September 13, 2008

Can we replace oil for shipping?

Sure - Long distance land shipping can go by rail (which is 3x as efficient, and can be electrified): local can go by plug-in hybrid truck1.

Water transport is even more efficient, and can find substitutes for oil.

Substitutes for oil for water shipping? Pshaw, you say.

No, really. Substitutes include greater efficiency, wind, solar, battery power and renewably generated hydrogen.

Efficiency: Fuel consumption per mile is roughly the square of speed, so slowing down saves fuel: in 2008, with high fuel costs, most container shipping slowed down 20%, and reduced fuel consumption by roughly a third. For example, Kennebec Captain's ship carries 5,000 cars from Japan to Europe (12,000 miles) and burns 8.5 miles/ton of fuel at 18.5knots, for a total of about 1,400 tons of fuel. At a 10% lower speed of 16.6 kts, the ship burns 21% less fuel (about 300 tons).

Size brings efficiency: the Emma Maersk uses about 320 tons of fuel per day to carry 220,0002, tons of cargo, while Kennebec Captain's ship uses about 60 tons to carry about 23,000 tons (see here ), so the Emma Maersk uses roughly 60% as much fuel per ton.

Other substantial sources of savings include better hull (I've seen mention of "axe cleaver" designs - anyone seen details?) and engine design (very large (3 story!)marine diesels can get up to 50% thermodynamic efficiency), and low friction hull coatings (the Emma Mærsk saves about 1.3% with special paint, and bubbles work too).

Container shipping fuel efficiency rose 75% from 1976 to 2007, in an era of very low fuel costs.

Finally, reduction of oil consumption brings a kind of reverse-Jevons efficiency. Currently, some 34% of shipping tonnage worldwide is devoted to transporting oil [source , p.16]. If we reduce oil consumption, we reduce the need for shipping. Similarly, world coal trade was about 718Mt in 2003 [source , p2], at the same time as total world trade was 6,500Mt, so that coal was 11% of world seaborne trade by weight.

Wind: kites mounted on the ship's bow have been shown to provide 10-30% of ship's power - this is cost effective now. See an early article the leading company, Skysails, a followup article showing a commercial implementation, and the Skysails website. These are retrofits: it is likely that far more wind power could be harnessed if the ship were designed to accommodate kite assist (stronger more integrated ship structure to tug upon) rather than merely retrofitted with it.

It's astonishing what can be done with modern materials, computer-aided design, and electronic control systems, to turn the old new again.

Solar: The first question is: is it cost effective? Sure - it's just straightforward calculations: PV can generate power for the equivalent of diesel at $3/gallon (40KWH per gallon @40% efficiency = 16 KWH/gallon; $3/16KWH = about $.20/KWH, or $4/Wp, which large I/C installations have already surpassed.

Ships, trains and planes are outside all of the time, so they'll have a decent capacity factor. Grid tied systems have to deal with Balance of System costs, but a panel in a vehicle should be able to eliminate most costs: it's manufacturing, which is far more efficient than grid-tied systems that require field installation; redundant support structures; and dedicated power electronics. If a vehicle can add a panel for $1 per Wp, and get just 5% capacity factor, it could achieve $.15/kWh.

Let's look at the Emma Mærsk . With a length of 397 metres, and beam of 56 metres, it has a surface area of 22,400 sq m. At 20% efficiency we get about 4.5MW on the ship's deck at peak power. Now, as best I can tell it probably uses about 10MW at 12 knots (very roughly a minimum speed), 20MW at 15 knots, and 65MW (80% of engine rated power) at 25.5 knots (roughly a maximum). So, at minimum speed it could get about 45% of it's power for something close to 20% of the time, for a net of 9%. Now, if we want to increase that we'll need either higher efficiency PV, or more surface area from outriggers or something towed, perhaps using flexible PV. You could add a roof, or you could incentivize 10% of the containers to be roofed with PV - they could power ships, inter-modal rail, inter-modal trucks...

Here' a fun example of a boat that's 100% PV powered, here's a company selling a general approach, and here's a nice pure-electric

"Solar-powered sails the size of a jumbo jet's wings will be fitted to cargo ships, after a Sydney renewable energy company signed a deal with China's biggest shipping line.

The Chatswood-based Solar Sailor group has designed the sails, which can be retro-fitted to existing tankers.

The aluminium sails, 30 metres long and covered with photovolatic panels, harness the wind to cut fuel costs by between 20 and 40 per cent, and use the sun to meet five per cent of a ship's energy needs.

China's COSCO bulk carrier will fit the wings to a tanker ship and a bulker ship under a memorandum of understanding with the Australian company, which demonstrates the technology on a Sydney Harbour cruise boat.

"It's hard to predict a time line but at some point in the future, I can see all ships using solar sails - it's inevitable," said the company's chief executive, Dr Robert Dane.

Once fitted, the sails can pay for themselves in fuel savings within four years, Dr Dane said. They don't require special training to operate, with a computer linked in to a ship's existing navigation system, and sensors automatically angling the sails to catch a breeze and help vessels along." Source

Batteries: Large batteries could provide most of the remaining power needed, to be recharged at frequent port stops, as used to be done with coal 60 years ago (that's why the US wanted the Philippines' military bases, and why they're not needed in the oil era). Let's analyze li-ion batteries: assume 20MW engine power at a cruising speed a speed of 15 knots (17.25 mph) or 20MW auxiliary assistance to a higher speed, and a needed port-to-port range of 2,000 miles (a range that was considered extremely good in the era of coal ships - the average length of a full trip is about 4,500 miles (see chart 8 ). That's 116 hours of travel, and 2,310 MW hours needed. At 200whrs per kg, that's 11,594 metric tons. The Emma Maersk has a capacity of 172,990 metric tons, so we'd need about 7% of it's capacity (by weight) to add batteries.

So, li-ion would do. Now it would be more expensive than many alternatives that would be practical in a "captive" fleet like this - many high energy density, much less expensive batteries exist whose charging is very inconvenient, but could be swapped out in an application like this. These include Zinc-air, and others. It should be noted that research continues on batteries with much higher density still, as we see here and here, but existing batteries would suffice.

Here's a hybrid car carrier from (who else?) Toyota.

Refrigerated storage/transport could go via electric rail, which can certainly be low-CO2; refrigeration can always be made more efficient with better insulation; and there are "reefer" units that are "charged" on land, using grid power, that don't need any inputs from the ship during transit.

Hydrogen fuel cells: they can't compete with batteries in cars, but they'd work just fine in ships, where creation of a fleet fueling network would be far simpler, and where miniaturization of the fuel cell isn't essential. If batteries, the preferred solution for light surface vehicles, can't provide a complete solution, a hydrogen "range extender" would work quite well.

Hydrogen has more energy per unit mass than other fuels (61,100 BTUs per pound versus 20,900 BTUs per pound of gasoline), and fuel cells are perhaps 50% more efficient, so hydrogen would weigh less than 1/3 as much as diesel fuel.

Electricity storage using hydrogen will likely cost at least 2x as much as using batteries (due to inherent conversion inefficiency), but will still be much cheaper then current fuel prices. Fuel cells aren't especially heavy relative to this use: fuel cell mass 325 W/kg (FreedomCar goal) gives 32.5 MW = 100 metric tons, probably less than a 80MW diesel engine.

Hydrogen would have lower upfront costs versus batteries, and a lower weight penalty, but would have substantially higher operating costs. The optimal mix of batteries and hydrogen would depend on the relative future costs, but we can be confident that they would be affordable. Here's a forecast of affordability in the most difficult application, automotive.

Here's a demonstration project on a small boat.

Are shipping lines working on this?

Yes. Here's an example:

"The Auriga Leader, operated by NYK Line, was launched in December 2008 and can transport up to 6200 vehicles. NYK Line has set a goal to reduce car carrier energy consumption by 50 percent by 2010 through solar power generation, ship operation improvement, redesigned hull form, propulsion systems energy savings and improved cargo handling."

I suspect that container shipping will be able to out-bid other uses for FF, like personal transportation, for quite some time. We'll see the gradual addition of direct wind propulsion, like the Skysails, along with engine electrification and the addition of PV.

What about nuclear propulsion?

It would work, though I would be skeptical that it could beat the alternatives on cost or speed of deployment.

Don't forget that commercial nuclear plants are built as large as possible to maximize cost-effectiveness. The US Navy doesn't have to worry about cost-effectiveness - it chooses nuclear not on a cost basis, but on an operational effectiveness basis (maximum range without refueling).

The US Navy maintains a rigorous, labor intensive, costly safety program. Per Wikipedia, "A typical nuclear submarine has a crew of over 80. Non-nuclear boats typically have fewer than half as many." The Emma Maersk, the largest container ship in the world, sails with only 13 crew members!

My litmus test for nuclear proposals is their effect on weapons proliferation, especially relative to the complete fuel enrichment cycle. Per Wikipedia, "reactors used in submarines typically use highly enriched fuel (often greater than 20%) to enable them to deliver a large amount of energy from a smaller reactor." This doesn't seem encouraging.

What about the NS Savannah?

It was designed as a show vessel, not a workhorse, but it was only a few years after it was decommissioned as "uneconomic" that oil prices shot well above its parity point.

That parity point compared operating cost (excluding 1950's era capital costs, maintenance and disposal, etc) of nuclear to conventional operating costs, including fuel oil at $80/ton in 1974 dollars. Non-oil alternatives will be more competitive.

What about air transport in this age of just in time supply chains?

I would estimate less than 5% of plane transport is represented by the kind of small industrial components that go by air. Air freight transport uses surprisingly little: fuel is only 10% of Fedex's budget, so a doubling of fuel costs would only raise Fedex costs by 10%. The ratio of fuel cost to product cost is probably .1%. If Fedex fuel costs were to go up by 3x, it wouldn't have any significant effect on the affordability of sending such a part by air. Prices won't exceed an inflation adjusted $150/b anytime in the next 30 years in a sustained fashion - other things would change to prevent prices going over that level, including reduced fuel consumption by personal transportation & commuting, and US economic stagnation. The kind of small industrial components that go by air will be able out-bid other forms of fuel consumption.

What about passenger aviation?

Aviation will use liquid fuel for quite some time, as there will be some oil for many years, some biofuel will be available, and it will always be possible, though perhaps expensive, to synthesize fuel. Eventually substitutes like liquid hydrogen will be substituted if necessary - aviation will have to be dragged kicking and screaming to it, of course.

Won't the transition from oil take a long time?

Let's take trucking: first, it has some time for the transition to rail: trucking's consumption is only 27% of surface non-rail transport. Personal transportation is by far the big user, and personal transportation is mostly optional consumption which will be out-bid by commercial users (optional includes anything not essential, such as commuting that could be replaced by carpooling, albeit with great inconvenience).

Let me say that again: the food-and-goods freight transport network of the modern world uses about 1/4 of oil consumption in the US. Light vehicles overall account for 45% of oil consumption: their utilization could be doubled with carpooling in a matter of months, freeing up whatever fuel was needed by the freight network.

2nd, the transition is already underway: intermodal shipping is replacing trucking, and the trucking industry is under a lot of pressure.

Finally, truck efficiency can be greatly increased: here's a report by the US National Research Council that finds large truck fuel efficiency increases are technologically possible and cost effective.

"The report also estimates the costs and maximum fuel savings that could be achieved for each type of vehicle by 2020 if a combination of technologies were used. The best cost-benefit ratio was offered by tractor-trailers, whose fuel use could be cut by about 50 percent for about $84,600 per truck; the improvements would be cost-effective over ten years provided gas prices are at least $1.10 per gallon. The fuel use of motor coaches could be lowered by 32 percent for an estimated $36,350 per bus, which would be cost-effective if the price of fuel is $1.70 per gallon or higher. For other vehicle classes, the financial investments in making improvements would be cost-effective at higher prices of fuel."

Regarding water shipping: it's cost advantage will allow it to outbid other uses for a very long time. Here's a back of the envelope calculation:

1400 tons of oil to ship 5000 cars - 1400 tons is about 9,800 barrels. At $80/bbl that's $784,000. That's $157/car. If the average car sells for $20,000, that's 0.8% of the cost of the car. That's not much.

Jeff Rubin says that the Chinese have already lost their advantage in manufacturing steel for export to the US because total shipping costs, of both the ores and the finished product,are now so high that domestic American producers are now in a very competitive position again, despite higher labor costs. Doesn't this show that higher energy will make shipping infeasible?

No, it means that in selected areas it will be uncompetitive, which is very different. Commodities like iron ore and coal are very low cost per pound, so that the cost of transportation is a significant fraction of it's value. In competitive industries, a small change in cost makes a large difference, and a rise in shipping costs can tip the balance between regions and manufacturers. Moving high value added products will be relatively unaffected even if energy prices increase by a factor of five or even ten, as the shippng is only a tiny fraction of the cost of a camera or a computer.

On the the other hand, where all manufactures are affected, perhaps because there is a single source on which all are dependent, a change in cost of commodities due to shipping will raise all costs slightly, but have little effect on demand.


1The truck comes with a fast charger, which takes it to 80% charge in about 1 hour. The 6 hour charging time is for the remaining 20%. It might be fast charged during lunch, and slow charged overnight, giving a daily range of perhaps 145 miles ((72+90)*90% of max range).

The battery pack of 280kWh gives about 3.1 kWh/mile. With dense city driving a heavy diesel truck probably doesn't get more than 20% engine efficiency, which would give about 2.6MPG.

Here's a breakeven cost analysis:

miles (AM) 81.0
miles (post-lunch charge) 64.8
total miles per day 145.8
days per year 286
MPG 2.57
gallons per year: 16,216
10 years: 162,162
Fuel cost $1.43
Cost per day $81.20
10 yr cost $232,227

battery cost premium: $100,000
10 yr amort: $142,378

kWh/mile 3.1
pwer/day 453.6
cost/kWh-night (I/C) $0.037
cost/kWh-day (I/C+demand charges) $0.110
Cost per day $31
10 year cost $89,850

Net cost: $0

2 this figure conflicts with the wikipedia figure - IIRC it came from the Maersk line fact sheet, which is temporarily unavailable.


Todd Kes said...

What about nuclear? As long as we are going for high-capacity fuels, might as well go with the one that has the highest of all.

Also, for solar, wouldn't outriggers be better than dragging the panel through water (extra drag reducing efficiency)?

Nick G said...

I don't have any information about the cost-effectiveness of nuclear for merchant shipping - I would be skeptical that it could beat the alternatives.

Don't forget that commercial nuclear plants are built as large as possible to maximize cost-effectiveness. The US Navy doesn't have to worry about cost-effectiveness - it chooses nuclear not on a cost basis, but on an operational effectiveness basis (maximium range without refueling).

The US Navy maintains a rigorous, labor intensive, costly safety program. On the other hand, the Emma Maersk, the largest container ship in the world, sails with only 13 crewmembers!

On solar, I think outriggers are a great idea - you'd certainly want to minimize water friction. On the other hand, I suspect that a structure that's built at a right angle to the path of the ship will mean require a lot of structural strength that would be costly, both in terms of capital investment and weight, and would be difficult to stow in bad weather. Something towed could be flexible, lightweight and easily brought in for storms.

Nick G said...


I added more information on nuclear to the post.

Nigel Williams said...

The challenge we have is that shipping is only part of the oil-fueled entire supply chain. While there may be some cute ships around that can do without any sort of oil (plant-based lubrication for the main shaft bearings, Lloyds-certified electric powered lifeboats, sustainably powered auxiliary power units for emergency steering, lights and pumps etc), come Der Tag the supply chain will in all probability fall over on the land-side, regardless.

Electrical generation or oil supply for dock-side cranes and container shifters, freight trucks and rail will all be in trouble with no oil to run either the vehicles or get the coal to the coal fired fuel stations or the uranium to the nukes,

So dabbling with smart ships with is nice, but frankly it is tokenism.

The three-masted sailing ship conquered the world and never before or since has freight been shifted so efficiently and with so little impact.

While we have time, we should convert to building full-blown steel sailing ships in the 200 to 2000 tonne range with conventional clipper, barque or barquentine rigs. A 'clever' auxiliary power unit could be handy, but since we have got by without such luxuries for all but the last 80 to 100 years we will probably manage ok without.

Its important we don't kid ourselves that some grand solution will come along. We need to cut to the chase and adopt what worked before oil become king of the seas. The oil king is dead, long live the resurrected king of sail!

Nick G said...


I agree - wind power will certainly be important.

Dock-side cranes and container shifters are fixed, and can be electrified easily - the Port of LA is doing it right now (the Port produces an astonishing amount of pollution).

Electrical generation is run by utilities, who are busily buying EVs and plug-ins - they love the idea of powering their own vehicles.

Rail can be electrified in the long-run, and in the short run, doesn't use that much diesel. For instance, it takes only 2 gallons of diesel to transport a ton of coal, on average.

Freight trucks? Well, short haul trucks can and have been electrified, and long haul...well, they'll be replaced by rail.

See for more info.

LG said...

I think you are discarding nuclear based on the most common version of Nuclear, which are the deadly, costly, and large Uranium-fueled Light Water Reactor, where there are technologies currently being developed that are smaller, far more cost effective, such as the very-feasible Thorium-Fueled "Liquid Fluoride Thorium Reactor" (LFTR) which was designed and hypothesized in the '60s but never built because it didn't have nuclear weapons capability in an age where Nuclear Weapons Capability was considered necessary. In Fact,a lifetime electrical for the larges electric consuming state in the US can be held in the palm of the average human hand

LG said...

Also, you seem to be almost fanatically supportive of measures like Wind and Solar (Solar is unsustainable in most of the US, with only the Desert Southwest being consistently sunny enough for it, while Wind is unsustainable in much of the US As well, especially in places where the wind is unpredictable (Read: Midwest, Great Plains, Mountain Northwest, American South, Everything in Between...) Geothermal while the best option also is very geographically dependent, and I doubt many people want to see Dams built every 50 miles of every river.

The best way to deal with pollution is to study LFTRs, and for things like Rail, Truck, and Cars, focus on Carbon-Neutral Fuels, like Methane/Propane/Butane

If you don't know what Carbon Neutral Fuels, it's where we use electrolysis on water and carbon dioxide, and combine the Carbon and Hydrogen to create hydrocarbons, which comprise most of the fuels.

Nick G said...


What do you think is the most viable thorium-based nuclear power program out there?