Does a genset still make sense?

[rslifkin]

Originally Posted by Na Mara

For this very reason I also refuse to have a bimini on Na Mara. I’m a tilly hat and full length clothing kind of guy when on deck, else I’m below in the pilothouse. But in very hot climes and on boats without a pilothouse I can except your logic.

Having a pilothouse makes a huge difference there. For those without (which is likely the majority of sailboats on this site) having some shelter in the cockpit becomes more important for being able to use the boat comfortably.

[Na Mara]

When I did the calculations I used the correct formula for inclined planes. I don’t have them on me now and can’t remember the calculations in detail save that they weren’t straightforward. In any case, it is a significant turning moment on the boat that has to be trimmed out and it is significantly more drag upwind than one gets if one assumes that the panel is horizontal.

It also has the undesirable feature that the turning moment on the boat increases with heel. The more overpressed you are, the worse the panels will affect your helm.

They aren’t for me.

[s/v Jedi]

Originally Posted by Simi 60

It's a perfectly valid argument
Small battery bank does not require as large a charging source as a large battery bank
And I did say the Honda is fine on a small battery bank running a smaller charger.

If they have an 18kw Genset I would assume they have an even larger battery bank and probably 3x 120 amp chargers.

So they to would have a valid argument, for their big battery bank
As would we that the 6kw genset and 1 X 130amp charger is ok for medium battery bank
As would the Honda with 40 amp charger be good for a smaller battery bank.

No, they may find that you have a small battery bank. Big, small it’s all meaningless. You put everything you write in your window of reference but that’s not how it works when people are on very wide, diverse range equipment. We have members with two 12V 100Ah batteries who consider it plenty big and we have others with 15-20 times as much who think it may just be enough.

[team karst]

It is all quite scalable. Even the Honda 2.2 can get more numerous or larger/smaller. Chargers, banks, solar area, genset size, wire size.
You can buy a 18MW wind turbine these days. [emoji15]

[sailingharry]

Originally Posted by Na Mara

When your boat heels the underside of your panels is exposed to the wind doing the heeling. A 3m2 panel heeled 20 degrees has the same windage as a 1m2 panel. Try holding a 1m2 panel face on into a Force 6.

The exposed windage is perpendicular to your direction of travel, and has no net impact on your boat speed. It does provide about as much heeling moment as your boom provides.

[malbert73]

Originally Posted by sailingharry

The exposed windage is perpendicular to your direction of travel, and has no net impact on your boat speed. It does provide about as much heeling moment as your boom provides.

Not when you’re sailing and heeled over- then there’s a ton of drag particularly upwind, as well as loads more weather helm. All are compromises

[NYSail]

I have a balmar 150 alt, 400 watts solar and a 3.5kw genset. Each play a needed part especially now that we have moved off the dock permanently.

Greg

[GordMay]

Originally Posted by noelex 77

You are assuming the same drag coefficient, which is not accurate. The drag coefficient of a 20° inclined plane is around 20% of a flat surface.

The impact of wind is typically measured, in [lighting] specification sheets, by Effective Projected Area [EPA], which is a physical [drag] coefficient, used to evaluate the wind-induced loads, expected on a structure.
EPA = Frontal Projected Area x Drag Coefficient
Comparing a round surface object [drag coefficient of 0.5] and a rectangular flat shape object [drag coefficient of 1.2], for the very same area, the rectangular object will create around 60 % more resistance, than the round object.
The commonly assumed Drag Coefficient values are:
Flat Plate Body DC = 1.20
Spherical Body DC = 0.85
Angled Body DC = 1.00

Effective Projected Area Calculator
➥ https://calculator.academy/effective...ea-calculator/

[s/v Jedi]

Originally Posted by malbert73

Not when you’re sailing and heeled over- then there’s a ton of drag particularly upwind, as well as loads more weather helm. All are compromises

No, not at all. Have you had this large array and had to remove it because of the issues you claim? I think not, I think it’s speculation.

We found zero impact, no weather helm, nothing. Maybe it even lifts the stern up from the water a bit.

[The Yacht Rigger]

Originally Posted by dhenline

I hope a generator is still needed. I am buying a new Cat and opted for the Generator and did NOT opt for Lithium batteries.
in all my previous chartering in the Caribbean, I use AC most evenings and since we are headed to the Pacific Ocean, I know I will use AC. the amount of Lithium needed to run AC is mind boggling. So a generator for me. I will find out later if I made the correct decision

Its certainly all a compromise. We do a lot of installs that negate the need for a generator and allow for AC usage whenever desired, but you're correct, it requires a large, expensive battery bank, large solar array, and high output alternators.
The trade off is the benefit of not having to listen to, maintain, and or fuel up a generator ever, and freeing up storage space and weight.

It's all a trade off, neither choice is correct or incorrect.

[Fuss]

Originally Posted by s/v Jedi

No, they may find that you have a small battery bank. Big, small it’s all meaningless. You put everything you write in your window of reference but that’s not how it works when people are on very wide, diverse range equipment. We have members with two 12V 100Ah batteries who consider it plenty big and we have others with 15-20 times as much who think it may just be enough.

Very wide, range of diverse equipment!! They shouldn’t be….
This is the cruisers forum, cruising boats , cruising people , cruising answers.
So we are talking about cruising and cruising means self sufficiency …cooking, moving, running systems…this is not the at the dock every 2nd day Forum.

Now if we have a problem with that, look at the heading of the app in the top left corner. That exactly what it says…. cruisers forum, cruising boats , cruising people , cruising answers.

Ok now, this means that we want batteries to last 4 days at anchor, we want to be able to charge them back up.
So who are you to specify a number like 4 days I hear you say… well that’s because I said so. It’s 4 days with no charging back up , whether solar or diesel. Of course the solar people will be boasting that by xx in the morning the batteries are full again…but I don’t care about this, partly because I can’t charge mine back up by xx as I only have 400w of panels….they’re a bit old now.
Charging up by xx in the morning is not important these days with lifepo4 but putting back what you took out is.
One day, the charging back up by xx in the morning cruisers will have no sun for 4 days and then they will revert to only charging while motoring or using the generator or using the motor while not motoring. So…I guess some people might still need it occasionally.

[noelex 77]

Originally Posted by Fuss

One day, the charging back up by xx in the morning cruisers will have no sun for 4 days and then they will revert to only charging while motoring or using the generator or using the motor while not motoring. So…I guess some people might still need it occasionally.

One of the myths about solar production is that on poor days the output is zero. This is not accurate. If you have enough solar production that on good days you are back to 100% SOC by the morning, on poor days the total daily output will likely still be close to the consumption.

[Fuss]

Originally Posted by noelex 77

One of the myths about solar production is that on poor days the output is zero. This is not accurate. If you have enough solar production that on good days you are back to 100% SOC by the morning, on poor days the total daily output will likely still be close to the consumption.

How much solar and battery do you have and how much consumption?
I am upgrading my solar soon …but just to keep everything in balance.

[noelex 77]

Originally Posted by Fuss

How much solar and battery do you have and how much consumption?
I am upgrading my solar soon …but just to keep everything in balance.

We have just over 1000w of solar. 600 Ahrs @24v of lead acid batteries.

When solar energy is reasonable we do all cooking and hot water heating via solar with a consumption around 5kw per day. However, our electrical consumption is variable, by design, with propane and diesel backups for high draw devices (no generator). These alternatives are used when cruising in areas of poor solar insolation such as Scotland in winter.

[deltaten]

At the exorbitant $$ outlets get for new diesel gensets, I'd go with the Honda portable..or two, mebbe even a larger model. Not to run the whole boat, mind you; but as back-up charging for those times sun or runs are short.
You could buy 8-10 Hondas for the cost of a new inboard diesel
They sip fuel! A gallon or two of gas, stored and vented safely/properly could last quite a while.
Noise is minimal and a bit of sound shielding helps too. Just don't be a d!@k about running it .

There are alternatives to the $1200 (MSRP!) Honda 2200w, too. A quick poke around RV sites revealed quite a few comparisons. Honda also makes portable; but large-ish diesel gensets, in the same price range as NL and others. With all the troubles folks seem to have with "marine" gennies, if I needed all that power, it's the way I'd go.
HTH