The Emerald Ace—Japan's Prius of the Sea

Illustration for article titled The Emerald Ace—Japan's Prius of the Sea

Japan, China, and South Korea together dominate 90 percent of the global shipbuilding industry. But compared to the neighbors, Japan is getting killed on production costs. So how do the Japanese respond? By inventing an entirely new kind of ship.


"Eco-ships are prerequisites," said Masafumi Okada, managing director of Mitsui Engineering & Shipbuilding Co., at a recent press conference. "We cannot fight without them." Indeed, while Japan has led the world in shipbuilding since the '70s, the 2008 financial crisis effectively strangled the industry. In response, the Japanese simply changed the rules of the game. The island nation sponsored a revision to the International Maritime Organization's Marpol convention, which gradually reduces the amount of carbon ships are allowed to produce while operating.

And, at the same time, Japan began developing a trump card, the Emerald Ace. It's the first ship of its size in history to employ a hybrid electric power plant, and the first ship ever to produce zero emissions while berthed. That's no typo—that's zero emissions, baby. No carbon whatsoever when the ship isn't moving. It pulls off this amazing feat with the power of the sun.

The Emerald Ace was the very last ship built at the Kobe Shipyard (which now produces submarines exclusively), launched this past March. It's 200 meters long by 36 meters wide, with a 34 meter draft, and it weighs 60,200 gross tons—about a third as large as the Emma Maersk. It's big enough to transport 6,400 passenger cars on its 12 decks at just over 20 knots. Well, not all the decks, the very top deck is reserved for the 768 panels of HIT Double—Panasonic's new double-sided solar cell modules.

Each individual cell produces up to 210W, and each panel of cells can generate upwards of 160kW—about enough to power 50 homes. 2.2MWh of this energy is stored in 324,000 Li-ion rechargeable batteries. Packed into 20-unit modules located at the very bottom of the ship, the batteries double as ballast. These batteries, type 18650, are actually the same kind used to power notebook computers.

When the ship is at sea, it relies on its diesel engines for locomotion, and any excess solar-generated power is used to run the ship's navigation, instruments, lighting, and A/C. Once the Emerald Ace pulls into port, the diesel engines shut down.

"We made a difficult and significant decision after considering recent conditions surrounding (the industry)," President Hideaki Omiya said at a news conference. The benefits are apparent—the ship should shave its emissions by four percent for a two-month trip to Europe. [Break Bulk - Nikkei - AJW 1, 2 - Panasonic - MOL - MHI - Image: Mitsui O.S.K. Lines Ltd.



This sounds amazing, but really expensive to buy and maintain. I mean you do save fuel by shutting down the engines in port, but last I checked, gigantic solar panels weren't exactly free.