SunPower 327 E-series or 335 / 345 X21 series panels ONLY

Dave Angelini

The E20's are very nice, Panasonic has a similar efficiency new panel for the American market. Just like your application, I use them on trackers where wind/snow limit the square footage.  The side benefit of both these panels is how well they do at high temperatures.

BrokerDon

Great to know about the high temperature benefit... Especially since we camp in the Southwest most of the time.

SolarPowered

I stick with LG mono X's right now they are the biggest bang for the buck.

BrokerDon

I agree about the "biggest bang for the buck" of the LG X panels... but they wouldn't fit in the 73" x 44" open area of our RV roof.  Size Matters.  8-)  LG X is 77" x 39" while SunPower is 41" x 61"... and both have panels up to 360W in these respective sizes.

Dave Angelini

Definitely more power per square foot with SunPower and Panasonic.  Both are the 41 and 61 or so inches. If you have trouble buying the Sun Power or any of your RV friends want that size Panasonic will start distributing widely their new Panels in April 2016.

SolarPowered

People that just live in a world of conversion efficiency without taking into account temp coefficients aren't paying attention to PTC.

SUNPOWER is a great panel that competes better than any other mono panel at high tempratures with a -.38%
LG works much better at harvesting in winter insolation at a -.41

The problem I have with new generation Panasonic is that they want a screaming premium on their panels at almost $1.40 a watt. Thats double the price of solar world. Not worth the investment cost at the moment.

BrokerDon

Thanks for pointing out the Panasonic HIT panels are an almost identical size (62.6" x 41.5") to the SunPower panels. These will be a great alternative to the SunPower panels since you can actually buy just the panels.  SunPower will only sell their panels through their distributors who install them and charge $1,524 a panel installed for their 327W and $1,894 a panel installed for their new 360W panels.

Dave Angelini

My price is $1.15 for the Panasonic which are not available until next month. You have completely different requirements than the OP here and myself.
 The price will go down in the fall as this panel becomes plentiful in North America. These panels have been in Europe for 2 years and have done extremely well as far as quality.

SolarPowered

The only problem I see with sun power and the hit 330 and 325, the voc spec is to high to use a micro inverter. Enphase C250/M250 series.

The sunpower and panasonic could use the abb .3 ousd/HV models though.

I f I wanted a container of 270 or more could you get me down below $1?

Dave Angelini

I especially like the hi VOC and MPV because I run arrays 1000 feet or more for the offgrid home.

I really do not sell PV,  I get it for my clients systems and the best part is I am mostly retired and work when I want.

SolarPowered

Dave Angelini said:

I especially like the hi VOC and MPV because I run arrays 1000 feet or more for the offgrid home.

I am not understanding your logic behind this.

Engineering for costs at or below grid parity you would want reasonable voltages, that are paired within a reasonable MPPT range of inverter/charge controller selected for its system size and efficiency.

If you have a 600V inverter system, or if you have a 12V inverter system there is no difference in the higher voltage potential of a panel, only the associations of voltage drop (home run conductor), and MPPT conversion for the appropriate voltage selection for the battery management size.

Only the size of the home run conductor from point of array, to charge controller/inverter, matters in regards to length. The only advantage to higher voltages is that smaller conductors can be used under load side. In regards to the association of voltage drop there is no difference if its 600v or 12V if the conductor diameter is not rated the voltage drop percentage whether its 600v or 12v goes unchanged in regards to distance.

In most circumstances dealing with MPPT at an efficiency of 90% or better, higher amper ratings are better, since voltage is volatile by temperature and resistance from variations in seasonal weather.

Dave Angelini

We never ever use 12 V inverters  for offgrid homes and 24 V is really rare.  While efficiency is important, it is down the list compared to hours of usable power. If you lived offgrid you would know this I think. One is on the battery later in the evening and off the battery earlier in the morning. We azimuth track or virtual track at least 1 or 2 of the arrays. The rest can be fixed.

The array is all in series and sometimes a second string. There are no balance of system components other than a disco, JB, and SPD.

If you ever have to run a conductor pair 1,000 feet in different soil/rock types, you would agree that pair of #10's is much easier.
An armored 1/2" conduit is your ground.  Maybe #8's if the array warrants it.

I hope this helps, I have been doing this since the early 90's and the thick wire I used then was not fun.

Dave Angelini

Really nice Panasonic's. I just received some. Alot easier to lift size and weight.

bayst

I am trying to find a quality 275w to 350w solar panel for marine application.  Can anyone suggest some I can research?

mcgivor

275W would most likely be a 60 cellpanel, 350W would most likely  be a 72 cell, generally speaking, what is the application, charge controller, battery voltage, etcetera, etcetera, details are important   

BrokerDon

Our now 5 year old 327W SunPower solar panel (96 cells / 20.1% efficiency) https://us.sunpower.com/sites/sunpower/files/uploads/resources/sp-e20-327-320-ds-en-ltr-mc4comp-527846-0.pdf on our 2011 Winnebago View 24 foot RV is a high efficiency panel (more power from the same sq. ft.). High efficiency is important when you have limited roof space and non-ideal sun angles like an RV roof.

sunPower now makes an even higher efficiency (96 cells / 22.7%) 370W panel https://us.sunpower.com/sites/sunpower/files/uploads/resources/sp-x22-370-ds-en-ltr-mc4comp-527787_2.pdf that is the same size as our older 327W panel.   I’d love to find a 370W panel to replace our existing panel since it would only take a couple of minutes to swap out the panel... and our existing 40A Renogy Tracer MPPT controller, wiring, and DC breakers can handle the additional power. 8-)

Dave Angelini

Don,  I think you would be better off making another  SP 327 watt fit up there. I have a friend who is a dealer for Sunpower and they want quite a bit of cash for the new modules. A 43 watt difference is pretty small even in your app. They are amazing panels though   Covered in ash from fires and ambient temps of 100F this summer here. Can't say much more other than amazing. As mentioned  before the LG and Panasonic modules also have a 25 year product warranty like SP. 

If you want efficiency, the battery is the place to start, some pretty nice LI options out there.

BrokerDon

Unfortunately no room for another SunPower 327W panel on our 24 foot long 2011 Winnebago View 24K roof.  Easier to just install a higher efficiency panel... IF I can find one a a good price like the $1.10 per watt price I got on our "lightly used" 327W SunPower panel.

We're extremely satisfied with our RV solar set up for now.  Best $700 RV upgrade IMHO since it has enabled us to boondock almost anywhere.  We also upgraded the cheap dual 12V NAPA batteries that cam with our coach to much larger capacity dual 232Ah Energizer GC2 Premium batteries from Sam's Club.  This solar system and our 3.2kW Onan diesel generator enable us to go for ~ 10 days boondocking... only because we need fresh water or to dump our holding tanks... and get food and beer.  8-)  Great well balanced system.