6Kw going in soon in Aliso Viejo

[J.P.M.]

I live 5 miles from the beach.... the days where its cloudy in the evening ( west facing) and clear in the morning ( east facing) are outnumbered about 1000:1

I heard a meteorologist say that probably the toughest thing about being a TV weatherman in San Diego was trying to figure out how to say "cloudy til 10 then sun" and keep it interesting. Pretty benign and predictable most of the time, Near the coast, SWAG/1st cut approx. for initial design: Face an array at ~ 210 deg. & iterate.

[Alisobob]

I live 5 miles from the beach.... the days where its cloudy in the evening ( west facing) and clear in the morning ( east facing) are outnumbered about 1000:1

[sensij]

There are days where west facing are worth less too. J.P.M.'s suggestion to run PVWatts will help... the model is based on historical weather patterns (including "typical" May gray and June gloom), and you can test out different orientations to see how it might affect your output.

[Alisobob]

Some of my neighbors have east facing panels... and when the marine layer is in effect, they put out nothing. Then, around 11am, the layer burns off,and the south facing panels work, as do the west facing in the late afternoons / evenings.

solar105.JPG

This is a typical June Gloom day..... as described above.


It is... what it is... but you can see how east facing panels are worthless on days like this.

[J.P.M.]

Your regular updates and all the replies have been a great learning experience. Thanks! Could you please PM me who you contracted? Unless they are only local to your area -I'm in San Diego.

I was also wondering if you have results from a consistently cloudy day (admittedly, I have not read every single page of this thread)? I'm interested because I do live fairly close to the coast and May Gray/June Gloom have me worried I'll get nearly 0 generation for the many weeks of marine layer in these two months.

Run PVWatts for North Island (Coronado) and Miramar for comparison. They're about a dead heat - w/in ~ 1%. Conditions will change daily. Those are long term estimates over many years.

[Mojave]

Wow..... (wow, wow, wow)

I took the boards advice, and contacted a small, local company with nothing but 5 star reviews on Yelp. No Russ..... I wont say the name.

This is their deal....
24 , 270 watt Solar World MONO panels ( 6480 watt total)
24 Enphase Inverters
Envoy monitoring with life time web access
Attic run electrical, nothing on roof
Move v ents as needed
R/R all Roof Tile under solar panels to repaper roof.
25 year warranty for all parts and labor. If product supplier goes out of business, they will pick up the remainder of supplier warranty
4 year maintenance agreement ( Wash panels, inspect wiring, etc..etc.. 2 x per year) after 4 years, service is $150 per year if so desired
NO PANEL UPGRADE NEEDED! They will flip around some circuits to make the panel "End Fed" which will satisfy the building inspector without replacing the panel.

All permits and HOA paperwork included

Price: $23,291 ( 3.59 per watt installed)

-30% Tax Credit $16,303 ( $2.51 per watt installed)

It looks like this is the way I'm going to go.....

Thanks everyone. Bob

Your regular updates and all the replies have been a great learning experience. Thanks! Could you please PM me who you contracted? Unless they are only local to your area -I'm in San Diego.

I was also wondering if you have results from a consistently cloudy day (admittedly, I have not read every single page of this thread)? I'm interested because I do live fairly close to the coast and May Gray/June Gloom have me worried I'll get nearly 0 generation for the many weeks of marine layer in these two months.

[Alisobob]

A TOU Update....

solar112.JPG

solar113.JPG


The big news for me is that I am now on the "Summer " SCE TOU-D-T billing schedule. Everything pretty much stays the same as the winter billing rates, except for "Peak Generation" rates, nearly doubled on June 1st.

Had my whole month been on these rates, my monthly credit would have been about $40 greater.

As my consumption during "Peak " is very small, due to the TOU-D-T scheduling, there is little downside to this rate increase.

Things continue to go well..... heading into summer.

I am looking forward to having a freezing cold house, every ( 100% off peak) weekend!

[bcroe]

Today has been a solar nightmare. Hot temps and no sun. Production down 30%,
surprised got as much as I have today. But the A/C has been nice even without the sun. Really helps. Now
just have to make it up on the sunnier days.

Solar owners on the left coast are pretty spoiled; we in the cloudy mid west see 30% down and much worse
on a pretty regular basis. Handle your situation and mine with the right system design. Bruce Roe

[rwb1921]

Today has been a solar nightmare Hot temps and no sun. Production down 30%, surprised got as much as I have today. But the A/C has been nice even without the sun. Really helps. Now just have to make it up on the sunnier days.

[Alisobob]

Suggest you don't get too frazzled if you're off the spec. sheet temp. coeff. by some.

I'm not frazzled.... just throwing out what I see going on with my system.

Was most interesting that the increased temp hindered output enough to eliminate the clipping I usually see on a cloudless day.

Life goes on......

[bcroe]

I thought it was going to be a the new record day for me as well (which isn't hard granted when you only have 7 of them) but nope, it was just under. I came to the same conclusion - heat. The LG300's I have have a .42 panel coefficient and it was 11C above 25C for the high yesterday. That works out to 11C * .42 = 4.62 percent less efficient at peak.

Its doing what its spec'd to do. I avoided that by boosting the number of panels in each string from
10 to 12; I never see a temp effect. Helps under clouds too. Panels have become cheap; harder to
do though if you're not using strings, or are trying to cram them onto a roof. Bruce Roe

[J.P.M.]

[ATTACH]7006[/ATTACH]

Here's a great, "real world" example for you all....

Yesterday was a beautiful, cloudless, 12+ hour generation day. Output should have been huge.... right?

Wrong. It was also hot!

I barely made it over the 40 KwH mark, and peak production was barely 5KW, where it should have been 5.5. And look, no clipping either.

I have the monocrystalline style panels, that are supposed to be a little more heat tolerant... Poly's would have felt the heat effect even more.

Heat is not your friend ....

Bob: FWIW, REAL ROUGH SWAG - knock ~~0.7%/1.8 off expected performance per ESTIMATED deg. F. of panel/array temp. The rub there is to get the panel temp. est. close to reality.

Or get two consecutive/close in date "clear days" that have a relatively large temp. diff. between them and divide the output diff. to the temp. diff. for an ESTIMATE of performance change per deg. F. or C. as you choose.

Suggest you don't get too frazzled if you're off the spec. sheet temp. coeff. by some. Lots of variables and this ain't rocket science, but high temps. do hinder performance, often in qualitatively noticeable ways.

[rwb1921]

[ATTACH]7006[/ATTACH]

Here's a great, "real world" example for you all....

Yesterday was a beautiful, cloudless, 12+ hour generation day. Output should have been huge.... right?

Wrong. It was also hot!

I barely made it over the 40 KwH mark, and peak production was barely 5KW, where it should have been 5.5. And look, no clipping either.

I have the monocrystalline style panels, that are supposed to be a little more heat tolerant... Poly's would have felt the heat effect even more.

Heat is not your friend ....

I basically have same system as AlisoBob but a little smaller. 21 Solarworld 285 mono panels. My total yesterday was almost at 35 (34.7) kWh. Peak was 4.5 at most I think. Same as others, the earlier days had higher peaks and more total than yesterday. Only live a week now, highest has been 35.9 on Sunday. But it also did not have highest peak which came on an earlier day with clouds.

Bob in Mission Viejo

[OftheSeven]

Yesterday was a beautiful, cloudless, 12+ hour generation day. Output should have been huge.... right?

Wrong. It was also hot!

Heat is not your friend ....

Same here in north Orange County. Sunny all day (low 90s) but slightly less output than previous partly cloudy, cooler days.

[sensij]

I have the monocrystalline style panels, that are supposed to be a little more heat tolerant... Poly's would have felt the heat effect even more.

Not really. Monocrystalline panels are capable of having a better thermal coefficient, but in the case of the SolarWorld 270's, your coefficient for power is -0.45%/deg C. Compared to the Canadian Solar 260P (poly), with a -0.43%/deg C, the Solarworld coefficient is slightly worse. Even an LG300 mono panel is only -0.42% / deg C.

Also, keep in mind that the mono panels tend to be darker in color, and are therefore likely to get hotter under equivalent solar conditions.

For those reasons, I don't think there is much support for mono's categorically being better in heat. If anything, with the panels on the market today, they might be slightly worse.