Are Renewable Powered Ships Possible?

The video talks about engery reduction by cargo ships slowing down based on "fuel consumption per day". But as a cargo ship slows down it takes longer to transit the same route so the reduction in fuel used to deliver a cargo is not nearly as large as it appears when fuel consumption per day numbers are quoted. A better metric is fuel consumption per distance unit such as fuel consumption per nautical mile or similar.

 

The video almost became irrelevant at about 1min 30sec; ships transport 80% of the worlds goods and only use 1.7% of the world's energy. The engines are already the most efficient ever made (along with big turbofan engines). And what do you do with dirty heavy fuel if you don't burn it?

 

I guess it might be nicer to burn "dirty" fuel in some land based long term heavy use power-plant application where an extra 1,000 or even 10,000 tons (including maybe water filtration) of some "scrubber" apparatus wouldn't be a deal breaker to install like it would on a ship.

But if I had to reduce energy consumption AND manhours in transport I'd focus on making highly efficient rail and even ship borne use of Con-Ex box based shipping more consumer friendly. Have 10', 5' and 2.5' long Con-Ex boxes that can be dropped off for filling, then picked and transported by rail or even ship by flatbeds with lift-gate and rollers, in a timely manner. The idea would be to replace a typical 100 mile private company truck delivery that requires a full trip length human driver and dedicated truck, and empty return trip, with multi-load 10 mile trips on each end and 100 miles of rail or ship in the middle.

Make it easy for both private cars and commercial trucks of all sizes to roll on/roll off a long distance railroad flatbed to transport the vehicle and passengers (disposable J-bottles supplied in case you forgot because this train ain't stopping for next 5hrs/400 miles).

 

Transporting trailers and containers by rails has been done for decades. Loading trucks makes absolutely no sense. The norm is to transport the trailers and have a local tractor deliver them, which actually makes sense.

 

Perhaps we could build a huge floating ring in the North Atlantic that spanned the ocean from Cape Hatteras to the Iberian peninsula and back. Let the Gulf Stream current drive it for free and all you have to do is get the cargo on and off at two ends points. There are other, smaller scale routes that could be exploited as well. It also would double as a transoceanic bridge and more.

If we could just gather all the lost cargo containers and weld them up water tight, I'm sure most of the bridge/ring would already be built. Home for sea-life exclusive ocean front resort space that changes seasonal appeal weekly, nowhere else could you stay in a resort that took you through so much diversity. Deepsea fishing from your porch or glacier excursions from the same apartment you went on a shopping trip to Morocco from. There would be Aquacultural businesses and research facilities. The possible benefits are endless and all of it energy cost free, at least for the transportation part. I mean, if we want to save energy cost by slowing down the ships, what about slowing down to 3 or 4 knots and have no energy bill?

-Will (Dragonfly)

 

Of course it's possible, the question is if we are prepared to pay the price. Right now we can make fuel directly from air and water. Sail transport is viable, but even more expensive. Don't know how nuclear holds up, probably somewhere in between.

 

Turbofans are not really that efficient. But they are the best solution at that speed. If you look at the powerplant of the turbofan you can use a turboprop to get at fair comparison to piston engines. And most turboprops is a fair bit less efficient than most piston engine propeller pime movers. The best thing would be if you could use regenerators on the gasturbine part of a turbofan like you do in powerplants. But that would end up taking to much extra weight and volume to be used in a airplane propulsion application.

And what you can do with the heavy fuel? Crack it to lighter better fuel before using it.

 

cool idea

 

why has there never been a nuclear powered container ship. would it never recoup its initial cost.

 

What is the cost compared to a heavy oil engine?

 

I'm going to take a rough guess and say 'bureaucratic nightmare'. Some ports may not permit it and licensing and certification would be horrendous. And yes, the initial cost; for example, every weld in all of the (stainless steel) plumbing (water-cooling, etc.) has to be x-rayed. I knew a guy who'd been a nuclear engineer; he told me that the amount of paperwork required to construct a nuclear power plant weighed as much as the reactor vessel itself.

 

Sevmorput - Wikipedia https://en.m.wikipedia.org/wiki/Sevmorput
Otto Hahn (ship) - Wikipedia https://en.m.wikipedia.org/wiki/Otto_Hahn_(ship)

The nuclear navy's biggest problem is perception. Finding ports of call might be impossible. The costs are higher then for a conventional diesel engine, but not horrendous. The reactor is a self contained unit, buildt in a factory, and there actually is more experience with this approach, since there were more naval reactors buildt then land based ones. The ships would benefit from an increase in load capacity, the machinery room is smaller and liquid fuel requirements are low (for the diesel gensets). The operating costs would increase significantly. Personnel will at least double, they would have bigger salaries, flags of convenience would be history. The biggest cost is shoreside facilities, the waste needs disposing and has to be paid for.

I don't actually believe in nuclear merchant shipping in the near future. It can be a solution, but the world is not yet prepared for it, and I don't know when it will be.

 

Having spent years at Electric Boat Corp. (where they make US Nuclear Submarines), then transitioning to commercial Nuclear Power Plant Design for a few decades, I can clearly state that Nuclear Power is not cheap, and it is significantly dangerous. The nuclear power industry fell apart in the mid-1970s when the industry found out that they actually had to conform to the safety rules, which drove up the price so high that most US Nuclear power plants were cancelled back then. Only the ones that were already being built, and had too much $ already invested, were completed.

Then came Three Mile Island, and that kept the Nuclear industry alive for another decade or so, installing all the new safety stuff the TMI accident revealed, and that cost plenty. Then came Chernobyl, with most of Europe abandoning Nuclear power entirely. I was living in Italy at the time, designing Nuclear power plants for the Italian Government, we were 1250 miles from Chernobyl, and had to keep our children indoors for six weeks. Italy had to destroy 6 weeks of all foods due to radioactive contamination. That kind of risk is just not reasonable to endure.

The Nuclear industry is good at stating that everything is safe and nothing can go wrong, however the core fuel in a single typical utility size Nuclear power plant contains the radioactive equivalent of roughly 1000 Nagasaki atom bombs, something that is not publicized, but effectively true.

Nuclear powered merchant ships, I believe will never be made again. There is not a single US State Governor that will allow shipment of spent Nuclear fuel to the repository out west. This is because the risk of transporting such danger is simply not reasonable.

 

I'm curious, what does the military do? Do the governors have anything to say about them moving nuclear things around at will?

I agree with you, it's not likely that we will see nuclear shipping soon. The nations able to do it do not actually need it, and the public is not willing to take the cost. When the true cost of using fossil fuel becomes a big enough concern, the most likely solution will be synthetic fuel (carbon based), or hydrogen.