Wondering why more power boats aren't using solar power to recharge house batteries?

[Stumble]

It really just depends on the design. Our big power boat is not designed to be off of generator or shore power ever. It isn't just the refrigerator or AC, things like hatches that don't open so there's no way to get ventilation. There's no ice box, or freezer plates to keep things cool, there is effectively no ventilation in any of the boat, all lighting is 110v except for some work lights on deck.

We have the generator on all the time because that's how the boat was designed to work, and we don't have any real intention of changing it. Solar panels and a battery bank large enough to power the boat would be incredibly expensive for the loads we need to run.

On the other hand she was bought as a party day boat. Go out in the morning with 25 of your friends and hang out on the water for the day then head back to the dock. A few times we have stayed anchored out over night, or for a few days with just another couple, but thats rare. In part because of where we are, and in part because if we are dong that I would rather take the sailboat.

[SeaSon]

As a trawler owner that lives aboard 6 months per year and anchors out 70+ pct I can share that my reason for not going solar is financial. To run the generator it costs about $1.50 per day on those days I am not running the primary engines. So about $100 per year vs $2500 for a solar set up. It would be really nice for silent charging vs the lousy old generator banging away, but the Missus talked me out of going solar for merely ego reasons, and to save the money for repairs and cruising.

And I just don't really give a crap about my carbon footprint.

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[mitiempo]

Originally Posted by JohnEasley

Hoping some of you engineering types can explain to us why more power boats aren't taking advantage of solar panels.....

Most seem to be running a single group 27 house battery.

Any idea why more power boaters aren't using solar?

John

I haven't seen many powerboats of any size running a single group 27. Most have either 4 or more golf cart batteries or the once popular 8D's.

Powerboats have several advantages over sailboats when it comes to power management, as well as some disadvantages.

One advantage is a powerboat's battery bank is usually fully charged when they arrive at an anchorage - sailboats not so much.

Another advantage is larger and often multiple alternators which when fed to the house bank can improve charging times.

Their disadvantages are often larger refrigeration systems and more home comforts that use power - either DC or AC.

I sell solar systems and more and more powerboat owners are getting on the solar bandwagon. With large biminis on many boats and without the shadowing of mast and rigging to deal with a pretty nice array can be installed.

As an example I have several customers with Bayliner 3288's that have installed enough solar to gain about 200 AH or more per sunny day. If there is no air conditioning - not used often in this area anyway - that can mean not running a generator at all.

[Pizzazz]

The issues are cost and looks. Installing more than 100-200 watts on a typical 30 ft boat is difficult. It gets in the way or shaded by the boom. It looks ugly, sort of like the big satellite TV dishes of the 80s. You get 30 amp hours per day, equivalent to running the engine for half an hour at a cost of less than a $1 per day. The carbon footprint argument for boats is minimal. It just does not make sense unless cruising for extended periods of time. It could also be a backup in case you run down both batteries at an anchor but that is rare. I would still do it one day but more for the novelty argument than need.

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[mitiempo]

Originally Posted by Pizzazz

The issues are cost and looks. Installing more than 100-200 watts on a typical 30 ft boat is difficult. It gets in the way or shaded by the boom. It looks ugly, sort of like the big satellite TV dishes of the 80s. You get 30 amp hours per day, equivalent to running the engine for half an hour at a cost of less than a $1 per day. The carbon footprint argument for boats is minimal. It just does not make sense unless cruising for extended periods of time. It could also be a backup in case you run down both batteries at an anchor but that is rare. I would still do it one day but more for the novelty argument than need.

A powerboat often has an easier time of installing un-shaded solar panels than a sailboat. More wattage as well.

[captain58sailin]

I recently installed 540 watts of solar panels, and I have 150 amp alternator on my M.E., and a 30kw gen set. Granted my application is more commercial than most here, however I am delighted to have the solar panels producing power when I am at anchor and I don't want to run the gen set. I try not to run the gen set except for keeping my fish hold refrigerated. I can sit at anchor for several days at a time and my battery voltage stays up. I don't run microwaves or A/C or a lot of items that many have come to think of as necessities, and I am in the process of replacing all of my 12 volt incandescent bulb fixtures with LEDs. My intent is to get things as efficient as possible and not run any engines if I don't have to, more of a cheap skate thing than carbon footprint thing, though it does serve both purposes, plus I don't want to listen to the engine run if I don't have to.

[ranger58sb]

Originally Posted by JohnEasley

Been looking at some mid-80s Chris-craft Catalinas. Most seem to be running a single group 27 house battery.

But none of the example boats we've seen online have solar panels. Seems like a no-brainer. Any idea why more power boaters aren't using solar?

As many have said, many of what you've been looking at would have been expected to be used for marina hopping, only limited anchoring...

A couple other thoughts: (often) limited real estate, and age. Many of the boat with soft biminis and no arches (or arches already over-subscribed) don't have obvious places to install solar... without some additional work. Not un-fixable, but not always a walk in the park. Better on boats with existing flat hardtops...

But then there's that age thing. Relatively new technology (solar) on a 1980's boat... would have meant an owner along the way who decided to upgrade... an old boat. There are reasons to do that, but often upgrades don't really add much (if any) monetary value to the basic boat... so often owners use the money for maintenance and living, instead of upgrading like that.

A point you can use during your shopping: upgrades like that may give you some insight into the owner, and how likely he was to have kept a boat up.

Another is about batteries; a single Group 27 can suggest how the boat was used... in this case, I'd guess mostly tied to a dock or marina hopping, maybe day trips.

-Chris

[MV Wanderlust]

Originally Posted by SeaSon

As a trawler owner that lives aboard 6 months per year and anchors out 70+ pct I can share that my reason for not going solar is financial. To run the generator it costs about $1.50 per day on those days I am not running the primary engines. So about $100 per year vs $2500 for a solar set up. It would be really nice for silent charging vs the lousy old generator banging away, but the Missus talked me out of going solar for merely ego reasons, and to save the money for repairs and cruising.

SeaSon, that was exactly what we needed to hear. Thanks.

Originally Posted by mitiempo

I haven't seen many powerboats of any size running a single group 27. Most have either 4 or more golf cart batteries or the once popular 8D's.

Powerboats have several advantages over sailboats when it comes to power management, as well as some disadvantages.

One advantage is a powerboat's battery bank is usually fully charged when they arrive at an anchorage - sailboats not so much.

Another advantage is larger and often multiple alternators which when fed to the house bank can improve charging times.

Their disadvantages are often larger refrigeration systems and more home comforts that use power - either DC or AC.

mitiempo: Thanks. Been wondering why they only had one house battery so, yeah, they probably marina hop. My wife and I are planning to anchor out, too. A house battery bank is probably something we'll invest in. We're in Florida and planning to run coastal and into the Caribbean so we'll be running the a/c and the refrigerator pretty much all the time.

What if we hooked up six 6 volt golf cart batteries in a bank and ran the refrigerator, A/C, and stove off of an inverter with the anchor light and interior lights running, too? Would that likely deplete such a bank overnight? Seems like it would. If that's the case, we'll need the generator running, anyway.

Originally Posted by ranger42c

...often owners use the money for maintenance and living, instead of upgrading like that.

A point you can use during your shopping: upgrades like that may give you some insight into the owner, and how likely he was to have kept a boat up.

Another is about batteries; a single Group 27 can suggest how the boat was used... in this case, I'd guess mostly tied to a dock or marina hopping, maybe day trips.

Some great points, Chris. Good insights. Thanks.

[StuM]

Originally Posted by JohnEasley

What if we hooked up six 6 volt golf cart batteries in a bank and ran the refrigerator, A/C, and stove off of an inverter with the anchor light and interior lights running, too? Would that likely deplete such a bank overnight? Seems like it would. If that's the case, we'll need the generator running, anyway.

Generally, if you are running aircon at sea, you need to run it off a generator.

Assume you are looking at a minimum of 12000BTU a/con in your proposed area. You're looking roughly 1000 Watts draw (approx 80 Amps @ 12V).

Even at a 50% duty cycle overnight (which is likely to be on the low side - it could well be 80%), that's around 500Ah (80A x 0.5 * 12 hours). If you are on Lead Acid batteries, that would require at least 1000Ah of storage just for the a/con without considering the other loads.

Your 6 x 6V golf cart batteries will probably only give you around half of your a/con requirement alone.

[MV Wanderlust]

Originally Posted by StuM

Generally, if you are running aircon at sea, you need to run it off a generator.

Assume you are looking at a minimum of 12000BTU a/con in your proposed area. You're looking roughly 1000 Watts draw (approx 80 Amps @ 12V).

Even at a 50% duty cycle overnight (which is likely to be on the low side - it could well be 80%), that's around 500Ah (80A x 0.5 * 12 hours). If you are on Lead Acid batteries, that would require at least 1000Ah of storage just for the a/con without considering the other loads.

Your 6 x 6V golf cart batteries will probably only give you around half of your a/con requirement alone.

Thanks, StuM. That pretty much settles it. Generator, it will be.

[savoir]

Those motorboat guys do love their aircon. Today on my dock 4 unoccupied mortorboats were running theirs.

[SeaSon]

K

Originally Posted by JohnEasley

Thanks, StuM. That pretty much settles it. Generator, it will be.

You'll want at least 4 or 6 6v batteries to run the boat, with out aircond. I use Trojan T105s. 4 gives me total 440ah, at half depletion 220ah of usable power - on night one from the marina or an 5 hour run on engines. That runs a 120v 4.4cuft fridge(6-9amps at 50-80pct duty based on ambient air temp), tv/dvd for a couple hours, microwave for 3 minutes (1000watts is 110 amps when on battery), lights, coffee maker in the am, maybe run the 120v 4cuft freezer (we don't use it if we are anchoring for several days in a row without travel). Gen charge time is maybe 2.5 hours at 80+ amps smart charger, but you'll never get them up to full after the first night solely at anchor (those last amps don't want to get stuffed in, so take much longer, so you turn the generator off prior to reaching 'float'), so figure 80-90pct, or for me night 2 solely at anchor, I've got 120ah available. Let me know if my meaning is not clear regarding night 1 vs night 2.

Engines charge time maybe 5 hours at perhaps 60 amp average to full charge. If we are doing a short run, then I'll fire up the generator as we drive to make sure the batteries are fully topped up prior to anchoring.

My generator is 7.5kw, and can run one ac unit (breakers pop trying to run two), but I couldn't bear to listen to it all night, so I wouldn't go to the Bahamas unless it is winter. Perhaps the modern gens are quieter.

Ps the Erie Canal is really nice and cool this time of year vs our home in Fort Myers. We'll be on Lake Huron by mid July.


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[SV THIRD DAY]

Originally Posted by sailorboy1

that was ridiculous and unneeded insulting

I see larger powerboats with solar panels around. They are the ones that seem to stay on moorings or at anchor for a while and which don't motor from place to place as often.

I agree...acting as if blow boaters are somehow environmentally superior to power boaters is ridiculous, divisive and plain BS.

[pickpaul]

Originally Posted by SV THIRD DAY

I agree...acting as if blow boaters are somehow environmentally superior to power boaters is ridiculous, divisive and plain BS.

Sailboats are clearly environmentally superior to powerboats.

[knockabout]

stink boats don't move with out the motor running and the alternator charging /have noticed one with 2 large panels for rear shade /converted trawler liveaboard/most large stink boats have gensets.