Checking wattage

[provr6]

Is it possible to verify the wattage of your panel from the serial no? Obviously a manufacturers 190 w model looks the same as their 200w model. How can you check?

 

[mattiker]

I wondered about this also.....what's to stop unscrupulous installers fitting a lesser panel, 220W instead of 250w. You'd have to be pretty on the ball of generation stats to work out something 100% right. Still, even if you did question what panels you actually had fitted - there are so many variables at play that any one of them could be deployed as a decoy - i.e. shading, weather, system losses, inverter...bird poo.

 

[SolarCity]

I wondered about this also.....what's to stop unscrupulous installers fitting a lesser panel, 220W instead of 250w.

The sad thing is, with all the dodgy tactics that are being employed, to do this would be very, very easy. And therefore I have no doubt at all that it has happened a lot.

 

[SpitfireW'sale]

Do you need to supply serial numbers to claim the FIT, or just MCS numbers of panels? We hold a record of every panel that goes through our hands, so it would be possible to check with the supplier (if you know who that was) what the output of the panel is from the serial number.

There are also some manufacturers who have a service on their web page whereby you can check the validity of warranty from the serial number, this often includes showing what the panel type and output is. If you are in doubt, you should be able to find out from the manufacturer, or distribution partner of the panel in question.

 

[jupestar]

every panel should be flash tested.... we supply the flash test results for every panel on the roof. so you know exact wattage. to be honest i assumed all installers did this.

 

[mattiker]

flash tested!

Dont think that happened to mine - cant imagine it happens much at all.

 

[SpitfireW'sale]

Flash testing is normally done under lab conditions during the manufacturing process. The modules are then graded according to the output from the test. How do you test each panel on site jupestar? I didn't know this could be done!

 

[jupestar]

sorry we don't actually do the flash test. the manufacturer does it before they go out the door, and provides us the results for every panel we buy. eg a 190w panel is only nomianl 190 and could be 192.5.. then we pass this on to the customer in a list showing the technical spec of every panel. i thought it was standard, i guess if you ask the manufacturer they should be able to tell you.

 

[SpitfireW'sale]

Ah I see, sorry I misread your post Jupestar. Yes I believe any quality manufacturer will flash test each module. Some (like Mitsubishi) print the result on each panel which you can supply to the customer. Others will give the panel tolerance rating, which describes how close each panel is to the rated output. Positive tolerance is a good selling point.

But I think the OP's point is that you could (if so inclined) lie about what the rated output of a panel is. I think checking serial numbers is the only real safeguard against bad installers who wanted to do this?

 

[jupestar]

yes your absolutely right it would be easy enough to lie. if fact i saw it last week the next door neightbour to our install claimed to have a 4kw system. but i could assure you he didn't. it was exactly the same roof as the one we were on and he had 16 185/190/200w modules on it. unless i've missed a trick and standard mono modules are coming in at 195w/sqm.