The Future of Solar and Wind Powered Shipping

[OKIsItJustMe]

http://www.technologyreview.com/view/516661/the-future-of-solar-and-wind-powered-shipping/

[font face=Serif]
Kevin Bullis
June 28, 2013

[font size=5]The Future of Solar and Wind Powered Shipping[/font]

[font size=4]Solar and wind power could reduce fossil fuel consumption in shipping.[/font]

[font size=3]People like to build solar whatnots, even if they don’t make much practical sense. Solar cars. Solar planes. This week I stepped aboard the world's largest solar-powered ship, a 100-metric-ton catamaran that, last year, motored around the world without using any fuel. Now it’s being used for a scientific expedition—the fact that it doesn’t emit exhaust gases makes it good for collecting data about the ocean and atmosphere.

Exclusively solar-powered ships almost certainly aren’t the future of shipping, but solar power could help reduce emissions.

…

But while solar power likely won’t replace fossil-fuel power outright in large cargo ships, it could work for some smaller ships, or to help lower fuel consumption on the big ones. D’Aboville says solar panels might work well for small ferries—indeed a company called SolarSailor already operates such ferries. One option is combining solar and wind power to produce some or all of the power for a ship.

A recent demonstration project used solar panels to provide about 10 percent of the electricity for a cargo ship to reduce emissions from the low-grade fuel such ships use. Such systems could also reduce shipping costs by reducing the amount of fuel consumed. Prices for fuel are so high now that some shipping companies are slowing down their ships to the point that they’re travelling slower than old sail-powered ships. That could open an opportunity for wind powered ships, at least for some applications.[/font][/font]

[wtmusic]

1. There is no future in solar- and wind- powered shipping.

but you knew that.

The headline might make people kinda think that the sun can actually move a cargo ship.

You knew that.

It can't, and you knew that, too.

[pscot]

2. 76 days from San Francisco to Boston

by Northern Light in 1853





Tanker with conventional sails


Solar "sails"


sky sail

[oldhippie]

3. I like the solar sail tanker, but .......

... a little back of the envelope math says ....



.... it's gonna be tough.

Let's see, Wiki says that the Alaska Class VLCC (typical big oil tanker) has a 31,658 BHP diesel engine for propulsion. That's equivalent to 23.6 MW of electrical power. So it needs a 23.6 MW solar array to power it. A 23.6 MW solar array would cover about 2 million sq ft (if you could point it directly at the sun.) But the whole ship is only 987 ft long and has beam of 166 ft. Even with some cool cantilevering you might get about 164K sq ft, or about 2 MW of solar power.

So, the total ship covered with solar panels would give it less than 10% of the power it needs to move at it's current rate. You would probably have to sit somewhere in the ocean with good sun for 12 sun hours or so (two days of actual time), figure out a way to store that energy (in heavy batteries, maybe?) and then you could move for about an hour before you ran out of energy.

That's gonna be really hard to compete with just burning a small bit of the cargo to power the diesel engine continuously.

But I'm sure the Church of the Renewables will find a way to make it work.

(Disclaimer - I just did that math on my iPhone calculator after two glasses of wine before dinner. I hope I didn't screw up too bad! )

[OKIsItJustMe]

4. I may be wrong but…

…I believe the idea is that the solar sails provide an assist (not sole power.)

http://solarsailor.com/

[oldhippie]

10. But why take on the weight and cost penalty .....

... of the panels, support equipment, big electric motors, the gearbox need to match slow speed diesel with electric motors, etc., to get a less than 10% assist, when you already have 1.5 million barrels of energy dense liquid fuel in your hold? Yes, it is great to cut down on the carbon emission, but at what cost?

I notice the website says that a study of the economic benefits "solar sail" concept would be ready in June of 2012, but there is no sign of it. That might be telling. I am all for use of PV and other solar power for almost any application, but it has to make sense.

[OKIsItJustMe]

14. I find it difficult to imagine the equation works out that badly

However, that's just a failure of my imagination.

[pscot]

5. That's a metaphor for the whole renewable vs fossil fuels

argument. Renewables may keep the lights on, but we won't be going anywhere. People have a hard time grasping the scale of the problem.

[NickB79]

6. People think we can maintain perpetual economic growth

So long as we just replace the coal and gas with solar and wind.

It's hard for people to realize that perpetual economic growth cannot be sustained indefinitely, no matter what energy source we sub in.

[Not Sure]

7. I think you nailed it

That's why we not only need alternative sources of energy, we also need improvements in efficiency.

[pscot]

8. That's all they hear from

government and business. Why should they think otherwise.

[wtmusic]

9. And the PV cells in the picture would be enough to heat the crew's quarters.

Thanks for that contribution of sanity.

[Yo_Mama]

11. Is about zip?

Really, I don't know whether to laugh or cry.

There are very good, workable uses for solar and wind power, and to be focusing on an area in which they can be of little use????

[wtmusic]

12. I wonder how long someone spent mocking up that stupid picture...

and how much energy was used.

[Yo_Mama]

13. It was putting the word "cargo" in there

That made my brain cells convulse.