Mixing 12v solar panels

[jac]

I'm in the process of fitting solar panels over this winter and I suspect like many, i'm faced with a large number of small, oddly shaped / sized bits of deck necessitating a real mix and match approach to get the cover I want so 2 questions.

1) Are there any practical considerations that aren't immediately obvious when it comes to using panels from a range of manufacturers and paralleling them all together.

2) Is there a site / supplier that provides either an ability to search for panels by dimensions or who provides some odd shapes - e.g. long and thin rather than usual short and fat

 

[noelex]

1) Are there any practical considerations that aren't immediately obvious when it comes to using panels from a range of manufacturers and paralleling them all together.

With a non MPPT regulator/controller there are no great problems. They will obviously all need to be 12v panels (these normally have a Vmp around 17v).

With a MPPT controller you want to try ensure the Vmp of the panels is close. Ideally use the temperature coefficients to work out the Vmp at a realistic operating temperature. There is no need to obsessive. The panels will be under different lighting conditions anyway, but the Vmp should be within 0.5v. If it is outside this range you won't do any damage, but the effeciency will go down