Electric Boats

[IfItsWorthDoing]

This new thread is very timely, thanks. We are in fact building a fossil fuel free trawler this year. It is basically a 34ft/5ton sailing cat lacking mast and rigging.

It is normally specc’d with twin 15hp diesels but we will instead have 3 x 6kW pod drives, with about 72kWh of LiFePO storage, 20 sqm of solar and 3 wind turbines. There will also be a kite sail for when the wind is blowing from a suitable quarter.

We will be using composting heads so will be able to repurpose both diesel and black water tank spaces.

Our dinghy (11.2ft GRP/carbon mix) will likewise have electric propulsion, solar on its T-top and a smaller kite sail.

Both mothership and tender are designed to cruise at 6kn consuming 6kW/h and will be used for coastal hops in the Mediterranean with an occasional longer passage (e.g. 200nm from Menorca to Sardinia, and onwards to Sicily or Tunisia).

They will be featured in a series of articles in Powerboat & RIB from November 2022 onwards.

Over the next two decades we expect to at least double onboard battery capacity using next-generation technology while our motors should easily last with minimal maintenance. At that point fossil fuel should be nigh unaffordable to anyone not belonging to the wealthiest one percent …

[N4061]

Great timing and looking forward to hearing more about your new boat. Will this be a new build or retro-fit of an existing boat?

John T.

[IfItsWorthDoing]

Ours is a new build @JohnT. If it works out the manufacturer is likely to start building it in series as a new trawler variant.

[darkside]

For electric foiling boats I think Artemis are well ahead of Candela for what most here are looking for.

https://www.artemistechnologies.co.u...ing-workboats/

[JRO]

I think this really should say hydrogen-electric vessels, trucks, cars etc.. The future is hydrogen to create electricity to create torque.
The decisions that need to be made is best ways to distribute hydrogen throughout the world.

[twistedtree]

Originally Posted by JRO

I think this really should say hydrogen-electric vessels, trucks, cars etc.. The future is hydrogen to create electricity to create torque.
The decisions that need to be made is best ways to distribute hydrogen throughout the world.

There was a good discussion recently about hydrogen as a fuel in another electric boat thread here. A quick search should locate it.

[Kit_L]

Joining this thread; in time we will be hybrid-electrifying Suu Kyi. A bit like hybrid cars having the smallest carbon footprint of all vehicles (considering manufacture of batteries and the boat itself, whole of life), I think hybrid boats are the foreseeable future. Thanks to the TF team for creating this thread; it's exciting.

By hybrid, I mean small DC or AC generator coupled to a modest Li-Fe-PO4 battery bank, and solar panels—our vessel is perfect for this. We have done some initial calculations, and our efficient top speed will be 9Kn, rather than the 15kn it is now, and that's a sacrifice I make happily.

[JESSEDIVER49]

Originally Posted by KnotYet

As much as internal combustion power is a fad, yes.

Steam was the motive power of choice until internal combustion took over.
IC had many detractors until there were robust power plants and fuel
supplies. It was a new concept that had many negatives the steam didn't.
Couldn't use coal, etc. The new fuels were toxic, expensive and technically
harder to create.

That 'fad' had most of the kinks worked out now as steam had before it.

Electric motive power is already practical for many situations and will only
become more so. Hydrogen still has a long way to go as a widespread fuel
for electric fuel cells but at least it is the most abundant element.

I agree with your analogy - never underestimate our ability to bring technology to the next level. It's happened so many times before. Just look at the this James Webb Space telescope now orbiting around the sun and what it has been able to do. It's a wow! Seems to me is all we need is a breakthrough in battery technology.

[Nomad Willy]

Originally Posted by darkside

For electric foiling boats I think Artemis are well ahead of Candela for what most here are looking for.

https://www.artemistechnologies.co.u...ing-workboats/

Attachment 130441

I think Boeing did this in the 60’s w a larger boat and a gas turbine engine. Better looking too.

[Benthic2]

Originally Posted by Portage_Bay

That leaves dockside charging. I'll say I want at least 500 nautical mile range with adequate reserve. How long will it take to recharge the propulsion bank at 30 AMPs, at 50 AMPs? How many of the smaller marinas in my cruising area that I will need for support will be able to re-wire their facilities for larger, beyond 50 AMP, service so that a boat can recharge overnight?

Sent from my SM-T500 using Trawler Forum mobile app

What percent of boaters would require a 500+mile range ? Totally guessing here, but I would guess that 75% of boaters only use their boats for a few hours each weekend. Many boaters just putter out to the sandbar and put out their big umbrella.....or head over to the dockside restaurant for a meal....cruise around the harbor, etc. This type of boater would probably be fine with 4-5 hours of run time and then 5-6 days to recharge.

I think some people are just resistant to new technology and then look for reasons to shoot it down. The first solution is obviously not going to work for every boater. The hardcore fisherman with a 48 foot Egg Harbor that cruises 8 hours at 25 knots to the fishing grounds may never be able to make the transition to electric boats, but the people that troll for trout at 2 knots in a 20 foot boat can probably transition now, and every time someone does make that transition, the knowledge base, technology and general acceptence get advanced a little more.

Most significant advances in technology are not a point in time, but an evolutionary process. Think of sail to power, wood to fiberglass, charts to chartplotters. I had an uncle that worked for Hewlett Packard in the 70's when they developed a calculator that cost $800 and most people thought that it was a waste of time and money ( except NASA ), and would never catch on....... Everyone has a different risk tolerance. Some people like to be on the bleeding edge of technology while some people are troglodytes....Some people need twin 1000 horsepower engines, and some need a trolling motor.

Enjoy the transition as a participant or a spectator. Jump in when and if you are ready, but don't discourage those that are willing to push the envelope today. We will all benefit from their efforts tomorrow.

[Kit_L]

Have a look at this:

https://electricboats.biz/electric-b...-powercat3400/

The variable speed generator is the key to range anxiety. Yes, you'll still be burning diesel, but much less than the 2 x 285hp Volvo Pentas we have now, and only one generator needed. Our current 6Kva Kohler uses about 2.5 litres an hour, but I don't know what the variable speed ones use per hour.

I have contacted the NZ site above to see what performance is possible on the 10.5m cat in the video if running with the generator on, and using that to power the batteries (but without using battery power). Thinking long distance here. It might be quite slow, but let's see what they come back with.

[Portage_Bay]

Originally Posted by Benthic2

What percent of boaters would require a 500+mile range ? I think some people are just resistant to new technology and then look for reasons to shoot it down.....

....Jump in when and if you are ready, but don't discourage those that are willing to push the envelope today. We will all benefit from their efforts tomorrow.

I ask you to re-read my post and pay attention to the opening sentence

Another consideration is support infrastructure with respect to charging. I'll speak to my cruising grounds of Wa State, BC and Ak.

And the closing sentence

I'm a proponent of electric power where appropriate but this geographic area is not ready nor is it likely to be to support electric propulsion for a very long time.

I am not looking for reasons to shoot down electric propulsion. I am not resistant to the technology. I look forward to the days of quieter, cleaner cruising. I am raising concerns about the viability of electric propuslion for my cruising grounds and style. As is the style for many of the cruisers in my area. Because onboard solar here with current technology isn't going to do the job.

Yes, the 500 nm range is on the long side. Here's why. A common leg when headed north is Port MacNeill BC to Prince Ruper BC which is 285 nm on a direct route. Add in some exploration of inlets that are tens of miles long and I'm looking at the range I want.

Looking at local cruising of the San Juans and Gulf Islands a typical day's run would require recharging at night. Imagine the load on the infrastructure when dozens of boats require charging every night.

You make good points about the resistance to the adoption of new technologies. Please don't confuse me with someone who is against electricl propulsion just because it's different that what I'm used to.

Sent from my SM-T500 using Trawler Forum mobile app

[rslifkin]

Originally Posted by Portage_Bay

Looking at local cruising of the San Juans and Gulf Islands a typical day's run would require recharging at night. Imagine the load on the infrastructure when dozens of boats require charging every night.

That is a concern, but at the same time, other loads like air conditioning are highest during the day. So in many places, there's at least some excess grid capacity once the sun goes down and things cool off.

[backinblue]

It's the same concern with electric cars. Probably more psychological than reality. Most people never drive more than 100 miles at a time, but they angst at the 400 mi range limit.

[mcarthur]

Originally Posted by Kit_L

Joining this thread; in time we will be hybrid-electrifying Suu Kyi. A bit like hybrid cars having the smallest carbon footprint of all vehicles (considering manufacture of batteries and the boat itself, whole of life), I think hybrid boats are the foreseeable future. Thanks to the TF team for creating this thread; it's exciting.

By hybrid, I mean small DC or AC generator coupled to a modest Li-Fe-PO4 battery bank, and solar panels—our vessel is perfect for this. We have done some initial calculations, and our efficient top speed will be 9Kn, rather than the 15kn it is now, and that's a sacrifice I make happily.

Any idea of your long-range speed? Obviously depends on the genset size...

[Kit_L]

Any idea of your long-range speed? Obviously depends on the genset size...

The variable-speed generator used in the NZ power cat I linked to is 60Kw; that's ten times the output of our current fixed-speed Kohler. I have asked the NS dealer to indicate the boat speed (the demo. boat that uses that generator is a 10.5m aluminium cat) using only the generator, and what speed that gives, as well as fuel consumption at that speed.

Hybrid diesel–electric has many losses, you'd imagine. I will post when he replies.

[Benthic2]

Massachusetts based Cape Air has agreed to purchase 75 electric commuter planes from Eviation. The plane carries 9 passengers, has a range of 500 nautical miles, a speed of 250 knots and needs only 30 minutes to recharge for each hour of flight time. Recharging will be done by truck based generators between flights.

If it can work for planes it should be able to work for boats.

https://www.futureflight.aero/news-a...ctric-aircraft

[HTurner]

Originally Posted by Benthic2

Massachusetts based Cape Air has agreed to purchase 75 electric commuter planes from Eviation. The plane carries 9 passengers, has a range of 500 nautical miles, a speed of 250 knots and needs only 30 minutes to recharge for each hour of flight time. Recharging will be done by truck based generators between flights.

If it can work for planes it should be able to work for boats.

https://www.futureflight.aero/news-a...ctric-aircraft

Gee, what can go wrong...?

[Blissboat]

Originally Posted by Kit_L

Have a look at this:

https://electricboats.biz/electric-b...-powercat3400/

The variable speed generator is the key to range anxiety. Yes, you'll still be burning diesel, but much less than the 2 x 285hp Volvo Pentas we have now, and only one generator needed. Our current 6Kva Kohler uses about 2.5 litres an hour, but I don't know what the variable speed ones use per hour.

I have contacted the NZ site above to see what performance is possible on the 10.5m cat in the video if running with the generator on, and using that to power the batteries (but without using battery power). Thinking long distance here. It might be quite slow, but let's see what they come back with.

Thank you. That's what I'm talking about . . .

[twistedtree]

Originally Posted by Kit_L

The variable-speed generator used in the NZ power cat I linked to is 60Kw; that's ten times the output of our current fixed-speed Kohler. I have asked the NS dealer to indicate the boat speed (the demo. boat that uses that generator is a 10.5m aluminium cat) using only the generator, and what speed that gives, as well as fuel consumption at that speed.

Hybrid diesel–electric has many losses, you'd imagine. I will post when he replies.

Keep in mind that a variable speed generator driving a hybrid system is really no different than a variable speed propulsion engine driving a propeller directly, except the hybrid is less efficient.


Since a hybrid drive is fundamentally less efficient, it only helps if it enables other ways to gain back the losses, and hopefully more to create a net gain. On a boat, the advantage is being able to harness solar and use it for propulsion, and by storing shore power that is hopefully more efficiently generated than you can do onboard.


If you figure that the hybrid drive is 10-15% more loss vs direct drive, then the break even point is when you can produce 10-15% of you propulsion power from solar. So that's an interesting benchmark to look at in this and other designs.