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Comment by austincheney | Hacker News Reader

Then just imagine if shipping tankers became electrified. The world's 6 largest shipping tankers produce more CO2 than all the world's personal vehicles combined.

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That’s not true. They produce more sulphur dioxide, a pollutant that cars don’t emit much of in general, and which the heavy fuel used by ships generates in abundance. Somehow the story morphed from “a few ships emit more of this specific pollutant than all cars” to “more pollution” to “more CO2.”

The entire worldwide shipping industry accounts for about 3% of humanity’s CO2 emissions.

And how does that 3% compare to the total CO2 from personal vehicles?

"Road transport" was 16.5% of global emissions in 2008: https://www.who.int/sustainable-development/transport/health...

Road transport includes all transportation on roads, which isn't passenger vehicles. Passenger vehicles are less than half of that and growth of the CO2 emissions from passenger vehicles is nearly flat year over year. The maritime shipping sector, on the other hand, is growing emissions output as much as 75% every 15 years.

> The entire worldwide shipping industry accounts for about 3% of humanity’s CO2 emissions.

To my knowledge personally owned vehicles account for a similar percentage of total CO2 output, so that number while small is a red herring. People tend to generate more CO2 per capita as a result of air conditioning than from the vehicles they drive.

Do you have sources for all of these claims?

You are very incorrect on most of what you've posted here, but this is embarrassing since you could verify this with basic math.

An air conditioner typically consumes in the neighborhood of 4kW, less than half the day, less than half the year.

So, being generous, 6000kWh annually for air conditioning.

Gasoline has the equivalent of 34kWh/gallon, which implies air conditioning uses the equivalent of 176 gallons of gas per year.

The average person in the US drives over 13,000 miles per year. The average car gets 25 mpg. That is 520 gallons.

In reality difference is probably 4x - household has two cars and AC is shared over 2 people.

> An air conditioner typically consumes in the neighborhood of 4kW

That is not true globally. I live in Kuwait, which can get up to 140F during the day in the summer.

At any rate if you want numbers (since people are crying about research without doing any of their own) here are some: https://news.ycombinator.com/item?id=19438999

How many days was Kuwait over 130F last year?

Most days May through September experience an average high of actual temperature of around 120F each day with 100% sunshine. Its the heat index that brings it up to about 140F. You have to understand that during the summer here there is relatively lower humidity during peak sunlight which refracts less light before hitting the ground. The ground here is also highly reflective of heat, which is felt at least 5 to 6 feet off the ground (the height of most people).

Another way to look at (and there is a lot of data on this) is which nations produce the most CO2 per capita and then work backwards asking why that is.

Developed countries with high car ownership and countries with very small populations and very large hydrocarbon extraction industries.

That isn't accurate either. The country that outputs the highest CO2 per capita is Qatar. Qatar left OPEC within the last year because their oil extraction is so low. Qatar's primary hydrocarbon extraction is LNG (liquefied natural gas) which is a low CO2 emitter relative to oil refinement.

Also, most the countries here have a higher than average population density compared to the global average due to a small geographic footprint.

Trinidad & Tobago, Australia, and Turkmenistan are high in addition to Qatar. What they all have in common is they are high LNG exporters, which involves liquifaction trains. LNG liquifaction trains are extremely CO2 intensive, along with heavy oil refining (see Curacao, Aruba, et al per capita CO2)

> which implies air conditioning uses the equivalent of 176 gallons of gas per year.

Yes, cars do produce more CO2 than air conditioning, but in the context of CO2 emissions, you can't just compare "equivalent of gas gallons".

First, not all electricity is generated from fossil fuels (63% in the US, much less e.g. in many parts of Europe).

Second, to produce 6000 kWh of electricity from fossil fuels, you have to burn much more than the theoritical amount, because the efficiency of conversion is much lower than 100% (although in cold climates you may use combined heat & electricity production).

In the end these are irrelevant details, as we must stop burning fossil fuels anyway. Every part of the chain is important, and the argument "but x produces even more CO2 than y, so I keep using y" is of course stupid.

It's quite believable that passenger cars also account for something the neighborhood of 3% of total CO2 emissions. My point was not to say that shipping is completely irrelevant, it's to point out that it is not so grossly overpowering as your original comment suggested. The idea that a handful of ships match the CO2 emissions of all cars is completely divorced from reality.

If you want to find the exact number that cars account for, I'm sure you can find it. Just don't use whatever source you got that initial CO2 claim from.

This is false information that is commonly repeated. The ships produce more of a particular pollutant, sulfur dioxide (SO2), not CO2. Personal vehicles produce barely any SO2 (gasoline contains no sulfur, diesel contains a small amount) so it isn't surprising a few container ships, which burn sulfur-heavy bunker fuel, produce more.

I always want to think of sulfur in HFO are contributing to the total heating value because the stuff used to be 3% sulfur. Realistically it's probably 1%. Sulfur only has about 1/3 the energy content as HFO.

But they are phasing out high sulfur HFO in 2020 I think ships are restricted to 0.5% sulfur.

Afaik shipping tankers are very efficient; among the lowest CO2 per mile travelled per ton of cargo moved.

Trains are 185km/L per ton, and ships get about double that. The only more efficient method is bicycling.

Electrification won’t do much to help because batteries are so big and heavy you’re basically shipping batteries instead of cargo back and forth. There’s been recent advancement in adding sails though, that actually make non-trivial differences. [1]

[1] https://www.cnbc.com/amp/2018/08/31/maersk-tankers-installs-...

Forgive my ignorance, but couldn't nuclear power be used to generate electricity on these tankers in the same way its used to power submarines?

Nobody sane would give civilians in a poorly regulated sector nuclear fuel and expect them to operate a generator safely.

It is even debatable if the US using nuclear power on their subs/warships is wise. It is great for natural disasters relief (mobile power plant) but terrifying if the US ever loses one.

The US has lost several, as have the Soviets and Russians.

You're right[0]. Terrifying.

[0] https://en.wikipedia.org/wiki/Nuclear_navy#Accidents_involvi...

If you must dump an operating nuclear reactor somewhere with no supervision, at least the deep ocean is a pretty good place to do it. I mean, far better not to do it at all, but it could be worse....

92 lost nuclear warheads including one near Seattle/Vancouver, one near New York and one near Miami (https://genecurtis.wordpress.com/2011/11/12/lost-nuclear-bom...)

Just for clarification its not anywhere near Miami (that is a small map graphic). It is right off the coast of Savannah, GA. There have been numerous books written about it and there is a wikipedia page about it.

Yep, you're absolutely right. I'd heard about the other two, I just assumed the third even though it’s listed in my link X_x

It's worth noting that, as long as they don't explode (or get stolen), a lost nuclear warhead is pretty benign. They contain a relatively small amount (a few dozen pounds) of low-activity nuclear material and it all tends to stay together.

A reactor contains way more material, probably several tons at least. If it's been operating, it contains lots of nasty, highly-radioactive fission and decay products. Reactors also like to go all melty and sometimes (non-nuclear) explodey when they fail, although I suspect that's less of a factor when it's underwater.

Nuclear power plants on land could be used to generate power for producing synthetic hydrocarbons, which would in turn be used for powering ships. But putting nuclear reactors on merchant ships is totally impractical for security reasons.

This is true. Naval reactors need to be relatively small and light, which means that they end up using HEU fuel, which is a security risk.

Yes it can. Check out the Russian Sevmorput.[1] It is the only active nuclear powered merchant ship in the world.

[1] https://en.wikipedia.org/wiki/Sevmorput

That’s surprising to me. Do you have any references for that?

Why are the ships so emissive?

I think it’s because once they are in international waters, they use extremely dirty burning bunker fuel.

I think it's because they use cheap oil that tends to be really, really dirty when burned.

I don't think that could be a full explanation. Perfectly clean burning turns all of the carbon atoms in the fuel into carbon dioxide.

[hydrocarbons] + O2 -> CO2 + H2O

"Dirtier" burning would result in less CO2 emission.

The problem is that you are assuming that what these ships are burning is [hydrocarbons] when it’s much more than just that. There are various impurities including sulphur, which lead to extremely dirty emissions such as SO2.

The OP is misinformed with regards to the “6 largest ships” claim and the “CO2” claim — as covered elsewhere in comments on this article.

There are worse things in cigarettes than nicotine. In a similar way there are worse things in bunker fuel than hydrocarbons.

It's simply not true. It started out as a factoid, but got jumbled into nonsense by a game of telephone:

1. True: 16 of the world’s largest ships produce as much _sulfur_ pollution as all the world’s cars.[1]

2. False: "How 16 ships create as much pollution as all the cars in the world", headline from Daily Mail.[2]

3. False: "world's 6 largest shipping tankers produce more CO2 than all the world's personal vehicles combined", from OP.

While SOx and NOx pollution is extremely bad, they're not as culpable in causing respiratory diseases and climate change, and that's why legislative action has been slow coming.

[1] https://www.lngtransfer.com/news/the-16-biggest-ships-produc...

[2] https://www.dailymail.co.uk/sciencetech/article-1229857/How-...

I am visiting Tauranga for couple of days - a big port here in NZ. I can smell sulphur quite often around city. Reminds me my childhood when playing with chemicals.

Similarly I can smell NOx out of some modern diesels. Reminds me a jar of nitric acid I used to keep under my desk, until the lid rusted thru...

> Separate studies suggest that maritime carbon dioxide emissions are not only higher than previously thought, but could rise by as much as 75% in the next 15 to 20 years if world trade continues to grow and no action is taken. The figures from the oil giant BP, which owns 50 tankers, and researchers at the Institute for Physics and Atmosphere in Wessling, Germany reveal that annual emissions from shipping range between 600 and 800m tonnes of carbon dioxide, or up to 5% of the global total. This is nearly double Britain's total emissions and more than all African countries combined.[1]

> Passenger Cars: 749.4[2]

[1] https://www.theguardian.com/environment/2007/mar/03/travelse...

[2] https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100USI5.pdf

According to the data it appears I am not completely wrong. The maritime transportation sector is of roughly equal CO2 contribution to the US passenger vehicle fleet in 2007. According to the trend indicated by The Guardian in the next 15-20 years (from a 12 year old article, which would be a few years from now) maritime transportation emissions could rise by 75% while the US passenger auto fleet emissions remain flat thereby indicating a slice of tankers contribute more CO2 emissions than passenger vehicles.

These sources weren't hard to find or read, so I am not sure why you think my statement is false.

Before you wrote the world's passenger vehicles, not the US'.

Your statement was not that the maritime transportation sector is roughly equal to the US passenger vehicle fleet. Your statement was that "The world's 6 largest shipping tankers produce more CO2 than all the world's personal vehicles combined." Those two statements are several orders of magnitude apart, and the second one more than qualifies as "completely wrong."

With the amount of optimization that goes around the bunker industry and fueling shipping tankers, I’d would be extremely interesting to see how electrification plays into this. Right now you have such fun cases as a Bunker company selling fuel cheaper than it bought it yet still making money through discrepencies in volume/weight measures, and by pumping gas or loading gravel into the fuel, and of cause you have such things like false headings on fuel tankers to drive down local prices prior to fueling, with headings then reverting.

A lot of thise optimizations are a sort of cool hyperoptimization that only make sense because of the scale of things. I wonder if electrification, likely through subsidies, would suddenly mean we’d see the tanker industry “weaponizing” weather models to predict which ports can provide cheap wind or solar energy. Or aggressively pushing the battery stacks because even a 0.01% margin is suddenly very attractive.

Could you say put solar panels on large tankers?

And orient them so they act as sails. Here's a prototype: https://futurism.com/new-ship-rigid-solar-sails-harnesses-po...

Not really. A TI-class supertanker has a length of 380m, breadth of 68m, for a surface area of less than 7 acres, and run on a 37,450 kW engine. (Wikipedia). Meanwhile, a 50 MW solar installation in Ohio takes 500 acres of space.(https://www.greentechmedia.com/articles/read/anatomy-of-a-50...). You would need to find a way to increase the surface area by a factor of 10 without ruining the aerodynamics, or use wind power instead.

That is actually way closer to possible than I thought it would be.

Of course, that stil only lets you run under power during the day!

Assuming OP’s numbers are right, it’s actually a factor of 50, not 10. Somewhat less close to possible.

If you cover your ship in solar panels and can save 2% of energy costs, it would mean a huge win nevertheless, as oil is expensive.

A fair amount of waste comes from idling in port. There are still issues with loading and unloading containers if you cover the ship with panels.

If a ship's in port, there is no need for using the on-ship engines at all. You could just connect it to the land based grid, which, optimally, uses renewables. Hamburg harbour has project to do this precisely, and it seems Cuxhaven has one too.

Using the same density as they achieved in an open field where land is cheap, they could cover 2% of their cost.

Using the latest solar tech in a space-conscious deployment I would assume you could probably 2x that at least. So we’re in the realm of 5% of energy cost.

Give the technology another 10 years and where would we be? Unfortunately panels are already astoundingly efficient going from about 15% in the 60s to 20-25% today. In the lab we can approach 50% so there’s probably one more doubling.

To cover 10% of the energy cost of moving that much cargo just from the sun is mind boggling to me.

It makes me wonder if a different ship design which would scale down to have more surface area per volume, driving the solar power factor up, could actually work economically.

Since the trend has just been bigger and bigger super-freighters this would be an interesting shift.

Is a Tesla cargo ship in our future?

Wonder why they are not nuclear already.

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