Marine-specific or domestic panels?

[drugboatdreams]

Greetings All!

We are starting to plan out a solar array, in preparation for an extended cruise. Our yacht is a 57' cutter-rigged 1990 Nordia sloop, currently housing 6 x 260Ah AGM domestic batteries on a 24v system.

Admittedly we are yet to replace / update a number of electrical systems, including swapping all lighting for LED; we will of course undertake a power audit to work out the appropriate storage and required input. Irrespective, she is a big boat with a lot of electrical systems and appliances, so we anticipate needing a substantial solar array. She currently only has a 12 kVA Onan generator to produce power, the use of which we would like to keep to a minimum.

The working plan is to have an arch fabricated above the davits, which across our ~15ft beam should offer a good amount of space. What I am specifically confused by is whether or not marine-specific panels are necessary or worth the investment...

I had taken interest in the Solara M-Series panels, which are explicitly marine-rated, but they only go up to 140W, at which they cost over £900 a piece! Yet when I look to a cheaper manufacturer such as Photonic Universe, I can get a 280W panel for £350. This is still described as being 'suitable for a boat' (not explicit about the protection in a harsh marine environment), but for an array of 3 panels I would spend half as much money as with Solara and apparently see double the power.

I have made an enquiry with Sunpower about their X-Series 335W black panels, which are apparently the most efficient available, but am yet to hear back with a price.

Does anyone have any particular tips or advice, particularly regarding whether we are likely to have problems with 'domestic' panels when sailing offshore and in remote destinations?

[Pete7]

I bought a smaler Solara M 45w panel about 7 years ago second hand, couldn't afford the then new price of £500. It failed last year with the top layer of clear plastic going white when I think water got in it. It had been mounted in front of the spray hood since fitting and we don't walk on it. Disappointed and thankful I didn't pay the full price it went within minutes of me leaving next to the marina bins.

That panel has been replaced by a 30w Lensun Black Panel in April last year.

The other panels I am looking at is the Solar World from Photo universe. I am about to buy a single 150w from them at £219, compared to the cheaper Chinese panels they sell which are 150w for £144 each. I hope that the German cells are better quality, but there is no real way of telling. Output is the same of course. Interestingly their German panels have just gone up in price from £209 to £219 this month, but worth checking there e bay store photonic_universe and their web site as the prices differ sometimes.

As to your question of domestic panels in a marine environment, well we have also had a 80w cheap chinese panel on the pushpit for 3-4 years 24/7 through the English winters and it has survived everything. Well apart from another yacht in East Cowes Marina who crashed into it and bent the frame, but that's hardly the fault of the panel.

I certainly won't be buying Solara again because they are just too expensive, and if a cheaper panel fails in short order well I will take the risk and sort it if it happens.

Pete

[fallingeggs]

Many, many boats sport "domestic" panels for the very reasons you stated... the price of marine versions are off the charts. If you can replace a domestic panel at a third of the cost of a marine version, who cares if it only lasts half as long? And this is coming from a community of people that more-often-than-not spend the extra money for marine quality gear because it is really worth it.

I don't think enough people have had problems with the cheaper panels to warrant the high price of Solara and the like for most situations. There are better Chinese panels and there are worse ones. I picked from the better side of the spectrum, at least according to the high number of reviews online. For $100 per 100 watts, I'll be happy if I get five years of use. Ecstatic if I get ten.

If you're doing a $100k+ refit to sail for ten years away from major cities, perhaps the add security of Solara would be worth the extra $2k. You certainly won't be disappointed with them.

(Sorry for using '$' and not '£', but you get the point...)

[sailorchic34]

I have one 130 watt high quality solar panel and two cheap Chinese solar panels from solar . The high quality one has a thicker aluminum extrusion then the cheap Chinese panels but otherwise they look identical.

After 5 years there is no deterioration in any of the panels.

[john61ct]

I think we're getting close to commodity time for panels, efficiencies rising, prices falling. IMO buy cheap expecting five years max, if you get more that'll be a bonus.

By then it'll be part of gelcoat paint or something

[wiekeith]

I went through the same thinking process. I concluded that even if I did have to replace the panels two or three times over a ten year period, say, I would, in doing so, be keeping up with the ever-improving efficiencies of solar panels. Not only would my overall spend still be less than buying marine grade in the first place, I would likely end up with significantly higher wattage panels for the same area at the end of the ten year period.

[Paul L]

Originally Posted by john61ct

I think we're getting close to commodity time for panels, efficiencies rising, prices falling. IMO buy cheap expecting five years max, if you get more that'll be a bonus.

By then it'll be part of gelcoat paint or something

I think you are on to something here. High cost panels just don't offer 3x the utility of commodity panels.

As far as efficiency is concerned, you can purchase low cost panels made with Sunpower cells.

[zeehag]

the term marine means 400 percent increase in pricing. outdoor use is adequate and works well for looong time.
all my panels have been outdoor use and minimum duration of use has been 10 plus years. no sweat. they work, i use

[Cotemar]

Domestic Solar panels work very well on boats. Many, Many are already using them.

SunPower is by far the best with 22% efficiency. They are the lightest and smallest for there power output.

Panasonic HIT panels would be my 2nd choice at 19.7% efficiency .

[Rapanui]

Again, we have used domestic panels 3 times now on 3 boats, longest were 10 years with no apparent physical or electrical deterioration. The anodised aluminium frames seem to last very well as long as you use insulating washers between stainless bolts and frame.
The only 'marine' panels we ever had were a couple of Solarex flexible panels on coach roof, not walked on and they deteriorated within 5 years. When you think I can buy used German made 210 W panels for £85, its a no brainer if you have the real estate.

[skipgundlach]

Originally Posted by Cotemar

Domestic Solar panels work very well on boats. Many, Many are already using them.

SunPower is by far the best with 22% efficiency. They are the lightest and smallest for there power output.

Panasonic HIT panels would be my 2nd choice at 19.7% efficiency .

A note about Sunpower...

I have two 360w which fit into the space previously taken by 3 panels with 370W, 12 years old.

I'm thrilled.

But they closely control their channel; if a dealer installs it, it's warranteed. Movable platforms (RVs and Boats, maybe something else) get a 12 year warranty. If you DIY, I presume it has none, based on the conversation I had with Sunpower. Dealing with a Sunpower rep and getting installed may also be much le$$ than buying outside the channel; in our case it was notably so. AND be aware that residential panels have no mounting holes. The commercial ones do, and it was eventually what we installed.

So, while you'll pay a premium for the efficiency, if your space works, you can get up to double the output for a given space. OTOH, if you have acres of room, the cheapest panels you can get will deliver cheaper amps.

You pays your money and takes your choices. Ours was to go efficient and double our power in the same footprint.

L8R

Skip

[john61ct]

I assume the above only applies to where Sunpower is the mfg of the whole panel assembly.

When another brand uses sp cells, then everything about the warranty is on the panel brand, nothing to do with sp.

Also there are jurisdictions where there is always some minimum guarantee by law.

[skipgundlach]

Yah, I expect that's right.

My research didn't include panels made with Sunpower cells; I never saw any panels with their efficiency other than from Sunpower.

Can you suggest some such manufacturers? It might be a great option.

[LeeV]

Originally Posted by fallingeggs

Many, many boats sport "domestic" panels for the very reasons you stated... the price of marine versions are off the charts. If you can replace a domestic panel at a third of the cost of a marine version, who cares if it only lasts half as long? And this is coming from a community of people that more-often-than-not spend the extra money for marine quality gear because it is really worth it.

I don't think enough people have had problems with the cheaper panels to warrant the high price of Solara and the like for most situations. There are better Chinese panels and there are worse ones. I picked from the better side of the spectrum, at least according to the high number of reviews online. For $100 per 100 watts, I'll be happy if I get five years of use. Ecstatic if I get ten.

If you're doing a $100k+ refit to sail for ten years away from major cities, perhaps the add security of Solara would be worth the extra $2k. You certainly won't be disappointed with them.

(Sorry for using '$' and not '£', but you get the point...)

So which panels did you go with, since I'm trying to make the same decision?

[Training Wheels]

Originally Posted by skipgundlach

Yah, I expect that's right.

My research didn't include panels made with Sunpower cells; I never saw any panels with their efficiency other than from Sunpower.

Can you suggest some such manufacturers? It might be a great option.

I've got Sunbeam Systems panels, which use Sunpower cells. 22% efficiency.