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Gryf: Top stuff, as always. I really do think we have the bones of 'good enough' zero net carbon technologically and economically more or less in place. EP: Can't wait for the details on your book!
And here is beautiful bamboo, able with modern treatments against water and insects to be grown at a phenomenal rate, soaking up CO2, in many of the areas of the world where population growth will be fastest, and where labour is cheap to craft it. That includes South east asia and India/Indonesia, South America and Africa:
For cement and also steel I am keen on where possible replacement of its use, to complement CO2 reduction in their production where this is not possible. So modern tech can do a great deal with wood for buildings, if the legislation supports this: The video also does a good job of highlighting the issues and caveats of the technology, as well as the potential.
Hi Gryf Interesting comments as always. I'm not sure where you get your figure of less than 1% by weight for on board hydride storage, although of course the GKN Hydrogen system is not designed for that use. But anyway, if the rest of the tech pans out Kubas Manganese Hydride can certainly do way, way better than that: ' The material—KMH-1 (Kubas Manganese Hydride-1)—demonstrates a reversible excess adsorption performance of 10.5 wt% and 197 kgH2 m−3 at 120 bar at ambient temperature with no loss of activity after 54 cycles. It could enable the design of tanks that are smaller, cheaper, more convenient and energy dense than existing hydrogen fuel technologies, and significantly out-perform battery-powered vehicles. A paper on their work is published in the journal Energy and Environmental Science. ' And: the formic acid CO2 cycle is pretty good, with fairly high efficiency. From your link: ' When they used potassium lysinate, the researchers achieved an H2 evolution efficiency above 80% and a CO2 retention of over 99.9% over ten charge and discharge cycles, without having to re-load CO2 between these cycles. The team also found that this reversible hydrogenation process could be scaled up considerably, without significantly reducing the system's productivity.' Your comment: ' Actually the Energy Dome CO2 Storage sounds better for seasonal storage and it would be above ground.' On re-reading subsequent to your comment it seems this is correct. I had thought that for longer term they intended to use caverns for storage, as here: This has the advantage of higher efficiency than the very respectable RTE of 75-80% claimed by energy dome: ' Subsurface energy storage can solve the drawbacks of many other energy storage approaches, as it can be large scale in capacity and time, environmentally benign, and highly efficient. When CO2 is used as the (pressure) energy storage medium in reservoirs underneath caprocks at depths of at least ~1 km (to ensure the CO2 is in its supercritical state), the energy generated after the energy storage operation can be greater than the energy stored. This is possible if reservoir temperatures and CO2 storage durations combine to result in more geothermal energy input into the CO2 at depth than what the CO2 pumps at the surface (and other machinery) consume. Such subsurface energy storage is typically also large scale in capacity (due to typical reservoir sizes, potentially enabling storing excess power from a substantial portion of the power grid) and in time (even enabling seasonal energy storage).'
The first question which came to my mind is of course efficiency. I have dug out their figures on their website: ' Generating hydrogen for energy storage with elec- tricity is about 50% efficient. Converting the stored hydrogen back into electricity is about the same. Therefore, the electric efficiency for a hydrogen system is only 25%. Fortunately, our engineers are cr eative. They consi- dered tha t the main energy demand of a house is not only electric, but also thermal. Heating accounts for nearly double the amount of energy compared to elec- tricity. Generating thermal energy with a hydrogen system increases its efficiency to 90%. This is comparable to the efficiency of a battery system and is more cost-effective' As they note, this ties in very well with power demands for electricity and heat. My view is that hydrides appear to be the way to go for seasonal storage, without the need for deep caverns etc which liquid and supercooled CO2 has.
@sd For shorter haul and lighter loads, you use batteries, no question about it, just as Daimler is. But for longer haul and bigger loads, especially where there is swift turnaround or no return to base, everyone with the exception of the VW group have gone for hydrogen, and VW are hedging their bets. I would disagree about blue hydrogen being inevitably a scam, although for sure there is substantial room for abuse, so it has to be watched carefully in each case. And rising prices of fossil fuels mean that technology aside, in places like Europe and the far East the price gap of green hydrogen against fossil fuels is drastically reduced, even before technological improvement and economies of scale kick in. Many years ago I was in cost and works accounting, and some future costs reductions can be calculated with a high degree of confidence - they are 'baked in the cake'. Massive falls in the cost of green hydrogen are going to happen, far swifter than for batteries which are at a later point in the falling cost curve. None of that means that where practical you don't fool around converting energy from one form to another, so you use batteries where you can, but it does mean that hydrogen, blue and green, can be a reasonably cost effective competitor with fossil fuels, aside from the benefit of not frying the planet.
@Hold Time: I am assuming that there is a misprint or something in that table. It goes: @100% 10h @80% 130 h @50% 200h All fair enough. Then: @20% 130h WTF? Presumably s/be 1300h or something?
And here is 'Engineering with Rosie's' interview with the Nuscale CEO and on SMRs, including perceptive comments: I was particularly struck by this comment from 'Social Down Climber' ' As you probably know, in conventional nuclear they need to shut the reactor down if they detect a maintenance issue. This loses the plant a ton of money but after a couple of months it is back up and running again. With Nuscale, if they detect an issue they may need to recall the reactor if it isn't built for on site maintenance. With factory production, this recall may extend to other units. If any SMR manufacturer has to do a general recall, the losses will sink the company instantly. This is one of the main reasons I'm skeptical that unit production of reactors is really a benefit.' On the whole I think Rosie gets a good balance on the issues, potentials and problems. The big difference for me in my current and previous assessments is the huge falls in renewables costs, and even storage at 'good enough' efficiencies is looking ever more do-able.
Rosie in 'Engineering with Rosie' does a pretty good job of highlighting problems with high altitude wind, especially kites here: Especially amusing is at around 1:03, where Skysails seem to be using an 'inventive' video, which Rosie picks up on for the supposed automatic furling abilities! Other issues are that the kites and tethers need relatively frequent replacement of relatively expensive materials, compared to conventional wind turbines - highlighted earlier in the video.
Gryf: My man! A bit above my head, but the case for supercooled hydrogen against liquid seems pretty solid?
@sd My pro nuclear credentials are impeccable, having supported it for 60 years. I would particularly like to see SMRs using waste heat for district heating systems, as well as hydrogen production. But to my considerable surprise, it now seems to me that massive drops in costs and improvements in technology mean that even in Europe most energy could be produced and stored using renewables, although I would still like to see perhaps 20% of electricity produced from nuclear to add additional flexibility and redundancy, in the event of, say, a major volcanic eruption greatly reducing solar output. My remarks are based on some variation of solar, with improved efficiency and use of by product heat, and some variation of high altitude wind. Here is Sunovate: The basic idea is that there is a backing panel on the solar array, with retrofitting possible, and the use of air, not water, to cool the panels. The heat in the simplest variant is then used to provide hot water in a house. Keeping the panel temperature lower increases efficiency linearly, even in a Swedish winter, whilst even with current panels we can hit overall electrical plus thermal efficiency of 50% or so. For storage different solutions depending on duration etc are needed, but liquid carbon dioxide strikes me as the great enabler. Here is Energy Dome: For high altitude wind, recently the Bendix tower was looked at on this site, which is reasonably conventional, but there are also kites, from Kitepower and Skysails. Here is Kitepower: They are only at around 100KW at the moment, so size has to be upped to perhaps 3MW for viability. However, high altitude wind however done would up the renewable energy potential of Europe greatly. So the bottom line is that I agree with you that large scale hydrogen/ammonia imports from Australia to Europe may be unlikely, but OTOH renewables produced and stored right here appear able to cope at a good price even with northern european winters.
@sd I have long said that Germany had the dumbest imaginable energy policy, and that risks from nuclear in the Linear No Threshold model derived from massive doses in Hiroshima etc are exaggerated by perhaps three orders of magnitude. But I try to compartmentalise evaluations, and take things on their own merits in view of the political realities. Would I prefer internal nuclear in Germany, with where necessary conversion to hydrogen for transport etc? Absolutely. But that does not mean that building up renewable hydrogen production in Australia and exporting it, including to Germany, is a dumb idea or no improvement on importing fossil fuels from Russia and the Middle East.
Interesting use of subcooled hydrogen, together with their rationale for employing it. I have not readily turned up data sheets for energy per litre etc for subcooled hydrogen, so if anyone has some handy, it would be appreciated. Naively, at 1.6MPa versus 0.6MPa for liquid hydrogen, it might be assumed, probably wrongly, that it has similarly reduced volume. Of course, not only may that extrapolation be erroneous, but the mass of the tank to hold it at pressure may increase. Any info would be welcome.
North Africa and the Middle East are certainly a lot closer to Europe than Australia, However recent unfortunate political events show that it is pretty dumb if convenient in the short term to rely unduly on unstable countries which may have a very different agenda. And there is an element of limits to rising costs from longer distance transport once the ammonia or whatever is loaded on a ship in the first place. Just the same with umpteen places closer than Australia which have wonderful wind and solar resources, from Namibia to South America, I am none too convinced that Australia will end up longer term supplying a large percentage of the European hydrogen market. But not only are there plenty of potential suppliers, there are also loads of potential customers for hydrogen, with the likes of Indonesia, Japan and India stepping into the breach. So even if they don't end up major partners long term, in the more immediate future setting up both ends of the supply chain with both customer and supplier as early adopters moving the technology to far cheaper mass deployment makes a lot of sense in my view. As both other customers and other suppliers come online, then they can all swap partners to more convenient/cheaper options.
There is a bit more here: ' Bendix wants to build the tower itself out of standard steel tubes, which substantially reduces the overall cost. The structure stands on a turntable so that it can always face into the wind in the optimum direction. This could involve a trolley, similar to those used on container cranes, or a ball bearing slewing ring. Bendix knows all about the latter because he designed the rotating sphere on the Berlin Television Tower. Bendix is working on a prototype with support from the Federal Agency for Disruptive Innovation(SPRIND). How effectively could machines of this kind “harvest” high-altitude wind in the future? Horst Bendix says that his wind turbines would be able to deliver ten times the power of today’s best facilities – and this would be possible with an 80% reduction in land use. Bendix and SPRIND have also considered possible locations for high-altitude wind turbines. The systems would be “the most intelligent solution for repurposing the former lignite mines”, says the SPRIND website. “Not only the current coal fields in the German states of Saxony and North Rhine-Westphalia but also the former fields in Saxony-Anhalt and Brandenburg can very realistically become wind energy-based regions for innovation and production.”' I fancy this one - the guy at the heart of it seems to have some serious engineering chops and this is not ultra speculative as Makani was, in my view. What do you folk reckon?
I was wondering if Volvo are going to use liquid hydrogen, as Daimler intend for their heavy trucks, or gaseous. Here is what I have found out: ' Currently, Volvo is focusing on gaseous storage. As with other H2 trucks, such as the Hyundai XCIENT, the hydrogen pressure tanks are placed behind the cab. Volvo does not stack the pressure tanks horizontally here, but has placed five large tanks vertically next to each other. The tank connection is also located on the driver’s side of the clearly visible tank unit. For the fuel cells produced jointly with Daimler Truck, it is not a problem how the hydrogen is stored on board – in the fuel cell itself the H2 arrives in a gaseous form anyway. “The fuel cell can process both liquid and gaseous hydrogen, there is no difference,” Daimler Truck CEO Martin Daum said last year. “The filling stations will only be able to support one technology – gaseous or liquid. So the industry has to make a choice.” Roger Alm, president of Volvo Trucks, does not comment on the issue of storage – there is not a word in the memo about the use of liquid hydrogen.' It sounds to me as though they are feeling their way, and have not reached a decision as yet. It probably depends on how much weight Daimler can bring to bear to enable liquid hydrogen roll out.
Here is an analysis of theoretical and actual energy losses in liquifying hydrogen: As can be seen, worse case is something like a third of the energy embodied in the hydrogen, using off the shelf current technology. That is certainly not high enough to rule it out, in my view, and multiple strategies are possible to reduce it. Fortunately both liquid hydrogen tanks and liquification technologies are currently being developed for use in heavy long distance transport by the likes of Daimler, so the aircraft industry does not have to do it all itself.
Hi sd. Using liquid hydrogen in aircraft is certainly challenging. You are probably well aware of Airbus's approach, but anyway here are a couple of links to their development of storage technology: Of course there are multiple other issues as well as on board storage of hydrogen, but my view would be that it is preferable to look at them separately instead of bundling the lot and getting buried, as we are actually very good at actioning very complex technological integration. So for instance it now appears that renewables to ammonia and then to hydrogen can be done with excellent efficiency, and ammonia could certainly be provided at airports to be chilled and liquified. But there are numerous other possible approaches which can't be ruled out.
Those who seek to dismiss whole vast areas of technology, and those working in it, with sweeping assertions have an absurdly high opinion of themselves, often wholly without knowledge or expertise. Airbus, for instance, to name just one. are working right now on hydrogen for aircraft, including the cyrogenic tanks needed. Maybe it will work, maybe it won't, and there are no guarantees, but they are certainly not just innumerate morons, nor are their financiers. Scepticism is fine. Blanket dismissals are folly.
They seem to have settled on hydrogen for aircraft, at Airbus and others as well as these guys. What I would like to see though is retrofitting of conventional aircraft using ammonia, as the brilliant folk at Reaction Engines have suggested:
Here is a plan in the Netherlands to retrofit medium aircraft, 40-80 seats, with hydrogen by 2028, suitable for flights for example between London and Rotterdam: They reckon it will add about 10% to flight costs, in my view an acceptable premium to achieve rapid decarbonisation in the sector
There is a bit more here: ' The project employs DC rather than AC electricity for the project, which helps reduce power losses, eases the interface with renewable power sources, and allows thinner cables. It also uses aluminum cables to distribute current, which the company says costs half compared to copper while being lighter and easier to recycle. '
@gryf I would imagine that the engineers at H2 Clipper follow all news on hydrogen engineering very closely, including this theory on the airframe acting as a capacitor and building up charge. It would seem to be a very specific set of conditions needed to create a problem, so for instance: ' The skin was lashed to the aircraft's aluminum frame, but kept from touching it by wooden pegs inserted between the two. The gap between the frame and the skin would prove fatal to 35 of the 97 individuals onboard the airship plus one ground-crew member.' So perhaps the answer would be not to do that. It hardly sounds to me like a completely prohibitive barrier, with no potential solutions.
And here is H2 Clipper, a hydrogen airship: One of its uses they foresee is for hydrogen delivery. Here are some of their claims: ' By using liquid hydrogen and fuel cell technology for propulsion, the H2 Clipper can operate efficiently at service ranges from under 500 to well over 6,000 miles. At 175 mph, and using vertical take-off and landing, the H2 Clipper can deliver goods directly from a factory in China to a distribution center in the U.S. in less than 36 hours.' 'With an average cruising speed of 175 mph, the H2 Clipper operates at a cost of between $0.177 to $0.247 per ton-mile for distances of 1,000 to 6,000 miles. This is less than one-quarter the cost of traditional air freighters. The combination of the airship’s range, speed, payload, and cost make the H2 Clipper highly disruptive.' ' The H2 Clipper utilizes 100% green hydrogen both as a lifting gas and as fuel. By using modern fuel cell technology, fresh water is the H2 Clipper's only operating by-product. It is not only 7X to 10X faster than a ship and 4X less costly than an air freighter, but also the only climate pledge friendly alternative for long-haul transport.' Also of interest, and a claim I would go along with having looked at several CF tank safety testing videos and read the regs, is this under 'FAQs - explosion risk: ' Although hydrogen is flammable, based on the use of proper safety technology, the hydrogen that provides lift and propulsion for the H2 Clipper will not explode even in the most severe of circumstances. Hydrogen fuel cell electric automobiles and trucks have been subject to extensive testing to prove this is the case. For example, it is well documented that a rifle fired at a tank filled with gasoline, diesel fuel, or natural gas will cause the tank to explode like a bomb. However, the same rifle shot from short range at a tank filled with hydrogen will cause a hole in the tank from which the hydrogen will be released, but no explosion (see video here). It is also well documented that if a gasoline leak from a car is ignited, the tank will explode and rapidly consume the entire vehicle. But doing the same thing – igniting a leak – in a hydrogen tank will result in a faint blue flame escaping the tank until all the hydrogen is exhausted. Unlike the gasoline tank, this does not create an explosion and doesn't even raise the internal temperature of the vehicle by more than a couple of degrees (see video here). The reason for this is the enormous expansion rate of hydrogen, and the fact that hydrogen is lighter than air and naturally moves to rise. In short, rigorous testing has confirmed that hydrogen is by far the safest fuel known to humans, as has been repeatedly demonstrated whenever a hydrogen accident has occurred, and no explosion followed. Honda, Toyota and Hyundai currently sell hydrogen fuel cell cars in California; and with over 60,000 hydrogen refueling events by ordinary citizens, not a single explosion has ever been reported. That’s a record that even battery-powered electric vehicles would envy!' I am a lot keener on this than the use of helium for lift, but it is early days of course.