My Nissan Leaf Forum

West facing at 270º will get no direct sun until after "sun-noon", so the direction is rather sub-optimal. Your expected DC production is likely to be only 50% of the panel's ratings.

VERY GOOD TOOL:
Have you used (played with) the on-line expexted-energy calculator, provided by the folks that calculate the CA Rebate for a PV system?

A copy of its results should be included in your copy of the Rebate paperwork.

It's not so bad. West facing shifts the peak time a little later compared to South. The CSI solar calculator can tell you how much you're "missing" in the winter compared to those south-facing guys (who will have something "missing" in the summer when the sun is more directly overhead).

http://www.csi-epbb.com/default.aspx

Looking at the spec sheets, it looks like a circuit breaker for each panel that is controlled wirelessly to switch panels off like a diode when they are not adding current. It is controlled by a centralized processor monitoring the panels.

http://www.atensolar.com/m5/200-225--ti ... 0w-4w.html

http://www.atensolar.com/m5/200-258--ti ... eless.html

However, I may be misinterpreting it, as they use some marketing terms that make the datasheets a little confusing from a technical perspective.

5.8kW DC 28 Kyocera 210W
Sunnyboy 8000
Location Lancaster, Ca
South Facing

Sunny Portal Info Report for plant for the 12/16/2010
Daily Production: 25 kWh
Daily Power (max.): 4.55 kW

I'm so jealous! I take it you had clear skies all day yesterday? I can't wait to see what I get for our first day of all-day sun. If there ever is one again, now I have a system!

I've only estimated 26kWh for a full on summer's day. So if I can get even close to that on a winter's day, and blow it away completely in the summer, I'll be laughing all the way to the bank!

My 3.24 kW system had a max of 22.8 kWh on it's best day in late May earlier this year. That month also had the highest average output I've seen at 19.5 kWh/day. It was nice and cool and sunny month - only a couple days under 20 kWh.

Have only had a couple months under the expected PVwatts output so far (system has been running since late March) - July and August. Both months had an abnormal amount of cloudy days.

So unless your panels aren't mounted towards the south - I'd expect your peak production months to be late spring and early fall (lower temps = more production). And with a 6.2 kW system I'd expect you to get around 40 kWh on your best days.

Sorry, I was wrong.
The "Solar Calculator" (link above) says West-facing is less than 1% less (year average, in my zip code) than South-facing (for a 20º tilt).

I want solar! Way to go!

My system:

4kw DC
20 200watt Sanyo HIP-200B11 panels:
10 facing South ~176deg, 10 facing West orthogonal to the South's
18deg roof inclination
Fronius 4Kw IG4000 Inverter, grid tied (94% efficient, fan cooled)

Max engery output so far was Aug 26, 2010 - 26.66kwh AC
Max power was Aug 26, 2010 - 3.33kw peak.

http://solarweb.fronius.com
Username: public
Password: public
PV System: Tustin0 (QT)

December 17th, 2010: cloudy and rain all day: 3.07kwh

JPV, since your roof pitch and location is close to mine (Tustin Ranch, near Peter's Cayon and Irvine Regional park), and your DC system 4.3Kw is similar to my 4.0Kw, you'd expect the output to be the same. However, I noticed all of your panels are facing west, that would reduced the efficiency a bit.

Also keep in mind, for much of OC summer, the inversion layer doesn't burn off until ~11am to 12noon sometimes, so the South vs West orientation doesn't make a whole lot of difference. For the Winter and Spring, where we don't have the inversion layer, and we get direct sun in the morning, then South vs West is more noticeable...but since Summer is when the day is the longest, West facing system isn't all that bad at all in comparision with South's...at least here in the OC.