Monthly Archives: March 2019

Can Ocean Going Ships Be Battery Equipped?

Wind and Solar energy assumptions by the warmers greatly exceeds these sources actual capability.  Let’s look at how renewable energy plays out as a possible replacement of diesel fuel for container ships.  This is discussed in a 27 Feburary 19  IEEE Spectrum  posting by Vaclav Smil  titled “Electric Container Ships Are Stuck on the Horizon”.   It opens up with the following:

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.

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.

When warmers quote emissions from battery powered engines, they always tell us that such engine is “Zero-emissions”.  Most batteries charges are provided by fossil fuel power plants.  So the real emissions are never zero but rather those emissions from the fossil fuel plant that created the energy to charge the batteries.  And more from the posting:

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..  Maersk’s Triple-E class ships load 18,000 TEUs.   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.

 The author makes a comparison with a hypothetical battery powered container ship and an actual diesel-powered container ship:

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. Those batteries alone would take up about 40 percent of maximum cargo capacity, an economically ruinous proposition, never mind the difficulties involved in charging and operating the ship. And even if we push batteries to an energy density of 500 Wh/kg sooner than might be expected, an 18,000-TEU vessel would still need nearly 60,000 metric tons of them for a long intercontinental voyage at a relatively slow speed.

The conclusion is obvious. To have an electric ship whose batteries and motors weighed no more than the fuel (about 5,000 metric tons) and the diesel engine (about 2,000 metric tons) in today’s large container vessels, we would need batteries with an energy density more than 10 times as high as today’s best Li-ion units. 

That’s a tall order indeed: In the past 70 years the energy density of the best commercial batteries hasn’t even quadrupled.

I have read accounts of “fuel anxiety” that electric car drivers get as they wonder if they can make the next recharging station before the batteries are totally discharged.  Can you imagine the anxiety the ship’s captain might have knowing there are no recharging stations in mid ocean.

If the container ships were equipped with a nuclear reactor as in our navy’s submarines, we could probably match the performance of the diesel container ships and actually have a no carbon emissions ship.