fuel. But we call that the _____ _____ family. So we have a large number.
Of course, hydrogen actually is a derivative of natural gas and heating, but see, hydrogen really has a very large number of pathways, with _____ methane, whether it is conventional-sourced, like conventional gas, or shale gas, or renewable sources such as biogas from some _____ streams. We do well under our carbon capture sequestration and electrolysis is an important pathway, so we look at them: electrolysis, solid electrolyte high-temperature electrolysis with different electricity generation sources. We look at electrolysis with nuclear energy. We have biomass electrification. We have several pathways on byproduct hydrogen, whether it is from chlor-alkali or steam cracking or coke oven gas. We have coal gasification with or without CCS, pit coal gasification. So a very large number of pathways. And then we cover actually how to package the molecule beyond the plant to get actually compressed liquefaction, transportation with different mods, compression at the station, all of that is covered in the hydrogen pathways.
Hydrogen also can be an intermediate. I mean for other I mean fuels, I mean for example, electrofuels that we _____ _____ _____ to is hydrogen, we can synthesize a varied – a wide range of chemicals or fuels. Hydrogen also is available for ammonia, and when you talk about green ammonia production, actually have also these pathways in GREET.
There is a group here for biofuels, as you see, and of course the power cycle is important across the board. Any industry or process has something that you can use electricity. Electricity is also a feedstock for the electrolysis pathway. Electricity is important for compression, liquefaction, pre-cooling. Electricity is also the major source for charging battery electric vehicles. So we cover this extensively.
The focus today will be selectively on hydrogen because the community here is more interested in the hydrogen pathways.
So one thing actually, since our baseline hydrogen production is Steam Methane Reformation, of natural gas, what we call SMR. So it is important to understand the natural gas supply chain. I mean one major issue there is anything _____ emissions or leakage actually flows out of the system whether in recovery or processing or transportation or distribution.
So methane is important because it has a very high global warming potential. Our reference gas is CO2, with a global warming potential of 1. The GWP, or the global warming potential, is mainly impacted by two things, the ability of the gas to absorb energy, and how long actually a gas can survive into the atmosphere. So I mean here I show actually, so the CO2 is our reference of gases with a GWP of 1, and it's lived really in the atmosphere hundreds of years.
CH4 in contrast actually has a short life, actually, a decade or two in the atmosphere. So it matters really the timeframe that you look at – I mean the impact of the CH4, or the methane emissions. I mean a typical GWP of a timeframe of 100 years actually really is the global warming potential of methane of 30, and this is typically what is being used in most regulatory schemes. Some will promote that since it has a shorter life the timeframe should be shorter, for example, 20 years, and if you do that actually then you'll see the GWP close to triple. And depending on the study of the GWP, 20 or 100, you may see very different results. So this is a sensitive parameter that we need to pay attention to when we look at the natural gas seen within the forming for producing hydrogen.
So what really matters for when we do life cycle greenhouse gas emissions accounting, of course CO2 is usually dominant there. So as I mentioned earlier, I mean depending on what is the source of our carbon and what is the fate of our carbon. So in general if a carbon would come from the ground and go into the air, so basically you unlock the carbon that was already sequestered, and I mean underground, and you put it into the atmosphere, therefore you increase the concentration of fuel to the atmosphere, and therefore you increase the global warming potential due to that increase of concentration. So a fossil source or releasing CO2 that has a fossil origin is important for us.
Now one way actually to mitigate that is to say, well, after I bring the carbon from the ground, they use the energy, release the carbon. Bur when we are putting it into the atmosphere I will try to capture as much as I can, put it back into the ground, sequestration basically. And depending on the amount you can capture or the share of the capture, typically you can do like about 90 percent, and then you can mitigate much of the carbon emission from a fossil source.
Now one way actually people are thinking about the carbon actually, if I bring the carbon from the ground, I use it, I produce CO2. Rather than letting the CO2 go into the atmosphere, perhaps I can capture it, and rather than restore it, extend its life. So in this case you need some renewable source that is a zero-carbon in this case it could be renewable electricity, you could make hydrogen and then pair the hydrogen with the CO2 to synthesize some hydrocarbon fuel, and then use it, and then once you use it you combust it, you release the CO2. So you would see here we have two life cycles for the CO2, the original one and then the one that goes post-capture. So as if really you are extending the carbon emission over two fuel cycles, which kind of you spread the emissions over two fuel cycles, therefore you reduce in essence the carbon emission from that fossil source.
I mention the methane emission that is important because of the GWP. And the usually with fossil sources, whether it is natural gas or even like coalmining there is something significant within emission. If we use our dependence on fossil sources automatically then methane emission will be reduced.
Actually they don't have the waste stream, which is important, actually, in the front regulatory scheme, which is a renewable natural gas or the biogas sometimes have created actually that will result in a negative carbon intensity. Now if we landfill an inorganic waste, let us say plastic, I mean it is better off to leave it there because actually it will remain there actually and will not decompose over time. So if we bring it from the ground it will be a pretty similar to a fossil source, actually, it was carbon in the ground, you bring it out, it applies some fuel actually from plastics and use it, then this will be actually a positive CO2 emission that will be significant.
Then we have the organic waste. So the organic waste, if you leave there it will not remain there, like the inorganic portion. So organic waste in general will decompose over time and will release CH4. Actually much of that for landfills is really captured and the flare, there will be some leakage there and some of it will be oxidized anyway. I mean if you change or convert the CH4 through flaring and oxidation into CO2, the CO2 is benign because its origin is organic or biogenic. So that CO2 actually will not count. However, if you are able to collect the CH4 rather than flaring it, process it, collect it, purify it, and then use it, then the CO2 that will come actually out of using your renewable gas or a biogas will be biogenic in that case.
I mean if you look at some organic waste, in this case food, for example, if you are able to collect food waste instead of landfilling it you can really kind of process it and like digest it using anaerobic digestion, get your biogas, clean it and have really pipeline-quality renewable gas, you can put it in pipeline and use it and the origin of the carbon is biogenic. However, in that case actually, because you avoid the typical CH4 emissions by diverting it from the landfill, there is some significant credit there and this would extend the life for some of the renewable natural gases and negative carbon intensity. And the animal waste will be in a very similar way. Actually, you will get some significant credits for avoided methane emission in a business, as usual, if you do not really digest it and let everything go into the atmosphere.
And finally, there is a version of biomass that you can grow, I mean and as you grow it you will sequester carbon from the atmosphere into the biomass and then you can convert the biomass into a fuel, and then when you use the fuel release this carbon in the fuel, the origin of it is biogenic.
So in essence here what I am trying to tell you, along with the life cycle, I mean along with that pathway, we just attract carbon sources and the fates. I mean and it is important for you to understand the life cycle analysis is not really a mystery; it is a simple accounting. You just need to make sure you do proper accounting, you do not like miscount or double count.
So this is our baseline pathway for hydrogen. We have some sources actually of the methane come from conventional wells and some will come from the shale gas in the _____ _____ or so, and the ratio of these actually change over time. But the difference you could say roughly 50/50. You get that gas, you gather it, you send it to our processing plant, the processing plant will just separate all the heavies, like the NGLs, and then will give you a pipeline quality natural gas that you can compress and send into a pipeline for transportation and/or distribution.
If you look at a renewable natural gas source, for example a municipal solid waste, MSW, again, actually this is what I was mentioning before, you can avoid the landfilling by going actually directly into some anaerobic digestion to get your renewable gas, and then you put it into a pipeline-quality, purify it, process it, and then put it into the pipeline.
Whether you use conventional gas or renewable gas actually is important some emissions associated with this. And this supply of gas to the SMR plant, I mean will result in some methane emission. That methane emission is significant, has some significant impact, as I will show you in my next few slides. But that SMR plant, basically you reform the methane, you reuse the carbon in the form of carbon dioxide into the air and then you get your pure hydrogen.
So the sources of CO2 for SMR plants are two. I mean ones that come out of the formation process, this is kind of roughly 60 percent of the carbon in gas will end up bringing in CO2 from the reformation process. Why would we _____ that from the carbon that comes out of the stack when you combust the natural gas, loss some of the combustion gas to generate your steam for the process. I mean, because that reformation CO2 is a much higher concentration than CO2 and the combustion gas, and therefore requires different energy for capture compared to CO2 from combustion gas that is much more diluted.
But depending really on whether you capture only from the reformation or from both, actually your capture ratio could really be in the low to mid 90 percent, that some actually are able to achieve like 96 or more capture efficiency.
What you produce typically from the SMR plant is hydrogen, but there is some significant amount of steam produced – what produced is typically shipped to the end-user. In many cases the SMR plants are next to refineries, so as I said, the hydrogen, they also shift the steam across the fence to their end user.
That steam is also important, because as I spread the CO2 emissions from the SMR plant over hydrogen process steam, because that steam in essence really displaces all our voids using some natural gas in a boiler to generate that amount of steam. So there is some steam credit that we provide as a component from the hydrogen SMR plant.
So another important pathway actually that is getting momentum for producing green hydrogen is the electrolysis pathway. So you can split water into hydrogen plus oxygen and then the hydrogen, depending on the source of the electricity, will have certain carbon intensity. The idea here is just use the renewable or very low carbon sources, such as wind, solar, or nuclear to power your electrolyzer and split water so that your hydrogen is near zero carbon.
There are different ways to split water. There is the low-temperature electrolysis, such as the PEM electrolyzer. There is also the solar or oxide electrolyzer that can go source electricity plus the steam improves the electric efficiency, but then you're compensating the balance of that with high-quality steam. So in GREET we covered both low-temperature electrolysis and the high-temperature electrolysis from the front power sources.
So this is a slide that covers several of the important pathways today. So on the far-left here I should really mention here that I put the units here in kilogram of CO2 to equivalent a kilogram of hydrogen. And on the far-left here you see our baseline. This is SMR including the same credits I mentioned. So we are talking about 9.5 kilograms of CO2, well-to-plant, including all the natural gas, obviously including one percent methane emission in the natural gas supply chain, so including the same credit.
Now depending on the methane emissions, depending whether we count the steam credits or not, actually that number you could see in some publications actually in the whole part of 10 or 11. So I put some arrow bars, because again, the results are driven by the plant operation. Efficiency is important; byproduct credit is important; supply chain, especially methane emissions, is important. So this is all a range of data you can see in the literature, in addition really of using a GWP for methane of 20 or 100 can really make even that bar go much higher.
Then we have the byproduct, actually hydrogen from the chlor-alkali plants and the steam cracking. These are the next two bars. They have actually some marginal benefit if you consider that if you export hydrogen you will substitute and buy a natural gas from these plants, because it is needed to actually for the chlor-alkali plants for drying and other purposes, and it is needed actually along the way of the other actually gas coming of the steam cracking to provide the process heat.
Then we have natural gas reforming with CCS, what is called the blue hydrogen, versus the gray hydrogen if it is a reformed without CCS. And there again you see a wide range there, depending on the energy you use for capturing, depending on the opposite emissions, depending on other use. Again, in some papers they use a GWP of 20 and the very high steam emissions. So you see that number even can be much higher.
Then we have some of the waste streams that are collecting from a landfill gas. Actually we will give you a very small footprint for hydrogen, less than half a kilogram of fuel to per kilogram of hydrogen. There's even some negative numbers if you use an _____ or animal waste because avoiding methane emissions is going to give you a credit, so put you in the negative.
Solar/wind electrolysis will to plan to get actually, because solar and wind do not really emit carbon as you produce them. So, in our system boundary we will plan to get, will be essentially zero. Nuclear has a very small footprint due to uranium mining, transportation, enrichment. It isn't the whole part of only 0.1 kilogram of fuel to per kilogram of hydrogen. And then we have coal actually, and we look at coal as a fossil source of CCS here actually, and you see you are in the whole part somewhere between two and a half to four. And again, depending on how much you capture, depending on plant efficiency, actually your arrow bar would be bigger. And then you have the biomass gasification that is in the whole part of like 1.5 kilograms of CO2 per kilogram of hydrogen.
Much of this actually results are driven by key parameters. In the next slide I will show you, for example, for the SMR. So for the SMR with – it was methane leakage, our default is 1 based on the EPA numbers. I mean if we was half or if we could get it to 1.5 you could see for each roughly additional half-percent of methane leakage you will add another half kilogram of CO2 per kilogram of hydrogen. And there is a typo here, this is instead of grams, should be kilogram and similarly there. So this will be fixed actually before we post that presentation.
But you see actually that it has some significant implication again, this should be kilograms of CO2 per kilogram of hydrogen. Whether you count credits for the CM export or ignore it, actually canceling by over a kilogram of fuel to per kilogram of hydrogen. So typically you co-produce I mean the share of the CM and the co-products stream actually for each megajoule of hydrogen you have 0.145 megajoule of steam. So it's a significant credit because you displaced steam that would have otherwise been created from a natural gas boiler.
And then plant-level efficiency. I mean we see a good consensus or like many plants to be in the ballpark of the low 70 percent. Our default is 72 percent, but we have seen a lot of plants actually I mean in a wider range. So again, the plant-level efficiency will be really important.
Then for blue hydrogen actually was a reconfigured GWP on 100, GWP 20 actually makes a big difference, as you can see _____ significantly. I mean, again, within emission for the steam and also how much electricity used for the capture, for the compression, which also depends on the pipeline and how long is the pipeline. So if we consider 100 kilowatt hour versus 200 versus 400 you would see your results would swing from 3 to more than 4.
So results are driven by key parameters, and every plant will have unique operation data and the best on base data. Actually your number actually would be higher or lower.
So I will break here. I want to take you quickly through a demo and then we'll wrap up and take your questions.
So I mean how to access GREET. I mentioned it is free for download. So here I'll show you actually a Google page. I will go get GREET, ANL for Argonne National Lab and usually it comes up first. So if I click there it should take me to the GREET website.
So this is our GREET webpage actually, and you see here actually kind of a description, our release, and our release typically happen at the end of the fiscal year, so an FY21 and the September 30th, like a week or so after we just released, we just show what is new actually in some memo here, and then give you the download options for the development platform for the GREET fuel cycle, for the GREET manufacturing cycle. So you can click on any one of these. For example, if I click here it should take me there, and if I click there down below actually it will download.
Now for a new user actually it will ask you to register actually. But once you register actually the next time it will be more straightforward. I mean "publication," you can click there, you can search by keyword there, and you can also come through here, the .net or the Excel version. The Excel version is there actually, so if you click there actually you can – if you are registered all you need is to put your e-mail, because the system recognizes you, then you click Submit, then it will start to download the file that has the Excel versions for actually most of the slides. We click there. Then it will take me to as a folder, and then from there you can just kind of – let's see if I can get it here. Yeah, and you will see there this is the GREET one, GREET tool, the STOCHASTIC tool, and then other actually supporting modules for GREET, for biofuels, and for building technologies.
So I mean the other thing I want to mention here, actually as you scroll there you can download there, but you will see also we have a YouTube channel there. So if you go there it is a tutorial for the .net platform, there is a tutorial for the Excel platform, and you will find these useful short clip videos in like the timeframe of five minutes each or so.
So once I download the .net I can load it and I will just lead you through that, because it is more straightforward. I mean maybe in a different session or if you have questions you can look at the Excel tutorials and we will be happy to answer questions actually after that in either of the two platforms.
So I put here the GREET.net. I just loaded it. Okay, so this is what you will get as you download the GREET.net. This is actually would be the page; it might take like a few seconds to load, as you heard the beeps in the background. And this is our database for all products, there or otherwise. And I can search there for anything I want. For example, if I want to see hydrogen I input "hydrogen" and then it will just kind of tell me what is there. We see actually in the biomass pathways hydrogen is there, but I am interested with the _____ hydrogen, gaseous hydrogen. And then actually over there you could see actually have a very large number of pathways, but let's say I want to say hydrogen from central plants, so I can expand to that. And let us say I am interested in the natural gas pathway, so this would put up there and then you would see actually what it is. This is hydrogen from SMR, this is the transportation step for hydrogen, and actually this will be the compression step for hydrogen.
So I mean if you want to dig deeper about let us say at the station I can collect that and say, "Well, give me the carbon intensity per unit of mass," for example, I want a kilogram of hydrogen. Then you will see here it will tell you that from well to your pump and basically it really is a fueling station, you have roughly 11.5 kilograms of CO2 equivalent per kilogram of hydrogen. I mean if I want to know actually what is ahead of the session I just add the station gate, and again, I can look at million Btus, I can do per megajoules, for example, I can do unit of math. I mean since most likely it is a kilogram, I will do it there. And you see actually there you can be in the ballpark of 10. So between 10 and 11.5, you know, the footprint of the session is roughly 1.5. It is a difference, right? It is a compression for compressing to 700 bar and the pre-calling.
And then if I want to know – I mean this is almost 10. If I want to add the plant to gate, actually, and again, if I want to do it in a consistent unit per unit of math then you will be able to see the difference again. So we had 11.5 at the station, we have half the compression. Before compression it was like 10, and here you see almost 9.5. This means that the transportation added roughly a half a kilogram of CO2.
And then if I want really to even navigate through I can right-mouse click and say "navigate." So it will take me actually to natural gas delivered to the SMR plant. And if I look here, for example, what is out of the SMR plant to or to plant to gate here, again, we'll do per unit of math a kilogram of hydrogen, and then you will see actually it is a 9.5. This is really kind of what was going into the high point in that scenario. And so on and so forth.
If I would like to know out of the 9.5 how much of that is on-site emission actually then you will see actually out of the 9.5 it is roughly 8 or 8.2. This means that the supply stream of natural gas is the difference between these two; it is like 1.3 kilograms of CO2 to get natural gas from the well all the way to the hydrogen plant. If I want even to venture further and say let me look at my natural gas supply chain I can say "navigate." So you would see actually natural gas coming out of the processing plant delivered to the hydrogen plant. If you want to modify that step you will just say "edit" and if you edit it will just take you there actually. Then you could really click and say "edit the step parameter." How long is that transportation, for example? I can even define the missing emissions are here.
So I mean if there's just – I mean like plug and the play, actually. Once you set your parameters you say "apply" and then you hit F9 to recalculate. If you want to look further, I mean I can navigate through where is the gas coming from. Then you see the gas recovery. I mean conventional you see the shale gas actually and you see the processing steps. I mean all the way to getting to the pipeline.
So it is user-friendly and then you could really examine per different units to understand the implication of inside, on-site; obviously each step will add how much from your well to end-use.
So with that actually I will stop and go back to my slides.
Is it on? Yep.
So as you see actually we have actually the hydrogen pathways, but we have other capabilities, going from plant to gate to end use. I mean pipelines, compression into fuel trailers, liquefaction and the cryogenic liquid delivery, for example, to end-use. To all of these are in GREET, each one of these is considered a process, and we evaluate, I mean the energy and the emission associated with this. Of course in many cases we compare again with the baseline fuel, so we have a very large number of petroleum derivative fuels and the products: biofuels; electricity, as I mentioned. So for hydrogen delivery from the plant to gate all the way to the end user it is a station or otherwise. We can do pipelines, we can do tube-trailers, we can do even a combination of these. And similarly for liquefaction and the liquid delivery we can do the same.
So petroleum fuels, as I mentioned, whether your fuel here is gas, diesel, jet, marine fuels actually – all actually are covered from the well with the different crude diet going into our refinery, whether it is domestic; depending on the – I mean is it conventional; is it shale oil; is it from Alberta, for example, oil sands; is it from overseas; depending on the qualities of sulfur; all of that actually will play actually into this pathway.
Similarly biofuels will cover the feedstock growth and the conversion into the front fuel, so very large number of biofuels in GREET. And then the electrification actually for plug-in vehicles, whether a plug-in hybrid or battery-electric vehicle for charging, and the source of electricity is important.
GREET covers all transportation modes for road transportation; we cover light, medium, heavy-duty vehicles. GREET also has a rail module. We have hydrogen actually covered for both road and rail applications, and there is the air, aviation, and the marine applications.
So with that, I mean since we are at the 40 minutes, I will just stop at this slide, the variabilities, as I mentioned, depending on the data. Everything is data-driven. There is uncertainty in certain parameters, for example, like methane emissions, and it is important to be transparent to inform the stakeholders.
So our models and publications are available there. And I will stop here, so I will be happy to take questions.
Neha: Thank you, Amgad. We have a bunch of questions; we are going to get to as many of them as we can, and then others we can follow up on later.
So one question is on slide 10, if you can speak to what the assumed rate of methane leakage is, and then in general whether GREET can account for variations in methane leakage easily.
Amgad: Yes. I first assured when I developed here – maybe I should go back there. I will go back and say this is the natural gas going to the hydrogen plant. If I edit this process I can specify for each step of the way. You can always specify. If I like mouse click I say "define losses."
So our defaulting grid, as I mentioned earlier, is one percent throughout the entire natural gas supply chain. I mean about 65 percent of it is opposite of the transformation line and about 25 percent is related to transportation and about 10 percent related to distribution. But since it's an SMR plant actually typically sourced from one submission, so we avoid counting any with an admission from the solution system. Furthermore, actually senses the transformation distance, if any, between the SMR plant and the end use actually could be small or big, actually depending on how many miles, then the methane emission amount associated with that distance can grow or shrink.
So users can define these actually in different ways. And whether in .net or Excel for each step of the way you can define your own parameters. Our default, as I mentioned, is one-percent. So if I show you here – actually if I go back to the slides, I mean you can see here actually the metal here is really our default, it is one-percent.
Neha: Great. Thank you. We have another question. Is GWP of 100 or 20 the standard?
Amgad: GWP is 100 is the standard, and it is really what is being used by California and other agencies, whether in the US or overseas. GWP 20 is promoted for others for the reasons I mentioned to you, because methane has a short life and they want to, I mean consider a GWP 20 instead of a GWP 100. I mean it is really – I mean every, again, point of view actually has some merit and legitimacy. The problem with counting the GWP 20, as I put here and I didn't elaborate, is if we only focus to meet our target for greenhouse gas emission and say, "Actually I will use a GWP of 85 so I can easily meet my target if I avoid this small amount of methane," and then suddenly after 20 years, actually I mean because the target keeps decreasing over time, you will need a very steep step production in CO2 suddenly because you do not have the leverage of using a reduction of a high GWP species.
So GWP 100 actually is what is being used as a standard in all regulatory schemes that I am aware of.
Neha: Thank you. Another question we have is what is the difference between this version of GREET and the California GREET?
Amgad: So I mean California GREET is based on an older version of GREET. But California also, as I mentioned, that everything is driven by your inputs, the key parameters. And California uses GREET as a framework with many of the defaults about certain estimates are being adjusted by GREET. And as I understand, actually, I mean you could petition the California ARB if your plant data are different from the default. And then they will consider that after some audits.
Neha: Okay. Next question. Does the LCA of electrolysis include the emissions associated with producing or transporting the unit and supporting renewable energy assets?
Amgad: Can you repeat the question? I am sorry.
Neha: So does the LCA and electrolysis include emissions associated with I think manufacturing and delivering and installing the unit?
Amgad: You mean the electrolyzer itself, or the _____?
Neha: Yeah, I believe the electrolyzer itself.
Amgad: So this is an activity we are doing with support from the office this year actually to include that, and then depending on the electrolyzation, depending on the throughput, depending on the capacity factor, how much you produce over the lifetime of the electrolyzer, I mean and then the carbon emission associated with manufacturing it actually, so these two I mean measure numerator and denominator will decide the contribution. We imagine it will be small, but we are quantifying it to show, I mean how significant it is in the full life cycle.
Neha: Next question. Can you speak to how significant an impact the account counter for actual scenarios have on negative emissions? So I think maybe the slide where you had negative emissions, how much the credit is affecting.
Amgad: It is important. It is extremely important actually. I mean if you consider the forgone emissions here actually, I mean this is what will go otherwise. I mean it has some significant amounts simply because CH4 has a very large GWP, and even a small amount of avoided emission has a large impact.
Neha: Thank you. Then follow-up question, are these credits part of current regulator schemes in the US?
Amgad: Yes, I do. I do understand that it is the case, I think California, at least.
Neha: Next question. For a retail seller of hydrogen does the model account for emissions associated with hydrogen distribution?
Amgad: Yes, this is what I mentioned here. So I show the results well-to-plant, again, but here I alluded actually that we cover the delivery portion. And if it is really for vehicles, a fueling portion as well. So hydrogen from production to end-use, actually these are covered with a pipeline or for certain applications. If you need a smaller payload, tube-trailers, or cryogenic tankers, tube-trailers can carry today up to a ton or slightly more, and the cryogenic tankers can carry 3.45 to 4 tons in a single delivery. But for larger scale we imagine pipelines would be the way to go, at least to move a very large amount of hydrogen.
Neha: Next question, so to avoid too much subjectivity, is there like a guidance document that describes the default values of input parameters, like a user manual type of [inaudible - static]?
Amgad: Yes. So I showed that on the grid page, we have our publications and we have a large number of papers covering the pathways, SMRs, the byproducts, among others. So these should be available there. Of course we cannot update every pathway every year, so depending on the priority for the DOE and the industry, every year we are _____ a few of these pathways. We pay close attention to the midline pathway, which is SMR's hydrogen for _____ performing, because it is a baseline today.
Neha: Aside from transportation, what other end uses of hydrogen is the model capable of modeling?
Amgad: So as I alluded to, I mean hydrogen for light-duty vehicles, or medium-duty vehicles, or heavy-duty vehicles, hydrogen for rail application actually is new this year in GREET 2021. And as I mentioned here, I mean we have carbon end users, hydrogen neutralization, as I mentioned, for e-fuels, is there hydrogen for green _____ production, is there hydrogen for potentially green steel manufacturing using – by the production of iron there. So there's a large number of pathways outside really hydrogen for vehicles.
And then of course hydrogen for petroleum refining, right? For bio-oil actually to deoxygenate. I mean any bio-oil. I mean significant hydrogen renewal there, so it is there, hydrogen in that place and to fertilize that production is there. So at this time of embedded – it's one of the key pathways in GREET that goes beyond this period of hydrogen and to other chemicals and the manufacturing.
Neha: Next question, what is driving emissions associated with electrolysis from nuclear energy?
Amgad: It's upstream, small upstream, as I mentioned, is about 20 to 1 kilograms of CO2 per kilogram of hydrogen, just a small amount and it really has to do with the recovery, mining for uranium, transportation of it, I mean enrichment – some energy for enrichment, but it is the impact is just too small. I mean as you can see on this slide.
Neha: Thank you. Next question, so of the parameters within the supply chain, which assumptions do you feel have the greatest uncertainty?
Amgad: So as I mentioned, the variability plant to plant could be significant. I mean how efficient is a plant, how well actually the energy is integrated? So plant energy efficiency, if you talk about SMR, right, how much you can squeeze of the natural gas to make your main product and also some of the co-products that can receive credit, for example, in this case steam. So plant energy efficiency is a big factor and it is variable; every plant is unique.
We did kind of a national study and we arrived at 9 kilograms of CO2 per kilogram of hydrogen, not counting for edits. This is at plant level, and our paper in there, and there are many other studies, but again, the variability actually could be significant. So plant-level efficiency is important, as you see at the bottom of this slide.
I mean within _____ upstream actually, I mean if you could look at, for example, your SMR with your NDO you could avoid all emissions associated – assumed to be associated with the transportation. Our default there is 100 miles actually; if it is more you will have more impact, if it is less you will have less impact, if it is zero then you can eliminate all transportation methane leakage, which will help you.
So depending really on the – I mean the variability, I mean whether you count the core product or not – some studies do not count integrated for the core product, while we count by default this actually. So these are not necessarily subjective, Actually there are some LCA guidelines and protocols, so if you have a core product that has value usually we give it credit. So this is our default there. But again, there is variability for plant efficiencies, big uncertainty about the CH4 upstream _____, and then the difference – I mean subjective opinion of if we want to use GWP 20 or GWP 100, and this is why you see very different numbers in different publications depending on really some of these are subjective, some of these actually follow some guidelines. And depending, of course, on the uncertain parameters, like methane emission reported actually could be up to two-percent actually, and it could be as low as, as we understand the problem, like some pipeline natural gas suppliers that is much, much lower than that.
So I mean depending on the unique situation your number could be either/or. We try to put data representative of the industry and the past credible sources in our model, but again, every scenario and every plant will have a unique data set that can drive the results.
And finally, actually, I mean even regional differences could make a big factor there. So embedded in here, we use US average _____ support in _____ _____. For example, if you go beyond the plant, look at a station in California is very different; actually the grid makes it there much cleaner than the US average. So rather than what you have seen in my demo, like 1.5 kilograms of CO2 per kilogram of hydrogen associated with the fueling, in California it could be half or less than half of that, and the northeast it would be even much lower, right, 'cause it's much cleaner there with a lot of hydro and a lot of nuclear.
So depending on the reason, actually you may have even some variability there. And I didn't have time to dwell actually on these, but actually this is an important slide actually to understand the variability and uncertainty. And the question actually is pretty legitimate, and this is why transparency is very important.
Neha: Great. Thank you. Next question, are manufacturing emission associated included within the fossil pathways? So I think like the manufacturing of the natural gas reformer or the coal gasifier, are those…?
Amgad: So we did some study that actually not all of it is in grid, but we did evaluate actually the build of an SMR plant, for example. We did look at build-up of refineries, even platforms and pipelines to move things around. And for many of these really the impact is just too small. Despite the fact that you may use a lot of steel or concrete and you may have a larger footprint in like several tons of CO2, but when you spread it or while you are a functional unit, your unit of energy that you make or deliver and the lifetime throughput actually of this, which is just a very, very, very large number, your _____ is just so big to make really per unit of fuel produced or delivered to be adjusted too small in the noise actually.
And so it might not be the case, but in others actually this is the case.
Neha: So across the board manufacturing emissions are not included, correct?
Amgad: In my results here it is not included. In GREET there is some pathway that you could enable like the manufacturing or what we put infrastructure LCA, and these are selective, but not really consistent across all pathways. So by default, because of the lack of coverage for everything we just mute it by default, but you can enable it and look at some manufacturing, for example, for power plants or windmills or even nuclear power plants, and these are efforts that are ongoing to update this because these are like some legacy pathways in GREET that lead to some significant updates. And this is _____ we will tackle this along with components like electrolyzers, for example. So in GREET 2022 much of this will be in place.
Neha: Thank you. And then I think this is the last question we'll have time for. Does the biomass _____ pathway at CM CCS?
Amgad: It does not _____ to CCS and it would be in the negative. I mean the only portion there, I believe it was close to 1.5 kilograms of CO2 per kilogram of hydrogen was mainly due to the growth actually. So here it is like a version to the spot, I believe, when you deal with the biomass by defaulting the _____. So you need like – you need some fertilizer use or some farming use that is also the transportation of the biomass to the hydrogen plant. So all of this will play a role, and then some electricity to there. So if you do CCS as you create the same gas from the biomass and then reform to get the hydrogen, if you capture that CO2 with originally why you ran it, put it actually sequestered in the ground, basically it is carbon from the atmosphere that goes into the ground and you will be in the negative.
Neha: Right. Thank you, Amgad. I think we got to most questions, but any that we didn't get to we can follow up later. Thank you all for all your attention and participation. I will turn it back to Eric to close out the webinar.
Eric: Thank you, Neha, for headlining the Q&A, and thank you, Amgad, for the presentation on GREET today. That was great. But that does wrap up the time we have today. If we didn't get to your question and you think of it later, feel free to reach out. Otherwise, we will be posting, as I saw a few of you ask, this full presentation, including the recording online at the HFTO website under the webinar archives. So please be on the lookout for that the next week or so. But otherwise keep an eye on your inbox for future topics and have a great rest of your week. Thank you. Bye.
Amgad: Thank you.
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