Electric harbour tug

[Ianab]

Ports of Auckland's new electric tugboat is now officially in service. It's a full scale harbour assist tug, with a 70 ton bollard pull rating. It's technically a plug in hybrid, as it has a backup diesel, but they expect to only need to use that a couple of times a year.  It's mostly to cover the "What if there is a ship in trouble and the battery is flat?" scenario. The tug was sailed from the shipyard in Korea to NZ under it's own (diesel) power, so it's passed that test already. 

Aboard Sparky the electric tugboat for its first job in Auckland | Stuff.co.nz

[bigblockyeti]

Does it burn off road diesel or bunker fuel?

[Ianab]

I'm guessing regular diesel. We don't have a specific "off road" diesel here. Diesel doesn't have road tax levied on it (diesel road vehicles are taxed separately), so boats / tractors etc don't pay any road taxes. 

The auxiliary diesel is basically just an off the shelf gen-set for backup power. 

[dgdrls]

That Tug is a dandy Ian,

D

[tule peak timber]

nice looking boat. So where does the energy come from to charge it? The article stated zero emissions???Where I live everything is going electric with no apparent power source or distribution capability.Just curious.......

[Ianab]

About 80% of NZ electricity is currently hydro, geothermal or wind. New generation has been wind and geothermal in recent years.

[SwampDonkey]

According to your own government 60% of your generation is fossil fuels (oil, gas, coal), 40% is renewables. Roughly a 3rd of your generation is lost in the conversion process and distribution, especially geothermal. Wind and solar is less than 1% of the mix. Geothermal, hydro and wood are the bulk of the renewable energy. And of course the hydro is the most efficient, you don't need steam.

[samandothers]

Well, that is pretty cool!  It will be interesting to see how it survives its environment. 

[Ianab]

According to your own government 60% of your generation is fossil fuels (oil, gas, coal), 40% is renewables.

2021 figures here show 82.1% renewable. 
https://www.mbie.govt.nz/dmsdocument/23550-energy-in-new-zealand-2022-pdf

That number is set to increase in the future as new generation being built is mostly wind, and some geothermal. 

The "efficiency" is geothermal is really a non issue because you aren't buying the "fuel", it's tapping naturally heated ground water. If you don't recover ALL the energy it's  not a deal breaker. Just like solar panels are only ~20% efficient. Would be nice if that number was better because you would need less panels. But we deal with it because the sunlight itself is effectively free, so only capturing a % is still OK.

It will be interesting to see how it survives its environment. 

Most ships have pretty serious electrical systems already, and some are even hybrid drive. So most of the technology is already in use in the marine industry. It's just getting them all together in the same boat, with a big battery that's new. 

[SwampDonkey]

Makes sense. I see I was looking at energy use not electric generation exclusively. If you look at consumption you see the big picture.

https://www.energymix.co.nz/our-consumption/new-zealands-consumption

[Ianab]

Yeah, I thought about this after I replied. Your numbers for total energy would be right, that's with transport fuel, gas heating, industrial uses etc. 

Thing is the renewable electricity generation is already being increased, although it probably will need a BIG ($$$) pumped hydro scheme as a "dry year" backup it's technically possible for NZ to get near 100% renewable for electricity, even with an increase in electric vehicles. At times during the pandemic NZ was running on 100% renewable electricity, the thermal plants where actually "off". But that's not the normal scenario, they have to fire up some gas turbines just down the road from us to cover cold mornings, and there is a big base load gas / coal plant up at Huntly.  Those plants make up the ~18% that's still fossil fuel based. 

But each system like this moves the % a little bit more in the right direction. So busses, harbour ferries, rubbish trucks etc are gradually being replaced with electric. Technology isn't quite there yet for even short haul aircraft, but being a group of Islands, with some of the shorter routes being under 30 mins, there is serious interest in electric planes. Air NZ basically has a standing order with Airbus for some electric planes, once they get off the drawing board that is. 

The interesting thing about Sparky is that it's the first one built. Ports of Auckland researched the market, and no one was manufacturing them. So they commissioned a suitable design, and had it built. None of the technology involved is new, just the pieces of the jigsaw had never been put together before.