Here is some monthly power generation data for our (4.4 kW DC) PV solar system.
The array points southwest (225 degrees true bearing) and is partially shaded by my neighbor’s roof.

Month Ending PV Production (kWH)
6/25/2008 709
7/25/2008 611
8/25/2008 568
9/27/2008 624
10/24/2008 394
11/24/2008 427
12/24/2008 217
1/28/2009 347
2/26/2009 461
3/27/2009 547
4/29/2009 565
5/29/2009 522
6/29/2009 611
7/29/2009 706
8/27/2009 602
9/28/2009 536
10/27/2009 418
11/25/2009 350
12/30/2009 280
1/29/2010 277
3/1/2010 356
3/29/2010 495
4/29/2010 626
5/28/2010 678