What Solar System is Best for Us?

[D&D]

Originally Posted by noelex 77

Thanks, I would be very interested in their response.
Difficult conditions for solar panels such as hot temperatures, partial shade and low light are common on boats, so performance under these conditions is important for those that like cold beer

Indeed...and be assured cold beers (& bubbles!) are high on the priority list here!

SunPower's claims about performance in difficult conditions are well supported by both specifications and independent studies.

Looking at hot temps, for example, and this is an area where power loss is always an issue, SunPower's -0.38% Temperature Coefficient Power rating (the power degradation for every 1 degree C over 25 degrees) is one of the best on the market. The average is between -0.40% & -0.50%. i.e. for every one degree, the average panel losses 0.5% whereas SunPower only loses 0.38%. The only thing better is thin film, which has really low efficiency (taking up lots of space).

A Photon test published in June 2012 said this about SunPower...
“The device has a nearly straight efficiency curve with almost no change in the medium-to-high irradiance range and only a minimal drop at low irradiance levels. No other module tested thus far has such an efficiency curve.”




SunPower's superior degradation rates are also confirmed by their market-leading power warranty, the only panel with a 25yr warranty. While it should be noted the SunPower warranty will not apply to vessel installations because of the salt water exposure - We are pressing for this to be reviewed - the warranty still says a lot about the quality of the panels and especially the pv cells. Just as importantly for sailors, the proof of SunPower's salt water durability can be seen in both the voyage of Turanor Planetsolar (circumnavigating the globe Sep 2010-May2012 on SunPower solar power alone...and now still cruising as a mobile solar power ambassador) as well as the panels on our beloved CatNirvana, now with ~5000nm along the OZ east coast and Tasmania.

Finally, SunPower points to all the cutting edge organisations that use their panels as proof they are the best in the word…. NASA, Honda, Planet Solar and many more.

Enough spruiking eh? We can certainly say with confidence that our SunPower panels perform amazingly well...and it seems there's plenty of independent evidence that confirms our experience.

[D&D]

[a bit of clarification...] Really? I'm not sure, but I believe Krocera's warranty covers "mobile use" which includes marine. No. These warranties specifically exclude mobile and marine use and salt damage. Haven't looked at the others, maybe some one else could chime in? And the Solbian panel can hardly be described as "high" efficiency by today's standards(although for a flexible panel that is true, but having been in the solar biz in the past, I don't want any plastic glazing on my panels).Solbian panels are available with SunPower cells or regular cells. The Solbian panels with SunPower cells are indeed "High efficiency", as they incorporate cells of 22% plus efficiencies. Check out the specs. Why is Solara so proud of completely manufactured in Germany if the most important part is from a US company? Although SunPower is an American company, their cells are made in Taiwan, The Philapines, and Indonesia. [We're advised the SunPower cells are made in the Phillipines and Malaysia]and where is it documented that they are using SunPower's most efficient and latest cells? Because if they're not, there are better values to be had out there. SunPower cells are very expensive [more expensive than many others, but not (in our view) "very" expensive relative to durability and output; the latter especially so under less-than-lab conditions] and are only available to major manufacturers in high volume [the cells, perhaps, but the panels are of course widely available]. What value do you put on a high efficiency solar panel that is lightweight, very flexible and durable, and can be installed on existing canvas bimini's or dodgers using zippers or velcro, snaps, grommets, etc? No expensive, heavy, or ugly tubular framework involved, and can be removed easily and stored below. [what are the 'wear' tests/experiences with the Solbian panels? ]
I know this sounds argumentative, however, I don't mean it that way I mean it more from a skeptical point of view. I'm looking to narrow my choices in the near future also. I'm not just baiting anyone.[/QUOTE]

[danmarc]

Thanks very much for all the fantastic info, we are very much more informed and will be researching all the links provided. Cheers for the advice! Dan

[noelex 77]

Originally Posted by D&D

SunPower's claims about performance in difficult conditions are well supported by both specifications and independent studies.

Thanks for the very detailed answer.
This is what I love about a forum like this.

Having looked over a lot of technical specifications you have me convinced that there is justification for promoting the view that the real world performance of the Sunpower solar panels is better watt for watt in real world conditions when compared with the older generation Kyocera etc panels.
My apologies for saying otherwise in post 35.

The gains are only small perhaps about 2% improvement due to the temperature coefficients and 1-2% due to low light performance.

These sort of improvements are minor, but when added to the high overall efficiency of the panels meaning more watts can be squeezed in, the results can be very significant gains.

One proviso is competing HIT panels promoted by Panasonic and Sanyo. These have slightly better temperature coefficient again with a further 1-2% gain in the real world. The low light performance of these panels is difficult to compare, but I believe it is slightly better.
One concern with these panels is the incorporation of ultra-thin amorphous silicon layers, which raises some concern about the long term output.

Comments from Sunpower? I am sure they know one way or the other.

The overall efficiency of the HIT panels is lower, but still very good, with cell efficiencies around 21.1% (verses 22% for the Sunpower cells) and panel efficiency of 18.6% (verses 20.1%)

In summary:
The Sunpower panels allow the most watts to squeezed into the limited space on board a yacht. I would expect slightly better performance watt for watt from the Sunpower panels compared to older generation from Kyocera etc.

I think they are the best rigid solar panels for marine use.

[settingsun]

We have three 185 watt 24 volt solar panels from Kyocera, wired in parallel, and they have performed flawlessly. Last week we plugged our boat into shore power for the FIRST TIME since September, 2011.

This is an overview of the components in our system and the panel mounts:

Sailboat Solar - Installing Solar Power & a Solar Panel Arch on a Boat

[HenryD]

D&D - it's great that SunPower has good panels. Since they will not sell the panels except through their dealer network, and the dealer network will not install on boats, I am not sure it does us much good. Even if I happen to find a dealer who will sell them, do I want a product onboard that if something goes wrong, I have no support except back to that one dealer who may not even be in business. If SunPower does not want marine business - fine. I have called SunPower, chatted with their marketing folks on their web site, and called 4 dealers in my area. Oddly enough, when chatting with their web site chat agent, they gave me the name of two off grid dealers - both of which had disconnected phone numbers and web sites that had been taken off line. I have a 22'x11' roof area to mount the panels, so the difference between the Sunpower 345w and other brand 260-275w panels, even with the efficiency difference, I can add two or four panels and come out ahead and for a lot less money.

[careka]

read this*DANMARC

SV Letitgo

we are putting on al Victron on our boat
3 x 190 watt solar , MPPT 150v/70amp, and 12/2000W/80-30***WHAT*BATTS*TO*GO*FOR*?**Not sure yet.
Gels or LiPo4 ? or just wait some more and use the org Leads that is there now.

[foggysail]

Originally Posted by settingsun

We have three 185 watt 24 volt solar panels from Kyocera, wired in parallel, and they have performed flawlessly. Last week we plugged our boat into shore power for the FIRST TIME since September, 2011.

This is an overview of the components in our system and the panel mounts:

Sailboat Solar - Installing Solar Power & a Solar Panel Arch on a Boat

Nice installation! You have good reasons to performance results!