Jimmy Cornell goes Electric, with a Cat

[Tupaia]

Originally Posted by yvest

Some updates from Cornell, not very clear ... :
https://cornellsailing.com/fr/2021/0...ra-zero-plans/

Acceptance of failure is always hard. It would seem that the systems propaganda does not meet up to expectations.

[danstanford]

Originally Posted by Tupaia

Acceptance of failure is always hard. It would seem that the systems propaganda does not meet up to expectations.

Sure you can say this but neither of us knows what was promised during these discussions. For sure, there was enough information around on the risks for all the parties to do proper due diligence on the power sources and uses to determine if it would work with a suitable safety factor.

Another question arises however as we review the situation. The objective of zero carbon is a LONG way from the aspiration of most electric boats. This plan, as covered in the notes above, included many electric draws like the induction cooktop that many of us would not even contemplate knowing that a propane stove would handle our uses without risk to motive power. Also, they did not want to use shore power to charge the batteries.

Ultimately when we discuss electric options here in this forum, most of us would not contemplate these needs nor the rigors and time needed to circumnavigate when we think about cruising with electric motors.

Dan

[Hodgdon87]

Originally Posted by danstanford

Sure you can say this but neither of us knows what was promised during these discussions. For sure, there was enough information around on the risks for all the parties to do proper due diligence on the power sources and uses to determine if it would work with a suitable safety factor.

Another question arises however as we review the situation. The objective of zero carbon is a LONG way from the aspiration of most electric boats. This plan, as covered in the notes above, included many electric draws like the induction cooktop that many of us would not even contemplate knowing that a propane stove would handle our uses without risk to motive power. Also, they did not want to use shore power to charge the batteries.

Ultimately when we discuss electric options here in this forum, most of us would not contemplate these needs nor the rigors and time needed to circumnavigate when we think about cruising with electric motors.

Dan

They did use shore power to charge the batteries and planned several key stops along the circumnavigation route specifically for that purpose.

[harlem24]

@Hodgdon

To my knowledge was the original plan not to use shore power, because it was not clear from what sources the electricity came. And if you look especially at islands or other remote locations, there almost everywhere oil- or coalplants or even big diesel generators running.
They only chose to charge in Tenerife to get safely back to France.

[mglonnro]

Originally Posted by harlem24

@Hodgdon

To my knowledge was the original plan not to use shore power, because it was not clear from what sources the electricity came. And if you look especially at islands or other remote locations, there almost everywhere oil- or coalplants or even big diesel generators running.
They only chose to charge in Tenerife to get safely back to France.

In my mind, shore power is good. It is a part of the zero-carbon solution in the form of enabling infrastructure that will (ideally, at some point) be able to load it with 'zero carbon' electricity. So, I agree with Cornell's revised opinion on that point.

The seaworthiness question is a separate one, of course. If you spend weeks on the water, shore power won't help to recharge the batteries

[Tupaia]

Originally Posted by danstanford

Another question arises however as we review the situation. The objective of zero carbon is a LONG way from the aspiration of most electric boats. This plan, as covered in the notes above, included many electric draws like the induction cooktop that many of us would not even contemplate knowing that a propane stove would handle our uses without risk to motive power. Also, they did not want to use shore power to charge the batteries.

Dan

The fact that you have isolated cooking with electric goes to highlight the fundamental issues. A cat of similar performance as this will maybe use 100-150 litres of fuel per year. So by this logic would be better to replace to the gas cooker with an electric hob and keep the diesel engines. A logic that does make some sense. Catamarans are weight sensitive so the more you load them up, the less they can sail and the more motive power you require, a cycle of diminishing rewards. A cat light and fast enough to sail in 3 knots of wind cannot expect to get anything from re-generation again a cycle of diminishing rewards.



I think the whole "zero" carbon thing misses the point. Much better to aim for the most efficient "appropriate" technology. To put this into context; most people use more fuel driving their SUV to the marina every weekend than their boat uses.

[Belezar]

“I think the whole "zero" carbon thing misses the point. Much better to aim for the most efficient "appropriate" technology. “

I agree. It’s great to strive for things, and push boundaries. I applaud Cornell for trying to be pure, but for practical purposes, finding the right balance will win more converts. And in the end should produce better overall results. It’s also better risk management.

[danstanford]

Originally Posted by Tupaia

The fact that you have isolated cooking with electric goes to highlight the fundamental issues. A cat of similar performance as this will maybe use 100-150 litres of fuel per year. So by this logic would be better to replace to the gas cooker with an electric hob and keep the diesel engines. A logic that does make some sense. Catamarans are weight sensitive so the more you load them up, the less they can sail and the more motive power you require, a cycle of diminishing rewards. A cat light and fast enough to sail in 3 knots of wind cannot expect to get anything from re-generation again a cycle of diminishing rewards.



I think the whole "zero" carbon thing misses the point. Much better to aim for the most efficient "appropriate" technology. To put this into context; most people use more fuel driving their SUV to the marina every weekend than their boat uses.

I love different perspectives on how to slice this lemon but I cannot believe one would use more carbon (or fuel) cooking than they would for motive power!
I do concur with your last point but am not sure how it relates to this discussion. We likely are going to drive to the marina anyway no matter how carbon efficient our boat is. If buying an electric car is better, then buy the electric car and save with the boat too.

[aqfishing]

Originally Posted by Tupaia

The fact that you have isolated cooking with electric goes to highlight the fundamental issues. A cat of similar performance as this will maybe use 100-150 litres of fuel per year. So by this logic would be better to replace to the gas cooker with an electric hob and keep the diesel engines. A logic that does make some sense. Catamarans are weight sensitive so the more you load them up, the less they can sail and the more motive power you require, a cycle of diminishing rewards. A cat light and fast enough to sail in 3 knots of wind cannot expect to get anything from re-generation again a cycle of diminishing rewards.



I think the whole "zero" carbon thing misses the point. Much better to aim for the most efficient "appropriate" technology. To put this into context; most people use more fuel driving their SUV to the marina every weekend than their boat uses.

100-150 L ??? Surely not on a cruising yacht???

[Hodgdon87]

Originally Posted by harlem24

@Hodgdon

To my knowledge was the original plan not to use shore power, because it was not clear from what sources the electricity came. And if you look especially at islands or other remote locations, there almost everywhere oil- or coalplants or even big diesel generators running.
They only chose to charge in Tenerife to get safely back to France.

I was privy to the planning of this trip since my friend was the professional crew onboard. They realized early on during sea trials of the boat that it would be necessary to top off the batteries from shore power sources along the route.

Part of the challenge with re-gen is that it has a hard time taking the batteries all the way up to 100% full charge. The boat was also equip with two separate battery banks that needed to be equalized occasionally. In order to fully cycle and equalize the battery banks, it was necessary to plug into shore power once in a while.

This has already been posted but if you want some more backstory on the trip, you can watch my interview with a first-hand source. He was essentially the captain onboard although Jimmy chose not to refer to him by that title.

https://www.youtube.com/watch?v=6EplXM0fksw&t=4s

[Tupaia]

Originally Posted by aqfishing

100-150 L ??? Surely not on a cruising yacht???

Sorry, that should be 200-300L

I only calculated for one engine. I averaged 270L per year for 10 years full time cruising 750 hours per engine 1.8 litres per hour per engine.

[aqfishing]

Originally Posted by Tupaia

Sorry, that should be 200-300L

I only calculated for one engine. I averaged 270L per year for 10 years full time cruising 750 hours per engine 1.8 litres per hour per engine.

750 hrs at 1.8L/hr = 1350L x 2 = 2700L. That makes more sense.

As a matter of interest what would you guess your genset used?

Did you perhaps keep record of your total fuel spend per annum? Purely as a matter of interest.

[CatNewBee]

Originally Posted by Hodgdon87

I was privy to the planning of this trip since my friend was the professional crew onboard. They realized early on during sea trials of the boat that it would be necessary to top off the batteries from shore power sources along the route.

Part of the challenge with re-gen is that it has a hard time taking the batteries all the way up to 100% full charge. The boat was also equip with two separate battery banks that needed to be equalized occasionally. In order to fully cycle and equalize the battery banks, it was necessary to plug into shore power once in a while.

This has already been posted but if you want some more backstory on the trip, you can watch my interview with a first-hand source. He was essentially the captain onboard although Jimmy chose not to refer to him by that title.

I somewhat disagree with the findings and the setup.

First of all, living on board and cruising with a DIY electric galley setup, we need our 1650Wp solar and 15kWh lithim bank exclusively for living and navigation. Induction cooking is not a big deal, as it is quick and actually energy savvy if you not run the cooktop plates full throttle all the time, for a gourmet meal cooked on 3 burners simultanously (meat, veggies, side dishes) you typically sacrifice about 80 to 100Aa or 1...1.5kWh of energy. Refrigerators and freezers suck up mucjh more energy, also the watermaker. But having this is enough to live offgrid.

Now to propulsion. I agree, a performance Cat is a good thing, being light, fast and moving in light winds. But for full time cruising you need carrying capacity for cargo of your stuff, food, toys, clothes, spate parts, tools. A performance hull suffers overproportunally from weight, it is made for racing, not for transporting stuff.

Next thing is, you have two huge breaks when sailing - the regen props, that screws the expensive performance design. A heavier boat may behave better and steadier in rough conditions than a performance cat with regen props. I would be curious to see the same model side by side in the same conditions with classic diesel engines setup regarding speed, comfort, range, weght.

Overall looking at my engine hours - we motored in the med 1/3 of the time or distance due to changing wind conditions and weather in the Med, while used very little engine on the ocean crossing.

A range extender will kill a performance catamaran. You still have the heavy electric engines and batteries and add diesel tanks and a generator on topp. You can do this to a wide hull Lagoon with carrying capacity of 4-5t but not to an Outremar without getting her as slow as a Lagoon, bur with less comfort.

It simply does not make sense.

I am not impressed with the speed (4kn @1kW, 6kn on both engines full power) in a performance cat, and a maximum range of only 60...80nm in dead calm and energy savvy motoring. You cannot run from weather by engine, run against a current or even up of an river or cross a significant duldrum that way.

[bowa]

Definitely the entire hybrid hype should be taken with a pinch of salt! I too sometimes get carried away with ideas of implementing new tech....but it has always paid off, to lean back, take time off.....and go at it a bit later again!

By that time hopefully one has "come to better reason" ...and not just discarded all of the old tech.


I have seen well designed motorsailers cruising very efficiently with an old Gardener diesel lump.....achieving under 200g/kWh !! Most similar powered normal injected diesels get 260 or more. The best caterpilkar C xx commonrail Td intercooled types dont achieve that!!
The smaller diesel units (in most boats) reach only 290 g/kWh.....BUT in some cases even those setups still proved more "Carbon conserving" than some fancy and hugely expensive serial hybrid with regen capabilities.
I am not saying a hybrid solution wont save fuel...it can. But each system and its planned use must be matched.


I still believe that installing of a LiFePo bank with its fast charging capability and a beltmounted motor/generator is the most energy and $ efficient way to go.
The beltdriven Motor/Generator hybrids are a bit more expensive but with 2 clutches give a lot of options, while a powerful alternator or pmdc generator of 30%-50% engine cap. is the cheapest way to use electricity sparingly. 2hrs running engine for 1 week el. use on the hook...if no AC is used.
Heating and cooking can be done with diesel very efficiently too.Although I would go for induction cooking.
S

[donradcliffe]

VERY interesting video interview. Should be required viewing for anyone who is contemplating zero carbon cruising. It was a great leap 300 year leap backwards, although 300 years ago you could still get a hot meal. I can understand why the boat is for sale.

It did turn out there were some significant energy system miscalculations, which could be corrected as long as you were able to put up with some carbon footprint:

1. Max out solar panels from 1200 watts to at least 2500.
2. Dump the induction cooking and put in a propane stove.
3. Put in a 3-4 kw gas or diesel generator

The regenerative power system was an untested disaster in real world conditions. The Servoprop spent its time hunting for the optimum output and putting out none. Its possible that a KISS compromise might have saved the project.

Or you could have put the Pardey's on board and let Jimmy Cornell stay home.