Sun-Power generation claims

[tomkat]

The Sun-Power rep claims that Sun pv Panels generate 10% more electric than they are rated. I am quessing a 10 kw system will generate 11 kw. Does any one know how true that is? I know their efficiency is rated at 18%. But I thought that had to do with electricity vs. physical size. Any thoughts. Tom

[Mike90250]

Anyone can put a 200W sticker on a 220W panel, but why ? I'd like to know how they monitor the output, with measuring tools, or just using inverters with the settings jacked up 10 %, like many of them are.

[tomkat]

please explain what "inverters with the settings jacked up 10%" means? tom

[russ]

The salesman is trying to make his system cheaper per watt with a little creative BS.

In reality you will rarely get the rating and even more rarely you will get some small amount above the rating.

Ask him about the output of the same panel on a nice day in December - say the 22nd of December.

It ıs nice of the salesman to point out that either:
1) He is a liar or
2) He has no idea what he is talking about.

Remember - this is before you buy the system - what happens afterward? I prefer a company/sales rep that I can have confidence in.

[Mike90250]

please explain what "inverters with the settings jacked up 10%" means? tom

Inverters have internal voltmeters and current (amps) sensors. They are supposed to be calibrated at the factory. However, one brand is known to be very close - + 2% of reality, other brands are known to consistently read 10% high, and your buddy, with a true reading inverter, and other brand panels, is always lower than you are, and there for, your {panels, wire, inverter} is better than his. In reality, your displayed information is wrong, like a bad car speedometer.

[tomkat]

Mike , I understand the part about the meters not being calabrated to give an accurate reading. Is a Sunpower inverter one of the inverters that give true readings or jacked up readings? What other Inverters are known to give false readings. I am looking at SMA inverters. I am under the impression that SMA and SunPower inverters are the same inverter just branded differently. Tom

[Mike90250]

I should not really name names here, try a google search for "inverter over-reporting" or something like that.
Cmopanies do it because it keep folks from calling back, " My x is broken, I'm only getting y amount sold".

[tomkat]

Mike, I googled "inverter over reporting", and I came away empty. Do you know of any other searches that would bring up the info I am looking for? Tom

[DeltaFox 25]

http://partsonsale.com/gridtiequestions.html

[russ]

good link!

[tomkat]

thanks Tom