PVSOL Update

[SRE]

Apologies for those who have already picked up on this but this may be quite useful info for those who haven't yet.

I was worried that my PVsol software was providing me with very low estimates of yield. Over 40% lower than was being actually produced from my own system. Solar Design Company have been helping out and in short - it looks as though the irradiation factor is wrong.

For my area it was showing as 825 where it should be showing 910. The end result is now much closer to what I expected and matches more or less with PVGIS.

Moral of the tale - don't take the figures as gospel double check them with pvgis and/or even simpler the sun potential post code checked from Encraft.

 

[Echo]

Hmmmm, I have to say I have noticed this in our area too, the PV sol figures aren't all too good, was the update automatic?

 

[SRE]

NO, apparently there's a way to update the meteo data with data downloaded from the valentin website, using PVGIS, but we use Windows 7 and I don't think it's compatible. I'll be on the phone again to them on Monday - I have to say they've been really helpful once I'd given them specific data.

 

[SolarCity]

Did they explain exactly why the figures were wrong? And if the figures are likely to be wrong elsewhere?

 

[SRE]

No explanation why they were wrong and to start off with I think they just thought I'd got something wrong with the software. I sent them my stuff over and that's when they compared the irradiation data. I've fixed it temporarily by using another location relatively near with the correct irradiation reading but it seems that I will be able to put a lot more local areas in once I've cracked how to do it.

Once they had told me about the difference I had a look at other areas and discovered Glasgow (880) had a much higher irradiation than us (825) even though we're 150 miles south of Glasgow. Now I've picked somewhere that is 20 miles away but with the correct irradiation the figures look almost normal! I double checked with pvgis and Encrafts solar potential gadget and they both reckoned 910 was what the figure should be for our area.

 

[edexlab]

Any program is going to have a few errors here and there ,but I don't like to rely on Pvsol as it will give a good match to an inverter which when checked against manufacturers design programs will tell you that the design is incompatible, this happened to us a while ago and i did some varying designs to see and it got 2 out of 5 wrong which does'nt fill me with confidence ,this happened mainly with Sma / Fronius selections and it may just be the case that these two manufacturers software have stricter parameters (or better design programs then other manufacturers) than Pvsol which has to cover many different Inverter suppliers
Having said this it is still a useful tool for other reasons

 

[SolarCity]

Any program is going to have a few errors here and there ,but I don't like to rely on Pvsol as it will give a good match to an inverter which when checked against manufacturers design programs will tell you that the design is incompatible, this happened to us a while ago and i did some varying designs to see and it got 2 out of 5 wrong which does'nt fill me with confidence ,this happened mainly with Sma / Fronius selections and it may just be the case that these two manufacturers software have stricter parameters (or better design programs then other manufacturers) than Pvsol which has to cover many different Inverter suppliers
Having said this it is still a useful tool for other reasons

Which calculations did PVSol get wrong? I always check the inverter selection manually anyway and I've never noticed an issue with any of PVSol's calculations with regards to inverter selection.

 

[edexlab]

Which calculations did PVSol get wrong? I always check the inverter selection manually anyway and I've never noticed an issue with any of PVSol's calculations with regards to inverter selection.

To be honest I can't remember specifically which inverters/modules as it was last year, but the issue was the power ratios ,some were around the 130%+ mark which the manufacturers software gives as an incompatible selection, but if your finding it to be accurate then perhaps i did something wrong ,I'll have to run a few through again and see if the same thing happens again .

 

[JD6400]

Just doing a quote for a 196 module Schott poly tm 235 array , and PV SOL Expert recommends a Fronious CL 48 but Fronious solar configurator recommends at least 220 modules !
Does anyone know what i have got wrong this time ?
Thanks in advance if anyone can help ?

 

[JD6400]

It gets better !
Doing a quote for another site with 208 Schott poly 235 modules , PV SOL Expert has now said a Fronious CL 36 is good ( right on the limit ) but Fronious site as good a damn it says your avin a laugh !
Why o why o why !

 

[SolarCity]

By which parameters is the Fronius calculator saying it is incorrect?

 

[SRE]

Speak to the guys at Solar Design Company - they've been spot on at sorting out my issues, even yesterday. I've been quite impressed so far.

 

[JD6400]

Sorry Biggs have been down at my digs in Bucks , the tinter net is shockingly slow and been too busy to get in the office down there this week !
I think the Fronious site said the system would need another 16 modules to even work or some think like that .
I lost the will after that !
On a separate note i had another design for 12 east 12 west and 18 south schott 235 modules and PV SOL says the east and west will each catch about 800 kwh more on the PV Array irradiation reading than the south ????
Have spoken too them today ( very polite ) and will go through it tomorrow now i am back home .
I also mentioned about the wrong readings as mentioned on previous posts by others as all our laptops are windows 7 and will not up date automatically ,he rather disappointedly made out that they were not aware of a problem and if i was not happy with their readings i could import data from the likes of PV GIS .
I will let everyone how i get on tomorrow hopefully !

 

[JD6400]

Spoke to them today , it was my fault !
I did have to chase a little for the answer but i must admit when they did respond they were above more than helpfully , most impressed !!
They are also now looking into the differences between PV*SOL and the fronius solar configurator site .

 

[Echo]

I know you say it was your fault but what did you do wrong, hopefully we can learn from each others mistakes