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]

New Boat

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.uk/worlds-first-zero-emission-electric-foiling-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]

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]

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]

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

https://www.artemistechnologies.co.uk/worlds-first-zero-emission-electric-foiling-workboats/

View attachment 130441

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

 

[Benthic2]

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-boats-hybrid-catamaran-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]

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]

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]

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-...er-intent-covering-75-alice-electric-aircraft

 

[HTurner]

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-...er-intent-covering-75-alice-electric-aircraft

Gee, what can go wrong...?

 

[Blissboat]

Have a look at this:

https://electricboats.biz/electric-boats-hybrid-catamaran-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]

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.

 

[Hippocampus]

Think the tech is already here but requires early adapters due to expense. Question in my mind is whether serial or parallel systems will predominate?

Much of the prior posts speak to other applications then the cruising trawler crowd. Given current available systems personally would prefer parallel mated to a LDL Al boat in the 55-65’ range. Such vessels are currently available at reasonable cost. They allow transoceanic range with a tiptoe rather then footprint on the environment.

In my harbor (Plymouth MA) at this moment is a autonomous power trimaran. She crossed the Atlantic (Plymouth to Plymouth) on solar power alone. Had to be towed in due to the restrictions placed on autonomous vessels in coastal waters locally. Even with the best wind and solar don’t think people would accept the time required nor limitations in inclement weather pure electric would impose on the cruiser. So some form of hybrid would seem necessary. Requirements include 200nm days work, ability to operate continuously even in inclement weather, 2500-4000nm range, operator servicing and repair, & no hydrocarbon need when at rest. Diesel/battery seems the most viable choice at present. Question is series or parallel. Diesel engine or genset. AGM or LiFeP or other. Infrastructure will lag. So a for a voyaging recreational vessel ability to function with the current infrastructure makes sense. Ability to not liberate any carbon for any hotel requirements makes sense. Redundancy makes sense. Ability to make onsite repairs and do onsite maintenance regardless of locale makes sense. Looking at those factors think at present hybrid rather than pure electric makes sense. Major question in my mind is what form of hybrid.

 

[Nick14]

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-...er-intent-covering-75-alice-electric-aircraft

This is very interesting, and if it works, would be a meaningful advance for electric flight (which until now seemed to be limited to about half or less of that range or flight duration).

https://www.flightglobal.com/airlin...le-electric-beaver-by-end-2023/148412.article

Two caveats. First, it seems the Eviation plane has not yet actually flown. Much can change between hyperbolic press releases and investor presentations, and reality (not that start-up tech companies ever exaggerate about anything...).

Second, I hope the 'truck based generators' are not simply using fossil fuel to operate them. That would defeat much of the purpose. If you start with a given amount of energy in the gas or diesel used to run the generator, you can't get more energy out of it by converting it to electricity and using it to charge and fly a plane. With conversion losses, there will be less energy in the form of electricity in the plane's batteries than was in the fossil fuel used to charge them (pesky but inviolable laws of physics).

There are other ways of capturing solar energy for propulsion and transport. It's possible to make hydrocarbon fuel (that could be used instead of kerosene, gas, or diesel) out of literally water and carbon dioxide. The problem is carbon fixation takes a lot of energy, and again the laws of thermodynamics mean it doesn't make sense to use fossil fuel to generate the electricity to create hydrocarbon fuel out of water and CO2 (you might as well burn the fossil fuel directly).

But, if you use purely solar power as the energy source for carbon fixation, you can create what is effectively a carbon-neutral liquid fuel. This was announced today as encouraging demonstration of this approach:

https://www.vice.com/en/article/wxndn9/this-solar-tower-generates-jet-fuel-from-water-and-light

https://www.cell.com/joule/fulltext/S2542-4351(22)00286-0

This approach wouldn't be as 'green' as solely using photovoltaic solar energy to charge batteries to use for propulsion. But it does have a number of advantages given the current state of technology.

The liquid fuel produced can be used in existing combustion engines (airplanes, boats, cars, etc.). The liquid fuel could also be transported and distributed using existing infrastructure (pipelines, gas stations, etc.). Importantly, it is also much higher energy density than batteries. Fossil fuels have about 60 times the energy density of lithium batteries, which is one of the main reasons range is inherently limited in battery powered vehicles. This synthetic fuel allows the range and rapid refueling of current fuels. It's also carbon-neutral, which would be a big step in the right direction of avoiding adding more carbon into the atmosphere.

This could be an important transitional approach for transportation while the necessary additional research and development on electric power and storage means continues.

 

[Benthic2]

If you start with a given amount of energy in the gas or diesel used to run the generator, you can't get more energy out of it by converting it to electricity and using it to charge and fly a plane. With conversion losses, there will be less energy in the form of electricity in the plane's batteries than was in the fossil fuel used to charge them (pesky but inviolable laws of physics).
.

It would be great if 100% of the power for the planes came from solar ( or other renewables ) but that probably isn't practical at the moment unless Cape Air has it's own commercial scale solar field.

There are 3 significant points:

#1. As long as the percentage of electricity from renewables is greater than the losses from conversion that you mention, the net effect would be a reduction in carbon footprint for these electric planes.

New England gets its electricity from the following:

Nuclear 25%
Renewables: 9%
Hydo 7%

We also import 19% of our electricity, primarily from Quebec which is primarily hydro power. (I'm going to assume half of that is hydro)

Since aprox 50% of our power is nuke/renewable the planes seem to make sense for this region of the country.

#2 There are additional savings in fuel for transporting the aviation fuel.
Traditional fuels require the use of additional fuel to transport it to the airport. Fuel for the tankers to get crude to a refinery and then fuel for the trucks that bring it to the airport. This is an additional factor that can offset the conversion losses.

#3. This is a total guess so feel free to shoot it down, but I would have to think a commercial electric plant is more efficient than an individual plane engine at extracting power from fuel, so while there are some conversion losses, there would be some gains in the greater efficiency of a huge power plant compared to a single plane engine.

source for % of electricity:
https://www3.epa.gov/region1/npdes/merrimackstation/pdfs/ar/AR-1744.pdf

 

[Simi 60]

I have an as yet unlaunched 55ft cat that I have toyed with the idea of completing one day as an electric hybrid.

Something to bear in mind on boats that don't carry weight well, which multihulls generally don't is the weight of all those panels and battery.

My back of a beer coaster maths based on systems we already have.

Silent 60 power supply as an example if using common aluminium framed 275w panels 42 x @ 20kg each there is 840kg just in panels, let alone framework and cabling
If using near new 2nd hand that works out cheap at around $2500 in panels

Batteries to match it's (standard) 145kw bank will come in at 950kg just in cells alone if using EVE280 as an example.
That's $30,000 there
If using Winstons, closer to $60,000

If going the 225 ah option let's say at a guess 1800kg and EVE $50,000 Winston $100,000

Add in inverter chargers, mppt, BMS wiring, framework, boxes etc it could easily get to 2500kg / 5500lb
Cost if using 5 X Victron 10,000va inverter chargers and Midnite Classic mppt
Approx $80,000

And you still need to carry a big Genset and a diesel load to run it let's say a 50kva head on a Cummins B series and 650 litres of diesel across 2 alloy tanks so another 1000 kg

Things are adding up in weight and most definately cost
Not toying with the idea anymore
Diesel mile's are still cheap (-;

 

[Simi 60]

As an aside, can lifepo4 cells be used in an electric boat?
It's the only option I would consider safe.

I notice that silent yachts do not use lifepo4 but instead use lithium ion NMC chemistry

A bit of info on the differences here
https://www.evlithium.com/lifepo4-battery-news/901.html

 

[rslifkin]

As an aside, can lifepo4 cells be used in an electric boat?
It's the only option I would consider safe.

I notice that silent yachts do not use lifepo4 but instead use lithium ion NMC chemistry

A bit of info on the differences here
https://www.evlithium.com/lifepo4-battery-news/901.html

They certainly can be. They're just not quite as energy dense, so space and weight are bigger issues.

 

[Seevee]

All of this electric crap is interesting, but it's miles away right now and not a viable replacement for diesel and gas for trucks, cars, boats and planes.



Most of it is way over subsidized by YOUR tax dollars and we need to slow up the transition to a reasonable pace, which will be several years away.



Today, still the vast majority of new cars sold are gas and in the current used market it's about 100% gas cars. Big vehicles like boats, trucks and planes, just aren't even close.


Yes, we'll get there, but if we try to expedite this we can easily end up on the short end of the stick.


I'll keep my electric bike, but that's it.



Drill, baby Drill!

 

[Chris Leigh-Jones]

Can I chip in here? My claim to a voice is we have been involved in the recent design and build of a 78 foot hybrid electric boat. The end result is not what we initially envisioned but maybe as good as recent technology and application would allow. I'll throw out a number of points for consideration.

- with existing battery (LiPO) EV technology then the energy storage capacity limits propulsive applications to low speed harbor activities and silent maneuvering.
- any yacht claiming greater than this on electric will be lightly built to save propulsive power and unsuited to anything other than recreational cruising in sheltered waters.
- charging of any significant battery capacity is a problem. 3 phase shore power or hybrid drives are the solutions.
- conversion losses are killers. Solar to battery to propulsion, shore power to battery to propulsion at about 5/10% per conversion.
- solar is no good for propulsion, only maintenance loads and anchorage. We have 6.5 kW theoretical peak, still insufficient for overall needs ongoing. Solar improvements will be marginal as we are fighting the basic physics of the process, even with high band width prevoskites. Cost though, may improve further (thanks China).
- new battery technology is, on the short-term post prototype horizon (think Na, S, graphene ....) that will produce the 1000 mile EV 20 minute charge and a capable electric boat propulsion for coastal operations in the next 3-5 years.
- I welcome the day of reliable podded electric drives and "place anywhere" DC generators creating a serial hybrid system that is again, reliable. Maneuverability would be superb and space efficiency similarly creative. No rudders either though following seas may be interesting!
- lastly, with a system centralized around BIG batteries (140kWh), rather than a generator, we hope to see long silent periods at anchorage with much lower diesel maintenance. Time will tell.

Anyhow, some thoughts to mull over a beer or four.

 

[O C Diver]

This is very interesting, and if it works, would be a meaningful advance for electric flight (which until now seemed to be limited to about half or less of that range or flight duration).

https://www.flightglobal.com/airlin...le-electric-beaver-by-end-2023/148412.article

Two caveats. First, it seems the Eviation plane has not yet actually flown. Much can change between hyperbolic press releases and investor presentations, and reality (not that start-up tech companies ever exaggerate about anything...).

So I guess the other question is how long does it take for the FAA to aprove a new aircraft with previously uncertified engines and fuel to be certified for commercial passenger use?

Ted

 

[Seevee]

So I guess the other question is how long does it take for the FAA to aprove a new aircraft with previously uncertified engines and fuel to be certified for commercial passenger use?

Ted

There's a few factors.... and a lot of politics involved. To get a "type certificate" it take a boat load of money and testing, after which the FAA will consider it. Most likely revisions and extra time and money and it goes on.

Then there's the approval for part 135 or air taxi, for which any certificated aircraft will work, or the part 121 airline operation which is more demanding. Several years, likely.