Which Solar Panel Brands Are Considered The Best?

[Ndavies]

I have Siemens on my boat. I do not know their age as they were on when I bought the boat, but must be less than 20 years. The output is way down based on the meter at my panel. Has anyone had experience with Siemens warranty? I believe its 20 years, but not sure if it transfers different owners, or if there's any way to find the date of manufacture.
Neil

[Steadman Uhlich]

Howdy All!

I have started a new thread on CF that is to serve as an "Illustrated Guide to Solar Installations on Boats"

I hope you will participate in that thread too, by posting some photos and answering a few questions related to your own Solar Installations. The questions are easy but may help others.

The new thread is not intended to take away from this current discussion, but is intended to provide an easy way to look at a lot of different installations for ideas and information. I hope you will add to it too.

Here is a link to that thread:

Illustrated Guide to Solar Installations on Boats
Illustrated Guide to Solar Installations on Boats - Cruisers & Sailing Forums

[Ardbeg]

I installed Kyocera 2 x 240 W in 2011. I have never had a problem, I am fully charged at 900am on a sunny day up north. Seems to me they were made in Mexico , not China. They are on a frame on top of Bimini. I would like to change just to reduce weight but otherwise hard to justify. I seem to remember costs of $450 each in 2011.

[iseadreamer]

19 years on two Siemens 75 watt panels swapped for two higher wattage Renogy panels. Third 19 year oild Siemens 50 watt still putting out full voltage as were the two 75 watt I swapped.

[epiic]

From my reasearch, Solara are the best solar panels available today.

With that said, they are very expensive when compared to other options.

I purchased them because of their efficiency (22%). I am limited in space so I wanted the most efficiency possible.

If space was not a concern, I would just buy twice as many cheap panels.

[noelex 77]

Originally Posted by epiic

From my reasearch, Solara are the best solar panels available today.

With that said, they are very expensive when compared to other options.

I purchased them because of their efficiency (22%). I am limited in space so I wanted the most efficiency possible.

There are a lot of traps for the unwary when dealing with solar panels.

The Solara ultra series list the efficiency as 22%, but I think they are refering to call efficiency. The efficiency of the total panel will be less because of the space taken up by the frame etc.

By my calculations the panel efficiency of the best Solara product I can find is around 16.75%. Good, but not state of the art.

It is important to compare apples with apples.

There are other brands with a panel efficiencies of over 21% that are available.

Solar panels change rapidly so if you can provide a link to any other better Solara panels I will repeat the calculations. Perhaps Solara have produced something better that I have not found. The smallest possible solar panels for a given wattage are often important on yacht installations, so these numbers can be important.

[Paul L]

Originally Posted by thinwater

The more important trend is that rigid panels are nearly always durable (even cheap panels have very low failure rates) and flexible panels are not (even slight flexing and the most expensive fail).

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[GafferMate]

Originally Posted by Paul L

....

Amazing. What's the use of touting them as Flexible if not?

This is the first I've heard that and I don't understand, or, to clarify my situation and hope someone has more information:

1. I have NO place on deck for rigid panels
2. have low freeboard where they might have attached to the mizzen boom gallows/boomkin frame but understand that the salt water exposure would not be good for them when sailing

So I've been looking into installing two flexible panels (backed to make them more rigid) between the mizzen shrouds, port and starboard, attached to a ratline at top, angle adjustable from the bottom.

Diane

[CAELESTIS]

I think Noelex gave you the straight story. 100w is 100w, but the foot print may or may not allow enough panels to fit. Sunpower is the most efficient, followed by Sanyo/Panasonic.

Here is a brief comparison: Kyocera KU270 is 65x38 or 2470sq in and weighs 41 lbs. The Sanyo HIT 240 is 62x32 or 1922 sq in and 33 lbs. Depending on your fitment issues you may or may not be able to hold more than one KU270. On my boat, with a split backstay, I could only have one Sunpower or one Kyocera panel instead of two Sanyo 240w. 270 vs 480 is a big difference.

[john61ct]

Originally Posted by GafferMate

Amazing. What's the use of touting them as Flexible if not?

Flexible just means they can be * affixed * directly to a rigid surface that has a slight curve, usually spec'd at 20-30°.

The cells themselves cannot be allowed to actually flex in use. Why they put the "semi-" hedging qualifier in there.

If you are mounting to a non-rigid surface, be sure the vendor supplies them already fixed to their specified backing plate for maximum longevity.

Which will be likely much lower than a fixed frame panel, but making best of the situation.

[Dave_S]

Does the efficiency run linear to input?

We have plenty of strong sun light but can go a week with cloud cover.

Do they all perform to there efficiency rating in low light or are some better than others when cloudy or morning/afternoon or when in the shadow of the sail.

I think I am better served with panels that work harder in poor conditions.

[noelex 77]

Originally Posted by Dave_S

Does the efficiency run linear to input?

Generally the high effeciency panels do better in low light and hot conditions than the less effecient panels.

So typically a 100w 21% efficent panel will produce a little more amp hours than a 100w 14% efficient panel. But the difference is not great. The big advantage is that the 21% panel will be significantly smaller allowing more watts to be fitted into the same space.

A 150w 21% effecient panel will produce slighly more than 50% more amp hours than a 100w 14% panel in both good and bad conditions, but both panels will be the same area.

A high output in shaded or low light conditions would be fantastic, but no solar panel can do this.

[GafferMate]

Originally Posted by john61ct

Flexible just means they can be * affixed * directly to a rigid surface that has a slight curve, usually spec'd at 20-30°.

The cells themselves cannot be allowed to actually flex in use. Why they put the "semi-" hedging qualifier in there.

If you are mounting to a non-rigid surface, be sure the vendor supplies them already fixed to their specified backing plate for maximum longevity.

Which will be likely much lower than a fixed frame panel, but making best of the situation.

Thank you, much appreciated advice.

[jmtindle3]

Can you name some panel manufactures that make 21%+

[smj]

I'm pretty sure Sunpower are the most efficient, and they are also the least affected by partial shading.