I'm in Pasadena, CA, which puts me around 33'N. I'm in a 1912 Craftsman bungalow with a separate garage, the electric panel was moved to the garage when the garage was built in 2004. Both the house and the garage have a ridgeline that points around 35' E (adjusted for declination), the roofs are 6/13 pitch which I believe is about 25 deg slope.

My current usage (pun intended) is about 20 Kw/day. I'd like to aim for somewhere around 15 Kw/day PV, which would generate credits during the winter months and help offset the central air during the summer.

My first choice for panel placement is the garage roof, 312 sq ft per side, but that idea has these issues, the ESE (125) roof has over 50% shadow until 10 am during summer months from a huge tree off my property. The WNW (305) roof has great exposure except for the utility mast and two power lines (my neighbor's and mine) that would cause thin shadows for most of the afternoon.

Next I would consider panels on the main house roof, same direction and pitch. The ESE (125) roof is in full sun by 9:00, with no further shading. There's a small SSW (215) roof that has good exposure but it's probably less than 150 sq ft. I've got a long run of WNW (305) that has virtually no shading issues except maybe a few winter months.

I feel that any panels on a WNW exposure will need to be tilted strings on the pitched roof, to bring them back towards a South influence. I'm willing to run 2 smaller arrays to optimize my exposure.

What does anyone think? What else would you like to know?

Thanks,
Eric

Hi neighbor (I'm by LAX)
I had a dilemma too, a north /south ridge, with pitches facing east or west. I opted for the west pitch, and have panels flat on the roof. Being near the coast, we often have AM fog/marine layer, so a lot of east facing panels would be wasted in AM clouds. My non-tilted west facing array of 4.4KW STC, is neting me about 25KWH /day this last week(Aug). (20KW in Sept)
I don't know if you get AM clouds, or what. Do you already have panels, or looking to see where you can fit them best?

http://members.dslextreme.com/users/mik ... stall.html

Eric,

I'm in San Gabriel and I did an east/west mounting (90/270) on my garage because the house is shaded by a very large tree that I did not want to cut down.

I have three identical GT systems of 2.88kW each, one with two strings facing west, one with two strings facing east and the third split with one string each direction. Each string is eight Sanyo HIP-190s on GT-3.0s and covers about 250 sqft of roof. The east system suffered from tree blockage until around 9:00-10:00am depending on season. The split system suffers from much less shading from trees off my property and the utility pole.

Last month we trimmed the tree shading east. Daily production averaged over 30 days doubled from 3.97kWh/day to 8.90kWh/day. You really don't want morning shade on east facing panels. My west panels have my utility line crossing them but are my best performers averaging 11.28kWh/day. Split weighs in at 7.38kWh/day. All data is from 7/10-8/19 to account for the tree trimming.

If you look at the graph you can see East is still having some morning issues which is affecting output. GT-View 1 needed to be restarted hence the missing data for 9/18 & 19.

http://inverter.speacock.com/cgi-bin/summary.cgi

Sean

That was an interesting link from speacock.

However, as a newbie hopefully I can ask a few questions about it. I was wondering which direction was for Inverter 1, Inverter 2, and Inverter 3. Also, to me it seems incredibly quick how it goes from no output to full output and back to no output. I thought it would gradually increase as the sun rose and then gradually decrease as the sun set.

I actually live in Lakeland, and I got to meet Henry! He's a great guy, and really willing to help people. As you can see, he's a patient guy too as he answered my basic solar questions.