Good day for Production in AZ! What did you hit?

[FNG AZ]

February 1st was my worst day yet 17.88 kwh. Followed up by my best so far! 55.19 kwh today!! Even clipped for a little over an hour.

What did you guys see today?

[Yaryman]

How big is your system?

Logic tells my your system is bigger than mine ( 5.04 kW ). All South facing.
Just had my biggest day in three months yesterday, 25.48 kWh.
On Jan. 17th had my worst, which was a whopping 1.99 kWh.
I'm in SF Bay Area. Just interesting to compare systems around the US.

[FNG AZ]

How big is your system?

Logic tells my your system is bigger than mine ( 5.04 kW ). All South facing.
Just had my biggest day in three months yesterday, 25.48 kWh.
On Jan. 17th had my worst, which was a whopping 1.99 kWh.
I'm in SF Bay Area. Just interesting to compare systems around the US.

9.3kw DC. 7.7 Kw AC. Also all South facing. Ouch 1.99!! That hurts.

[DanKegel]

Zero. Damn system hasn't been hooked up to the grid yet

[MikeInRialto]

The day started off with promise as if it was going to be the best day ever since installation... and then a BIG cloud hung overhead for about 3 hours : / Tomorrow looks more promising than today looked.

[solarix]

I monitor several systems that we have built for customers. Normal for this day historically is 76% of the April max. My system produced 19% on Feb 1 and 81% on Feb 2. Another system located a few miles farther north where the snow did not melt off until the morning of Feb 2 did 3% and 61% respectively.
January 2016 came in as the 5th month in a row with solar production here at least 10% below normal. (But we never complain about the rain in Arizona)

[J.P.M.]

I monitor several systems that we have built for customers. Normal for this day historically is 76% of the April max. My system produced 19% on Feb 1 and 81% on Feb 2. Another system located a few miles farther north where the snow did not melt off until the morning of Feb 2 did 3% and 61% respectively.
January 2016 came in as the 5th month in a row with solar production here at least 10% below normal. (But we never complain about the rain in Arizona)

Questions: Where does your history come from ? Any modeling used for clear sky ?

[solarix]

Clear sky forecasting is easy - just smooth out the highs in the historic data. Forecasting the effect of clouds and storms - that's hard. Weather generally happens slower or faster than expected, and figuring the thickness of clouds is difficult. I use the accuweather.com site for doing solar forecasting and I've suggested to them a few times they ought to come up with a solar gain model and produce a solar gain metric for every location they cover. If all of you would also request this from them, maybe they would get to it.....
What if across the country (countries?) we had local solar contractors sponsoring the "solar gain index" broadcast as part of local weather reports?

[J.P.M.]

Clear sky forecasting is easy - just smooth out the highs in the historic data. Forecasting the effect of clouds and storms - that's hard. Weather generally happens slower or faster than expected, and figuring the thickness of clouds is difficult. I use the accuweather.com site for doing solar forecasting and I've suggested to them a few times they ought to come up with a solar gain model and produce a solar gain metric for every location they cover. If all of you would also request this from them, maybe they would get to it.....
What if across the country (countries?) we had local solar contractors sponsoring the "solar gain index" broadcast as part of local weather reports?

Thank you. So, no clear sky modeling based on 1st principles or close to 1st such as the NREL stuff done by Bird ? I'm always on the lookout for ways to tweak what I've got in solar estimating models.

[azdave]

Phoenix, in Gilbert area. On a cool, clear day last April 16th I maxed at 46 kWh from my 6.6kW system. Yesterday was a cool clear day too but only 38 kWh collected.

[Plut]

Today was my best day (44 kWh) since I went live 12/2. 6.6kW system. Just outside Albuquerque, NM.

[J.P.M.]

Today was my best day (44 kWh) since I went live 12/2. 6.6kW system. Just outside Albuquerque, NM.

You are in one of the best overall solar climates in the U.S., if not the world. Lived there for several years. Enjoy.

[HX_Guy]

02/02 and 02/03 were almost identical for me...56.41kWh and 56.44kWh respectively. 12.4kW system both E and S orientations and some heavy shading on the south plane from a 2 story house this time of year.

[sensij]

Thank you. So, no clear sky modeling based on 1st principles or close to 1st such as the NREL stuff done by Bird ? I'm always on the lookout for ways to tweak what I've got in solar estimating models.

I've been slowly working through this Perez/Ineichen model published in 2002,

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.453.9915&rep=rep1&type=pdf

It held up well in this comparison of models:

http://energy.sandia.gov/wp-content/gallery/uploads/SAND2012-2389_ClearSky_final.pdf

Python code here:

https://github.com/Sandia-Labs/PVLIB_Matlab/blob/master/WEB/html/html/pvl_clearsky_ineichen_help.html

That model gets around AOD influence by using the climateological monthly Linke turbidity data available here.

I've been cautious about the making assumptions about how constant the inputs into Bird will be throughout the year, but haven't tried yet to see mow many of them can be populated from publicly available local weather sources. At some point I intend to track down this paper in which the Bird model has supposedly been improved by adapting it to local conditions:

http://www.sciencedirect.com/science/article/pii/S0960148110002326

[FNG AZ]

02/02 and 02/03 were almost identical for me...56.41kWh and 56.44kWh respectively. 12.4kW system both E and S orientations and some heavy shading on the south plane from a 2 story house this time of year.

Hey hx. I read you were going to try the flat rate plan. (ET-12). How is it working out compared to the TOU (ET-2)