Why hybrid?

[Pete7]

Originally Posted by s/v Jedi

For live aboard boats with electric galley, watermaker etc. but no electric motor, I think you need two batteries of 9-10kWh each. If the weather is good you can just make do with one 9-10kWh battery, so the second is for redundancy and for bridging the rainy/cloudy days etc.

Kind of hoping to do it all on less power. Space for batteries and panels plus £££ being the main limits. We will see how we get along with 600w next summer, but hopefully produce 2.4Kwh a day in sunny conditions. Helped by carefully choosing electrical cooking appliances. If its raining and we are motoring, topping up with the alternator is a fall back plan. Thankfully we don't need a WM or AC, just occasional heating during the summer.

So disappointed LG pulled out of the market. Their 440w bi-facial panels offered an extra 15 > 26% on top of the 440w which would have made a big difference. There are other bi-facials, but actually sourcing them is a problem in the UK.

Electric propulsion possible, but needs some thinking about and occasional top up with shore power, say weekly. I don't have a problem with this as NW Europe marinas and harbours have the infrastructure and we want to stop shore side regularly anyway. Therefore a hybrid system seems expensive solution. If a new diesel is £6k, the beta hybrid is probably £12k, plus another £6k for 3 x 5Kw server rack type batteries. A £1k Honda petrol generator suddenly looks tempting rather than the hybrid.

Meanwhile the Remoska is doing sterling work so much so, we have bought another for use at home rather than the domestic oven.

Pete

[Rumrace]

I love gas engine hate diesels. I’ve mostly worked on BMW Chevy and Yamaha but built some rare Harley and Triumphs. As an honest tax payer of Ontario GM is no longer in my vocabulary and that wouldn’t change even if they paid us the 450 million they screwed us for. That said I love the LS3. Bought one at a bankruptcy GM dealer lot. For $8500.00 in a crate it’s just about the greatest engine in the world.
My prediction is no form of diesel will survive the next 15 years. Zip gone bye.
Gas engines will survive but be producing less horse power snapping Hydrogen. Which is kinda the same thing as gas without all the carbon.
Toyota,Yanmar, Yamaha have a winning team and are producing fuel grade pressurized hydrogen underway. Range. Fuel you’re parked in it.

At night time every big city on the planet sends the excess juice to earth except one. Toronto. In Toronto the night time waste is sent to Toronto Wards Island pump station. Pumps using the wasted energy fill huge air tanks under the lake which in the morning run dynamos on the mainland which folks think are art exhibits.
Who said we live in exciting times and when?

[Adelie]

Originally Posted by Rumrace

....

Gas engines will survive but be producing less horse power snapping Hydrogen. Which is kinda the same thing as gas without all the carbon.
Toyota,Yanmar, Yamaha have a winning team and are producing fuel grade pressurized hydrogen underway. Range. Fuel you’re parked in it.

....

Hydrogen as a fuel looks great from afar but fails miserably due to practical problems.
Storage medium weight and volume being key sticking points. Accounting for storage media weight and volume hydrogen is barely better than LiFePo batteries in terms of Specific energy and energy density.

It also has the same low combustion efficiency as gas/petrol/diesel in ICE engines with little expectation of much improvement.
Fuel cells have significantly better efficiency of use and potential to improve a fair bit.

This video explains the problems better than I am willing to do here:

https://www.youtube.com/watch?v=vJjKwSF9gT8

Additionally hydrogen would require almost complete replacement of the existing infrastructure for fuel delivery and storage. That's pushing a trillion dollars of investment plus 30-50yr to make the change.

Short of some breakthrough in storage, hydrogen isn't going to replace liquid fuels.

The more likely replacements are synthetic ammonia, butanol, gas/petrol or diesel made from water and air using electricity. Ammonia would require some modification to fuel distribution infrastructure, and to ICE engines for use. Butanol is a straight replacement for gas/petrol or very close to one.

[s/v Jedi]

Originally Posted by Adelie

At Battleborn 100Ahr battery has about 1.2kWhr in it.
For boats in the 30-37' range I believe 300Ahr @ 48v is common, at least that's what a vendor I talked to implied in the literature they sent me.
That would be 12 batteries or 14.4kWhr, of which about 11.5 kWhr would be usable with 80% DoD.

Basically a 100Ahr LFP battery @12v nominal has 1kWhr usable at 83% DoD.

If you know of a boat with 40kWhr of battery capacity, that would be a big boat, because that would be a lot of batteries.

For boats near 35' I would expect to install 12 batteries, possibly 16 batteries depending on the available storage space I could reassign to batteries. 16 batteries would be 19.2kWhr, 15.4 usable at 80% DoD.

Battleborn is LFP so 4 cells in series: 4x3.2=12.8Wh per Ah so 1.28kWh for a 100Ah 12V battery.

If someone configures those as 48V 300Ah then that is 12 batteries: 12x1.28=15.36kWh.

This must be an attempt to do with one battery bank, right? To keep it in sets of four to allow 48V configurations, when using 8 instead of 12, you get 8x1.28=10.24kWh which is the magic number… for each battery.

To recap: with 8 Battleborn 100Ah batteries you can just run the boat. If you have more than 1,500W solar, you probably won’t need other charge sources as long as you get good sun.

For live aboard, you want two of those banks, and not all bought simultaneously. Make one bank from old batteries, and add a new LFP bank. A couple years in, replace the old batteries with new LFP. Now it is much more likely that the newest bank will be good when the older one reaches end of life. This means you don’t need to replace earlier to make sure it doesn’t die on you, because you have a second bank that will run the boat while replacing the old one. This is a significant saving when nothing goes wrong at all, but when there is a failure of some sort, you also gained redundancy, while the other option leaves you with a power outage.

My recommendation of 2x 9-10kWh and 1.5-2kW solar is based on:

- no additional charge sources needed
- diesel engine used very little
- full electric galley
- electric watermaker
- home cook and bake everything: we bake bread twice a week, make yoghurt once a week, make our breakfast cereal every couple weeks etc. All that uses electric appliances like oven for rolls, breadmaker for loafs, oven for cereal etc.

We have 1,875W solar and in the Bahamas during summer months, starting in May, we can even run the A/C a bit and this is one of those old power hogs. When using the new VSD types and only cooling the cabin for sleeping, I think it’s possible to run it through the night.

With 1,500W solar I think you’re back to occasional use of A/C with the new efficient units.

The above is based on doing this for two years. First years with just one 10.24kWh house bank, second year with an old 9.6kWh Lifeline house bank added and those batteries have now really failed so I’m looking at building or buying a second LFP bank.

[PaulCrawhorn]

Electric propulsion beyond just getting out of the marina requires both shore power overnight and a huge bank likely separate from House.

Aircon run off stored solar energy is barely realistic unless only a small proportion of a large boat is cooled.

Just the all-electric galley is thirstier than practical for an avid cook on a small boat aiming to be solar-only.

Even with a larger deck, unless you just don't care about your boat's lines and windage, FF sources or regular shore charging are required for all these use cases.

[Adelie]

Originally Posted by noelex 77

..

It is certainly possible to lead a comfortable life including all electrical cooking with only 1000w of solar although for many boats this will not be enough to ditch propane (or a generator) completely. You also need to also accept the restriction of confining your cruising ground and seasons to areas of good or at least reasonable insolation.

We have just over 1000 w of solar and do exactly that, including many things not on your list such as freezer, washing machine and electrically heating water for showers, but we have taken a lot of trouble to maximise the efficiency of our electric system, and can easily switch to propane or diesel for cooking/water heating in areas of poorer solar insolation thus removing the restriction limiting the cruising area.

Most boats large enough to fit a 2 Kw array will have multiple fridges and freezers, large entertainment systems, electric dinghy motor etc. They do not have the facility to fall back on propane or diesel cooking/water heating as we do. Typical factory boat electrical systems are not designed with efficiency as a priority and it is tough to find shade free locations for very large solar arrays so the yield from each solar watt falls.

A boat that is large enough and has taken the trouble to install a 2 Kw solar array will generally demand a high level of electrical consumption from their house system. The amount of energy left over (if any) for electric propulsion typically will be small. It may just be enough for the 10 minute run time Jedi has suggested, but even this is likely to compromise the available house energy budget.

.....

Right, forgot about freezers, multiple fridges, washing machines, entertainment centers, water heating and AC.

Also forgot one of the maxims from my education in civil engineering, in highway design, if you increase capacity, demand will increase to fill and overfill it. That's why a lot of places in the US can't build enough freeways in cities to meet demand, demand just stretches to overfill new lanes and new freeways. Same applies here.

[Dirk01]

Originally Posted by Adelie

Preferred to motor for long periods, sure. Only a few probably had to, the only reasons I can see for actual need are injury, damage to the rig or did not provision properly and are running out of food.

If you have the engine, the fuel, the money for it and the preference that’s fine.

But don’t conflate personal preference with a actual need.

In a good hybrid design the ICE would be able to propel the boat just badly to hull speed in flat water, so throttled a little to cruising RPMs the boat would make about 75% of hull speed. This would put the motor at the optimum rpm for efficiency and longevity.
Full throttle would maintain that 75% against moderate wind and waves but would need an electric boost in heavier winds or waves which would only work as long as the battery lasted.

Of course in heavier winds a reefed main and a staysail would be to optimum way to go to windward, not a motor.

+1
Reduce your numbers by anothrr 25% and you're still fine enough.

[Dirk01]

Originally Posted by Joli

https://www.forbes.com/sites/michael...ever-meant-to/

You just post a single meaning of Michael Schallenberger who try to reduce a much more complex system to wind and solar energy production only.
However, this is in general off topic. Pls. switch back.

[Adelie]

Originally Posted by PaulCrawhorn

Electric propulsion beyond just getting out of the marina requires both shore power overnight and a huge bank likely separate from House.

Aircon run off stored solar energy is barely realistic unless only a small proportion of a large boat is cooled.

Just the all-electric galley is thirstier than practical for an avid cook on a small boat aiming to be solar-only.

Even with a larger deck, unless you just don't care about your boat's lines and windage, FF sources or regular shore charging are required for all these use cases.

EG, AC and EP all have significantly different demands.

Electric Galley (EG) would be the easiest to implement. Demand would be 75-125Ahr/d depending on how you cook. Let's assume 100Ahr/d.
That means you need an additional 300W of panels and 150-300Ahr of batteries. The reason for so much added battery capacity is to float you thru low insolation days and to make sure you have a large total bank size so that it can meet the high instantaneous demand of EG without having too high of a C-rate.

AC demand is about twice as large. The smallest AC window unit is about 5,000BTUs and draws about 5.3 amps at 120V, that's 53A at 12v. It would probably be good for one cabin. Assuming a 50% duty cycle for a 10hr period per day that's about 250Ahr/d draw.

I found a 2500BTU unit for doghouses. It still draws 4.3A, so near 200Ahr/d.
https://climateright.com/products/cr...34672044671128

I also found some Peltier units for cooling electronic equipment in industrial settings. Efficiency though is mediocre.
800BTU - 3.5A/120v https://www.eicsolutions.com/product/aac-141a-4xt/
400BTU - 8-10A/12v https://www.eicsolutions.com/product/aac-140-4xt/

By the time you get to 400BTU you are probably only making the cabin somewhat cooler and drying it out, and only if you insulate it.

Actually, insulating a cabin or even the whole boat would be a good idea just anyway.



Electric propulsion (EP)
To implement this you need to maximize solar installation and installed battery capacity and you need to accept limitations on use of the motor.
I figured out how to mount 1000-1200W on a Cal-34. Most would be on the dodger and bimini which I would have anyway so the only added windage would be the panels on a stern arch. Removing the Atomic-4 leaves room for the electric motor and another 800Ahr of batteries. There would be no change in weight using FLA batteries. Using LFP weight would be lower or more batteries could be installed and it would still be lighter with all available space filled.

With a 300Ahr/48v propulsion bank you could motor at 3kt for half a day (12hr) so about 36nm. That's 11.5kWhr of juice.
With 1200W of panels you will produce about 4.8kWhr/d on average, some days more, some less.
If house demand is 2kWhr/d then you have 2.8kWhr/d to recharge.
To recharge 11.5kWhr at 2.8kWhr/d you would need 4d including the underway day so 3 bye days between "long" motoring periods. By setting out extra flexible panels and setting them for a better angle, that could be cut significantly. If it's windy that wouldn't work but then you'd be sailing anyway.


If the batteries were FLAs then I would have the propulsion bank and the house bank be the same because of the Peukert effect, the larger bank would make any draw be at a lower C so there would be more total power available. This would be especially usefully for electric cooking which tends to have very high instantaneous demands.

[Adelie]

Originally Posted by Adelie

in post #3 the OP mentions Amels having had regen installed but makes no mention of ownership.



The best fuel efficiency info I have found is for ag-tractors.
https://tractortestlab.unl.edu/test-page-nttl

If anything 18hp-hr/gal is overstating their efficiency. There are large motors in the 6,000cc and up with get 17-19hp-hr/gal, a few break 20, but those motors are 300hp and up.

For motors in the 45-100hp range, all with turbos they get 12.6-18.5hp-hr/gal. As engine sizes decrease so does efficiency.
https://digitalcommons.unl.edu/cgi/v...actormuseumlit
https://digitalcommons.unl.edu/cgi/v...actormuseumlit
https://digitalcommons.unl.edu/cgi/v...actormuseumlit
https://digitalcommons.unl.edu/cgi/v...actormuseumlit
https://digitalcommons.unl.edu/cgi/v...actormuseumlit
https://digitalcommons.unl.edu/cgi/v...actormuseumlit
https://digitalcommons.unl.edu/cgi/v...actormuseumlit

Keep in mind too that these numbers are for full power, which few people tend to maintain for long. Efficiency also drops significantly as rpm and power drop.

If you want to argue that these are tractor engines not marine engines, keep in mind that a single tractor will use 10,000-25,000gal in a year sowing, tending and harvesting so efficiency is a big deal to farmers, there is a significant profit motive to get the most efficient tractor which provides the producers with a big incentive to provide the most efficient tractors.

I believe there is more motivation for tractor producers to make the most efficient engines than recreational marine engine manufacturers.

So here's an update of a previous post.

Since then I made a spread sheet using the data for about 50 tractors made in the last 40yr with engines up to about 75hp which is the maximum size that would go into a cruising boat.
I looked at a several pairs of engines where the base engine was the same but a turbo was added. I didn't see a significant improvement in fuel economy.
Research elsewhere indicated turbos offer about a 3% gain in fuel efficiency for gas and diesel engines.
https://www.caranddriver.com/feature...-economy-bust/

From my spreadsheet I also noticed that fuel efficiency decreased as the engine got smaller and it decreased as the engine output was throttled down.
This data is from tractors where rpm was kept near constant and power was decreased by throttling and because the output was thru a multi-speed transmission.
In cruising vessels rpm varies with output so that is maybe a significant difference from the tractor data. Since I haven't been able to find good boat data for the time being I am assuming they behave about the same.

Most engines had max efficiency at max HP.
For engines near 30hp I would expect about 14.0-15.0 hp-hr/gal.
I would expect a 20% loss of efficiency at 50% max HP output, for sailboats that's about 80% max rpm which is normal cruising rpm.

Despite the drop in motor efficiency the vessel mpg improves as a vessel slows because vessel drag is dropping faster. For ICE propelled vessels 30-40' best mpg is near 3kt. depends on the particular vessel and motor.

[s/v Jedi]

Originally Posted by Adelie

AC demand is about twice as large. The smallest AC window unit is about 5,000BTUs and draws about 5.3 amps at 120V, that's 53A at 12v. It would probably be good for one cabin. Assuming a 50% duty cycle for a 10hr period per day that's about 250Ahr/d draw.

I found a 2500BTU unit for doghouses. It still draws 4.3A, so near 200Ahr/d.
https://climateright.com/products/cr...34672044671128

I also found some Peltier units for cooling electronic equipment in industrial settings. Efficiency though is mediocre.
800BTU - 3.5A/120v https://www.eicsolutions.com/product/aac-141a-4xt/
400BTU - 8-10A/12v https://www.eicsolutions.com/product/aac-140-4xt/

By the time you get to 400BTU you are probably only making the cabin somewhat cooler and drying it out, and only if you insulate it.

Actually, insulating a cabin or even the whole boat would be a good idea just anyway.

When you select one of the VSD type units, the energy consumption is cut by 50% and start-surge is eliminated completely. It’s a game changer and enables A/C from battery. They are popular though so hard to find in stock. Here’s one place I keep an eye on… Velair is said to come out with new models “soon”: https://www.imarineusa.com/VelairI10VSD.aspx

[Adelie]

Originally Posted by s/v Jedi

When you select one of the VSD type units, the energy consumption is cut by 50% and start-surge is eliminated completely. It’s a game changer and enables A/C from battery. They are popular though so hard to find in stock. Here’s one place I keep an eye on… Velair is said to come out with new models “soon”: https://www.imarineusa.com/VelairI10VSD.aspx

There is a gain in efficiency from not cycling on and off, but if the unit is sized to the need there is a 100% duty cycle and VSD would provide little or no improvement. That said it's hard to find small units sized for boat use and the Peltier units have relatively low efficiency to begin with.

[wingssail]

Originally Posted by s/v Jedi

When you select one of the VSD type units, the energy consumption is cut by 50% and start-surge is eliminated completely. It’s a game changer and enables A/C from battery. They are popular though so hard to find in stock. Here’s one place I keep an eye on… Velair is said to come out with new models “soon”: https://www.imarineusa.com/VelairI10VSD.aspx

I am not sure about the 50% less energy consumption. The technical specifications for a velair i10 https://www.uflexusa.com/wp-content/...hure-pages.pdf shows a power consumption of 6.2 amps. My Midea 8000BTU has a similar power requirement, a soft start, and an energy saving cycle and costs about 17% of the Velair, (which also needs installation and water cooling pump).

So a window unit is rather inelegant but it provides good cooling for a low price and takes less room on the boat for installation.

Plus, I can swing it on and off in seconds with a halyard so I don't need to take it when we go racing.

We have used window unit AC's for about 20 years. They fit our boat. They have been cost effective and when one breaks we just replace it the same day with a trip to an appliance store. This new one, (the Midea 8000BTU) is much smaller, much quieter, and my electric bill this summer has been about $110 per month instead of $250 per month with my last unit, which was an LG 8000BTU, so we're thrilled.

[PineyWoodsPete]

Originally Posted by Adelie

So here's an update of a previous post.

Since then I made a spread sheet using the data for about 50 tractors made in the last 40yr with engines up to about 75hp which is the maximum size that would go into a cruising boat.
I looked at a several pairs of engines where the base engine was the same but a turbo was added. I didn't see a significant improvement in fuel economy.
Research elsewhere indicated turbos offer about a 3% gain in fuel efficiency for gas and diesel engines.
https://www.caranddriver.com/feature...-economy-bust/

From my spreadsheet I also noticed that fuel efficiency decreased as the engine got smaller and it decreased as the engine output was throttled down.
This data is from tractors where rpm was kept near constant and power was decreased by throttling and because the output was thru a multi-speed transmission.
In cruising vessels rpm varies with output so that is maybe a significant difference from the tractor data. Since I haven't been able to find good boat data for the time being I am assuming they behave about the same.

Most engines had max efficiency at max HP.
For engines near 30hp I would expect about 14.0-15.0 hp-hr/gal.
I would expect a 20% loss of efficiency at 50% max HP output, for sailboats that's about 80% max rpm which is normal cruising rpm.

Despite the drop in motor efficiency the vessel mpg improves as a vessel slows because vessel drag is dropping faster. For ICE propelled vessels 30-40' best mpg is near 3kt. depends on the particular vessel and motor.

The stats for my 2.5L VW 165 HP turbo marine engine - accepting that the GPH instrument reading under way is correct - and the HP consumed is picked off the prop demand curve below (with a 1.33X kW to HP factor) - at 80% max revs of 3200, the GPH is 4.76, with PD of 80HP, you get 16.8 HP/gal-hour. At WOT of 4000, 165HP and 8.5GPH, 19.4.

[Adelie]

Originally Posted by PineyWoodsPete

The stats for my 2.5L VW 165 HP turbo marine engine - accepting that the GPH instrument reading under way is correct - and the HP consumed is picked off the prop demand curve below (with a 1.33X kW to HP factor) - at 80% max revs of 3200, the GPH is 4.76, with PD of 80HP, you get 16.8 HP/gal-hour. At WOT of 4000, 165HP and 8.5GPH, 19.4.

I make it 58kW @3200rpm.
58hp /0.746kW/hp = 77.75hp.
77.75hp / 4.76gal/hr = 16.3 hp-hr/gal.

50% load and 16% loss of efficiency.

This is presuming that the propellor curve matches what is installed on your boat. It's probably close so I wouldn't quibble with your numbers.
Your engine is very new and very large so 19.4 hp-hr/gal is not unreasonable.