I'm told that the SunPower brand inverters are just PVPowered inverters with the positive DC grounded.

I'm also told that SunPower inverters don't have a data communication function.

Can anyone with a SunPower inverter shed some light on that?

And has anyone tried plugging a PC into the RS-232 port on a SunPower and running the PVPowered software?

Could you explain for us why your selecting inverters that don't have the features you desire?

I recommend the Xantrex GT3.3 as it exceeds the efficiency,harvest, comes with software that does everything you want and cost less than the options your looking at.

Henry, the SunPower panels require that the module frame be connected to the positive DC rail. This eliminates quite a number of inverters from consideration.

Because of space limitations, I need to use either Sunpower or Sanyo panels. They are about 1/3 more space efficient than any other panels available. Only the PVPowered (Sunpower) inverter works with the Sunpower panel, as Bailey pointed out. I want good communications features and am leaning toward a Sunny Boy inverter with Sanyo panels, but want to investigate this other alternative.

I would go with the Xantrex GT3.3 over the Sunnyboy. The Sunnyboy is fan cooled and costs more than the GT3.3 and is NOT more efficent. Also the Sunnboy is limited to 500VDC max vs the GT's 600VDC max. This will make string matching MUCH harder on the Sunnboy (i'm assuming this is the new 3.8kW box 3800U your looking at) and the GT.3. includes the communications hardware and software.

I would pick the Sanyo's over the Sunpower panels as well

This is the first that I have heard of the Sunpower panels are electrically connected to the cells, this I would have beleived violates a bunch of NEC rules. Of of which is ground fault protection.

Are the Sunpower panels CEC approved? and NEC approved?

I'll take another look at the Xantrex. However I have some friends who are familiar with Xantrex inverters in marine applications, and there are quality concerns with the Xantrex marine units which are made in China.

The Fronius inverter allows strings down to 4 panels with the Sanyo, so would be my choice for the best hardware and string flexibility. However part of mymotivation is the fun of monitoring the system, and I think Sunny Boy "gets it" in that aspect more than anyone else. I would need a wireless link to my PC and the Sunny Beam looks like it will fill that bill nicely besides being a nifty gadget.

By the way, speaking of string sizing, that is another advantage of the Sanyo panels. They are higher voltage so work in shorter strings than other panels, allowing for more flexibility.

The Fronius might have the connection strip for 4 strings but to connect more than two strings, but they are NOT fused and will require some sort of external fusing to be NEC/CEC compliant

More than two strings will require an external combinor or fuses regardless of the inverter you have looked at, SMA, PVPowered,Fronius or the Xantrex GT. This is why the GT is the best. You can have more panels in the strings with the higher allowed input voltage. Also the GT is good down to 195V , so you can do 4 Sanyo's series strings if thats what you looking at but thats only ~800 watts of PV

I went thru 4 Fronuis inverters, just for doing comparivie testing last year. They are qurikey and have a really odd circuit for handling the different voltage ranges. The fit and finish was horrible. I know the US sale people and they bent over backwards to get me a running product but it still didn't impress me that they had all these problems and the product was at the bottom of the pack in performance. There "reported" power also reports 5% high

SMA isn't perfect either, in my Testing in 2002-2003, I had two SB2500U's fail. On there communications, I tried there powerline products and could not get that to work reliably, SMA addmitted that it was a flaky products and refunded my money.

As for being made in china (xantrex GT), EVERYTHING we buy in the US is either made in Asia or Mexico. Its not the product but the company that stands behind it when iit comes time for warranty service. GT is 5 years on warranty.

I suggest you check out the xantrex forum (at www.xantrex.com) I know people have made the GT's work wireless with off the shelf adapters

I've tested PVpower, SMA, Fronus and Xantrex inverters, Xantrex is the best of them all and they don't nickel you to death for extras.

I run this website so people like you can make informed decisons. reading company provided data sheets doesn't tell you if the product performs well. I've tested all these products and stand by my top pick

Got in the mail today a B&B Electronics catalog, they have a nice wireless serial to Ethernet wirless 802.11b device for 249.00. #ES1AWB

While I understand your "gets it" messages, the reality is is usally cheaper and easier to use of the shelf devices like the B&B unit. Inverter manufactures don't make money selling a handful of custom metering devices, most owners don't ever look at the inverters. For the Geeks like you and I, we don't need SMA or anyone for that matter to provide anything more that the RS232 port and logging software.

I know some GT owners have simillar wireless setup working well with GT-View, which provides any data that one could want and also can upload to servers automatically png files for web-servers. Check out the real-time data link on the main www.solar-guppy.com page