Jimmy Cornell goes Electric, with a Cat

[NaClyDog]

Originally Posted by Adelie

Uma did fine without a generator for 5+ years. The generator was acquired specifically so they could cross the Arctic circle to Svalbard.
Before that they spent 3yr in the Caribbean and crossing the Atlantic without regen or mostly without regen. My sense is that they did a lot of charging at marinas when they were working on the boat and at marinas anyway. Otherwise they were usually anchored out and depended on solar for house and traction.

Recently they have been spending a lot of time at high latitudes, and off season for a lot of it so, yeah, they were marina hopping.

Other than gasoline/petrol nothing has the near the combined benefit (energy density and specific energy) of diesel.
Nothing will replace it for the performance it provides. Some people are still trying to find ways to eliminate or minimize it's use for various reasons. People that are unwilling to accept the tradeoffs of using EP don't need to, fossil fuel are still widely available.

Uma originally went electric because it was cheaper than repairing the diesel. They did a DIY EP system.

Your analysis of EP is very level headed and well thought out. I wish more EP proponents were like this.


EP is not a panacea. The sooner more people realize this, the better things will be.


All that to say thanks.

[Adelie]

Thanks.
My feeling is that the folks that are bad mouthing EP now will, in 30yr when they can’t find/afford fuel any more, appreciate the early adopters now who have helped work out many of the kinks.

[David Ess]

NaClyDog.......for sure. But nobody said it was a panecea, but like with cars, the way its going. It keeps getting better and cheaper all the time. Look at the Alva 60 I just mentioned, 20kw of solar, and 260 kwH battery ...thats massive already. And those who want the snob appeal of saying its a sailboat, can get it with the optional kite sail.

[David Ess]

Originally Posted by Adelie

Thanks.
My feeling is that the folks that are bad mouthing EP now will, in 30yr when they can’t find/afford fuel any more, appreciate the early adopters now who have helped work out many of the kinks.

Kinks already worked out, many just cant afford it.

[mvweebles]

Originally Posted by David Ess

NaClyDog.......for sure. But nobody said it was a panecea, but like with cars, the way its going. It keeps getting better and cheaper all the time. Look at the Alva 60 I just mentioned, 20kw of solar, and 260 kwH battery ...thats massive already. And those who want the snob appeal of saying its a sailboat, can get it with the optional kite sail.

David Ess - what kind of boat do you own? Power or sail? How much solar?

[captlloyd]

Originally Posted by Adelie

Thanks.
My feeling is that the folks that are bad mouthing EP now will, in 30yr when they can’t find/afford fuel any more, appreciate the early adopters now who have helped work out many of the kinks.

To be fair, most of them have said the technology is just not there at this point. Will it come, probably eventually.

[Adelie]

Originally Posted by captlloyd

To be fair, most of them have said the technology is just not there at this point. Will it come, probably eventually.

Will it come for what?

Replace diesel/gas/petrol with no change in performance at similar cost? That will never happen. The energy density and specific energy of fossil fuels is only matched by a few chemicals that you couldn't afford and that you would never want on your boat or to be within a 100m of for that matter.

Whatever comes next for cruising is going to be a significant change from what we have now. My guess is it will be a combined system of solar, wind, regen recharging a large to very large battery bank powering an electric motor in parallel with a small ICE engine using relatively expensive synthetic electro-fuels: ammonia, gasoline, diesel, butanol, methanol, ????.
The ICE will be used to slow-steam the boat in calms at 3-4kt (0.5x(LWL)^0.5). The electric drive will do what it does now: motor the mothership in and out of harbors/marines, set & retrieve anchors, get the boat out of the way of larger vessels, help thru tacks in heavy weather and motor the boat short distances at moderate speeds (4-5kt), and longer but still moderate distances at low speed (2.5-3.5kt). At very low speeds the boats may have almost unlimited range.

As personal vehicles shift from ICE to EV, I expect fuels costs to drop, until crude producers and refiners have no margin and start to drop out or go bankrupt at which point prices will rise past where they are now. At some point governments will mandate electro-fuels for remaining uses that can't convert to batteries. These elelctro-fuels are what will become available to us. This will take several decades.

In the long run all but the wealthy will be priced out of offshore motor cruisers. Inshore motor cruisers can convert to light displacement, moderate speed hybrid cruisers with regular recharging at marinas.

In the short term OV is almost on the right track for regen. I get that saildrives are the big market right now but putting all the electronic gear to control the blade pitch in a pod at the bottom will only end in tears.

For the existing market a controllable pitch propeller (CPP) system in the $2-5k range, with symmetrical blades will make a killing. Slight sacrifice in blade efficiency for traction counter balanced by a somewhat bigger improvement in ICE operating efficiency except at max output plus a big gain in regen. The increase overall efficiency of CPP is why a lot of European comm'l boats went that way, because fuel prices were always higher there than in the US where fuel prices never got consistently high enough to justify changing from Fixed Pitch Props (FPP) to CPP.

[captlloyd]

I was referring to battery technology.

[Seaslug Caravan]

Originally Posted by Adelie

Thanks.
My feeling is that the folks that are bad mouthing EP now will, in 30yr when they can’t find/afford fuel any more, appreciate the early adopters now who have helped work out many of the kinks.

Now that’s funny.

Firstly you need to understand the difference between ridiculing certain EP providers rewriting of the laws of physics with their electric HP, then selectively quoting supposed real world examples that on close inspection are a complete disaster, same providers using crazy unrealistic speeds to show how great their regen is etc etc.

Of course we (sailors) will need to transition from the dinosaur burning ICE, as do all the high powered gin palaces that grace our waterways. To say we have to be happy to bob around at low speed with a limited range is just silly. Is EP the solution? Maybe. Maybe not.

[JustMurph]

Originally Posted by Seaslug Caravan

Firstly you need to understand the difference between ridiculing certain EP providers rewriting of the laws of physics with their electric HP

Ahhh yes, the electric horses are bigger that diesel horses old chestnut. That's a load of sh*te.

[Tupaia]

Originally Posted by David Ess

I wish JC would test out the Alva Ocean Eco 60 cat that has 20 kW of solar and 260 kWh of battery capacity. Attn Alva Yacht company: If Jimmy doesnt want to, I would be happy to circumnavigate one for you. It would be good advertising.

More hype. FULLY ELECTRIC SOLAR CATAMARAN

Ocean Eco 60

Taking the smallest engine size 2 x 100KW (200KW) - Speed attainable about 10 knots @ 28 tonnes

Power input available 20KW solar - 1/10th of the requirement, 280KWh from largest battery bank 1.4 hours duration.
Recharge from the biggest DIESEL generator 100KVA (allowing a power factor for DG of .8 gives about 80KW.
The totals just don't add up.
This is not a Fully Electric Solar Catamaran.

Unless my sums are wrong, it is at best a solar assisted power cat.

Check out https://soelyachts.com/

The 48 ft "truly electric" is magic it does 30Nm with 2x71KW motors and 56Nm with 2x142KW motors a typo for sure but does lead one to suspect the credibility of the data. It does however give an indication of the expected endurance.

The "concept" 62ft has almost identical spec as the Ocean Eco 60 and carries 1800litres of diesel. Another "solar assisted" power cat.

They have a 12m resort cat that, ignoring any up front cost differences, is completely feasible for the purpose intended.

It is not the boats I have a problem with it is the rather disingenuous advertising.

[valhalla360]

Originally Posted by Adelie

Thanks.
My feeling is that the folks that are bad mouthing EP now will, in 30yr when they can’t find/afford fuel any more, appreciate the early adopters now who have helped work out many of the kinks.

It's not bad mouthing EP.

It's bad mouthing vendors who talk of magic HP and unrealistic capabilities and then rather than backpedaling to clarify the real capabilities, they keep claiming unrealistic things.

The systems are relatively straight forward and the technology is not new, so no real reason to "appreciate" the early adopters. What we need is good sound engineering where the marketing department is kept in check based on the real capabilities.

[David Ess]

Originally Posted by captlloyd

To be fair, most of them have said the technology is just not there at this point. Will it come, probably eventually.

Some have explicitly said that, yet several give the impression its only a 'trend', or not workable , etc. Yet electric, hybrid boats are already out there. Another issue seems to be that many just cant afford them. Another that they havnt even researched them, dont even know about them.

[BigBeakie]

Originally Posted by JustMurph

Ahhh yes, the electric horses are bigger that diesel horses old chestnut. That's a load of sh*te.

The claim by Oceanvolt is that there is functional equivalency comparing their electric motor of x kw to a marine diesel of 3x horsepower. So for example a 15 kW SD15 pushes a boat with an efficient hull form about the same as a 45HP diesel. That's the claim. They have clarified that the diesel will be able to push the boat at a higher top speed at WOT, due to the higher RPM's the diesel is capable of achieving. So that's the proviso.

You state that's a "load of sh*te". I'm genuinely curious...how do you know that is false?

As I have said before, ad nauseum, I have interviewed several OV owners and been on several OV installed boats, to see and hear for myself, BEFORE we made our decision to use a 20kW AXC in the new cat.They ALL told me as far as they were concerned their OV motor was at least as good ( ie powerful) as diesels they previously had experience with.

One of the most credible sources for me was Tony L. who owns and runs Boatworks in Coomera. His statement is quite dramatic, he sees his 2 x SD15's as easily equivalent to his 2 x 75 HP Yanmars he previously had on Kato. He does concede the Yanmars had slightly higher top speed. I don't think anyone who knows Tony's background, could credibly claim Tony doesn't know what he's talking about re HP !!

Anyway, not to flog a dead horse but let me ask, seriously, how would YOU test the proposition? What test would YOU put a boat through to judge this claim? Because JM, you are most welcome on our boat when we get back to Oz, anytime, to see for yourself.

There is a 20kW AXC in the port hull, and a Beta 45 Turbo in the starboard hull. They have the same 30mm shafts and the same 17" 3 blade flexofold props. There is not a better test platform out there, that I'm aware of.

So I'm asking, what would constitute a fair test?

[JustMurph]

Hey, I'd love to be proven wrong!

Your first sentence makes my point for me. They claim a "functional equivalency". It depends on what the function is defined as. Yes, functionally a 15kw motor will push the boat along at the same cruising speed as a 45HP diesel. It will also potentially do it more efficiently because that prop can be specified for that exact duty. You could put a pair of 20HP diesels in there with the same optimised props (assuming they have the same shaft speeds) and they would also perform the same at that load point.

But, IMO in a blue water cruising boat, you need that full power ability for emergency situations, e.g. motoring off a lee shore in storm conditions. In a day sailer, maybe not. The props will be specified to handle this full power load point and that will compromise their efficiency at lower revs and cruising speed. That's a compromise you accept for the ability to put down more power for that 1% of the time.

How do I know they're different? Props don't care what's turning them. Power is power. Your diesel will turn its prop faster and provide more top end than the electric. Will you use that ability day to day, no.

For the record, I reckon your hybrid setup is awesome. It's the only hybrid setup that makes sense to me. You still have the grunt available from the big diesel when you need it and have all of the advantages of the electrics for manoeuvring and regen.