On the SF Peninsula (warm side), my 3kW STC array produced a surplus of both $$$ and kWatt*hours...
Rate is PG&E E-7 (peak M-F noon to 6pm, off-peak otherwise).
http://www.pge.com/tariffs/pdf/E-7.pdf
Summer
Baseline Usage $0.29372 $0.08664
Winter
Baseline Usage $0.11472 $0.08966
From Sept 10, 2005 to Sept 9, 2006:
kWhrs from GT = 4720 kWhrs
PG&E balance = -$285.95 (in the "green" to me)
From the kWhr meter, 1 year:
Total Power Used: -1,200 kWhrs (generated more than I used)
Total Peak Power: -1,304 kWhrs (you can see, most of my surplus was Peak-time, I used about +104 kWhrs more than I generated off-peak)
This year, Sept-May 2006/7 vs 2005/6, my credit is:
-$127.16 vs -$61.18 (this year credit is better than last year at same time). It appears that much (if not all) is the result of my system generating about 200 kWhrs this Sept to date this year vs last year to date. (Oct 2005 was good, Oct 2006 was poor, April-May 2007 is great sun).
Looks like I bounce mostly around 8-10 kWHrs / day, except during winter if I crank up an electric space heater now and then instead of using natural gas (add a couple kWhrs per day for that).
Still have some power left over for that mythical electric car (or my wife who wants a portable A/C for those few weeks a year when it bumps near a 100F here).
-Bill