Some prior posts after the jump
From IEEE Spectrum:
Batteries still can’t scale up to power the world’s biggest vessels
Just about everything you wear or use around the house once sat in steel boxes on ships whose diesel engines propel them from Asia, emitting particulates and carbon dioxide. Surely, you would think, we can do better.Although it is the now sadly deceased David J.C. Mackay (Cavendish Lab, Regius Prof, polymath, probable genius etc.) I mention if someone wants to talk to me about energy i.e. "have you read his book?", Vaclav Smil is almost in the same league.
After all, we’ve had electric locomotives for more than a century and high-speed electric trains for more than half a century, and recently we have been expanding the global fleet of electric cars. Why not get electric container ships? Actually, the first one should begin to operate this year: the Yara Birkeland, built by Marin Teknikk, in Norway, is not only the world’s first electric-powered, zero-emissions container ship but also the first autonomous commercial vessel.
But don’t write off giant diesel-powered container ships and their critical role in a globalized economy just yet. Here is a back-of-the-envelope calculation that explains why.
Containers come in different sizes, but most are the standard twenty-foot equivalent units (TEU)—rectangular prisms 6.1 meters (20 feet) long and 2.4 meters wide. The first small container ships of the 1960s carried mere hundreds of TEUs; now Maersk’s Triple-E class ships load 18,000 TEUs, and OOCL Hong Kong holds the record, at 21,413. At the “super slow steaming,” fuel-saving speed of 16 knots, these ships can make the journey from Hong Kong to Hamburg in 31 days.
Now look at the Yara Birkeland. It will carry just 120 TEU, its service speed will be 6 knots, its longest intended operation will be 30 nautical miles—between Herøya and Larvik, in Norway—and its batteries will deliver 7 to 9 megawatt hours. Today’s state-of-the-art diesel container vessels thus carry 150 times as many boxes over distances 400 times as long at speeds three to four times as fast as the pioneering electric ship can handle.
What would it take to make an electric ship that can carry 18,000 TEUs? In a 31-day trip, today’s efficient diesel vessel burns 4,650 metric tons of fuel (bunker or diesel), each ton packing 42 gigajoules. That’s an energy density of about 11,700 watt-hours per kilogram, versus 300 Wh/kg for today’s lithium-ion batteries, a nearly 40-fold difference.
The total fuel demand for the trip is about 195 terajoules, or 54 gigawatt-hours. Large diesels (and those in the ships are the largest we have) are about 50 percent efficient, hence their useful propulsive energy demand is about 27 GWh. To match that demand, large electric motors operating at 90 percent efficiency would need about 30 GWh of electricity.
Load the ship with today’s best commercial Li-ion batteries (300 Wh/kg) and still it would have to carry about 100,000 metric tons of them to go nonstop from Asia to Europe in 31 days....MORE
Previously on Smil:
Meet The Guy Who Taught Bill Gates About Energy
"Vaclav Smil Takes on Jeremy Grantham Over Peak Fertilizer"
Vaclav Smil: Planet of the Cows
Our readers may know Mr. Smil as a big deal in the Thinking-about-Energy biz. Here he is thinking about bovines....
Previous Smil at Spectrum:
Vaclav Smil: "Advanced Economies Must Still Make Things"And non-Spectrum Smil:
Vaclav Smil: "Cellphones as a fifth-order elaboration of Maxwell’s theory"
Calories In, Kilowatts Out: Apparently Sweating Is Important
"Happy Birthday to Moore’s Law" (plus party pooper Vaclav Smil)
Vaclav Smil On Energy: "Revolution? More like a crawl"
Bill Gates on The Most Astounding Statistic In Vaclav Smil's New Book
Bill Gates Summer Reading List (Vaclav Smil has two entries)
Energy--'Vaclav Smil is Correct: Never Forecast'
Energy: "The man who’s tutoring Bill Gates … "
Vaclav Smil: "In energy matters, what goes around, comes around—but perhaps should go away"
Vaclav Smil: "The Manufacturing of Decline"
Serious Thinking on Energy: An Interview With Dr. Vaclav Smil
A Major Piece: "Why the tech revolution isn’t a template for an energy revolution"
Bill Gates Reviews Vaclav Smil's "Prime Movers of Globalization: The History and Impact of Diesel Engines and Gas Turbines"
