Saturday, November 29, 2014

Setting a Course for Carbon-Free Shipping

The world’s first electric ferry will enter service in Norway’s Sognefjord in 2015. It will have a capacity of 360 passengers and 120 cars without any emissions. (Credit: Click to Enlarge.
In conjunction with Fjellstrand, a Norwegian shipyard, Siemens has developed the technology for the world’s first electrically-powered car ferry.  The fact that the electric ship, which will enter service in 2015, causes no carbon dioxide emissions is in part due to the electricity mix in Norway.
Fjellstrand and Siemens engineers have come up with a simple idea to address the ferry’s batteries’ range problem.  “We want to recharge the batteries at the docks after each trip,” Moen explains.  Still, this will give the ferry operator only ten minutes for recharging while passengers and vehicles disembark.  The problem is that the power grid in the region is relatively weak, as it was designed to provide electricity only to small villages.  “Briefly consuming so much energy from the medium-voltage system to recharge the ferry batteries would cause the washing machines in all the houses in the area to stop running.  Obviously we can’t do that to the residents here,” Moen explains.

Siemens’ experts therefore plan to install one lithium-ion battery at each pier to serve as a buffer.  The 260-kWh unit will supply electricity to the ferry while it waits.  Afterward, the battery will slowly recoup all of this energy from the grid until the ship comes back again to drop off passengers and recharge.  The charging stations will be housed in a small building about the size of a newsstand.  The ship’s batteries will be recharged directly from the grid at night after the ferry stops operating.  This solution is both simple and ingenious.  “Under the prevailing conditions, it was the only feasible way of building and operating a battery-powered ferry,” says Moen.  “Otherwise we would have had to expand the entire grid, and that would not have been possible due to the high costs of such a project.”

It isn’t just its drive system that makes the new ferry so environmentally friendly.  Its electric motors are of course virtually silent and don’t burn any fossil fuels.  They also don’t produce any pollutants.  By contrast, a conventional ferry traveling the same route consumes around one million liters of diesel fuel and emits 2,680 tons of carbon dioxide and 37 tons of nitrogen oxide each year.  Nevertheless, the real reason for the positive environmental balance is the electricity mix.  “The electricity in this area is generated exclusively by hydroelectric plants,” says Moen.  “This makes the energy the ferry uses cheaper than diesel.  It also means the ship doesn’t emit even one gram of carbon dioxide, directly or indirectly.”
Moen believes the great potential offered by electric ships can already be exploited today. “There are 50 routes in Norway alone which battery-powered ferries could operate profitably,” he says.  “And we expect that batteries will become considerably more efficient and less expensive over the next five years.”  He also points out that Norwegians are very enthusiastic about innovations.

Read original article at Setting a Course for Carbon-Free Shipping

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