Last year, as an experiment I've launched a tiny solar-powered boat ([1]). Ultimately, it was too small and underpowered only making ~900km ([2]) before dying.
I hope to build a bigger drone boat next, hopefully with an ability to move up to 1 tonne of cargo. Apparently, it's possible, but (unfortunately) requires very delicate engineering.
For bigger boats solar does not seem to scale. It appears that nuclear is the ultimate future for megaships.
If you want an efficient modern cargo sail ship, you should start with freestanding self trimming wingsails. These have roughly 3x more lift vs drag at the same sail area. But far more importantly: they can be controlled entirely by deflecting a small control surface, similar to the rudder on an aircraft. This can be automated nearly trivially with commodity hydroelectric actuators, redundant electronics, etc.
Making those out of a sustainable material vs the common composites is an open project. But I strongly suspect even using modern materials, over the lifetime of the ship, such a ship would have better net carbon footprint than modern tall ships, if you're honest about the staggering amount of labor that goes into building and operating tall ships, and the footprint that has.
Cargo ships as currently built cede the entire middle section of the boat to cranes. Cranes they won't see until the end of their voyage, or the beginning of the next. The whole rest of the time you can't use the vertical axis for anything else.
Things that slide around tend to break loose in heavy weather, and boats don't stay afloat if the center of gravity moves too far, so sideways seems like a bad idea. I don't know what the solution is, exactly.
1) Nuclear reactors produce waste that needs long term storage. There are lots of hypothetical / partial solutions for this and a lot of nuclear waste sitting there in temporary storage patiently awaiting the day that this problem is actually solved. Adding more waste to that pile is not a great idea.
2) Ships go to sea. The sea is treacherous. Meaning that waste might end up at the bottom of the sea when ships sink.
3) Seas have pirates. E.g. the coast of Somalia is a security risk. Pirates and nuclear reactors are not a great combination. Pirates with Muslim extremist backgrounds even less so. Basically, nuclear powered boats are dirty bombs waiting to get hijacked.
Burning fossil fuels is the problem that needs solving. However, burning synthetic fuels is perfectly fine and engines don't really care how the fuel is created. Synthetic fuels can be produced using clean energy and then pumped in large storage tanks on ships; very much like is the practice today with normal fuel. It's the obvious future. Hydrogen is an obvious candidate for this and there are multiple companies working on this and a few prototypes already sailing. Add some solar and wind to the mix and you get some efficiency gains. Other synthetic fuels are feasible as well. Even diesel could be synthesized eventually. The main challenge is building the infrastructure that is going to generate enough fuel at reasonable cost.
There are a few drone ship operators out there. They are not used for cargo and quite small but it works. These guys (https://www.saildrone.com/) use solar and wind powered autonomous drone ships for months long operations.
A more realistic solution would be to use land based reactors to manufacture carbon neutral synthetic liquid hydrocarbon fuel. Then burn that fuel in the ships as an alternative to fossil fuels.
How much diesel-equivalent fuel could a 1GW nuclear power plant create in one year?
Here's my back of the envelope attempt.
1000MW * 0.9 capacity factor = 900
900 * 24 * 365 = 7,884,000MW
7,884,000 * 0.3 = 2,365,200MW electricity to liquid fuel efficiency[1]
2,365,200MW * 1000 = 2,365,200,000kW
2,365,200,000 / 10 energy content of 1L of diesel being ~10kWh
236,520,000L of diesel per year from a 1GW power plant.
Australia alone uses something like 33,000 megalitres of fuel per year (that's not all diesel, a lot of it would be petrol, but close enough).[2]
So Australia alone would need something like 140 x 1GW nuclear-to-diesel plants.
Did I do something wrong here? That seems like a lot.
This[3] says Australia has electricity generating capacity was 66.5 gigawatts (2017 number), so my 140GW estimate to cover Australia's transportation fuel requirements by electricity-to-diesel seems within the correct order of magnitude.
1. Semi-educated guess from https://en.wikipedia.org/wiki/Power-to-gas#Efficiency
2. https://www.abs.gov.au/statistics/industry/tourism-and-trans...
3. https://www.world-nuclear.org/information-library/country-pr...
I'm not sure how true this is, as a number of sail-assisted designs are already in use around the world, and have been for at least a decade. There are even several insurance classifications for large-scale cargo ships that incorporate the various possible sail-assisted architectures.
If we assume for the sake of argument that it's not enough for most reasonable-length routes, maybe if there was charging infrastructure at regular intervals that would help? I'm imagining for example a ship crossing the Pacific from the U.S. to China, but stopping in at Hawaii, the Marshall islands, and the Phillipines to charge. Maybe not even in a port; maybe there'd be power lines that run out to buoys that have the maritime equivalent of a DC fast-charger.
Also, one could imagine overhead lines being installed over the Panama and Suez canals. Ships could reach up with pantographs and charge their batteries as the traverse the canal.
The extreme case would be to have power lines that stretch from one continent to another, and ships cross whole oceans without ever unplugging. I'm not sure how that would work, exactly: floating cables? Cables that run along the sea floor, but the ships run an extension cord that drapes down to meet it? Lots of mechanical problems that would have to be solved.
Even with charging infrastructure only available in some places, if ships were configured with diesel engines that can take over when the batteries are dead, running off of batteries at least part of the time could reduce the fuel consumption by quite a lot.
Yes, I am in SFBA; I know about Saildrone; Sailbuoy, Liquid Robotics and a few other similar companies pursuing small data-collection drone boats. I didn't hear about Sofar yet - thanks for the link.
As a full disclosure, the boat I launched was made under collaboration with Blue Trail Engineering ([1]) known for SeaCharger ([2]). All cool parts on the photo are from them; my parts were camera / extra satellite modem / some cloud autopilot. I am way less cool than Damon from Blue Trail Engineering.
As for my solar drone boats hobby, it's so slow moving that there's nothing to follow at the moment. If I get the second boat out of the CAD stage, I would probably get something on my low-profile youtube channel ([3]). But I would not expect anything too soon: bigger boat requires very careful engineering, and with my limited hobby budget it will take time.
Anyway, thank you for the words of encouragement. :)
1. https://www.bluetrailengineering.com/ 2. http://www.seacharger.com/ 3. https://www.youtube.com/channel/UCXLwwf3muIhUs7zYIbRTHNw
* https://www.youtube.com/watch?v=xOAXi5huV1U
A better solution, for the time being, may be what Rebuilding Tally Ho is doing and use a hybrid engine:
* https://www.youtube.com/watch?v=xohxmwPfctg
He specifically chose a Beta Marine (marinized Kubota) diesel that has an electric motor/alternator connected to a 48V battery bank. If either the mechanics or electrics go, he can use the other. For short jaunts, like in and out of harbours, he can use the electric system to preserve fuel. The system has re-gen capabilities under sail.
More pricey though.
What would be wrong with a hydrogen fuel ship or a biomass fueled ship?
> All of this is technically possible, and as we have seen, it would produce less in emissions than the present alternatives. However, it’s more likely that a switch to sailing ships is accompanied by a decrease in cargo and passenger traffic, and this has everything to do with scale and speed. A lot of freight and passengers would not be travelling if it were not for the high speeds and low costs of today’s airplanes and container ships.
> It would make little sense to transport iPhones parts, Amazon wares, sweatshop clothes, or citytrippers with sailing ships. A sailing ship is more than a technical means of transportation: it implies another view on consumption, production, time, space, leisure, and travel. For example, a lot of freight now travels in different directions for each next processing stage before it is delivered as a final product. In contrast, all sail cargo companies mentioned in this article only take cargo that cannot be produced locally, and which is one trip from producer to consumer.
This speaks to me. I see much more conversation around "how can we use technology to remove the negative environmental impacts from our lifestyles?" than I do around "how can we change our lifestyles to cause fewer negative impacts?"
Unless “changing lifestyles” is “give up all daily transportation, heating, cooling, meat, and 99 percent of electricity”, it’s not gonna cut it.
And, come on, then want to haul sails by hand on a ship of that size? And use rowing machines to generate electric power? They'd need a huge crew.
Liquid natural gas carriers often run on their own natural gas. There a few natural gas powered freighters now, but they're built in the US for the run to Puerto Rico, which, under the Jones Act, is limited to American ships.
https://en.m.wikipedia.org/wiki/Jacques_Saad%C3%A9-class_con...
The larger your ship is the more efficient it can be, and the less of it in the water the less energy is needed to push it.
So make big big ships with really really big sails. You want the ships to fly with just the keel in the water to steer against the wind.
You might think I'm joking or talking nonsense, but look up Alexander Bell's cellular geodesic kites, and Bucky Fuller's "Cloud Nine" floating city.
Material strength doesn't scale well to go "properly big big" in the sci-fi sense.
OTOH, I am constantly amazed by what material science keeps managing to do, so I have hopes that maybe one day your dream will be true.
Are you familiar with Bucky Fuller's concept of "tensegrity"?
https://en.wikipedia.org/wiki/Tensegrity
https://mymodernmet.com/tensegrity-architecture/
He pointed out that the struts could recursively be made out of tensegrity structures. Or you can make them out of balloons:
https://en.wikipedia.org/wiki/Tensairity
I was being a little coy in my previous comment. The structures I'm thinking of are more like kites than sailing ships. They would "dip a toe" in the water to tack, perhaps, but they would be aerial not marine in nature.
A. Bell lifted a man with his cellular geodesic kites. https://en.wikipedia.org/wiki/AEA_Cygnet
In any event, I hope my dream does come true one day. :) Cheers!
Interesting article but I'd like to hear about other large scale sail boat designs, perhaps even mega-catamaran sailboats..
https://www.youtube.com/watch?v=i2WKJtbm8yM
IDK how many forrests have to be cut down though.
And if that is not a testament how stupidly efficient container megaships are, I don't know what it is.
Then the market will sort it out to find another optimum.
Eric Newby, The Last Grain Race
Take Daedalus yachts[0] for example, a USA built, lightweight (carbon fibre) sailing yacht with the aim of being zero emissions. They use a combination of solar, wind and hydrogen re/generation to get power for both the cabin and the drive system.
Perhaps a similar combination of technologies could be used to scale up commercial/cargo sailing ships?
Still though it seems nuclear would be a good fit for shipping. Most large ships use electric motors for their propellers anyways, and the US Navy has extensive experience deploying reactors in submarines. Theoretically you would only need to refuel such a ship every 10 years or so. Fears about terrorism or contamination will probably prevent such a ship from being made any time soon, not to mention the lack of infrastructure.
https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#Civi...
modern shipping is designed around stacked containers
I did a deep dive into the container ship industry many years ago in order to understand unit economics and how certain technologies could improve the ecologic impact of this massive industry. It was very interesting. I learned a lot.
I see a lot of comments about going electric, hydrogen, solar, sail, some kind of hybrid, etc. I don't think any of this is near any time horizon I can name or recognize.
Why?
Cargo ships use something called "Bunker Fuel" [0].
What is bunker fuel?
Well, to put it simply, it is what's left after you take petroleum and distill it into various grades of gasoline, diesel, industrial oils, etc. It is often referred to as "the bottom of the barrel". Another way to think of it is that bunker fuel is the waste product. Some grades of bunker fuel are so thick you can walk on it and will only flow if heated. This should not come as surprise, asphalt is the next level down and that stuff is solid enough to make roads out of it.
Why did I say "not so easy"?
Because these ships are effectively burning the waste product from the manufacturing process that leads to all the fuels and lubricants we consume in massive quantities.
What does this mean?
If we stopped using bunker fuel next Monday, what would we do with the absolutely massive amounts of bunker fuel produced every year? Think about that for a moment.
Sure, hydrogen and electric sound "clean", but you would have a potentially larger ecologic disaster in having to dump bunker fuel somewhere. The bottom of the barrel isn't going to magically disappear just because we transition cargo ships to something else.
What to do then? It's a tough problem. One solution, maybe, I don't know, is to evaluate how efficiently and cleanly we might be able to burn bunker fuel on land vs. on a ship. My point is that we might be able to extract and use this energy in a super-clean way, to charge batteries or whatever. I haven't studied this at all. I would imagine that if we set out to truly create a super-clean process to burn bunker fuel on land for energy generation it could be a good path forward. I don't know how much better we could do on land (in terms of clean burning) than on a ship. I'd like to think we could do a lot better.
I do think the future is electric, in some form. What I can't see or predict is how we transition from today's reality to that reality. This isn't a case of just having to solve the containership problem, you have to solve the entire oil/fuel ecosystem because, if you don't, you are going to have astronomic amounts of bunker fuel (waste product) to contend with. This is how shifting cargo ships to electric could actually be worse for the environment than letting it be and working to make them as clean as possible. Weird, isn't it?
Ammonia (NH3) is the new promising carbon free fuel for ships.
