Posts Tagged ‘green hydrogen’
an interminable conversation 12: more on hydrogen, and wondering about local power costs
filched from an anti-global warming dinosaur – all’s fair….
Jacinta: So we’ve learned a lot about the problems with hydrogen as a potential fuel, and its problems as a chemical, in the production of fertiliser, in the petrochemical industry, and the need to clean up such usage, for example the contribution of ‘fugitive methane’ to carbon emissions. We also learned that carbon capture and storage, mooted for decades, seems to be going nowhere, largely due to its unprofitability re the private sector…
Canto: So now we’re going to listen to Rosie Barnes, of “Engineering with Rosie”, at a Hydrogen Online Conference, one of many interactive conferences apparently being planned. I’ve heard Rosie before, expressing some skepticism about hydrogen in general, so I’m surprised that she’s prepared to enter the ‘lion’s den’ of what I naturally presume to be hydrogen advocacy.
Jacinta: Yes I’m not sure I want to listen to the post-talk interactive session of this video, as I’m a bit squeamish about confrontation. Why can’t everybody just be nice and agree about everything?!
Canto: Yeah well Rosie begins with the question – which hydrogen projects should we prioritise? And she also mentions the hydrogen energy supply chain, which is apparently a liquid hydrogen transport project between Australia and Japan, about which I know nothing.
Jacinta: Though actually we did write about this before, in a piece that now seems haplessly naive (linked below, FWIW). Anyway, the ScienceDirect website has this ‘headline’ in its overview of liquid hydrogen:
Production of liquid hydrogen or liquefaction is an energy-intensive process, typically requiring amounts of energy equal to about one-third of the energy in liquefied hydrogen.
which don’t sound promising.
Canto: But Rosie seems to think the hydrogen future is a bit more rosy these days. Another focus of her talk will be ‘giga projects’, presumably meaning ginormous projects, such as the ‘Asian renewable energy hub’ and the ‘western green energy hub’, about which more research is needed – by us.
Jacinta: So she was hearing a lot of hype, mainly from politicians, a couple of years ago, about all sorts of hydrogen ‘applications’, but mainly about ‘power system balancing’, which hopefully we’ll hear more about – maybe to do with balancing for the variability of wind and solar – and for vehicular transport. And clearly she didn’t get it, especially in respect of other applications, no doubt, such as home heating. I mean, why hydrogen?
Canto: Indeed. She identified four red flags at the outset – and we need to dig deeper into these. First, ‘will developers keep building wind and solar if prices are negative?’ I don’t know what that means…
Jacinta: Economics is definitely not our strong suit. Actually we don’t have a strong suit. So here’s Wikipedia:
In economics, negative pricing can occur when demand for a product drops or supply increases to an extent that owners or suppliers are prepared to pay others to accept it, in effect setting the price to a negative number. This can happen because it costs money to transport, store, and dispose of a product even when there is little demand to buy it.
Canto: So it’s not immediately clear what that has to do with hydrogen, but let’s mention the other 3 red flags: 2 – will negative electricity prices persist? 3 – round trip efficiency, and 4 – the head start for and rapid improvement of other renewable technologies. Just putting those out there for now.
Jacinta: The questionable nature of the first one is – if electricity production becomes virtually free (negative pricing) then hydrogen production will be virtually free too, using renewables. I think. So the first two red flags are clearly connected. Businesses need to be profitable, so they won’t build (wind or solar) if there’s no market or if the market is saturated. With green hydrogen anyway, the production costs are, or have been quite extreme and those costs would have to come down by a factor of three to be equivalent to ‘dirty’ hydrogen production, to say nothing of cheaper electricity competing for the grid. To wait for the energy to be ‘negatively priced’ and only then use it for electrolysis seemed risky and possibly unworkable. A lot of equipment, etc, for little return.
Canto: Much of this was looking back at 2020 – not so long ago – and looking to Germany as an example of a highly renewable grid, but now she considers our Australian state – South Australia, which produces a lot of wind, first, and solar, second. Over the past 12 months, 65% or so of our grid electricity has been from renewables. Largely wind and solar, rather than base-load renewables (meaning nuclear perhaps, in the case of Germany?)
Jacinta: Yes, presumably nuclear, also hydro could be base load, as presumably it is in Tasmania. Rosie mentioned that we don’t have a lot of geothermal, and that rather shocked me, as I thought there wasn’t much geothermal anywhere, that it was one of those eternally future technologies….
Canto: The USA’s EIA (Energy Information Administration) tells us more:
The most active geothermal resources are usually found along major tectonic plate boundaries where most volcanoes are located. One of the most active geothermal areas in the world is called the Ring of Fire, which encircles the Pacific Ocean.
Most of the geothermal power plants in the United States are in western states and Hawaii, where geothermal energy resources are close to the earth’s surface. California generates the most electricity from geothermal energy. The Geysers dry steam reservoir in Northern California is the largest known dry steam field in the world and has been producing electricity since 1960.
Jacinta: Well, thanks for that. Something new every day…
Canto: So Rosie tells us we have had persistent negative electricity prices in SA – which is interesting considering that our household bills are painfully high. She presents a couple of graphics that I don’t fully understand… I certainly can’t understand negative pricing. Clearly not talking about consumers…
Jacinta: I’d like to know why our electricity costs are so high. Right now please. We can get back to Rosie later.
Canto: Well it’s a worthwhile detour to pursue, but it’ll require a bit of research. So maybe next time. So having watched Rosie’s not-so-rosey presentation, without watching the Q & A, because I tend to be a bit squeamish about that format, I find myself wondering…. there was little mention of Prof Cebon’s concerns about the questionable future of blue hydrogen and CCS, or of the problem of fugitive methane in the production of hydrogen from natural gas, or of the obvious failure in the take-up of hydrogen for passenger transport, or of the cost and difficult logistics of hydrogen compression and transport. And as to its possible use in storage, the battery solution seems more likely, surely?
Jacinta: She did point out, either in this talk or her earlier one, that hydrogen often looks like a solution looking for a problem, and this seems surely to be the case for hydrogen fuel-cell vehicles. It seems that EVs have won that race, and the improvements continue to be rapid. Well, we might pursue the hydrogen issue, and why so many people are hooked on hydrogen, and the details of hydrogen production, and many other issues relating to renewables, for a while yet, but let’s have a look at the cost of energy here in South Australia, where rooftop solar is very popular, and wind farms are kicking up a storm, but our electricity bills are still painfully high….
References
https://www.sciencedirect.com/topics/engineering/liquid-hydrogen
an interminable conversation 11: Hydrogen?
yeah, hang on a minute
Jacinta: So green hydrogen – what is it, is it real? Does it really have a future? Where, if anywhere, does it fit in that future? It keeps getting put down, it keeps getting talked about, and it seems most experts say, yeah, it’s in the mix, but at a fairly low concentration.
Canto: Good topic – this will allow us to look back at some videos we’ve viewed which have left me scratching my head. So first, on the inestimable Fully Charged podcast, Robert Llewellyn interviewed a clearly Australian Prof, David Cebon…
Jacinta: And this interview received really rave reviews in the comments, I noticed, which surely says something.
Canto: Yes, so let’s try and get our heads around it… and wow, having watched that interview, I feel a bit dumb for having vaguely hyped green hydrogen’s promise, and for being overly skeptical of Elon Musk’s dismissal of hydrogen a few years go – especially in light of the difficulty of compressing and moving the stuff.
Jacinta: So let’s start at the beginning. Prof Cebon is with the Hydrogen Science Coalition (https://h2sciencecoalition.com), and is a professor of mechanical engineering at Cambridge University. He’s the Director of the Centre for Sustainable Road Freight, and he’s co-authored over a hundred papers etc etc, so he’s super-knowledgeable about this stuff, especially when it comes to vehicular transport.
Canto: So Robert started by talking positively about hydrogen fuel cell cars as clean and green – no toxic fumes. But, nowhere to refuel them – and refuelling is one of many issues.
Jacinta: And then it was onto the colours of hydrogen, which I didn’t know about. So you ‘make’ hydrogen in two ways – electrolysing water, that is separating into hydrogen and oxygen by means of an electric current, which is energy-intensive. Pulling the H2O molecules apart isn’t easy. If the electricity you use for this is renewable, that makes ‘green hydrogen’. If that energy isn’t renewable it’s called ‘yellow hydrogen’. Of course, energy out of the grid may be a mix – here in South Australia it’s largely gas and renewables, whereas in the eastern states a lot of it is coal – nasty brown coal in Victoria. And so on.
Canto: And as Prof Cebon points out, using green energy to produce hydrogen, rather than to grid it directly into houses and businesses, might seem a bit odd. He calls it an opportunity cost.
Jacinta: The next main ‘colour’ of hydrogen comes from fossil fuel, particularly gas (mostly methane, CH4). By treating gas with super-hot steam, you can break it down into hydrogen and CO2. That carbon dioxide normally goes into the atmosphere. Some 2% of the world’s carbon emissions comes from producing this sort of ‘grey’ hydrogen, which is used to make ammonia (NH3) for fertiliser, and in the petrochemical industry. That percentage is about as much as aviation uses (though fertiliser is pretty essential). However, if you can ‘carbon capture and storage’ that CO2, then the hydrogen involved becomes lovely blue hydrogen.
Canto: Yes but as the Prof points out, once you’ve stripped the carbon from the methane, the remaining hydrogen isn’t very energy intensive, so you need a lot of methane to make a useful amount of hydrogen. Better to use the methane directly via the grid!
Jacinta: As Prof Cebon says, you need more methane to fuel your economy via hydrogen (around 40% more) than if you just used natural gas directly. All very attractive to the natural gas industry!
Canto: Right – what with the ‘electrify everything’ trend, the gas industry will be worried about its market, so here’s an opportunity – pump up hydrogen. Beware of the fossil fuel industry’s lobbying! And it’s blue hydrogen they’re really after, for financial reasons.
Jacinta: So back to electrolysis, green hydrogen, and efficiency. The electrolysis process is about 75% efficient, but importantly the energy has changed form. Think of energy as either work or heat, and forget kWhs for the moment. It’s work that’s important. You want the energy to produce more work and less heat (as with LED versus incandescent light globes). The combination of the two is the total energy output according to the first law of thermodynamics, or the law of energy conservation. Electricity from your battery produces work (eg in an EV) with very high efficiency. Diesel, petrol and other chemical fuels, including hydrogen, produce a lot of heat. According to the prof, the efficiency of an infernal combustion engine, which is essentially its work to heat ratio, is around 30%. Diesel may get up to maybe 45% but that’s the limit. Electricity can reach 90 to 95% efficiency. Chemical energy apparently runs up against the second law of thermodynamics, which limits the conversion of heat back to work. There’s always going to be a loss.
Canto: Right again. So 25% of the energy used in electrolysis is lost as heat. You have to convert the heat back to electricity via a fuel cell, which also has limited efficiency. And this efficiency reduction is before the energy required for compression, transportation, etc. So it’s all very problematic, though hydrogen has been touted as a miracle energy source since the early days of the nuclear industry.
Jacinta: Yes, and there are plenty of other problems with hydrogen – first, it’s colourless and odourless, and it’s very hard to contain without leaks, being of course the most molecularly tiny element in existence, so to use it as a home fuel would require a massive infrastructural upgrade, and of course it’s highly explosive and generates high NOx emissions when burned in the home – more so than methane. It’s also very inefficient compared to electrified heat pumps, which the prof calculates as about six times more efficient. So why would you use renewable energy in this inefficient way? The industry, according to the prof, is trying to hide this impracticability from the public.
Canto: Professor Cebon is involved with, or maybe heads up, the Hydrogen Science Coalition, which highlights five principles. First, the only acceptable form, in terms of fuel, is green hydrogen, using electrolysis via green energy. Blue hydrogen isn’t clean – being gotten from ‘dirty’ methane, and what Cebon calls fugitive methane, emissions from flaring and venting and leaking, amounts to the total annual carbon emissions of Europe – it’s a huge problem, due partially to the unregulated nature of the gas industry in Russia, the Middle East and elsewhere. Carbon capture and storage, which has been mooted for decades, has gotten nowhere, because – where are the profits in it? No private enterprise would touch it.
Jacinta: The second principle, or project, is to clean up the chemical use of hydrogen in ammonia fertilisers and in the steel and petrochemical industries by preventing the escape of so much of the C02 byproduct from escaping into the atmosphere. Not so much via CCS as by more efficient processing. The third project is to speed up electrification – let’s not pretend that hydrogen is an option for heating homes, for example, or that hydrogen fuel cell vehicles can be competitive with EVs. That battle has already been won.
Canto: Fourth is to rid ourselves of the idea that blending hydrogen into gas for any energy purposes is going to be useful. Hydrogen is a low energy replacement for methane, so you would need much more of the stuff, with all the attendant problems. And fifth and last is that hydrogen can only be used locally – that’s to say, at source. Transporting hydrogen safely is hugely expensive – being very light, many vehicles would be required to transport a sufficient energy load – 16 to 1 compared to diesel, according to our Prof. Not at all practicable.
Jacinta: And apparently hydrogen fuel cell vehicles are much more expensive to run than EVs, requiring replacement parts and so forth. So why are people still touting hydrogen. We’ll look more into that in a future piece.
Canto: Yes, Australia’s ‘Engineering with Rosie’ vodcaster has participated in a webinar for Mission Hydrogen, which sounds ominous, but I’ve heard her being skeptical about the green hydrogen movement, so we’ll see what she has to say.
References
some more on hydrogen and fuel cells
an electrolyser facility somewhere in the world, methinks
Canto: Our recent post on democracy and public broadcasting has made me turn to PBS, in order to be more democratic, and I watched a piece from their News Hour on clean hydrogen. Being always in need of scientific education, I’ve made this yet another starting point for my understanding of how hydrogen works as an energy source, what fuel cells are, and perhaps also about why so many people are so skeptical about its viability.
Jacinta: Fuel cells are the essential components of hydrogen vehicles, just as batteries are for electric vehicles, and infernal combustion engines are for the evil vehicles clogging the roads of today, right?
Canto: Yes, and Jack Brouwer, of the National Fuel Cell Research Centre in California, claims that fuel cells can be designed to be just as fast as battery engine. Now according to the brief, illustrated explanation, diatomic hydrogen molecules enter the fuel cell (hydrogen occurs naturally in diatomic form, as does oxygen). As Miles O’Brien, the reporter, puts it: ‘A fuel cell generates electricity by relying on the natural attraction between hydrogen and oxygen molecules. Inside the cell, a membrane allows positive hydrogen particles [basically protons] to pass through to oxygen supplied from ambient air. The negative particles [electrons] are split off and sent on a detour, creating a flow of electrons – electricity to power the motor. After their work is done, all those particles reunite to make water, which is the only tailpipe emission on these vehicles.’
Jacinta: He tells us that the oxygen is supplied by ambient air, but where does the hydrogen come from? No free hydrogen. That’s presumably where electrolysis comes in. Also, membranes allows protons to pass but not electrons? Shouldn’t that be the other way round? Electrons are much tinier than protons.
Canto: Very smart. Maybe we’ll get to that. Brouwer talks of the benefits of fuel cells, saying ‘you can go farther’, whatever that means. Presumably, going farther with less fuel, or rather, you can have a lot of fuel on board, because hydrogen’s the lightest element in the universe. Clearly, it’s not so simple. O’Brien then takes us on a brief history of hydrogen fuel, starting with the conception back in 1839, and real-world application in the sixties for the Apollo missions. The Bush administration pledged a billion dollars for the development of hydrogen fuel cell cars in the 2000s, but – here’s the problem – they were producing hydrogen from methane, that infamous greenhouse gas. Ultimately the cars would be emission free and great for our cities and their currently dirty air, but the hydrogen production would be a problem unless they could find new clean methods. And that’s of course where electrolysis comes in – powered by green electricity.
Jacinta: The splitting of water molecules, a process I still haven’t quite got my head around….
Canto: Well the PBS segment next focuses on the sectors in which, according to Brouwer, hydrogen fuel will make a difference, namely air transport and shipping. Rail and heavy vehicle transport too – where the lightness of hydrogen will make it the go-to fuel. It’s energy-dense but it must be compressed or liquefied for distribution. This makes the distribution element a lot more expensive than it is for petrol. So naturally Brouwer and others are looking at economies of scale – infrastructure. The more of these compressors you have, the more places you have them in, the cheaper it will all be, presumably.
Jacinta: Right, as presumably happened with wind turbines and solar panels, and the more people working on them, the more people coming up with improvements… But how do they liquefy hydrogen?
Canto: Hmmm, time for some further research. You have to cool it to horribly low temps (lower than −253°C), and it’s horribly expensive. There was a bipartisan infrastructure bill passed recently which will fund the building of hydrogen distribution hubs around the USA through their Department of Energy. That’s where the action will be. The plan, according to mechanical engineer Keith Wipke of the National Renewable Energy Laboratory, is to do in ten years what it took solar and wind 3 or 4 decades to achieve. That is, to bring hydrogen production costs right down. He’s talking $1 per kilogram.
Jacinta: Okay, remember that in 2032.
Canto: Yeah, I won’t. They’re talking about improving every aspect of the process of course, including electrolysers, a big focus, as we’ve already reported. They’re connecting these electrolysers with renewable energy from wind and solar, and, in the bonobo-science world of caring and sharing, any new breakthroughs will quickly become globalised.
Jacinta: Yeah, and Mr Pudding will win the Nobel Peace Prize…
References
Could hydrogen be the clean fuel of the future? (PBS News Hour video)
green hydrogen? it has its place, apparently