Any experience with the new high capacity 400W plus solar panels?

[CampDavid]

invest in the MPPT control and wiring. that gets the most out of the input. two x 250 panels gives a lot of amps in the high noon hour

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[Martkimwat]

you should be aware that even '12 volt' panels normally output around 17~18 volts which is fine for small currents but would blow your electronics if connected directly with larger currents, therefore you would still need to put them through a controller for anything more than trickle charging. The other consideration is that one single panel if shaded, would not only suffer a drop of in output current but also a drop of in voltage, possibly down to around 12 volts or less in which case it would not provide any ' potential' and would not charge. With multiple panels if some are shaded, the unshaded ones would still output their full potential and you would still get some charge, additionally if a panel is damaged, it's a lot cheaper to replace one small panel than one large panel. You can mix and match panels since their power output is cumulative, it doesn't matter if you connect a 10 w panel and a 100 w panel together, so long as they are each fitted with a reverse current diode, ( not everyone is) it won't matter as all the poer will be added together at the controller. Some controllers can handle much higher voltages input eyed and still output a regulated '12 volt' output ( in practise probably something in the order of 12.5~ 13 volt) to the battery bank. The advantage as you say is smaller cable losses to the controller and additionally voltage losses due to to shading are less critical. Although much more modest than your requirements, I have a 68 w panel on my hatch garage and two 18 w panels each side of the coach roof behind the saloon Windows on a 26 foot boat (Parker 27) these easily provide enough power for me to keep a 22 litre compressor cool box running without interruption plus LED lighting, and if necessary my Eberspacher diesel heater. Only if I add in my electronics needs do I then have to supplement the power with some engine time which is taken care off usually by the engine run time required to enter a marina/harbour bearing in mind most of my sailing is coastal day sailing and anchoring or in a marina for the night. Nonetheless, I never have to connect to shore power. for my larger vessel (Tradewind 33) I shall be using a larger version of this setup i.e. 300 w of total panel power feeding into 400 Ahr of battery capacity. I will still use multiple panels rather than a single panel. At present the highest efficiency available is 22% from mono crystalline panels with polycrystalline panels putting out about 16~17% and amorphous crystalline panels way down at 10~12%.

[CarlF]

The biggest solar panel problem on a sailboat is shade. A very small amount of shade can knock out an entire panel (even shade from a backstay is a problem). That's because it only takes a small percentage drop in voltage to go below a battery charge voltage of 13-14v. A solar panel with a few shaded cells putting out 11 volts has zero charge amps.

MainSail had some really good tests of this back a while.

So the best thing to do is find places on your boat that receive no shade and then install panels to fit the sunny space. The 2nd best is to have the panels on the starboard side unshaded while the port side panels are in the shade of the boom - and visa versa.

[socaldmax]

Originally Posted by alansmith

W6GAC, your logic can't be ignored. The "what if's" can always come back to bite you at the worst time. No one needs a nuclear accident at 3 pm in the afternoon....smile

That's why we have the NRC. To protect us from ourselves. (A little Nuke joke there.)

While his fears seem logical, so is the fear of getting hit by a bus while walking across the street. Let's look at them one by one.

All the 400w panels I've looked at (for home/ amateur radio use) output at 48 volts. Having higher voltage helps keep conductor size down/ and lowers wiring losses. These panels are often connected into large scale installation with connected voltage at 600v or 1000v. While OK for stand-alone systems going into special inverters to directly connect/ sell back energy to the power grid... I'm personally very hesitant to install 'high' voltage (48v) solar system on my boat.

The facts he posted above are very true, but the fear of 48V is irrational. Some electric powered boats have 48v or 96v battery banks, submarines run 480v battery banks. The insulation is quite capable of keeping the electrons inside. THe only way the insulation will fail is if it is chafed by a sharp edge, and that's an installation error, not a voltage problem. You're still going to have the same problem at 18v as 48v.

The 'smart' controller has to deal with controlling it to charge/ direct power our 12v systems and usually creates a lot of annoying RFI interference to weak SSB signals. Also a wiring mishap could result in over voltage damage to practically every powered device on the boat.

Yes, any decent solar installation will use an MPPT controller(s) to convert solar panel voltage down to charging voltage of 12-15v. Whether they produce any harmful RFI is another matter. You'd have to test it to see if it does or not. If so, one could shut off the solar controller for the short period one is using SSB, or select a controller that doesn't produce RFI. I don't think "usually" is an accurate statement, not based on my experience or posts on CF. I can only recall 1 or 2 posts regarding RFI issues, but that's from memory.

My experience on boats is firmly wrapped around the KISS principle and understand the worse thing that could go wrong, because it might! Also, if 48v to 12v smart controller dies while enroute... you just can't 'direct wire' the panels to the battery and manually manage charging. I'll stick to 12v panels... for now anyway.

What I don't like about "12v" panels is that their nominal output isn't much over the charging voltage. Let's say the MPPT v for your solar panel is 16.6v, if you have 2 or more panels in parallel, your current flow will be pretty high, especially compared to a 48v panel, which will be putting out equal power, but at 1/3 the current, thus less current loss due to cable size and length. Early in the morning and late in the day, and possibly on really hot days, the output V will not even be high enough for the controller to produce any charge.

While it is true that the solar controller might fail, I've only seen two brands that have - BZ, and Go Power! I would strongly recommend staying away from those brands. It's just as likely, or possibly more likely, that a storm will rip all of your panels off of the roof than a good quality controller will fail.

Yes, things happen. Your engine might fail (much, much much more likely, based on the huge number of engine failure posts here on CF) your saildrive might fill with saltwater, your fuel tanks might grow all kinds of exotic algae, your fresh water tanks might all leak, your batteries might fail at the same time your bilge pumps clog and your EPIRB battery expires while your sat phone has a billing problem and your SSB and VHF won't work because your battery is dead so we should just rip all of the electrical systems and engines out of these sailboats because the only thing you can count on is Murphy's Law, drones buzzing you in a quiet anchorage, high winds when you want to sleep, and no wind when you want to sail and we need to keep it KISS.

Sorry for the run on sentence, but I had to get that all out before my computer blew up. They're very complex.

[Rough Magic]

Socaldmax: hilarious, love your run-on sentence, you made my day. :-)

[D&D]

Originally Posted by Stumble

...Sunpower panels generate 10% more power per sq inch than the competitors, this is a huge increase and can't be ignored.

Indeed...and the difference (between SunPower and others) is magnified when considering output in non-laboratory conditions, e.g. low light and high heat, exactly the conditions experienced on vessels. Official panel efficiency ratings are measured in lab conditions, but of course vessels do NOT operate in lab conditions! SunPower panels add to their product superiority by leading in all non-lab conditions output assessments.

We urge the OP (and anyone considering installing panels on a vessel) to (i) mount your panels as far aft as possible to minimize shading from both sails and bare poles/boom -- Also consider orienting your panels north/south, rather than east/west to increase your effective panel footprint by allowing more panels over any given beam -- and (ii) use SunPower panels!

Our experience is absolutely terrific with 2 x SunPower 327W panels, mounted aft (above our tender davits) and running through an Outback Flexmax MPPT. Our only regret is using a north/south orientation when an east/west orientation would've permitted an additional panel...ah well, a mistake that ended up saving our customers repeating it!

The Flexmax maximizes output in all conditions, including dealing easily with one panel being shaded.

Unfortunately and as confirmed by posts in this thread and others, SunPower panels are often unavailable for small (less than pallet-load) installations.

Anyone in Australia, however, can easily obtain SunPower panels for 'small' vessel installations by -- Here comes the plug! -- ordering them through Floating Impressions for delivery anywhere in OZ...

SunPower E20 327W Panel, Floating Impressions

[Hornloaded]

I installed 1250W (4 panels 10amps@44 volts per panel). I useded the Outback controller and I have 660 amp hr's of batteries.
I read every post about configuration and shading, but in the end I just paralleled all four panels. 3 are on top of the Bimini and one on my davits.
this system charges my batteries by 10 am every morning then starts heating my hot water. Even on rainy days my batteries are full before noon. I no longer even think about power, and never use the generator any more. No regrets going with high voltage panels. I could have gone larger but the Outback controller was the limiting factor.

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[belizesailor]

Originally Posted by StuM

...

TANSTAAFL!

Ha, one of my favorite sayings! Especially applicable to solar.

[spiv]

Most advice above is valid, so I will add just my additional experience.

6y ago, I installed 9 "Flexible", "Amorphous" panels.
The flexible means you can stick on anywhere you have space, you can walk on them, drop objects etc.

Amorphous, provide full power on the unshaded part and full power on the unshaded part of each panel, also if you happen to damage a part of it, the rest still works 100%.
The drawback is that they used to output less power than rigid, non amorphous panels and the coachroof gets slightly warmer where the panels are installed.

I wired them 3x3 in series to get 36V and hence reduce wire size to the controller, then the controller reduced the power to 12V and on a good day I get 35Ah+.

I know that there are newer flexible panels that output nearly double that mine, they would be my choice in a new install. I could just imagine the joy of getting 70Ah....

Also I would install then on 3x3mm polycarbonate 'cardboard' to keep them off the roof and cool better.

[GoingWalkabout]

Originally Posted by D&D

Indeed...and the difference (between SunPower and others) is magnified when considering output in non-laboratory conditions, e.g. low light and high heat, exactly the conditions experienced on vessels. Official panel efficiency ratings are measured in lab conditions, but of course vessels do NOT operate in lab conditions! SunPower panels add to their product superiority by leading in all non-lab conditions output assessments.

We urge the OP (and anyone considering installing panels on a vessel) to (i) mount your panels as far aft as possible to minimize shading from both sails and bare poles/boom -- Also consider orienting your panels north/south, rather than east/west to increase your effective panel footprint by allowing more panels over any given beam -- and (ii) use SunPower panels!

Our experience is absolutely terrific with 2 x SunPower 327W panels, mounted aft (above our tender davits) and running through an Outback Flexmax MPPT. Our only regret is using a north/south orientation when an east/west orientation would've permitted an additional panel...ah well, a mistake that ended up saving our customers repeating it!

The Flexmax maximizes output in all conditions, including dealing easily with one panel being shaded.

Unfortunately and as confirmed by posts in this thread and others, SunPower panels are often unavailable for small (less than pallet-load) installations.

Anyone in Australia, however, can easily obtain SunPower panels for 'small' vessel installations by -- Here comes the plug! -- ordering them through Floating Impressions for delivery anywhere in OZ...

SunPower E20 327W Panel, Floating Impressions

Thanks D&D. Having read all the great replies to my OP and reading the specs of the SunPower, I'm sold. They have a new model that is even more efficient.

The great thing about an install on a Lagoon is the space at the stern. Both width and length.

I'm leaning towards designing a tilt system propably using some kind pneumatic arms so we can pick up the afte Noon sun as well.

Some may think it overkill but I'm also thinking of 2 or 3 lightweight panels on both starboard and port safety railings with a hinge system that will allow them to be deployed like wings and then folded down in rough seas and docking or when not needed for extra power.

What I'm surprised is that there appears to be no dealer/reseller in the USA that has sprung up to service the boating community for SunPower pannels. Very strange that an obviously superior product is so hard to purchase for us boaters. Especially since more than a few dollars could be made. Makes me think about renting a storage room and buying a few pallets and then offering them to boaters.

Again thanks D&D for your advise along with everyone else. It's a great time to be alive and equipping with solar.

Regards,
Chaya

[alansmith]

DMax, you are as psychotic as me. Was giggling by the end of your post...

[D&D]

Originally Posted by GoingWalkabout

Thanks D&D. Having read all the great replies to my OP and reading the specs of the SunPower, I'm sold.

We're pleased to be able to contribute to your plans.

FWIW, we'll add that we too considered the tilting mechanism(s), but opted instead for the KISS principle...and we're glad we did, both for the solid, maintenance-free installation and for no sense whatsoever of suffering for loss of low sun angle power. SunPower are recognized for low sun angle performance and our experience confirms that. So we used only a slight (5-10 degrees) angle to encourage water run off, but otherwise set our panels facing straight up...





We've seen some very big seas crashing around our panels and, especially in those situations, we were comforted by no moving parts out there. Then if you add in cost saving on the install with only polishing required for maintenance, it makes a difficult case (in our view) for any tilting mechanism(s).

As for power, one of our customers installed 5 x E20 panels across the stern of their L450 using a north/south orientation -- BTW, we now note (and regret! ) our initial post here confused the orientations...north/south (as in thin bit across the beam w/the long bit sticking out aft) being the preferred way to go -- and then they added a further panel on the saloon top, giving ~2Kw (327W@ panel) in total...and they are finding all that power works a treat! As you note, the new SunPower panels are more powerful...but they're not available in Australia, yet...

So FWIW we'd suggest maximizing panel numbers...and then not worrying about the tilting mechanism...

In any event, we wish you well with your install...and then fair winds and following seas when you're out enjoying all that solar power!

[GoingWalkabout]

Thanks D&D. Great advise. I will reconsider the tilt mechanism :-)

[model 10]

Originally Posted by GoingWalkabout

Thanks again Stumble. So correct me if I'm wrong. The larger Wattage panels achieve the larger Watt output over others purely based on the larger area of solar cells. I was wrongly thinking that the newer greater wattage panels achieved the higher wattage from a better and more efficient solar cell itself.
e absolutely correct.
Thanks again.
Chaya

Oh they have high performance panels. Satellites have much more high performance panels and they last. I'm grasping here but their panels are like 80% efficient and the old style you refer to are 20% at best.

[Paul Elliott]

Originally Posted by Guy

Oh they have high performance panels. Satellites have much more high performance panels and they last. I'm grasping here but their panels are like 80% efficient and the old style you refer to are 20% at best.

46% is the best I can find:
https://en.wikipedia.org/wiki/Solar_...rev150806).jpg