‘Solar tower’ system produces jet fuel from CO2, water, and sunlight
singularityhub.com
singularityhub.com
Once you have the synthesis gas, there are existing methods to manufacture a wide range of chemical products. Jet fuel being just one of them.
https://www.niskanencenter.org/taxing-flaring-and-the-politi...
> One of the world’s leading oil and gas producers, Norway, has maintained extremely low methane release rates for generations. It combines tough regulatory standards with a hefty carbon tax explicitly applied to methane released at the point of production. The World Bank has championed the Norway model for decades, advising governments around the world to include released methane in severance tax or royalty regimes in order to reduce waste, deter both greenhouse and air-quality emissions, and capture natural resource value for citizens.
> We found that Norway has no rivals in America. Emerging research suggests similar findings for Canada and Mexico, although the Australian state of Queensland includes flared and vented methane in its royalty system. In fact, many American states responded to growing methane waste concerns decades ago not by deterring emissions but by sheltering producing firms from taxation. Surgical amendments to energy tax laws placed methane off-limits from leakage fees. Those historic protections remain largely operational in the shale era, providing either explicit statutory exemption or administrative review processes that empower officials to routinely waive taxes.
> "An additional advantage of the solar redox cycle compared with other solar approaches is its ability to co-split H2O and CO2 simultaneously or separately and therefore control the quality (both purity and stoichiometry) of the syngas in situ, consequently obtaining a tailored mixture of H2 and CO suitable for FT synthesis."
> "This direct approach eliminates the energy penalty associated with additional refinement steps for adjusting the syngas mixture. In contrast, the electrolytic pathway (also called “power-to-X”) requires the production of substantial excess H2 by water electrolysis using solar electricity... "
> According to Andreas Sizmann, SOLAR-JET project coordinator at BHL, a solar reactor with a 1 km2 solar field could generate 20,000 L/d of kerosene, which could fly a large 300-body commercial airliner for about seven hours.
According to [1] there are about 10000 planes in the air at any moment (excluding private jets, military, and cargo planes):
> Back in 2017, FlightAware determined there to be an average of 9,728 commercial airplanes in the sky at any given time. Of course, that number fluctuates on a minute-by-minute basis, given that planes are nearly constantly taking off and landing.
Doing the math of 10000 × (24 ÷ 7) gives us 35285 of these one square kilometer plants, or about 12% of the area of the entire state of Nevada.
So it might be actually doable from a back of the envelope math analysis, but it'd be quite a big endeavor to scale a facility that large.
[0] https://www.thechemicalengineer.com/news/first-kerosene-made...
[1] https://www.travelandleisure.com/airlines-airports/number-of...
In North America alone, 30,000 square kilometers for all oil and gas[0].
For a rough approximation, the US produced 14% of oil in the world in 2021[1] and this guy on Quora[2] says that 12% of the world's oil and gas goes into aviation fuel.
[0] https://www.science.org/content/article/thirty-thousand-squa...
[1] https://en.wikipedia.org/wiki/List_of_countries_by_oil_produ...
[2] https://www.quora.com/What-percentage-of-the-world-s-crude-o...
Oil wells have super long useful lives (50+ years) but The majority only produce <15bbl/day due to decline curves (especially pronounced gor.
The footprint of a well pad is pretty small one they’re in production ~<1/4 - 1/2 /acre. Many modern well pads can have multiple wells (4/6/12) due to directional drilling, further increasing well count.
There are a lot of replanted strip-mined mountains. It's not good, but does revert to nature... mostly.
Coal mines are horrible when they’re open and the horrible once they’re closed, don’t believe the P.R.
My point is not that coal is good, it is that the acreage comparison is not good.
Ok, it's mostly done in photovoltaic plants (and has advantages for both sides, because it stops plants that could eventually overgrow the solar modules), but I don't think there's anything stopping solar collector plants from being used the same way...
https://news.ycombinator.com/item?id=29217929
Also, if you put a solar panel on a roof of a building, there will still be a building underneath the solar panel. Many people live in them, they dont get obliterated just because they are underneath a solar panel.
I don't think anyone's saying coal is good or solar is bad here.
Citation very much needed.
For starters, assuming we're mining the coal in order to burn it, rather than just for rock collectors, then the pollution and waste from that activity alone is enough to make it worse than solar. Killing more people, and animals, and destroying more environment while also costing more money.
You claim you're not the kind of person to minimize how bad coal is, but that's exactly what you're doing.
We don't need to do what you're suggesting (there's plenty of sensible places to put solar PV) but even if we did I would be highly surprised if it was worse than coal mining.
https://www.sltrib.com/news/nation-world/2020/04/13/montana-...
Restating your math slightly, how can 3.5 of these be funded by a carbon fee from ~365 flights a year over 20 years? Doesn’t seem like an impossible problem to think through and at least gives us a path to a renewable cycle.
If you do that, the positive would still come out way way ahead. (And not it's not priced in already contrary to popular belief)
The reality is that we can't sustain a civilisation of 8billion people without fossil fuels. We should do what we can to find alternatives that are less pollutant and have higher energy density but for now that means fusion, thorium and traditional fission. But we still have to solve the materials issue and we still have to content with the fact that only 20% of our energy is based on electricity and any attempt at increasing that number will require lots of fossil fuel usage as you would have to replace all the machines out there.
We are going to be dependent on FF for a long long time.
This is just a failure to understand how much sunlight there is and how fast solar panels are getting cheaper.
Solar panels will neither solve our increasing energy need nor be a solution for any future civilization.
Energy is about density. There is a reason why solar panels needs to be spread over huge areas to capture the sun.
So no I am pretty aware of solar panels and more importantly i understand the physics.
It seems unlikely that we'll be able to sustain the same level of air travel once we're no longer able to rely on cheap fossil fuels for it. I suspect air travel will get a lot more expensive and less common.
Why would that happen?
https://www.worldometers.info/oil/
47 years of oil left given current reserve estimates, I'd bet my life there's a couple of centuries left at least
Interesting top 11:
1 Venezuela 299,953,000,000 18.2% sanctions/attempted coup
2 Saudi Arabia 266,578,000,000 16.2% strategic ally (petrodollar)
3 Canada 170,863,000,000 10.4% neighbour
4 Iran 157,530,000,000 9.5% sanctions/coup
5 Iraq 143,069,000,000 8.7% invaded
6 Kuwait 101,500,000,000 6.1% friendly relations
7 U.A.E 97,800,000,000 5.9% friendly relations
8 Russia 80,000,000,000 4.8% sanctions/global rival
9 Libya 48,363,000,000 2.9% bombed/destabilized
10 Nigeria 37,070,000,000 2.2% friendly?
11 United States 35,230,000,000 2.1% *ahem*See https://www.adamsmith.org/research/the-no-breakfast-fallacy for more background.
https://www.enapter.com/newsroom/reaching-price-parity-of-gr...
A lot of people are going to die of heat in the next month. That number will double every year until we address it decisively.
That’s not counting on eco-terrorism which will likely anticipate a lot of the reaction.
- Sea level rises leading to widespread flooding of vulnerable cities (and some particularly low-lying island countries too).
- Severe droughts and water shortages in desertous areas. Some of which may not have been desertous before.
- General weather changes (both reduced rainfall and increased rainfall) leading to disruptions in food production supply chains.
All of which will likely lead to significant political pressure to mitigate further disruption.
A lot of activists and governments have started responding (banning ICE cars in 2025, 2030, and 2035). My belief is that most will have increasingly strict rules because they will see increasingly obvious droughts, heatwaves, and hurricanes—that’s the part where I’m less sure about.
There are people and politicians who are delusional, so anything can happen. I expect them to move and be more popular in areas where the consequence will be dire soon.
There are people who protest and see no change. Them, and people who lose everyone they care about in climate-related disasters, will most likely resort to violence: this has already started with people attaching themselves with concrete to a highway or deflating tires of SUVs in London. That group is organized and they don’t feel heard. That much has happened and I can testify that it’s not blaming down. I believe that this will lead to more violence, notably targeted assassinations.
I'm not so sure about that
high-speed rail works perfectly (though there's an obvious chicken and egg problem, because setting up a new airport is relatively trivial compared to building HSR connections between points of interest, but networks effects do matter, if there's an already good network it makes sense to connect new cities)
and for long haul flights the convenience will still make a lot of people pay for it.
plus, if society wants to subsidize it, we could. (like the US already does for certain routes.)
Well yes, that’s what a square kilometre is. It’s (km)^2 not k(m^2).
20kL/km^2 means 20mL/m^2 (in american that’s a hair more than a tablespoon + a teaspoon).
There’s a lot of fudging factors like a tiny 1m2 panel vs. a massive 20m x 5m area, conversion efficiency, etc. but your point that “everyone would make their own fuel for car in small garden” isn’t that reasonable. Well, assuming they are not using gasoline.
So that one panel gets you 6-7 miles of EV range a day.
A typical house needs probably 15-20 panels to produces it’s needs (assuming you have storage) before EVs are even in the picture.
Of course most cars are not at home all day, and cloudy days have to be accounted for. So we have to assume some sort of system to get around that. (the obvious ones are battery at home to charge, or sell to the grid at home and buy from the grid where you are charging) Solving these problems is not easy, but the math works out that you can do it.
Your qualification of your numbers was
> very good sunny location
not
> some random unspecified location
Is not what your link says, it says:
> U.S. daily travel averages 11 billion miles a day — almost 40 miles per person per day
Which is a different metric.
Perhaps more pertinent is:
> (The Average Driver) Drives 29 miles a day
Having said that, just tax the externalities, and use the money to replace fossil fuels where a) it's barely an inconvenience or an actual improvement and b) it actually saves money, and lives, like EVs, and heat pumps.
Carbon is fungible, the relentless focus on the hard to decorbanize sectors is just misdirection, by the time they are the only sources of fossil carbon left, they'll be simple to fix with the abundance of cheap renewable energy we've built and the money we've saved as a result.
That policy would not produce green energy that would replace the existing energy that we're now using at a societal level, it would just stop economic growth as we now understand it (mostly meaning more stuff being made, among other things). Yours is a call for more global poverty, plain and simple, which comes with its share of externalities.
Case in point: make natural gas more expensive or harder to get a hold of -> price of fertilisers increases -> less agro stuff being produced -> a lot more people in the developing world getting under the extreme poverty threshold and, in the end, a lot more people dying.
We both want to help poor people in the developing world, but you're only interested in doing so if it involves giving money to fossil fuel interests.
Whereas, I believe (like basically all economists do) that increasing the price of fossil fuels would actually help the world, by increasing efficiency and incentivizing better alternatives, many of which are already better than the alternatives and a net win.
At least we can agree that we both want to help people, and we also agree that one of us is tragically misinformed and actively hurting the people they claim to be helping by promoting counterproductive actions.
Our only point of disagreement seems to be whether it's me that's accidentally hurting people by suggesting we burn less fossil fuels, or if it's you that's hurting people by advocating for burning more fossil fuels.
No, it's a matter of physics, you can't produce more agro stuff without fertilisers, that's what the Green Revolution has been based on. There's nothing to be "tragically misinformed" about when it comes to this simple fact. You need more agro stuff in order to feed 8 billion people and counting.
> by increasing efficiency and incentivizing better alternatives,
How does that help with producing enough fertilisers? Do those "better alternatives" produce the same amount of agro stuff as fertilisers do? Do they produce it now? If the answers to any of those answers is "NO" then those economists will have the deaths of tens of millions of people on their conscience. Again, there's no politics in this, it's just how physics works, you need energy to produce energy (which is what fertilisers are, in a way), nice and fancy words just won't cut it.
If your big thing is fertilizers, then you'd want a really cheap way of making fertilizers, which some people do actually want and they think that Green Hydrogen is already cheaper for this when you include externalities.
And even if you're the kind of person that really can't cope with the idea that externalities are a thing and just want to pretend they don't, then they'll be so much cheaper when we scale them up, that they'll still be cheaper even if you ignore all the misery and death that those externalities cause.
https://www.yara.com/crop-nutrition/products-and-solutions/g...
Weirdly, you seem to already know this, since you added in that bit about "Do they produce it now?". Maybe you're not accidentally killing people because you're misinformed after all.
Granted, I’m not a native English speaker, but this looks like a plain contradiction to me.
Again, and to re-iterate, fertilizers is not “my” thing, is not anyone’s in particular thing, in a political manner, because you keep mentioning politics, it’s our 8-billion people thing, without fertilizers we cannot feed us, without fertilizers many more of us will die.
You’re putting words into my mouth when it comes to externalities, I did acknowledge them, I was just saying that the externalities that you mentioned (presumably higher CO2 concentrations from using fossil fuels, granted, you didn’t get into much details) are different than the externalities that I explicitly mentioned, i.e. that putting taxes on things like natural gas will lead to increased mass poverty and hence to increased (mass) deaths.
And to end on a positive note, glad the getting fertilizers out of hydrogen is getting cheaper, that means we won’t need taxes on natural gas, the simple law of supply and demand will do its thing.
The point is that you can make H2 via the electrolysis of water at scale, eliminating the need for the natural gas, and feed that H2 into the existing Haber-Bosch plants. Since sunlight and water are available basically everywhere, this eliminates a lot of the geopolitical and supply chain problems that are currently plagueing countries around the world with respect to nitrogen fertilizers (mined fertilizers are another story, of course).
Perfect, so there's basically almost free money on the table for those wanting to invest in this.
And then we get to transportation costs, afaik we're nowhere close to getting hydrogen-powered vehicles into mass production. And transportation costs represent a big part of the final price of food in some of the poorest parts of the world, think Central Africa.
And then there are refrigeration prices, which might not sound cool as an industry but which bring enormous food-related benefits. Good luck with keeping the freezers on in the same Central Africa with the help of green energy only.
Again, this green energy policy that is forced on almost all our throats here in the West from top to down looks eerily similar to the Maoist policies from the Great Leap Forward period, I sense the same "you're not a true believer" vibe if one starts stating the obvious. I don't think that my opinion or the opinion of the majority of the populace as a whole will manage to change things, unfortunately, but these things need to be said.
This is true. Have you ever actually tried to take advantage of free money though, when there's a cartel of giant corporations currently profiting from it not being done?. Harder than it looks. For starters they can convince a lot of people that the free money doesn't even exist. And once you convince someone to publicly state opinions like "renewables are expensive" or "EVs are worse for the environment" humans have a real hard time accepting new information that contradicts their previous public pronouncements. But early Tesla (and other EV related) stockholders for example, got rewarded for their attention to physical reality.
I guess we'll need to wait to see how it turns out this time but "The global green hydrogen market size was valued at USD 0.3 Billion in 2020 and is projected to reach USD 9.8 Billion by 2028, growing at a CAGR of 54.7% from 2021 to 2028" so either we're going to make a lot of money, or waste a lot of money.
> And then we get to transportation costs, afaik we're nowhere close to getting hydrogen-powered vehicles into mass production.
Hydrogen powered vehicles are mostly less efficient than battery (and/or directly electrified) alternatives, so while better (which includes cheaper) than many current options, they're not going to be a big thing. But Hydrogen is and will be, just made with electricity not fossil fuels in future.
Appropriately, one of the advantages of green hydrogen derived fertilizers, is that you don't need to transport fossil gas around the world and then expend a lot of energy seperating it into hydrogen, you can just generate the hydrogen and then the ammonia basically anywhere you have access to sun and air. Places with no methane reserves, high transport costs, and lots of sunshine will be where the green ammonia S-curve starts its ascent.
The transport and production of fossil fuels is an absolutely astounding percentage of our current energy use. Half of all current global Hydrogen production is used in the desulpherisation of fossil fuels for example.
In the context of taxing carbon to prevent climate change, and you claiming that taxing it would prevent people from making enough fertilizer to feed the world leading to millions of unnecessary deaths you don't see why it's an important distinction that the carbon vented into the atmosphere today in their production is a waste product of an entirely optional process for making one of the input elements (hydrogen) that fertilizers are built from and not actually necessary, or even desirable, for the end result?
This is clearly political. You've been convinced by political people that it's just 'physics' and therefore not political, but you're wrong about both the physics and the politics.
Plus, even when finding out you're wrong about the physics, you're mostly happy that this means that we won't need regulation, rather than happy about avoiding the tens of millions of deaths you were worried about when you thought other people were being political about something.
Who convinced you regulations were a bad thing (even when 99% of economists support them as the best free market solution) and why is that not political? Or is that just physics too?
The energy density for electric planes just isn't there. So we need to do something. Generating jet fuel from some carbon-neutral source is about the only sustainable path we have to keeping an airline industry going.
A few thousand of these sites would be almost nothing compared to what exists.
There's a place near where I live where there are two Shell gas stations right across the street from each other! [0]
[0] https://www.google.com/maps/search/hamilton+rd+I-70+shell+ga...
Plus you'd have to find a place that: - is politically stable - is under the rule of law - has low corruption - has lots of sunlight
The Sahara desert only fits one of these constraints.
Short-haul flights are comparatively less efficient than long-haul as the high-energy take-off portion represents a greater fraction of total flight time. Once airborne, aircraft are remarkably efficient --- rougly on par with (single-occupant) automobile travel on a per-kilometer basis. (On a unit-time basis, of course, consumption is roughly 10x greater, and the induced travel via the Jevons paradox from reduced costs is considerable.)
But developing high-speed rail networks within countries and contiguous continental regions substitutes for a huge fraction of air travel.
It might also offload a considerable amount of overnight / express cargo delivery which presently moves by plane. Cargo utilisation of HSR might balance out passenger travel patterns and allow flexible capacity response to boot.
Airports tend to be large sprawling regions of urban land. Rail tends to be linear.
I'm not sure that the comparison is entirely fair: rail accounts for a small fraction of total passenger travel (though commuter rail is a surprisingly large portion). However there's an astounding amount of freight rail.
It's also possible to dual-use land near rail, especially where it counts (urbanised regions), through elevated, trenched, or subway routing. Mind, even then there may be noise and vibration issues, so you'd probably want to keep rail at some distance from residential areas, though I hear airports may have similar issues as well.
Freight rail also has a history of very large switching yards in areas. Compare the CSX yards near Chicago Midway Airport. Net direct land use appears roughly comparable.
https://www.openstreetmap.org/search?query=41.7813916%2C%2D8...
Mind that other transport modes also have large land-use demands. Private automobiles command a third or more of all land in many cities through streets and parking.
Of course you're right about dual use and adjacencies and everything. It's the land between the towns that really is the issue. The airplanes are up at 30,000 feet.
And aircraft generate carbon emissions and a heck of a lot of noise.
A bigger problem for rail in regions with strong private land-ownership regimes is that this cycle develops:
- Undeveloped area is unsuitable for settlement due to lack of transportation.
- Railroads are built providing transportation. Costs are low as land values are low. (Historically, land was often gifted to railroads as an incentive to build, with the bonus of getting into the land trade on the side.)
- Railroads facilitate settlement, commerce, and industry.
- Land values rise spectacularly.
- Building new trackage / routes becomes nonviable due to high land values induced by previous cycle of rail development.
The ribbon-of-land thing really is not an issue where that land has a low price, or where appropriation of land (by legal or other means) is an option. Yes, you've now got railroads tracking across the landscape, but relative to the volumes of cargo and passengers carried this really is a minor consideration.
What is a massive problem is where routes cannot be expanded due to subsequent increased land valuation. Unless there's planning in advance for this, the problem is extreme. The US has seen effectively no new major rail construction in about a century, with a very few exceptions for a few regional transit systems (e.g., SF Bay Area's BART, DC's Metro). Those have relied heavily on the tunneling/subway & viaduct/elevated trackage.
Thin strips of land between towns ... is a non-issue. That's cheap land, it's largely fungible (e.g., farming or pasture acreage, like substitutions can be made.
And what rail doesn't have is the massive noise impacts of airport approach and (far more) departure flight paths. For overall impact, see this article on noise in the Chicago area generally:
https://www.dnainfo.com/chicago/20170328/midway/chicagos-lou...
The maps show both Midway and O'Hare airports, as well as several smaller airports, freeways and possibly rail lines.
The site providing the maps has moved, this seems to be it: https://maps.dot.gov/BTS/NationalTransportationNoiseMap/
That shows data for road, rail, and air traffic, which can be viewed independently. There doesn't seem to be a way to link to a specific view, but if you zoom in on the Chicago are and compare rail, traffic, and aircraft noise, the relative impacts become clear.
See also: https://xkcd.com/1138/
For flight noise at Midway specifically: http://mediad.publicbroadcasting.net/p/wcbu/files/styles/med...
Is there a way to make a kerosene with less NOx and particulate emission that simply isn't practical today? Since we need to ramp up renewable energy sources to synthesize this fuel can that economy of scale justify some currently impractical process?
The way I read the Wikipedia article on NOx [1] it sounds like NOx comes from nitrogen in the fuel. Is it possible to reduce or eliminate this nitrogen and then emit less NOx? I also parse the Wiki article to suggest the nitrogen is from coal and oil based fuels, which the technology in the article is not.
On particulate pollution: soot and other particulates result from incomplete combustion, so I doubt there would be much change.
Note that particulate and SO2 pollution in the upper atmosphere reflect sunlight before it reaches the surface of the earth. So reduction in SOx and soot has actually allowed the earth to heat more! (It still was good that action was taken, and continues to be taken, on those pollutants)
The only way to complete remove NOx production is some sort of N2 filter in the air intake. While it is easy to propose such a thing on the internet, it is not known how to create such a thing in the real world.
There is even a trade-off here in that adjusting the engine for creating less NOx and ozone makes it emit more particulate matter.
Cool fires produce almost none of it from the atmosphere, so all the NOx comes from the fuel. Hot fires produce so much of it from the atmosphere that the fuel is almost irrelevant.
High-efficiency engines, that produce the least CO2, CO, and particulate matter run on very high temperatures, and produce a lot of NOx and ozone.
I’m neutral on this plan (scale up will have to be seen) but since you brought up this issue I’m responding.
also hydrogen is a leaky greenhouse gas https://energypost.eu/hydrogen-is-also-a-greenhouse-gas-so-l...
wish them luck, not trying to be negative, we need solutions asap, situation is dire.
Only four percent of the captured solar energy was converted into chemical energy in the syngas, although they see a route to increasing that to above 15 percent
Airlines -- makes sense because we're talking about jet fuel, but "system" isn't usually used in the context of planes I don't think.
Rail -- sort of makes sense because "railroad system" is at least a somewhat familiar expression. Maybe they are just using the size of the project as a point of comparison.
Highway System -- similar to the previous, this makes most sense if it is just a comparison WRT the magnitude of the project. Highway system is of course a very common expression.
Anyway this shouldn't be taken as needling at the original post or anything, it is just a little typo. The point is clearly that it is a very big project, and we have other worthy project of a similar magnitude and impact that we're not engaging in.
https://www.scielo.br/j/rca/a/GD3CT889nbKP8MZybWbTYfy/?forma...
And it's the most efficient crop we produce in a large scale.
But anyway, the efficiency is not very important. What is important is capital cost.
Sugar beets appear to be higher than sugarcane, but they're under substantial threat and they don't like the tropics. Then there's palm oil, which is such an environmental disaster that it practically ranks as a humanitarian disaster. Then something called chufa (a nutsedge), something called sacha inchi (Inca nut, a kind of spurge), and cassava/manioch bringing up the rear barely ahead of corn.
But some of these have a lot of calories in the form of oil, which means two paths are required to convert it to fuel. From a health standpoint, flooding the market with a cheap 'waste' product from a particular food process has kind of been our downfall.
But isn't a calorie a unit of heat? That seems like fuel to me.
Conversion efficiency is going to give you proportional results. If you’re trying to determine how many miles your car or jet can go it’s not accurate enough. But if you’re comparing crops to each other it should be fine.
> The transformity (TR) was equal to 1.78E+11 seJ kg-1,
> eMergy inputs are expressed in units of eNergy (usually in solar eMergy joules, seJ) [I capitalizad some letters.]
So, ignoring the "se" it's like 2*10^11J/Kg. Each Kg of sugar has like 1.5*10^7 J, so the "efficiency" is like 10^-4 that makes more sense than 10^-11
Photosynthesis has an efficiency of 1%-2%, but they are counting more things. For example the eMergy of planting and harvesting that makes sense, but also the eMegy of rain that makes no sense at all. So I'm not sure how relevant are the numbers they are calculating.
10^-4 is way more realistic than 10^-11. Anyway the "se" is supposed to mean "solar energy", but yeah, they add quite a lot of nonsense. On a second reading, I'm not sure they added solar energy at all into it so the number may be completely meaningless for that usage. (But no crop gets anything near the photosynthesis efficiency, because most of the plant's energy goes into surviving, not growth.)
> Per hectare per year, the biomass produced corresponds to 0.27 TJ. This is equivalent to 0.86 W per square meter. Assuming an average insolation of 225 W per square meter, the photosynthetic efficiency of sugar cane is 0.38%.
> One hectare of sugar cane yields 4,000 litres of ethanol per year (without any additional energy input, because the bagasse produced exceeds the amount needed to distill the final product). This, however, does not include the energy used in tilling, transportation, and so on. Thus, the solar energy-to-ethanol conversion efficiency is 0.13%.
So it's more like 10^-3
There are a few facts which are obvious:
- Powered heavier-than-air flight with large cargos and ranges will require energy storage densities on the order of present-day fossil fuels. That might be provided through continued consumption of fossil fuels (with offsets), by synthetic analogues (electricity-to-fuel, by several different routes), or at a remote stretch from biomass-derived fuels (the availabilty-vs-demand situation makes this highly unlikely).
- Rail is exceptionally well-suited to electrification. Generate electricity elsewhere, feed it to the rail system. This works quite well for continental trave. Oceangoing trains have achieved limited success.
That said, there are a number of reasonably traversable boundaries. The Channel Tunnel ("Chunnel") between UK and France, and Öresund between Denmark and Sweden, are two examples. Bridging or tunneling Gibralter and the Bering Strait have long been proposed, other links might be made between Malaysia and Sumatra across the Malacca Strait, along the Sunda Islands, and finally across the Timor Sea to Australia. The Timor sea is relatively shallow, at about 200m (~660 ft), though that's far deeper than the English Channel's 63m average (~200 ft).
The hard crossings would be the Atlantic. There'd likely be call for two of these, one from the British Isles to a landfall in Newfoundland, another from Recife, Brazil, to Monrovia, Liberia, or Freetown, Sierra Leone.
One possible option would be to construct submerged floating tunnels. Norway is considering these as options for crossing its fjords, which are too wide for traditional bridges and too deep for conventional tunnels. A floating tunnel, at a depth of about 20--50m (perhaps somewhat deeper in open ocean) could provide a potential transportation route across long stretches of open ocean. Speeds could conceivably range from lower-end high-speed rail rates to near- or beyond-supersonic speeds (with an evacuated tunnel), though I'd suspect that 200--300 kph (~120 -- 180 mph) would be more viable. For the Newfoundland-Ireland link, about 3,000 km, this equates to a 10 hour crossing. Longer than by present-day aircraft, but far faster than ship, or even airship (typically at 100-200 kph).
Safety, cost, engineering, sabotage, accidents, and all manner of other issues would of course be concerns. Piloting such a project as an automated cargo channel might be one option for development. Staged links might also be developed, say, within island chains (the Faeros already have an underwater tunnel network), say from Great Britain to Ireland, and from Scotland to the Orkneys, Faeros, and Iceland, or from Newfoundland to Prince Edward Island and Greenland.
But in a world of impossibilities, this is, if not especially straightforward, at least within the realm of the possible.
The LCoE for solar PV is around $30/MWh. [0]
One barrel of oil equivalent is ~1.7 MWh [0]. A 100% conversion from PV AC output to oil would give a barrel of oil for $51, which is considerably less than one pays for oil pumped out of the ground right now. But keep in mind that commercial solar plants are operating somewhere around 20% efficiency. Assuming this new technology had similar cost per unit collecting area, 4% would give a barrel of oil equivalent for not hugely more than the cost of an actual barrel of oil. 15% would cost less than a barrel of oil.
[0] https://www.eia.gov/outlooks/aeo/pdf/electricity_generation.... [1] https://en.m.wikipedia.org/wiki/Barrel_of_oil_equivalent
There's a lot of lost opportunity cost here as the planet cooks. We need maximum CO2 reduction as quickly as possible, and that will come only from wind/solar and electrifying as much as possible, and carbon taxation on corporations.
And why only tax corporations?
Energy conservation by improved efficiency is great, but it’s orthogonal.
Sure, improving efficiency may be one way to get cost down depending on how it’s done, but it’s not the end metric we should be chasing.
Maybe in an ideal world the engineering challenges would be comparable. In the real world, you also have political challenges to deal with.
Some countries are really bad at building new high speed rail. Or any new rail in general.
For example, if you can design a cheaper version of the plant that captures only 1% of the energy of the sun, you just need 4 times as many mirrors (and the land to put them on). That might cost more than the savings on the cheaper plant design, or it might cost less. It might depend on where you are building the plant and what the land values are there and how much sunshine the area gets.
That’s assuming that we have CO2-emitting factories, which are hopefully gone soon. If most of the hydrocarbon is synthetic and burned by airlines, tapping the exhaust isn’t an option. I’m not sure whether it will be cheaper to capture CO2 in the atmosphere or run alternative ways to travel.
There are a lot of open questions as to if this can ever actually work on an air , but it need not be economical to the better answer. Navys will pay extra if it works and means they don't have to ship fuel around. Even better if it can produce enough fuel to also refuel at sea all the other ships the navy has in a carrier battle group.
How much aviation fuel could a 100 MW power plant produce?
https://www.zmescience.com/research/us-navy-synthetic-jet-fu...
From this article [1] the "fully burdened" price of a gallon of gasoline was near $400/gal, factoring in security, transportation along every step. But this price is disputed and variable, an excerpt:
"To be fair, there has been a lot of debate and controversy on the true cost of fuel. According to National Defense Magazine, basic gas costs $2.82, and then quickly rises to $13 and $42 depending on transportation methods, and up to $100 to $600 in some hostile areas. In the past, the Pentagon has been criticized for not knowing its true fuel cost, which was a more obvious issue a few years ago when oil prices were over $100 per barrel. Even even with today’s cheap gas, the military is still paying more than we could ever imagine."
[1] https://www.cnbc.com/2014/12/17/you-know-whos-not-getting-ch...
For a military to produce jet fuel on an aircraft carrier and gasoline in a remote and hostile locale, the supply chain advantages are staggering.
"According to the company's CEO Alan Handley, the airship will be capable of making a transatlantic flight from the United Kingdom to the United States, consuming just 8% of the fuel of a regular airplane. It will be powered by a pair of solar-powered engines and two conventional jet engines."
https://www.digitaltrends.com/cool-tech/varialift-airships-s...
"Despite the facility taking up space equivalent to a small car park, it was only able to produce just over 5,000 liters of syngas in 9 days. "
In other words, if this was our only way of powering flight, flight would become enormously uncommon and staggeringly expensive. Even if they achieved their stated aim of 15% efficiency, there's no sane hope of scaling this. It is just yet another example of tech that we cling to in the hope of not changing our lifestyles. Neat, but not the answer.
We are in a red queen's race, carbon neutral is not enough, we might not have time for a long run.
The first step is reducing net CO2 emission, and these kind of things are a good first step. (I prefer biodiesel/ethanol instead of fancy chemistry, but both go in the same direction.)
$3,000 “carbon neutral” coach class tickets from LA -> NYC?
I’m being a little ridiculous but I legitimately don’t get it.
Tech like this only works under some carbon credit scheme that provides no value and just transfers wealth to the inventors of these Rube Goldberg machines and their already wealthy investors.
The qualifier about needing to be economic is really important here. We will never really run out of oil, but we might run out of cheap oil.
As market prices for oil rise, more and more alternative ways to get at it become economical. Shale oil was one example of this process. (Another one is to create something like oil from coal. The Germans did a lot of this kind of thing in WW2, because they had access to plenty of coal, but were short on oil. Similarly, world coal reserves seem to be much larger than oil reserves.)
However, renewables are getting better and better and thus prevent energy prices from rising as fast as the cost of oil extraction will increase.
Thus eventually making oil uncompetitive, as you say.
This seems like a good capability in and of itself. Not sure what the economics look like, but there could be a market if this enables other trade offs in the production or avgas—maybe producing some nominal amount with much lower electrical grid requirements?
But generally, you have kerosene and gasoline based fuels gmost popular of them are JET-A1 (kerosene with additives) and AVGAS100LL (gasoline based, low lead). There are others, including jet fuels that are heavily cut with paraffin (or infamously with lighter fluid) iirc and AVGAS variants that don't contain any lead.
Fully synthetic fuels have been used in the past, mostly for high efficiency (USSR had an R-7 aka Soyuz variant for extra hard orbits that used syntin in place of RP-1 aka kerosene) though lost people remember "coal to fuel" attempts of axis forces in WW2