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Hi
First - please forgive my horrible english.
This is great forum, everything you know about solar energy in one place... i've been reading this in whole day.
As more I read more questions i start to ask.
I cut my blah blah blah and I ask these questions now. I hope they don't sound very stupid.
I thank any experienced user who will find moment of their pecious time to give me some advice.
So
I'm setting up 11KW on-grid solar panel system.
Why 11KW? Because my goverment is supporting private renewable energy projects in our country and maximum supported power capacity is 11KW.
Support capacity is 70% of cost of all materials and works.
As usually, most important aspect is price (of course I have to pay only 30% but I still want to pay less
)
So I decided to buy 79pcs of 140W polycrystal panels (as I understand - choosing lower efficiency polycrystal panels just causes larger panel area, that is no big deal for me).
I have to use grid-tie inverters with MPPT functionality (no battery).
Now this is the moment where my questions have'nt got a clear answer (even after googling for a week).
1. As I understand, to have best MPPT and therefore maximum efficiency, then connecting less panels (ex. 2x140W) for each low power inverter (ex. 300W) is better than connecting many panels (ex. 10x140W) behind high power inverter (ex. 1500W) because, if any of these panels have partial shading or cell defect it will pull down the efficiency of whole array behind this inverter. Am I correct?
2. I also readed that, using bypass diodes (inside panel in cell arrays or outside panel) lets current to bypass defective or shaded cells/panels and therefore helps to get maximum out from solar panel/array. Am I correct?
3. So looks like these lovely little diodes allow me to connect many panels behind "high" power inverter instead of connecting less panels to "low" power inverter and same time keep the efficiency pretty high. Am I right?
4. I did also read that, I can connect panels in series and therefore increase voltage of array (to decrease losses in DC connections). My logic says that the efficiency loss problem (because of shading or defects) with series connetion still remains. But again, when I use bypass diodes?
5. Last question is about grid tie inverter stacking. As i know, this means connecting serially connected solar panels to serially connected inverters, and this helps to bring up solar panel array voltage and inverter total DC input voltage. Am I right?
Thank you
Lauri
First - please forgive my horrible english.
This is great forum, everything you know about solar energy in one place... i've been reading this in whole day.
As more I read more questions i start to ask.
I cut my blah blah blah and I ask these questions now. I hope they don't sound very stupid.
I thank any experienced user who will find moment of their pecious time to give me some advice.
So
I'm setting up 11KW on-grid solar panel system.
Why 11KW? Because my goverment is supporting private renewable energy projects in our country and maximum supported power capacity is 11KW.
Support capacity is 70% of cost of all materials and works.
As usually, most important aspect is price (of course I have to pay only 30% but I still want to pay less
)So I decided to buy 79pcs of 140W polycrystal panels (as I understand - choosing lower efficiency polycrystal panels just causes larger panel area, that is no big deal for me).
I have to use grid-tie inverters with MPPT functionality (no battery).
Now this is the moment where my questions have'nt got a clear answer (even after googling for a week).
1. As I understand, to have best MPPT and therefore maximum efficiency, then connecting less panels (ex. 2x140W) for each low power inverter (ex. 300W) is better than connecting many panels (ex. 10x140W) behind high power inverter (ex. 1500W) because, if any of these panels have partial shading or cell defect it will pull down the efficiency of whole array behind this inverter. Am I correct?
2. I also readed that, using bypass diodes (inside panel in cell arrays or outside panel) lets current to bypass defective or shaded cells/panels and therefore helps to get maximum out from solar panel/array. Am I correct?
3. So looks like these lovely little diodes allow me to connect many panels behind "high" power inverter instead of connecting less panels to "low" power inverter and same time keep the efficiency pretty high. Am I right?
4. I did also read that, I can connect panels in series and therefore increase voltage of array (to decrease losses in DC connections). My logic says that the efficiency loss problem (because of shading or defects) with series connetion still remains. But again, when I use bypass diodes?
5. Last question is about grid tie inverter stacking. As i know, this means connecting serially connected solar panels to serially connected inverters, and this helps to bring up solar panel array voltage and inverter total DC input voltage. Am I right?
Thank you
Lauri
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