Efficiency of solar panels when positioned at specific tilt, orientation and latitude

[jbd]

and tilted
I would like to quantitatively assess the efficiency of solar panels when located at 17.8 degrees south, facing due East and inclined at 6.5 degrees above the horizontal (i.e: constrained by a roof of that same pitch and orientation).
What percentage of energy collection would be delivered when compared to panels facing north and tilted at say 15 degrees above the horizontal, for instance?

Your suggestions would be much appreciated.

jbd

[car54]

I think the SMA Solarchecker IPhone app will help you to get the efficiency figure you want.

[gordon_s1942]

Very briefly I had a weather station with a solar panel and as part of the data collected was the measurement of UV rays.
I faced the panel North and I think it was inclined at about 45 degrees.
I was surprised to see the readings during the day between sunrise and sunset which once the Sun rose, stayed fairly consistent on a clear day but did it bounce up and down with different cloud cover.
Obviously the best efficiency would be if the panel could track the Sun from Dawn to Dusk but thats not always an option is it.
Because of the warnings about UV radiation being the most harmful between 1 and 3pm during Summer, If I could not have a Northern aspect, I would choose if possible to mount the dish towards the North West.
I base this on seeing some houses with a North/South roof line where the panels are mounted on the Western slope only.