Schatten, shadow problem, question in English

Öfters hier Angemeldet: 28.04.2008 Beiträge: 11

Mein Deutsch is nicht so gut, also eine Frage in Englisch, bitte.

Living in Brussels I post this message, because I can not find a adequate answer in Belgium (PV market not as developed as in Germany, I suppose).

On a small city roof, south west +40, I want to install 11 Sanyo HIT PV panels. In the morning there is some shadow on the roof, until 11.30, touching 4 panels max. see the pictures:

Pictures made beginning of may, at 10, 11 and 12 in the morning. The long pipe on top of the chimney to the right will be taken off.
I want to position 3 PV landscape between the two windows and the top of the roof. Plus 2*4 panels landscape under these windows, max to the left of the roof. Technicians warn me for enormous loss of production capacity, because of this shadow. I find this hard to believe. Others propose me two possibilities. These 11 PV's on a SB 2500 inverter. They say the loss in the early morning hours isn't that important.
Or using two inverters, SB 1100 for 5 panels, and the SB 1100 LV (low Voltage, six panels in parallel) . The last one to be used to connect the panels that will get some of this shadow.
What do you think? Reactions in German are welcome, reading your language is easier than writing. Danke!!

Verfasst am: 12.06.2008, 16:26

Kleine Übersetzuingshilfe, nun antwortet mal fleißig auf Deutsch Wink

Zitat:

Mein Deutsch is nicht so gut, also eine Frage in Englisch, bitte.

Living in Brussels I post this message, because I can not find a adequate answer in Belgium (PV market not as developed as in Germany, I suppose).

On a small city roof, south west +40, I want to install 11 Sanyo HIT PV panels. In the morning there is some shadow on the roof, until 11.30, touching 4 panels max. see the pictures:

Ich wohne in Brüssel und poste hier diesen Beitrag, weil ich in Belgien keine angemessene Antwort finden kann ( der PV-Markt in Belgien ist nicht so entwickelt wie in Deutschland)
Ich möchte auf einem kleinen Satdtdach, Südwest -40, 11 Sanyo HIT Module installieren. Morgens ist etwas Verschattung auf dem Dach, die maximal 4 Module betrifft, wie man auf den Fotos sehen kann.

Zitat:

Pictures made beginning of may, at 10, 11 and 12 in the morning. The long pipe on top of the chimney to the right will be taken off.
I want to position 3 PV landscape between the two windows and the top of the roof. Plus 2*4 panels landscape under these windows, max to the left of the roof. Technicians warn me for enormous loss of production capacity, because of this shadow. I find this hard to believe. Others propose me two possibilities. These 11 PV's on a SB 2500 inverter. They say the loss in the early morning hours isn't that important.
Or using two inverters, SB 1100 for 5 panels, and the SB 1100 LV (low Voltage, six panels in parallel) . The last one to be used to connect the panels that will get some of this shadow.
What do you think? Reactions in German are welcome, reading your language is easier than writing. Danke!!

Die Fotos sind Anfang Mai aufgenommen, am 10, 11 und 12 Uhr am Morgen. Der lange Aufsatz auf dem schornstein rechts wird entfernt. Ich möchte 3 Module Landschaft ( ? do you mean arrays ? ) zwischcen den beiden fenstern und oberhalb Richtung First montieren. Zusätzlich 4 mal 2 Module Landschaft (?) unterhalb dieser Fenster, bis ganz links an den Dachrand. Techniker warnen mich davor, dass ich wegend er Verschattung einen enormen Leistungsverlust haben werde. Ich kann das nciht glauben. Andere machen mir zwei Vorschläge:
diese 11 Module an einem SB 2500 WR. Sie sagen, dass der Leistungsverlust am frühen Morgen nicht so wichtig ist.

Oder 2 WR, ein SB 1100 für 5 Module und ein SB 1100 LV (niedrige Spannung), sechs Module parallel. An den letzteren werden die Module angeschlossen, die Schatten abbekommen.
Was denkt ihr darüber? Reaktionen gerne auf Deutsch, eure Sprache zu lesen ist einfacher, als sie zu schreiben. Danke![/quote]

Verfasst am: 12.06.2008, 16:46

First of all welcome in the Photovoltaikforum.

Shadows are something you can discuss hours without getting consense about it. It is fact, that shadow will bring down the efficiency of your generator as soon as you have shadow on one single panel. The situation will improve, if your panels do have integrated bypass diodes. In this case the affected panel is "switched off" without impact on the remaining panels.

The impact on the performance is not so big if you have many panels in series and only one of them is covered by the shadow. The problem is, that the generator voltage drops down with each affected panel and if the resulting voltage of all panels becomes to be below a certain limit the inverter will switch off. In your case you have a low number of panels and 4 panels can be affected, so in total about 40% of the system. This is a pretty high value. To improve this you should use panels with a high voltage and an Inverter with a wide input voltage range (don't ask me which ones....). In that case the performance will drop but not the complette system will be shut down.

On the other hand you are not loosing 100% of the performance if your system is not starting at 6:00am. To give you an idea I selected a link to the monitoring of a system in southern Germany during a wonderfull day in May. You can see by the graph the amount of performance you lose untill 10-11-12am. http://www.ottersweier-solar.de/visu.html?mode=0&offset=-38&inv=2147483648&flag=0

Anyway, I have no idea about the commercial conditions in Belgium. In Germany I would say leave it, because you can only make money with a very good designed system. So, I can't help you on the decision...

Regards,

Matze

Verfasst am: 12.06.2008, 17:24

Soyez le bienvenue sur ce forum
Hartelijk welkom op deze forum

Als u nederlands praat kan je hier mischien iemand finden die u kan helpen

http://zonneschijn.netfreehost.com/index.php?mforum=zonneschijn

Si vous parlez français - malheureusement je ne sais pas s' il existe un forum similaire en français

J'espère quelq'un peut t'aider

Salutations
Groetjes

kuki

Verfasst am: 12.06.2008, 20:12

Il y a un francais ici, c'est mawe. Je ponse qu'il sais tre beaucoup de photovoltaique.

Sorry, my french is definitely too rusty.

Öfters hier Angemeldet: 28.04.2008 Beiträge: 11

Thank you for translating. Dank u, merci. Ich bin ein Holländer.
Matze, isn't it so that any system builds up capacity towards 13.00? My roof 220, degrees south west, takes sunshine as off 9 o' clock in the morning. My question is that even if (part of) system shuts down because of shadow until 11.00, the production afterwards can still be interesting.
Technicians propose a SB 2500 inverter. Where can I check if this one accepts drops in production?

I am insisting on my project, because in Brussels authorities pay approximately 15000 euro for a installation that will cost 17000. That is why I am not bothering to much on the fact that perhaps two inverters will be more expensive. Authorities pay ten years for de green power I will inject in the system.

Thanks

Verfasst am: 13.06.2008, 09:05

remc hat Folgendes geschrieben:

I am insisting on my project, because in Brussels authorities pay approximately 15000 euro for a installation that will cost 17000.

Thanks

Wow, that explains why we see more and more Belgian systems in this forum. To be honest, with that conditions you can't do anything wrong, it is no question that you will make more than 2000€ in 10 years. Even with 100% of shadow.

I will check over the weekend about the inverter (if no other expert answers your question).

Smile

Matze

Verfasst am: 13.06.2008, 11:13

By the way:
Do you have an roof plan (top view) for uns? (Self made hand-lines/sketches..)
Perhaps some sections additionally?

ps: don't forget to draw in the north direction..
pps: Why do you need the especial for high temperatures designed "Sanyo HIT technology" in Belgium/Netherlands? (Cost reduction Rolling Eyes

)
.

Öfters hier Angemeldet: 28.04.2008 Beiträge: 11

Sorry, don't have roofplan, photo's above don't help?
I am advised to take HIT because of high production per square metre, since I haven't a lot of room on this roof. Alternative would be Solarpower, perhaps.
Thanks

Verfasst am: 13.06.2008, 13:28

Zitat:

I am insisting on my project, because in Brussels authorities pay approximately 15000 euro for a installation that will cost 17000. That is why I am not bothering to much on the fact that perhaps two inverters will be more expensive. Authorities pay ten years for de green power I will inject in the system.

Ich bestehe auf meinem Projekt, weil die Behörden in Brüssel 15000 Euro für einen Installation zahlen, die 17000 Euro kostet. Deshalb stört es mich nicht, wenn zwei Wechselrichter teurer sind. Die Behörden zahlen 10 Jahre für den grünen strom, den ich einspeise.

Wow, lucky you, that's a lot of money. I wish our politicians would be that smart.

Zitat:

Matze, isn't it so that any system builds up capacity towards 13.00? My roof 220, degrees south west, takes sunshine as off 9 o' clock in the morning. My question is that even if (part of) system shuts down because of shadow until 11.00, the production afterwards can still be interesting.
Technicians propose a SB 2500 inverter. Where can I check if this one accepts drops in production?

Matze, ist es nicht so, dass sich die Leistung erst um 13 Uhr so richtig aufbaut? Mein Dach hat die Ausrichtung 220 Grad, ab 9 Uhr ist Sonne auf dem Dach. Meine Frage lautet ob, auch wenn die Anlage (oder ein Teil) wegen des Schattens bis 11 Uhr abschaltet/herunterfährt, die Produktion danach nicht immer noch interessant wäre. Die Techniker schlagen einen SB 2500 WR vor. Wo kann ich herausfinden, ob dieser die Einbrüche in der Leistung akzeptiert?

remc, you should have some patience. A lot of those specialist in the forum are on the trade fair in Munich now. I am sure they will help you as soon as the trade fair is over.

I think your idea of getting a maximum out of a small roof is really good.

Verfasst am: 13.06.2008, 18:54

Beyenburgerin hat Folgendes geschrieben:

Kleine Übersetzuingshilfe, snip....Ich möchte 3 Module Landschaft ( ? do you mean arrays ? ) snip....

Er meint des Format "landscape", also Querformat.

Gruß
Udo

Verfasst am: 15.06.2008, 20:36

- - - mal nach oben schiiiiieeeeb - - -

Vielleicht könnten ja die heimgekehrten Solarteure und Spezialisten mal was dazu sagen Wink

Verfasst am: 15.06.2008, 21:13

Hallo,

den Thread habe ich erst heute entdeckt ...interessante Förderung, das sollte sich auch mit Verschattung rentieren.

Ich möchte gern weiterhelfen wenn ich kann. Allerdings benötige ich für die Auslegung den angedachten Modultyp oder wenigstens die Dachmaße.
Die verschiedenen Sanyo's unterscheiden sich ja doch erheblich in ihrer Größe.

Ein Stringwechselrichter wird wohl nicht funktionieren. Bei entsprechend zur Verfügung gestellten Moduldaten werden sich aber sicher zwei Einzel-WR finden lassen, an die die Module passen !

Gruß
Jörg

http://users.telenet.be/riho/PV · Verfasst am: 15.06.2008, 21:26

Remc,

I'm rik moderator of the belgium/dutch forum http://zonneschijn.netfreehost.com/index.php?mforum=zonneschijn

The effect of shadow is not good for a PV installation. The pictures have been taken recently I guess. During the winter you will have a lot more shadow. In order to see the effect of shadow see:

In the morning we have a shadow of a tree. You can see that the DC voltage is dropping down (some panels were automatically disabled bij Bypass diodes to avoid damage). The picture is taken in Januari, at that time it is not so bad. The production is not that high in this period of the year. If you have this shadow during the summer period --> it is very bad for your yield.

Regards,

rik

Öfters hier Angemeldet: 28.04.2008 Beiträge: 11

Hello Jörg, Rik,

Installers suggest to place Sanyo HIT HDE1 220, 86cm*161 cm. Between top of roof and two velux windows there is room enough for three panels. Horizontal. Available space 1.30*5.2 meters.
Under these two windows, max. to the left two panels horizontal, 4 rows. available space, 4.2 meters*5,2.
Here I just want to use the left side of the roof, because of the shadow. The pipe on top of the chimney up to the right, which causes a lot of shadow, will be taken down.
With these 11 panels installers suggest SB 2500, one string, system will produce a little less than 2000 kw a year, they say.

Rik, pictures are taken beginning of may. I just want to know if loss of production in the early morning hours, till 11.00, will be important. I think a roof 220 degrees (south, southwest) will start producing later anyway.