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Tesla Cargo Ship


Active Member
Nov 22, 2019
Breckenridge Co Ky
Charging ships at sea would be a massive undertaking.
Below is a screenshot from MarineTraffic and going there will allow you to see all major ships in real-time as they voyage around the Deep Blue Sea.


Image: Visual Capitalist
You may be wondering, does this really show every ship at sea?

Well, it might not catch your Uncle Steve’s sailboat off the coast of Florida, but this map will show all major commercial vessels. Any oil tanker, cargo vessel, cruise ship, or fishing boat can be spotted, and it makes for some interesting observations if you know where to look.


Upon loading the real-time map, the first thing we did was adjust the filters to only show oil tankers.

After all, we know that every day, about 18.5 million barrels transit through the Strait of Hormuz between Iran and Oman, and 16 million barrels go through the Strait of Malacca between Indonesia and Malaysia.


Image: Visual Capitalist
Here’s a screenshot of the Strait of Hormuz, showing only oil tankers. (Dots are tankers that are not moving, while arrows represent tankers that are currently on course.)


Image: Visual Capitalist
And here are the ships going through the Strait of Malacca, which at its narrowest point is only 1.7 miles (2.7 km) wide.


Image: Visual Capitalist
Have you read?
If you want to get oil from the Persian Gulf to the South China Sea, this strait is vital – otherwise a big ship must detour thousands of miles around the Indonesian islands of Sumatra and Java to find the next suitable waterway.


Compare those above straits to the coast off of Somalia, where piracy and hydrocarbon theft are major concerns.


Image: Visual Capitalist
All is pretty quiet, aside from the one daring tanker that is about 500 miles (800 km) east of Mogadishu.


One other easy observation?

It’s the few passenger boats hanging around the Antarctic Peninsula – which is the part of the continent closest to Argentina and a destination for cruise ships.


Image: Visual Capitalist
If you have a chance, check out the live map for yourself and play around with the filters. It’s also interesting to see what’s happening in your local waters, as well.


License and Republishing


Supporting Member
Supporting Member
Aug 18, 2012
3.5 MWh is the same as 35 Model S. I am not really sure how far that amount of energy can take a ship of that size? May be 300 miles? So perhaps for inter-Island travel in Mediterranean or Scandinavia?
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Reactions: Buckminster


Supporting Member
Supporting Member
Aug 18, 2012
Capacity 7 MWh (that’s equivalent to around 100 Tesla Model 3s)

It is kind of interesting if this becomes a new unit of measurement, like Horse Power. That ship is 100TM capacity.


Jan 22, 2014
How many hours can it get out of a charge? How long does it take to charge?
Like pretty much all batteries: 1C charging will take about 1 hour for a full charge. Working harder (battery cooling), one can charge it a bit faster. Of course, for a 6 MWh battery, that will require 6 MW of charging power.
For fun: charging on a normal 120v household circuit, it will take about 6 thousand hours or about 8 months :)


Active Member
Jul 25, 2019
QLD Australia
Electric ship with charging stations - With sea charging stations, the ships range could be reduced to c.800km with a 1.0gWh battery. This ship would be profitable, but more expensive (even with $100/kWh total battery & powertrain cost) and less profitable than the Maersk Triple-E. Even fuel cost would be more expensive than the Maersk Triple-E at $0.1/kWh. I think this ship will become economical vs the Triple-E eventually, but it requires significant further progress on the experience curves for batteries, electric powertrains and solar.

With the latest IPCC report cargo ships are a more pressing problem.

Apart for tesla which other company is likely to come up with a good solution?

While the direct distance between San Francisco to Honolulu is around 2,500 nautical miles,

I cited this example as for electric ships on issue is the longest journey at sea away from a charging station (or drone ship).

Seems to me like a 400km or 800km electric range would be the lowest acceptable... but even with drone charger ships we can't have fast charging everywhere.
the compromise may be to use a range extender, either hydrogen fuel cells or diesel motors acting as a diesel generator...

If done charger ships have a return to base range of 100/200 km, they can extend the charing locations reach and make it slightly more convenient to recharge at sea. The downside is the extra energy needed to power the drones, But the advantage, is drones could plug into the regular grid glose to major land masses taking advantage on onshore solar including.

So I am not sure we would have drone chargers, just raising the possibility...

A logical candidate to generate the electricity is off shore wind, with a HVDC link to a charging station, where done ships and/or cargo ships recharge.
Seems like price is an the important consideration, electric fuel cost need to be substantially lower than diesel.


Active Member
Jul 25, 2019
QLD Australia
After reflecting more on this I think a "battery swap at sea" is the best option..
I would opt for 400km range assign that that is 500 MWh or approximately 150 x 3 MWh Margapacks...
Obviously "battery swap at sea" is a tricky proposition and might not be possible in all conditions...
So all ships will have the fallback of the diesel generator(s), but I now think usage can be reduced to a small subset of trips.

Drone chargers become Drone Barges, their purpose is to carry charged Megapacks in shipping containers usually from land to the refueling point.
We mostly want the Drone Barges travelling no more than 30 mins.. to the refueling point, the aim would be to keep this overhead to 10% if the fuel cost.
400 KM range means the ship travels around 10 hours between. battery swaps, ideally we want to keep the swap process to 20 minutes, even though barges match speed and it doesn't need to stop, barges do need to return to base..

I'll go into some details on a hypothetical "battery swap at sea", I'm not claiming to have this 100% right, or that it is the only solution.

The cargo ship probably proceeds at 1/2 normal speed while swapping batteries, it should have an internal battery capable of powering it at 1/2 normal speed for up to 1 hour. This battery simply charges of the Megacharger packs while the ship is moving..

The target task in this case is getting 150 depleted Megacharger packs of the ship and putting, 150 fully charged packs on.
Assuming each trip on or of takes one minute we have 300 minutes work of trips.

My thoughts were that the cargo ship needs something like 15 bridge cranes to achieve the swap in 20 minutes...
Barges can be any capacity, they simply have to be able carry the right number of containers and be stationed in the right areas...
My hunch was 30 barges carrying 5 containers each... (15 each side of the ship).

As "battery swap at sea" is a tricky proposition it is best to initially practice with cheap cargo like shipping containers full of sand..

My other thought is each container can be in a metal journey cage made of steel with rubber impact absorbers on the bottom and inflatable mattresses around the container top/bottom and all 4 sides. The intention is the container floats and is waterproof, in the event of an unfortunate accident.
As wave action can result in bumpy landings, some impact absorption is good and waterproofing is good,

Overall the point here is the process can be purpose built and go though testing and successive design iterations...

A key point is the cost of the electricity using barges from the mainland ensure these are able to take advantage of the best current grid prices.
In a grid with a lot of solar power, prices should be low in the middle of the day...
In other locations offshore wind can be used...
The aim here is to get the electricity around $50 MWh or less, add on our 10% overhead and other costs that is $60 MWh or $0.06 kWh,.

Taking our hypothetical trip San Francisco to Honolulu that is 4,000 Km so would require 8 interim charging stops,.
A very large container ship like the EverGiven can carry 20,000 containers, if it was on station as a mothership to recharge other electric cargo ships it could recharge around 130 cargo ships...

Diesel would be the interim solution until it was economic to deploy motherships, the economics are a challenging aspect. We don't want to increase our $0.06 kWh by more that $0.02-$0.04 kWh.

Finally in shallow water on and reefs we could build large pontoons which could recharge Megapacks and load them one to drones. these could be feed from local generation and/or the mainland grid. As these would need to be at the most every 400 km, not many are required, the impact on the environment from a well considered pontoon can be reasonable.

Yes, it is still a difficult problem to solve, but an important problem..


Active Member
Jul 25, 2019
QLD Australia
After more though the alternative to "battery swap at sea" is artificial harbours.

On continental shelves there are area of shallow water where reefs exist these are locations where an artificial harbour could be constructed...

For the artificial harbour to be effective it needs some protection from ocean waves, it is possible to build a breakwater which harvests wave energy..

Add in some offshore wind in the location of the artificial harbour and it has local generation sources.

For most of the harbour the construction technique is a pontoon, similar to an oversized Jetty it can be constructed on top of the reef. with minimal disruption (hopefully)

The breakwater would be constructed first and this should make subsequent construction phases easier.

For this solution:-
  • Cranes are located on the artificial harbour not on ships...
  • The carbo ship ties up at the harbour - and can charge an internal battery.. while packs are craned on and off. - say 20 minutes.
  • The harbour length is as long as the longest carbo ship, currently 400 Metres.
  • The harbours is a series of wharfs with different water depths... boats of all types and sizes can tie up and charge.
  • This solution accommodates fishing boats and cruises liners in addition to carbo ships..
  • HDVC link for 2 way power transfer - during the day tap on shore solar for pack charging, overnight feed onshore with wind/wave energy.

With the artificial harbours being constructed we need to ensure sufficient capacity, each wharf is stall where a two cargo ships can charge and load (both sides)

The capital cost of constructing the harbours is significant, but can be optimised. The money made from selling electricity has to cover the cost.

To offset the time spent charging ships can travel faster and charge more frequently at harbours space say every 200 km rather than every 400 km.
Boats of all sizes and types, benefit from more harbour locations..

The ability to build harbours is limited by the depth of the sea, so suitable locations with islands and reefs being the preferred options.

Even though this seems like an expensive solution the key metric is the cost of clean energy and the differential between daytime solar generation and day time electricity demand... the ability to sell electricity generated offshore overnight is an additional advantage...

Like Supercharging thete needs to be a markup to recoup the cost of the recharging facility...

As we probably can't get harbours everywhere some compromises have to be found...
Ships may travel island-hopping routes closer to continental shelves and shallow water, the extra distance may be offset by travelling faster..
For other routes, "battery swap at sea" from a mothership or use of an on broad diesel generator are the alternative...
The more I thought about it "battery swap at sea" is a difficult problem, it may need a helicopter or a large powerful drone...
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Active Member
Jul 25, 2019
QLD Australia
Other options for a fast charge / battery swap at the the harbour dock include:-
  • Just plug in lots of charging cables - too slow?
  • Conveyor belts with packs riding on them - best is parallel across the ship... (a bit like a Sushi Train for containers)
  • Rail lines and a winch/train - similar to belts, but lower tech at the ship end... essentially just rail tracks...
A platform can be raised to the height of the ship and conveyor belts at same height dock with conveyor belts on the ship.... (this can be prebuilt standard heights.)
A number of packs travel on each belt.../ track..

The old discharged packs are taken off before new packs can be loaded on, the best way to accommodate this is moving the ship one slot forward/backwards. ... old packs no longer line up with the loading mechanism on the ship new, ones are lined up.

Rail lines are similar, packs travel in cars on wheels - 1 per pack... a simple winch/train can be used to pull them off, the same lengthwise shuffle aligns packs with the new packs... (or the whole thing can be more like conventional rail.. perhaps a small harbour electric train can move containers around...)

A well organised conveyor belt / rail system should be the fastest battery swap...

The advantage of using rail is, containers already travel in rail cars..standard equipment can be used...

Train tracks may rust in a marine environment so adaptations would be required.
Last edited:


Active Member
Jul 25, 2019
QLD Australia
Apologies for the rambling nature of the posts above, I was just "thinking on paper".
I can now condense this topic into my best guess proposal, in a simplified form...

Lot's of batteries are needed, so battery prices and volumes are a critical consideration.

Range/battery size assumptions:
I would opt for 400km range assuming that that is 450/500 MWh
Or approximately 150/166 x 3 MWh Margapacks...
Diesel generator is used to make electricity as a range extender... (where recharging/battery swap is not possible)

Charging at Ports:
Assume 4-5 hour stop
Normal Megcharing one connection per Megapack..
Like charging 150 semis at the same time...

Between Ports - Quick Battery Swap - Artificial Harbour (where possible - Continental Shelves and Island Chains)
These would be located approximately every 400Km, or more frequently, if ships want to travel faster.
Infrastructure is shared by Cruise Liners, Fishing Boats, and other types of vessel.
Some do battery swap (larger ships) others do plug in charging (smaller ships).
Artificial harbour is protected by a breakwater. (which could harvest wave power)
Harbour is constructed similar to a Wharf or Pontoon.
Harbour infrastructure is a shed to recharge packs, and rail lines on top of a timber/steel structure.
Harbour has a high capacity HVDC connection to the mainland grid. (and/or offshore wind farms)
Ship infrastructure is rail lines to transport packs in/out of compartments in the rear ships tower.

Pack Swap Process
Allowances need to be made for tides etc,,,,
Rail line on the ship is joined to a rail line on the dock via a small sturdy ramp at the right angle (gradient is very slight)
Each line has say 3 packs on interconnected trolleys.
After the track is connected - drone trains proceed up the tracks, automatically dock with the pack rail cars and pull the packs off the ship on to the dock
Loading/unloading happens in parallel with a done train for each line.. (or sufficient trains to achieve the required rate)
Lines are separated in parallel horizontal and vertical planes. (e.g. 10 horizontal x 5 vertical x 3 = 150)
After unloading the ship moves forward/backward to line up with rail lines for the packs to be loaded
Drone trains now dock with the new packs and push them onto the ship.
With refinement, the pack swap may be a 5/10 minute process. (perhaps faster)

Packs are owned by shipping companies.
To get a good ROI, the ideal situation is if every pack is used at least once per day.
The economics now favors faster travel with more battery swap stations, and standard size, perhaps smaller cargo ships..
Retrofit to existing cargo ships might be possible...
The key considerations are the price of batteries, and electricity sourced from RE - both are very likely to hit the sort of numbers that could make this viable,,,
Artificial harbours are fairly major construction projects, the markup on electricity needs to recoup these costs, shipping companies may help fund the construction.
If the markup is say $20 MWh ($.02 kWh) then a 500 MWh swap earns $10,000 - 10 swaps per day x 20 years = $750 Million
If this was viable, a lot of shipping, could be cheaper, and faster...

There may be better solutions, I was just trying to devise the best solution I could.


Aug 14, 2021
I ran some numbers on a ULCC class ship awhile ago (and created the 3D model below just for fun). A trip of 6800 nm would require about 30 GWh.

If you want to check my math, that's 17.75 days at 16 knot with the engine producing 35MW (440000 DWT, sea margin 15%, engine margin 10% no ice class notation, no currents, no reserve, source https://marine.mandieselturbo.com/d...rs/propulsion-trends-in-tankers.pdf?sfvrsn=20).

30 GWh at 100$/kWh that's a battery pack cost of... 3 billion dollars. A little bit on the expensive side.

For the foreseeable future, the financing cost kills the business case of long distance electric ships. It does work on short distances though, like ferries.

View attachment 375802
lol thats wild. Looks awesome

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