Sonic01
Member
- Joined
- Sep 19, 2017
- Messages
- 134
Hi All,
I had a question about the best setup for an array that gets a bit of shade each day - I've done what research I can and believe I know what the best solution would be, but I'd really appreciate your opinions on this.
I've made this lovely crude drawing showing my intended array setup, as you can see 6 of the 14 panels get shaded from about 12pm onwards, it starts with just the top left corner of the top left panel on the pitched roof but as the day goes on it grows to cover most of the 6 panels at once. by about 6pm its just covering the middle 3 panels.
The obvious solution would be to remove the chimney (its not even real anymore, the stack below it inside the building has been removed) but due to local laws I can't remove it from the roof.
Now from what I've read, any shading in any series setup will ruin the performance of the whole array. I understand that doing the entire thing in parallel reduces the impact of the shading but no 48v system can work off a 30v PV array. I also read that panels are less efficient in parallel than in series as well.
Even if the shaded 6 panels are all connected in parallel with the rest of the array in series, the group of 6 in parallel will still negatively effect the rest of the string won't they?
To this effect from what I've read in other posts on here and a quick google around it seems the most efficient way is to split the shaded and non-shaded panels into 2 separate strings with their own charge controller? So for example, have the 6 shaded panels in series connected to one CT, and the other 8 panels in series connected to another CT?
I see the MPP Solar "MAX" series has 2 PV inputs, and it looks they they both have their own current inputs (18a each it says) so I'm guessing this means it has 2 CT's inside?
I had a question about the best setup for an array that gets a bit of shade each day - I've done what research I can and believe I know what the best solution would be, but I'd really appreciate your opinions on this.
I've made this lovely crude drawing showing my intended array setup, as you can see 6 of the 14 panels get shaded from about 12pm onwards, it starts with just the top left corner of the top left panel on the pitched roof but as the day goes on it grows to cover most of the 6 panels at once. by about 6pm its just covering the middle 3 panels.
The obvious solution would be to remove the chimney (its not even real anymore, the stack below it inside the building has been removed) but due to local laws I can't remove it from the roof.
Now from what I've read, any shading in any series setup will ruin the performance of the whole array. I understand that doing the entire thing in parallel reduces the impact of the shading but no 48v system can work off a 30v PV array. I also read that panels are less efficient in parallel than in series as well.
Even if the shaded 6 panels are all connected in parallel with the rest of the array in series, the group of 6 in parallel will still negatively effect the rest of the string won't they?
To this effect from what I've read in other posts on here and a quick google around it seems the most efficient way is to split the shaded and non-shaded panels into 2 separate strings with their own charge controller? So for example, have the 6 shaded panels in series connected to one CT, and the other 8 panels in series connected to another CT?
I see the MPP Solar "MAX" series has 2 PV inputs, and it looks they they both have their own current inputs (18a each it says) so I'm guessing this means it has 2 CT's inside?