How many solar panels can I fit on my rooftop?

[shadowmaker]

If you go with bifacial panels (as you should if you have/can make white background for them like white concrete, white gravel, paint), you should have some spacing between rows/panels to maximize backside production. 14 bifacial panels installed this way are about equal to ~17 conventional panels of same size (+20-25%). Three rows would enable easier maintenance if some is needed. Also 15 degree angle should help (marginally though) with production and water drainage.

 

[Texas-Mark]

This will allow me to fit panels without any shadow. This is a solution from Ennovabloc named 'Vela 10º':

First thing that comes to my mind when seeing that, is possible issues with high winds if coming from the rear.

 

[shadowmaker]

About that chimney, I think you better use optimizers or microinverters in your setup. People here who actually uses those can tell you more about pros and cons. I have a big open field with no shadows for my array so I can manage with simple string inverter.

 

[SeaGal]

And East-West solution is a fantastic option for a clean surface. Considering I have the chimeney. I will be limited in the space.

Bit of an out-of-the-box thought, but... is the chimney in active use? If not, could it be removed? Or, if it is not for discharge of a real-fire, could the piping be re-routed to give you a clean surface?

 

[frasere2]

In addition to the actual dimensions, you need to show the dimensions to the chimney (and its size), and then also any setback requirements (from the edge or from the chimney). In many places, you need about a 1 meter edge of clear space to the main roof, and a distance around the chimney. The ENNOVABLOC solution is essentially the same as the East west solution as both of your south facing roof edges are almost exactly 45degrees from south. If you were angled either way more, than the ENNOVABLOC solution could be more optimal, assuming no issue with weight (the large blocks are 117Kg each).

 

[Propalen]

In addition to the actual dimensions, you need to show the dimensions to the chimney (and its size), and then also any setback requirements (from the edge or from the chimney). In many places, you need about a 1 meter edge of clear space to the main roof, and a distance around the chimney. The ENNOVABLOC solution is essentially the same as the East west solution as both of your south facing roof edges are almost exactly 45degrees from south. If you were angled either way more, than the ENNOVABLOC solution could be more optimal, assuming no issue with weight (the large blocks are 117Kg each).

Thanks for the suggestion. I came across this solarbloc east-west 15º solution:

solarbloc east west - Solarbloc

WHAT IS THE NEW EAST-WEST SOLARBLOC? In an East-West orientation, half of the panels of our installation are oriented towards the East and the other half towards the West according to the "Delta wing" configuration, a concept imported from the aeronautical industry and which is very similar...

solarbloc.es

I presume the structure is 15º due to shadowing the next row. Is there a solution with a higher angle?

 

[Propalen]

Please find attached two videos on vimeo with a simulation (Dec & Jun) for the 18 panels ennova vela 10º structure.

June:

PLANOS_3D_SOMBRAS_21JUN_R

This is "PLANOS_3D_SOMBRAS_21JUN_R" by Propalen on Vimeo, the home for high quality videos and the people who love them.

vimeo.com

December:

PLANOS_3D_SOMBRAS_21DIC_R

This is "PLANOS_3D_SOMBRAS_21DIC_R" by Propalen on Vimeo, the home for high quality videos and the people who love them.

vimeo.com

First thing that comes to my mind when seeing that, is possible issues with high winds if coming from the rear.

I have contacted the manufacturer. Share location and they stated that panels are well-above the max winds. The largest blocks weigh 73.4 kg ...

Bit of an out-of-the-box thought, but... is the chimney in active use? If not, could it be removed? Or, if it is not for discharge of a real-fire, could the piping be re-routed to give you a clean surface?

That would be great. The chimney is currently in use for mechanical ventilation, and kitchen fumes. It is required at that height by regulation ....

In addition to the actual dimensions, you need to show the dimensions to the chimney (and its size), and then also any setback requirements (from the edge or from the chimney). In many places, you need about a 1 meter edge of clear space to the main roof, and a distance around the chimney. The ENNOVABLOC solution is essentially the same as the East west solution as both of your south facing roof edges are almost exactly 45degrees from south. If you were angled either way more, than the ENNOVABLOC solution could be more optimal, assuming no issue with weight (the large blocks are 117Kg each).

Please see the below videos. This is from a company I am working with to define the system. This distribution is legal in Spain. Total weight is 1.689.5kg so it is not a problem for the reinforced concrete structure.

About that chimney, I think you better use optimizers or microinverters in your setup. People here who actually uses those can tell you more about pros and cons. I have a big open field with no shadows for my array so I can manage with simple string inverter.

This is my concern now. If you observe the videos, there are potentially 6 panels affected by shadow (if an extra one is added behind the chimney). I am mostly concerned about the dec shadow that will affect 4 of them (including the missing one.

So I have divided to use a Voltronix Axpert MAX II Duplex 11KW. I think I cannot use optimizers for that, please correct me if wrong.

I was thinking if using bypass diodes for the 6 critical panels will be an optimal solution. Also, I am not sure if bypass diodes are already fitted into the panels (JA solar JAM72S30-545MR). If not fitted, what's the best bypass diode to fit? how is best to fit it?

Any alternative idea to optimise the panels is most welcome