INTERVIEW THP13: Ravi Prasher / Bloom Energy – Bloom Energy Now Has The Most Efficient Solid Oxide Electrolyzer In The World!

June 19, 2023 • Paul Rodden • Season: 2023 • Episode: SIS13

Listen Now:

>Direct Link To The Hydrogen Podcast MP3<

Listen On Your Favorite App:

Welcome to The Hydrogen Podcast!

Special Interview Series – Ravi Prasher / Bloom Energy – I have been excited about this interview for a while now. I had the great privilege to talk to Ravi Prasher, the CTO from Bloom Energy to do a deep dive on their Solid Oxide Electrolyzer, AlwaysON Microgrid, and the future of Bloom Energy. He gave fascinating insights on their record setting performance of their electrolyzer technology and explained why every company should be using their microgram technology. This is game changing technology for the hydrogen industry.

Thank you for listening and I hope you enjoy the podcast. Please feel free to email me at with any questions. Also, if you wouldn’t mind subscribing to my podcast using your preferred platform… I would greatly appreciate it.

Paul Rodden



WANT TO SPONSOR THE PODCAST? Send us an email to:


Start Here: The 6 Main Colors of Hydrogen


Paul Rodden 0:00
Hello, everyone, this is Paul Rodden. And I want to welcome you back to the hydrogen podcast.

Paul Rodden 0:05
So the big questions in the energy industry today are, how is hydrogen the primary driving force behind the evolution of energy? Where’s capital being deployed for hydrogen projects globally? And where are the best investment opportunities for early adopters who recognize the importance of hydrogen? I will address the critical issues and give you the information you need to deploy capital. Those are the questions that will unlock the potential of hydrogen. And this podcast will give you the answers. My name is Paul Rodden, and welcome to the hydrogen podcast.

Paul Rodden 0:35
My guest today is Ravi Prasher, the Chief Technology Officer for Bloom Energy and also serves as an adjunct professor in the Department of Mechanical Engineering at UC Berkeley where he advises PhD candidates. Prior to joining Bloom Energy, Ravi was the Associate Lab Director of Energy Technology Area at Lawrence Berkeley National Laboratory (LBNL). His responsibilities included managing research and development in a wide variety of areas, including fuel cells, hydrogen production, storage and transport, electrochemical and thermal storage, carbon capture, microgrids, and renewable energy among others. He was also a Senior Scientist at LBNL where he conducted research in thermal science and engineering. Ravi’s experience includes being one of the first program directors at US DOE’s high-risk high-reward funding agency, ARPA-E, and serving as the technology development manager of Intel’s thermal management group. Ravi has published more than 125 archival papers in top science and engineering journals and holds more than 35 patents. Welcome, Ravi, thank you for joining us on the hydrogen podcast, it’s great to have you on the show.

Ravi Prasher 1:58
Thanks for having me, Paul. Delighted to be here.

Paul Rodden 2:02
So I’ve got a bunch of questions for you. But before we gonna do a deep dive into Bloom Energy, I wonder if I can get your thoughts on the overall state of the hydrogen industry? And would you mind talking about what you think is driving this resurgence in the industry? And how it will play a role in shaping the energy transition?

Ravi Prasher 2:22
Yeah, I mean, I think this is a great time to be in the hydrogen field. And why there is a resurgence is because you know, there are certain sectors which are very hard to decarbonize, particularly the industrial sector, like chemical, steel, or long haul transport, like shipping or trucking. These other sectors are very hard to decarbonize. And hydrogen provides you the pathway to decarbonize those sectors. In fact, if you look at today, in a lot of these sectors, natural gas, for example, is not only the fuel in the industry, it’s also the feedstock. So hydrogen, in a way, you can look at hydrogen as a replacement for natural gas sometime in the future where hydrogen becomes the fuel as well as the feedstock. And that is one of the biggest reasons, you see so much of innovation and excitement about hydrogen.

Paul Rodden 3:12
Now, Bloom Energy empowers businesses and communities to take responsibility and to take charge of their energy. The company’s leading Solid oxide platform for distributed generation of electricity and hydrogen is changing the future of energy, fortune 100 companies around the world are turning to Bloom Energy as a trusted partner to deliver lower carbon energy today for a netzero future. Can you give our audience a detailed overview of what makes Bloom Energy so special? And really, what sets your technology apart from your competitors?

Ravi Prasher 3:50
Yeah, so I would say let’s start with this. First of all, as you mentioned, the blooms technology, whether it is electrolysis for hydrogen, which we will talk about further in this podcast, as well as the fuel cell, both of them are based on the solid oxide platform. Okay. So that platform is basically as a high temperature platform, which converts in the case of fuel cell, very efficiently converts any kind of fuel is more fuel independent, so great. So natural gas, it’s going to be hydrogen, or it could be methanol, or it could be ammonia, right? That can be fed into the fuel cell, and it will give electricity and, and on the other way around, when you reverse it, you know, you put up steam and then we get hydrogen out. Okay. So the solid oxide fuel cell, which Bloom has perfected it over the period of 20 years, that platform is very robust. And one of the biggest advantages of very high temperature system like the solid oxide system is the energy efficiency is very high. Okay, so when you get gas let’s say you have natural gas or biogas You know, when you converted electricity at the beginning of life, their efficiency is as high as 61%. Which is same as combined cycle natural gas power plant large scale power plants, okay. But you’re getting the same efficiency at a distributed scale, imagine outside the building, you have this Bloom Energy servers. And efficiency of that energy server is same as a very large scale combined cycle plant, right. And then if combined at very high efficiency, you really get minimized amount of co2 coming out per unit of electricity. And another reason why it is preferred by a lot of customers is because of the distributed nature, because it provides high level reliability and resiliency in the system. In fact, we if you go to our website, we say we have an AlwaysON micro grid. Right? And we because the way the system works is that if it’s configured in a way that it can run completely independent to the grid, and it can completely follow the load. And that provides very high level of resiliency to the customers as well as reliability. In fact, there have been cases where some of the customers have lost power from the grid for seven days, but because they had a Bloom server, they did not lose any power, which was any system which was being kind of operated by the Bloom server. And those are some of the main reasons that on the fuel cell side, there’s so much excitement among the customers.

Paul Rodden 6:23
I love that and I want to talk about that more, a little bit later. And I could just pepper you with questions about blooms technology, especially that solid oxide electrolyzer before I do though, would you mind giving the audience a comparison of the various electrolyzer technologies that are out there like the solid oxide electrolyzers the PEM, Proton Exchange Membranes and alkaline electrolyzers?

Ravi Prasher 6:48
Yeah, so, first of all at the highest level, you can say there are two types of technologies, one is the low temperature technology and other the high temperature technology one is based on low temperatures are based on very feedwater high temperature based on any feed steam, okay at the highest level. Now, the low temperature here… two mature technologies is: one of the PEM the proton exchange membrane, as you mentioned, and the alkaline. Alkaline is the oldest technology in the market is more than 100 years old, I believe. And at the height of it aside with steam fed is the solid oxide system okay. So, and that is where the blooms technology is based on solid oxide. Now, the advantage of the high temperature is I put it two ways. One is the physics itself tells you that the energy efficiency that emits amount of hydrogen kilogram of hydrogen that you get per unit of electricity is going to be much much higher at for the high temperature system, like our solid oxide system roughly 25 to 30% better, okay, compared to the low temperature system, right, that’s just comes from the physics itself. And the second thing is that you if you go to a low temperature system, typically, your PEM, for example, you have to use very expensive catalysts like platinum and Iridium, that again goes back to chemistry. If you have higher temperature you can get away with with cheaper catalyst. You know, that’s what catalyst does catalysts can reduce the temperature at which a reaction takes place. If so, since they are low temperature they have is a very expensive catalyst. Whereas in a high temperature system. You know, we can use industrial catalyst, readily available. Catalyst like Nickel, that makes overall I would say, system cost, as well as reliability, probably more robust, and you don’t have to depend on very expensive materials. So…

Paul Rodden 6:50
That’s a good overview. Can you also talk on the energy efficiency of the different types of technology and, you know, as if someone were to be a consumer of those technologies, what the difference is, and why those efficiencies matter. It really It sounds like it also boils down to just the cost of the unit itself, the materials used within those.

Ravi Prasher 9:00
Yeah, so two things, I mean, you have the energy cost and the cost of the capital. And you know, how supply chain is another major issue, we’ve been looking at developing technologies, but overall, you know, the cost of energy is gonna dominate, okay? 70 To 80% the cost of hydrogen will be basically because of the energy cost, electricity cost, right? So energy efficiency becomes very, very important. And there’s no way out of it because just just the basic chemistry of breaking hydrogen molecule into hydrogen and oxygen, the theoretical minimum energy required itself is high, okay? So there’s no way out of it’s going to be energy is going to be dominant factor in the cost. So, every ounce that you save, or in this case, every kilowatt, that kilowatt hour that you save, the more ounces of a kilogram of hydrogen you produce is going to be very, very critical.

Paul Rodden 9:50
So I reported on this fairly recently, that Bloom Energy Solid oxide electrolyzer, it’s one of if not the most efficient electrolyzers on the market. I was also reading up on the performance validation of Blooms electrolyzer by the DoE’s Idaho National Lab. Would you mind talking about how it works and the benefits of using your electrolyzer technology? I’m also interested to see if you could go into detail about the incredible efficiency that was recorded during the DoE’s testing.

Ravi Prasher 10:20
Right? Correct. That’s great. I mean, so look, having worked at the DoE and The National, I know one of the biggest benefits of doing a testing at the national lab is that they publish the results. Okay. Test many different technologies. Right? So I know lab testing started last year, and in fact they are next week, I’m actually going to be in Washington DC. They are reporting the findings in Department of Energy, merit review meeting EMR. So it’s a June 7, when Idaho National Lab is going to publicly show the results in the DoD meeting. Okay. And the result is amazing. First of all, this is the most efficient electrolyzer they have ever tested. Okay, is on record. This is when the director said that, you know, the best performance was roughly 30 points 37.7 kilowatt hour per kilogram of hydrogen. It’s just mind boggling. So that’s one part of it, you know, they have tested in adverse condition many times you can imagine what happens in that Oh, for the temperature fell way below zero. There it was, it still worked. They had to stop and start it, the electrolyzer many times primarily because they had some troubles on the grid side of things electricity supply, there are a lot of stops, stop and start see the electrolyzer beautifully. So we have already collected 500 thousand hours of data without any problem, beautiful efficiency. And at the same time, they also conducted as a test on on ramp up and ramp down. So you can go from 100% power to 5% power in 10 minutes. Right. And the beauty is, these are the results you’re gonna report is that even at 5% rated capacity, they’re finding out that energy efficiency is still better or as good as other technologies at the rated capacity, okay. So that has surprised them even further, which is which is you know, that tells you the robustness of the Bloom electrolyzer so. So those are the results, you know, they are already they will be published next month. And that you may you may have heard or seen the press release that we did that NASA Moffett site where actually the company started from the NASA Moffett site, that’s where, you know, 20 years ago. So we have access to big space there. We basically right now running the largest Solid oxide electrolyzer system in the world is a four megawatt system, which is producing hydrogen, we have a lot of visitors coming there, because that shows the commercial readiness our platform, and I will tell you that the energy efficiency of the four megawatt system is very similar to one box, that 100 kilowatt system that Idaho does love lab was testing that tells you the repeatability of the performance. And we were able to do this four megawatt project from start to finish in two months. And the reason I want to point that out, is that shows you that we could do things with speed or one of the main reasons is two reasons. One is the if you look at Bloom electrolysers are very modular, these are boxes you can like cut and paste and all the learning that we have on the fuel cell. We have deployed roughly one gigawatt a fuel cell in the market. We monitor every fuel cell and since it is the same platform, that learning has come very handy when we are developing or installing the electrolyzer system. So as you can be very pleased with all this performance.

Paul Rodden 13:49
That’s great news. It’s great technology, the way you’re pushing the electrolyzer technology forward. It’s amazing. The results are getting kind of cliche to say they speak for themselves, but they really do they’re, they’re phenomenal. And you know here on the show, we’ve covered bloom several times for a while now and I feel like the company has had a number of game changing announcements for hydrogen and the electrolyzer markets. The partnership with Xcel Energy at Prairie Island Nuclear Generating Plant to install your electrolyzer the massive project in Canada with World Energy GH2, and the world’s largest Solid oxide electrolyzer installation at NASA’s Ames Research Center, which you were talking about. Any one of these puts Bloom on a map but everything you have going on right now is fascinating. Would you mind discussing any of these large scale demonstrations… talk about how they’re important to the hydrogen industry?

Ravi Prasher 14:47
Very lucky. We are very excited. Let me talk about World Energy for example. Okay. So you probably saw this announcement that World Energy and SK eco plant. You know, they want to have developed a first of a kind ammonia world scale ammonia deployment in Canada, Newfoundland. And World Energy is a very is a large and a leading developer of renewable fuels projects and a pioneer in SAF, which is sustainable aviation fuel. And this This project is on green ammonia. You while they’re developing on the west coast of Newfoundland. And so they have they are looking at SOEC very seriously. And he saw the announcement. And we’re really excited about it, they have not exactly it is this going to be this World Energy project will have both PEM and solid oxide exact combination, they have not decided yet. Like how many exact megawatts will go to PEM and how much bigger SOEC. But it is a great first step because they want to first hydrogen is planned in 2025. And then they expect the first ammonia from that plant 2026. That project itself will be big deal because it will be producing hydrogen, and you know, there’s ammonia plant next to it. At the same time, it is located where there’s a lot of wind energy available, okay, high capacity, wind power, so capacity factors. So you have wind, because as I said earlier, that energy cost is very important. So, and you also need power, you need it with a high availability of renewable energy. And this particular site has a very high, good availability of wind power. We’re super excited about it. I would say just wait for the exact announcement, how many exact how many megawatts of soec, we are still under discussions, but you know, but the project will go operational in 2025. We have it… hydrogen production.

Paul Rodden 16:42
I can’t wait to see the results on that, going back to what you had mentioned earlier. Also, I really love that AlwaysON microgrid technology, I love it, can you take a moment to talk a little bit more about that, and the impact that can have on communities and businesses that need backup power generation, during catastrophic events, here in Houston, hurricanes, we also have had the freezes historically, where electricity and grids have gone down, it’s something that I feel like every city in America needs to have this tied into their local infrastructure. In case of emergencies. It’s like a, you know, modular power plant that can just save the day when it’s needed.

Ravi Prasher 17:23
Right, as I mentioned earlier, right, our AlwaysON micro grid. First of all, let me say how it is different, okay? It is different, because it’s configured to also run completely independent of the grid. Okay, and it can very nicely follow the load. So, whereas, you know, if you have a backup power, like diesel or something else, there are many challenges, you know, first of all, you can’t be completely grid independent, because you will require a lot of diesel just stored, then you of course, have smog and all kinds of particulates. NOx, and all these other kind of problems, a lot of the challenges that you have, right, but in our case, is connected to the natural gas line, which you have available next to most of the facilities, natural gas lines are buried inside the ground. So you know, it can very easily continue working. And that is one of the reasons customers will love it. Right. And at the same time, other technology like batteries, and all again, you know, batteries can last four or five hours, not more than that. Can’t provide you continuous power. So in a serious grid outage, batteries, not the answer. So those are some of the aspects of the technology of the micro grid, which the customers love. And at the same time, it’s decided that there’s hardly any noise, you know, if you are next to a Bloom system, you will not even know that this is generating electricity. But, you know, in the micro grid, also, we can also combine very nicely the, we have micro grid solutions, where the batteries, the solar panels, and then the bloom system, right, so it’s gonna be good also to have hybrid micro grid where you will have a lot of other technologies at the same time. So in that sense, again, the system is very, very flexible. And what happens in those cases is that, you know, when the sun is shining, great, you get all a lot of your power from from the sun, maybe charge some of your battery, but you know, Bloom, this modular power plant is always can give you the baseload, right, all the time, right. So those are some of the aspects of the technology and the flexibility. The technology is what the customers really love about the bloom AlwaysON micro grid.

Paul Rodden 19:24
You know, so much of the utilization talk now with hydrogen geared so much towards transportation that I think a lot of the applications for particularly these micro grids and the electrolyzers and fuel cells kind of get lost in the mix. But this is really one of those times when it should be highlighted what you can do with this micro grid technology. It’s not just cities but your hospitals, colleges, schools, anytime you can replace these diesel generators, with this fuel cell Technology and application. I mean, it seems like a no brainer. You know, there’s you don’t have to worry about greasing mechanical failures or anything like that. We do try on on this podcast to talk about it as much as possible. It’s just a great application for fuel cells outside of transportation.

Ravi Prasher 20:16
I would say yes, absolutely. I totally agree with you. So, and I digress a little bit. So fuel cell, that is one of the differentiators, so our fuel cell is much better suited for a stationary application? Okay, because that’s, that’s the beauty of the solid oxide. Whereas if you look at PEM, was it probably better suited for transportation applications. Okay? Because, you know, that’s the, that’s some of the tricks of the technology. So if you look at our fuel cell application, we are everywhere, it’s all stationary application, data centers, hospitals, Walmarts of the world, those are the kinds of customers we have. But in the future, as you say, you know, everybody’s shooting for much cheaper hydrogen, right? Today, today, we are using natural gas in our fuel cell, you can also use biogas, there are quite a few projects going on, but in the future, when hydrogen becomes, you know, really cost effective, then then yes, I mean, you know, your micro grid, fuel cell based micro grid could be running directly on hydrogen. And in fact, I would say even today, the technology that we have, essentially this hydrogen fuel cell, what we do is that we have natural gas coming in, we do reformulation on the cell, the solid oxide cell, and it basically their reformation creates hydrogen on the nucleus of the cell. And so, at the end of the day, it is it is a hydrogen fuel cell, which is actually right now, we are feeding natural gas in it. And internally, we of course, have really good results coming out on you know, pure hydrogen gas based fuel cell. But in the future. Yes, I mean, I think there’s a lot of interest in data centers, and some of the application data centers where they’re waiting for hydrogen to become much more cost competitive, and then probably that can become the fuel to power the data centers.

Paul Rodden 22:04
So I’ve got one last question for you, before we head out, that is, you obviously have a wealth of experience in the hydrogen industry. Would you give us your thoughts on the current state of the industry and where you think hydrogen is headed in the future?

Ravi Prasher 22:22
I would say as I said in the beginning, right, some of the very hard to decarbonize sectors, the chemical industry and the steel industry, are very, very seriously looking at hydrogen. And at the same time, you have the inflation Reduction Act was it provide a significant impetus to the industry, right. So the lot of flurry of activity is happening. Although we are talking mostly about hydrogen, hydrogen production, equally important is going to be, you know, transport of hydrogen storage of hydrogen, and offtake of hydrogen. Okay. Those are the thing which are still being debated and discussed, like, do we need solar or a wind farm next to the electrolysis plant and next to the ammonia plant? Or currently somewhere else? Those are all the things to watch for and probably six months, we’ll have a lot of clarity. So it’s almost like hydrogen is the electrolysis is the engine of a plane jet engine, but you need to be still build a lot of other parts together important parts. So so that is where I would say, there’s a lot of discussion and debate and still their answers. Not very, very clear. Right. But in terms of applications, I think it’s very clear, some of the industrial sector will be first offtakers of hydrogen. Particularly, as I said, the world energy project they’re very interested in ammonia is one of the biggest things people are talking about. And one of the main reasons is, apart from the fact that ammonia is this, I think, the second largest chemical produced in the world, because it goes in fertilizers, ammonia as a great hydrogen carrier. Right? Right. So it’s not easy to otherwise transport hydrogen. So ammonia is a great hydrogen carrier, you can do, you know, intercontinental transport of ammonia in ships. So basically, that’s another main reason that ammonia is probably one of the very first applications that industry is going towards.

Paul Rodden 24:15
Ravi, this has been an absolutely fascinating conversation. I really enjoyed learning more about your solid oxide electrolyzer. I look forward to seeing more of that in the future. Thank you for taking the time to talk with me today. Really appreciate it.

Ravi Prasher 24:30
Thanks a lot for giving me the opportunity, Paul, and thanks for doing this hydrogen podcast. This is… I call this the era of hydrogen… finally hydrogen has arrived.

Paul Rodden 24:41
I think so too, and we’re happy to do it. All right, everyone. If you enjoyed listening to Ravi’s views on the hydrogen industry and want to check out his company Bloom Energy, we highly recommend visiting our website at to learn more. Thanks again. I hope you have a great day and take care.

Paul Rodden 24:59
Hey, this is Paul, I hope you liked this podcast. If you did and want to hear more, I’d appreciate it if you would either subscribe to this channel on YouTube, or connect with your favorite platform through my website at Thanks for listening. I very much appreciate it. Have a great day.