Useful Website

[geoffd]

I recently came across this site that is really useful for anyone living in Europe and installing PV Arrays.

You can enter your lat/long and is gives you the optimum tilt angle for the highest average power over a year, or if you enter a tilt angle it gives you the possible power.

http://re.jrc.cec.eu.int/pvgis/pvestframe.php?en&europe

It reckons mine is 37 degrees.

Cheers

Geoff

[wooferhound]

Looks like it won't work in the  U. S. A.

[geoffd]

Sorry. As I said.

The site is sponsored by the European Union Research Fund, so I doubt whether the US is ever going to be in their target area.

Cheers

Geoff

[dconn]

If you have a stick poking out perpendicular from a sheet of wood, like a pencil stuck into a hole in a small bit of ply, its really easy to get your tilt - just get rid of any shadows.

Derek

[fishfarm]

I took a scrap piece of PVC pipe and attached it to the side of my array with a single screw so it could swivel but stay in position. When the sun is overhead, I can move the pipe to where the sun shines directly through the pipe, giving me a fairly precise angle. It's easy to compare the angle of the pipe to the angle of the array to see how far off it is.

[Phil Timmons]

And if one loves the math, it is pretty simple, too.

(but please correct me if I am missing something . . . )

Longitude makes no difference.  Just latitude.

For Spring and Fall the tilt (up from horizontal) = your latitude.

For Winter add 23 degrees. (the tilt of the Earth)

For Summer subtract 23 degrees.

[geoffd]

Thats the method I have been using, but I am about to build a new single axis tracker.

What the site calculates is the angle that will give you the highest power output over the year without altering the angle.  

So for mine 37 degrees fixed tilt pointins at -9 degrees south will give me the highest yearly rate.  I am not too worried about the winter because I plan to put in a small hydro system as well to make up for the difference in supply / consumption.

Cheers

Geoff