from the how-long-is-the-extension-cord? dept.
Powered entirely by batteries, Ellen is something of a Tesla among ferries. Fully charged, the 60m vessel can sail 22 nautical miles with up to 200 passengers and 30 cars onboard.
[...] Totalling 4.3MWh this is the largest battery capacity at sea and equivalent to the average amount of electricity a UK household consumes each year.
[...] After a 70 minute voyage, Ellen arrives at the harbour in Søby and moors alongside the charging station.
A mechanical arm plugs in and recharges the batteries in less than 25 minutes with clean energy supplied by local wind turbines.
[...] "We are paying maybe 25% of what you would pay for running a similar diesel vessel." says Ms Heinemann. "So that's the significant saving."
Electric propulsion is beginning to spread from passenger cars to trucks and now ferries.
(Score: 0) by Anonymous Coward on Wednesday January 15 2020, @02:55AM
More from the BBC link:
"It's maybe 40% more expensive than a conventional diesel vessel," Ms Heinemann says.
"Then you still have the transformer and the electrical infrastructure. So in terms of establishing an electrical vessel, we are looking at a significantly higher cost."
So while battery power is certainly greener, is it commercially viable? The team believes so.
"Some say within 14 months you break even and then it's saving from then on. We're being a little bit more conservative and saying maybe four or five years," says Ms Heinemann.
At Søby Shipyard, where Ellen was built, chief executive Roar Falkenberg thinks costs will come down.
"Ellen was a prototype. I think when we build the next Ellen, it will be only cost a bit more than a normal ferry. And if you look three to five years ahead, I think the price will be the same."
(Score: 4, Interesting) by barbara hudson on Wednesday January 15 2020, @03:08AM (2 children)
SoylentNews is social media. Says so right in the slogan. Soylentnews is people, not tech.
(Score: 2) by MostCynical on Wednesday January 15 2020, @07:44AM (1 child)
kWh [epsilor.com] vs MWh
"I guess once you start doubting, there's no end to it." -Batou, Ghost in the Shell: Stand Alone Complex
(Score: 0) by Anonymous Coward on Wednesday January 15 2020, @09:09AM
That is just one pack. While I can't find as much info as I would like, which I suppose is to be expected, everything I'm finding indicates batteries on the order of a couple MWh (and I imagine this is quite conservative).
http://large.stanford.edu/courses/2013/ph241/ditiangkin1/ [stanford.edu] mentions an ohio-class sub having 2.6 MWh capacity, citing an IEEE article I don't have access to.
https://www.suicideslabs.com/dw/arc/papers/223v1r2a.pdf [suicideslabs.com] has a table on page 12 (40 according to my pdf viewer) - indicating > 1.5MWh
https://fleetsubmarine.com/battery.html [fleetsubmarine.com] mentions WWII subs having a pair of 126-cell batteries with a combined discharge rate around 15,000A - while it doesn't mention capacity, the discharge rate is comparable to the trident cells above.
All of that is good old-fashioned lead-acid, and while I don't have evidence handy for larger capacities in more modern submarines, it certainly seems plausible that they exist.
(Score: 2, Interesting) by anubi on Wednesday January 15 2020, @03:49AM (1 child)
Ships sometimes need a gravitic mass at the lowest part of a ship for stability reasons.
Maybe the weight and size of the battery bank is inconsequential for this application.
Just make water doesn't get in it. As it will likely be submerged in use, which in itself may be a plus as under rapid charging, the battery may need to be cooled.
Could be an interesting design.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2) by corey on Thursday January 16 2020, @08:51AM
Interesting idea, that is true about ballast.
I think this is one of those "about bloody time" things. Ships are good at hauling heavy loads, batteries are just that.
(Score: 2) by Gaaark on Wednesday January 15 2020, @03:50AM (1 child)
Ellen McEllenFace?
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 0) by Anonymous Coward on Friday January 17 2020, @09:22AM
Just sayin'. Mix up your references a 'lil.
(Score: 0) by Anonymous Coward on Wednesday January 15 2020, @06:20AM (2 children)
An overhead wire would work fine. If it runs DC with the right polarity, it even suppresses corrosion.
Another way is to reel out a cable along the bottom.
(Score: 0) by Anonymous Coward on Wednesday January 15 2020, @09:21AM (1 child)
The other ships in those lanes would likely not appreciate smacking into overhead wires. I don't know the depths involved, but the route is on the order of 17km/10mi or so; not a simple river crossing. To support cable over a span like that would need lots of towers, again in a likely shipping lane (as a point of comparison, it looked like the longest/highest spans in the world were on the order of a couple km). Several miles of cable would also be quite a lot to spool on board, pay out, and retrieve - and last any length of time. No experience in these areas, but strikes me as terribly impractical - reasonable to do on land, but the sea is a different beast.
(Score: 1, Funny) by Anonymous Coward on Wednesday January 15 2020, @02:08PM
A more practical (and greener) solution would be to take advantage of wind power by placing a sail on the boat and using the batteries onboard as a power assist to blow a fan into the sail.
(Score: 0) by Anonymous Coward on Wednesday January 15 2020, @10:43AM (1 child)
Hope there's lots of spare range. Because if something goes wrong it's not always easy to stop in the middle of an ocean journey...
(Score: 0) by Anonymous Coward on Thursday January 16 2020, @12:44AM
They aren't going very far from their home port so if they have a problem then a tug can get to them in short order. It isn't like they are doing Atlantic crossings.