October 30, 2020, ©. Leeham News: In our series on Hydrogen as an energy store for airliners we now address the problem of liquid hydrogen supply for air transport.
Before we go into the ecosystem and its costs, let’s start with a more principle discussion. Is continuing today’s consumption pattern a valid alternative?
If we go directly into the hydrogen infrastructure needed and the cost of supply we shortcut the overall discussion on what options do we have for our energy supply in general and air transport in particular?
Figure 1 shows our energy consumption by energy type (right-hand pie chart) and the development of the types over time. If we group the energy types as Carbon-based, Nuclear based, and Renewable we get Figure 2.
Our energy mix by 2018 was 85% Carbon-based, 4% Nuclear, and 11% Renewable energy.
We know we live on borrowed time regarding our energy supply, as we to 85% (or more, data from 2018) burn Carbon-based fuels that were produced millions of years ago. The consumption of these fuels causes problems that are more manifest by the year.
Last year’s fires in Australia and this year’s on the US West coast tells us the development in Figure 1, where Carbon-based energy consumption increases and alternatives remain at around 15%, will create ever-larger problems for us.
There is no lack of renewable energy sources. The Sun creates enormous amounts of energy. It deposits a power of about 1kW/m2 on earth when in Zenith on a clear day (the solar constant). This energy goes to waste in the deserts and creates winds and rain over our land masses and waters.
Our problem with capturing this energy is that we don’t have an efficient form of storing energy so that we then can use it at places where we have the need.
Presently we build power grids to connect hydropower, solar panels, and wind farms with our consumption networks. This means these capture areas must be close to where we use the energy.
Hydrogen, through electrolysis of water, can be the means to fix this problem. It’s the most energy-dense way of transporting captured energy (to my knowledge).
Given the above, we can question if the general problem is that produced hydrogen through electrolysis is xx% more expensive than if we consume the same energy from our carbon sources? Is this a valid comparison?
Given the effects of burning carbon fuels, I would say no.
In my view, the question is, what alternatives do we have to the present consumption pattern and how much extra must we pay to achieve a needed change?
Can it be that the present energy prices are so cheap because our generation is consuming energy in a way that our kids will pay for in the future?
I know this is dragging values into the discussion but I think it’s worth a thought and debate. The question is, are we energy squanderers today, leaving the problems we create with our consumption for others to fix?
If we are, then it’s a question of what a more sustainable path costs, not if it’s too costly compared to our today’s consumption.
And to make matters worse: the pie chart above represents a static snapshot, whereas the situation is, of course, dynamic. The human population is increasing at an unchecked pace (first-order increase), and the energy demand per person is also increasing as a function of development and affluence (second-order effect). So the problem isn’t just increasing — it’s actually accelerating.
However, a question that needs to be addressed is: if I have X dollars at my disposal, which will be a more efficient use of that money in terms of helping the climate?
(a) Building a renewable energy plant, e.g. a solar farm or wind farm?
(b) Building a CO2 capture and storage facility?
At least (b) makes some attempt to address the CO2 *currently* present in the atmosphere (starting value; zero-order problem), whereas the Paris Climate Agreement only addresses future increases in CO2 (increment; higher-order problem). Today’s issues are being caused by the zero-order problem, which is not going to just go away of its own accord.
On Reuters: very interesting and relevant, though it relates to (short-distance) shipping rather than aviation:
There are steps on the way. Using Natural gas to produce hydrogen reduces CO2 emissions quite alot compared to burning JET A-1 even if the conversion process consumes power. Lots of trucks run on Liquid Natural Gas that could be mixed into the LH2 until its sustainable procduction capacity is sufficinet.
Todays cheapest powerplants for electrical power are land based wind farms. Sea based versions are topping 10MW Power each at its operating window of wind speeds. Sun Power parks also resored farm land in its shadows with grazing underneath the panels. In many countries the population is no longer growing and with property rights, house loans, schools, law enforcement and jobs follow a normal reduction of its population.
If you liquefy a mixture of CH4 and H2 you get a liquid methane with some desolved H2 and a lot of gas of mostly H2. You can’t add H2 to your LNG
It should be dependent on temperature. I know they do it in gas phase in Germany. For aircrafts you could have 2 tanks, one with LNG and one with LH2 and the mixing is done in the Engine fuel pump. The LNG network is fully industrialised by now and until LH2 get similarly efficient you either wait for it or do something pretty good.
Methane has a freezing temperature above the temperature of liquid H2 IIRC. The energy content of 1 molecule of H2 is much lower than that of CH4 so the aircraft is much more complicated for a little reduction in CO2 emissions.
The NG network is developed but it has issues reaching islands. But islands are exactly the market that require airplanes. Mainland EU can be served reasonably well by high speed rail
burning Methane saves you about 30% in Carbon emissions.
“producing” Methane by way of fracking and liquefaction, transport, evaporation. gains more than 30% in carbon emissions
from massive lack of efficiency.
i.e. burning clean fracking Methane is dirtier than burning your local lignite coal.
same for hydrogen as energy storage.
The H storage cycle is majorly inefficient.
energy cost does not model on environmental cost.
It models on production cost.
burning freshly captured carbon ( like in wildfires ) is
not really comparable to releasing sequestered carbon, removed over millions of years from the environmetal cycling.
Let me provide you with some optimistic view and very concrete ideas:
In Germany the share of regenerative in total electricity production is heading for 55% this year. The cost of both wind and solar power is now lower than carbon based electricity, which is why more and more coal and gas powered plants are running less and less and more and more are shut down. And that works perfectly fine, without any power outages although we are shutting down all nuclear plants at the same time. The “trick” is that production is distributed all over Germany, and over different types. Solar power for example is produced during the day only – which is great as that’s when demand is highest.
The total consumption of electricity is down, by the way, with the swap to LED lighting being one of the major drivers. Economic growth does not imply a rise in primary energy, that is an old and false credo. Just looks at computer, for example.
Next we have to address heating and we are not looking more and more into heat pumps and geo thermal to replace oil and gas. This is what is going to change that game again over the next one or two decades.
We are building more wind turbines, on and off-shore, install more and more solar panels on factories, barns, houses open land that is not very useful for farming. In the US you have no shortage of that, by the way, so you could install huge solar plants and produce more electricity than you can use and plenty of LH2 on top of that before you even need to think about anything else. But of course wind turbines produce even cheaper energy and you also have plenty of geo thermal potential of which basically none is tapped.
Oil and gas is the deal of the past, my dear American friends, please think ahead and get started seriously on renewables now. And please come back to the Paris agreement, by the way.
Carbon capture is very energy intense, which is why I think we should first address the energy production.
Producing LH2 for transportation needs required huge amounts of electrical power in addition to the power consumed by charging electrical powered cars. To solve this is not easy nor cheap. New reliable and efficient powerplants might need to be developed first like Fusion reactors and sea based power (wave and 10-20MW windmill parks) before enough volume of electrical power can be produced. Lots of Russian and Qatar naturalgas might be converted into green LH2 if money is to be made and control is weak.
We have not time to wait for fusion reactors to save our world. We have to brace for a very unpleasant warming with what we have caused by now, we can’t go on like this any longer, and nobody knows if and when fusion reactors might actually work. Wave power is also no option, but I can be bothered now and here to explain it, but I’m sure you will find more than enough material about it without too much trouble.
Look out of your window and check how many of the surrounding roofs have solar panes on them. Here in Germany it’s many 10% by now, and 50% would probably be useful. That’s a lot of electrical energy that can be produced quite easily.
Reliable: Wind, solar and geothermal is perfectly reliable.
Cheap: Yes, they are cheap too. Cost have come down dramatically and are still falling, and we don’t know where they will bottom out, but way below coal, oil and gas to sure, even without calculating the huge impact on climate and nature of the latter.
I did not say it is impossible but expensive, just look in Gemany more or less stopping new land based windmills ref Enercon, its electrical prices are among the highest in western Europé and they import more and more Russian natural gas (northstream 2) besides French nuclear generated electrical power. It is better than burning its coal that are still harvested but its zig-zag energy politics is strange for us outside Gemany. Still we can understand its drive towards H2 with Siemens and Linde in the country and its present limitations in electrical Power transfer capabilities from the North to its South.
Claes, apparently you are following the general gist instead of looking up the facts. As a matter of fact Russia would like to sell more gas to Europe, which is why they build Northstream II, but the natural gas consumption in Germany in the second half of this decade was quite a bit lower than in the first half. This trend will continue, as more and more homes are heated with a heat pump.
We are so unfortunate to have some right-winged old-industry-fanboys in our current government who managed to slow down land based wind energy with lots of bad tricks (sounds familiar?), but that has become publicly known now and all those with a green mind are now fighting it. Anyway, the next government will most certainly include the Green party, so that policy will change for good.
Germany has been an energy exporter for too many years, exporting about 5% or our annual production. In 2019 we have imported something like 0.5%.
The French have long since learned that nuclear power has no future and they have ceased constructing more plants – except for one they are at since somewhere in the 1980s and another (new) type since 2007. Both may never see service. Instead France is expanding their wind power big time, which you might not have been aware of: https://en.wikipedia.org/wiki/Wind_power_in_France
Due to their long cost lines to the North and West (from which usually the wind blows in our part of the world) they have the largest potential for wind energy. So in 10 years or so they might even surpass Germany.
In Germany we are currently building major electric line to transport energy from the North to the Sound, called SuedLink. So that problem will be solved soon.
LH2 will be useful in many applications, all around the world, and will certainly be used all around the world in a scale that will make us all wonder.
The big plus with hydrogen as a fuel is the variety of ways it can be produced. Electrolysis is an obvious one, countries like Australia can’t use all the PV they generate now. (Due to minimum load requirements of coal fired stations which provide “base load” power at night), so power supply is not as expensive as often claimed. Garbage can be used for hydrogen production, as can methane. Korea are pumping CO2 from power stns into seawater where a bacterial+sunlight produces hydrogen. The fossil fuel companies will naturally push natural gas with CCS. Canada have a project to pull hydrogen from tar sands leaving the CO2 in place. I think the biggest problem is picking which technology will be viable and which won’t. Diverging a bit, but maybe relevant, is the question of what storage technology will work best? Cars are using 700 bar to fill abt 150ltr tanks with 6 kg. NW Uni have achieved 43gm/ltd at less than 100 bar. Seen something about UK unis achieving something similar. So same sized tank as used now at 100 bar might bring same result as 700. Vast reduction in energy requirements. Or will 700 bar remain and tanks shrink? So, what refueling infrastructure do you invest in? Risk funding 700 bar if it might become obsolete in 5 years? 100 bar can be done at home by rooftop power, so built your stn in town or only on the highway. What about flat dwellers with no roof, how does that effect things? The pace of development is holding FCEVs back, and similar questions will arise in aviation. The biggest worry for investors might be “will someone achieve sufficient power density with compressed hydrogen? That would be wonderful, cost wise, for anyone who solves it.
Are you talking about absorption etc. of H2 in metals? Those are also methods to store H2 which doesn’t require extreme cold temperatures and/or very high pressures to obtain a reasonable energy density. but they add mass and are likely to heavy for airplanes
Can’t find the original article but Wiki reports MOFs have gotten up to 46 gm/ltr, which is better than I thought, as I recall this was part of a DOE contact which requires it to be at under 100 bar. H2 can be produced at 75% efficiency at these sorts of pressures. I don’t know if they can scale this up to higher pressures but if they can do it at 700bar, 300 gm/ltr, better energy density/ltr than A1? Weight suddenly becomes the issue, but it begs the question of LH2 or compressed, not today but in the near enough future to be a worry if you are risking a lot of development money. That’s why it has to be government money.
what kind of unit combo is “gm/ltr” supposed to be ?
Gram of H2 per litre volume, I’d assume. Remember, this is American research.
Mankind has been squandering since day 1 (whatever you want to put that at)
Extraction of any type never has been what the real costs are but what the immediate costs are.
Its a lot like a Pyramid scheme. The costs come due one day.
The US Western States silver and gold rush era is a prime example, many many toxic sites that were abandoned. Public pays for the clean up (or the consequences as when a dike was pierced and the contained toxic mess was released into a water system)
Or in Canada where a mine put the lethal stuff in a containment pond and yes, it rupture and flowed down the Stikine into Alaska waters.
The Alberta tar sands is an egregious ugly mess based on pure current economics.
The exploiters will be long gone while the consequences linger.
I claim no answers but it defines the issue.
I think that using a liquid hydrocarbon fuel to store energy is the most economical way forward. There are now companies that are down on the production cost of making liquid hydrocarbon fuels from Air and Water (and electricity) so that it will be competitive. This would be a much better solution than H2 since then todays global distribution network for liquid hydrocarbons can be used. So it must be much lower cost than any solution requiring new infrastructure around the world. I guess Methanol would be simplest and lowest cost. But I think it would not work for aviation due to the fire hazard, so for aviation it will still be something that is similar to todays jet fuels. I can not see that the worlds aviation industry can afford to phase in LH2 as a fuel worldwide in the next 25-30 years. It will not be possible economical. And in 20 years there will be several industrial processes for making hydrocarbon fuels out of water and air. ( I am using a reversible methanol fuel cell on the sail boat instead of the solar panels. Much better.)
Flying is special in that the energy in hydrocarbons is used very efficiently and going electric is very hard. But that isn’t true for most other uses of hydrocarbons. Heating is done easier, cheaper and more efficient with a (very inefficient) resistance heater than with electrically made hydrocarbons. Same is true for road and rail transport. Jet fuel is only a small part of the global oil distribution network and it is doubtful if the jet fuel network will be so everywhere if it can’t piggyback on the gasoline/diesel etc. distribution. There is even a question what the price of jet fuel will do when the demand for gasoline/diesel will start to drop around 2026/27
Add that a lot of cities, like Sydney, London & Bogota, have airports inside the city where local air pollution is a delicate matter and hydrocarbon fuels might not be politically acceptable.
Going electric on road transports (with batteries) is not an option as I see it since the cost of developing the electrical grid in all areas except high populated areas will be to costly. For trucks batteries are not an option. When it comes to Trucks I think that the hydrogen fuel cell will be the solution, but the energy storage/bearer will likely not be H2. It will again probably be some hydrocarbon fuel and then a reformer is used to produce H2. This is what Toyota and other Japanese car manufacturer are developing at the moment. Note the japanese are not making any pure battery cars. I was in Afraca 2 years ago and looked at when they were building a mobile vase station. The electrical power came from a H2 Fuel Cell but the actual fuel was Diesel (and then a reformer that produced H2). Diesel was used since it was available. The Fuel cell was used over a Diesel generator since it was more efficient and also lower in maintenance cost. So I think hydrogen Fuel Cells are a way forward , but I still think the fuel will be a liquid.
Most trucks drive less than 500 miles per day. Don’t see a problem with batteries. Longer distance should go railroad or the highways could be electrified
Trucks can be made to have current off-takes like trains and on a short distance while running charge its batteries with HVDC current. There are Volvo buses designed that way but charging at bus-stops. With electrical steering and computer Power it should be pretty straight forward to have trucks raising its Overhead Contact System and charge as needed during the stretch of available Power lines.
So glad to see someone working in the aviation sector showing environmental awareness and a lack of self-centred-ness by writing the words:
“Can it be that the present energy prices are so cheap because our generation is consuming energy in a way that our kids will pay for in the future?”
What a shame that it’s so late in the day; too late in fact to save our children. Feedback loops that were warned about 40 years ago have started years back. That’s why California/Siberia/Australia are all burning now. Who’s next? Years of climate science denial by the oil, aviation and motor industries have lead to this. Hold onto your hats, we’re in for one hell of a ride:
This is why capture and storage of the CO2 *currently* present in the atmosphere is a matter of increasing urgency…if it’s not already too late. Methane has *always* been a hideous monster under the covers, yet it enjoys virtually zero public awareness. And if you think the methane stored in permafrost is a headache, the metastable methane hydrate on the sea floor is orders of magnitude worse.
There are two schools of thought on the Artic methane issue. One is that the methane only needs thawing to be released. The other is that. based on sampling of ice cores through multiple global warming events, the excess carbon trapped in the ice was not old enough to have come from the permafrost (either from carbon dioxide production or methane). Instead it likely came from whatever event caused the warming. This indicates the carbon content of the permafrost remained stable in earlier warming events (NASA study).
The other aspect is that unlike CO2, where human emissions swamp the natural cycle, the natural methane cycle is only out of balance by about 5%. The agent which allows methane breakdown in the atmosphere is the hydroxyl radical, which serves as a catalyst (consumed in the initial CH4 reaction but produced in the subsequent NO2 reaction). So it remains relatively constant in the atmosphere.
This is not to say that methane is not a problem, but offers hope that we can still get our own emissions under control by effective measures. If the artic releases methane in large quantities, then that is a problem we can’t stop. And even if the release occurs as CO2 rather than methane, that still adds to the climate problem.
The ocean methane has a natural barrier in the low temperatures and double-diffusion that occurs in the ocean layers. Some release is actually beneficial as it allows the double-diffusive processes to remain stable, so that the layers don’t suddenly overturn. There are deep lakes in Africa that periodically turn over and decimate the surrounding area, because the CO2 production at depth is greater than the lake can handle.
Use huge renewable sources in deserts (solar, wind) to create ammonia using the Haber process (atmospheric nitrogen, hydrogen hydrolysis of water, heat & pressure to manufacture NH3). Efficient hydrogen storage at low pressure (50 psi or so). Easy to transport – we are in fact already doing so in huge volumes.
The NH3 can either be used directly in a turbine or fuel cell, or it can be split using heat and catalysts to produce pure nitrogen and hydrogen. Again, use renewable power sources to compress and liquefy the hydrogen at its point of use, not necessarily on an aircraft but at an airport. As far as I am aware there are no current technical barriers to any of this. There may be economic and investment barriers – a lot of infrastructure would be required, and the end products probably are, and may always be, more expensive than carbon based fuels sitting in the ground good to go. There’s a lot of literature on this – search ‘Green Ammonia Economy’.
Isn’t ammonia a deathly poison. I believe it kills every year a handful of farmers in my country. Moving electric energy by cables over a few thousand km is a solved problem so i don’t really see NH3 as future flow battery material. Other cheap & plentiful materials are much more likely candidates