Illustration of 8 KW (DC) GT Solar PV System Install for Residence in Urban Area

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  • raydiasraydias Solar Expert Posts: 68 ✭✭✭✭
    Re: Illustration of 8 KW (DC) GT Solar PV System Install for Dallas Area Urban Residence

    Very informative post and comments. I find it interesting that the installer didn't know about the local code requirements before the installation even started. It would have reduce the costs and time. A couple of questions:

    - Would it be possible to see the paperwork submitted to the local inspector? (with any personal info redacted)

    - Does the leasing company have someone come out and inspect the system as well as clean the panels? If not it would be interesting to see what cleaning the panels does for production now that we are heading into summer.

    - If you reduced your consumption would your cash flow increase?

    thanks for sharing the experience
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    Re: Illustration of 8 KW (DC) GT Solar PV System Install for Dallas Area Urban Residence
    raydias wrote: »
    ...

    - Would it be possible to see the paperwork submitted to the local inspector? (with any personal info redacted)

    - Does the leasing company have someone come out and inspect the system as well as clean the panels? If not it would be interesting to see what cleaning the panels does for production now that we are heading into summer.

    - If you reduced your consumption would your cash flow increase?

    thanks for sharing the experience

    Ray, you're welcome.

    It's now been well over 2 years since paperwork was submitted to local inspectors (Oct., 2009). Plus, since I'm not in an ownership position, all of the paperwork was between the installer and the city directly. At the time the city's inspectors were going to class, my installer was doing an installation in my city for the first time, etc. I think it's fair to say that everyone's come down the learning curve quite a bit, now.

    It's a plain English agreement with the leasing company, and thus no one comes to inspect. As a customer I contractually pay only for what's produced. Also as a customer I'm obligated to inform the leasing company if anything breaks so they can fix it. Absent broken equipment, and assuming I'm acting as a reasonable customer consistent with the lease terms, there doesn't appear to be a need for an inspector.

    After a couple of years of experience with solar panels now, at least for here in the Dallas area, I've concluded that there's enough rain such that there's no need for effort to clean the panels. For 2+ years now, no maintenance has been required for anything, including panel cleaning. Using just casual observation, the panels look no different today than they did 2 years ago. It may be a different story in other parts of the country (or with panels set up next to something unusual, like a restaurant rooftop near a grease exhaust), but for me, here, I truly just let the system sit there with no attention, generating cash for me with no investment. So far all looks to be fine.

    With the 12 mo. rolling avg kWh rate down below 9¢ at the moment here in the Dallas area, any and all consumption reduction actions directly translates to immediate improved/increased cash flow. Thus I've got plenty of incentive to keep on reducing consumption (i.e., more attic insulation is coming this week.

    Best regards,

    Bill
  • solar_davesolar_dave Solar Expert Posts: 2,329 ✭✭✭✭
    Re: Illustration of 8 KW (DC) GT Solar PV System Install for Dallas Area Urban Residence

    Here cleaning is almost mandatory, the rain levels are just to low and infrequent. On a 12.5 Kw system a simple hoseing off of the panels can produce a 500 watt jump in production. They do get pretty dirty here from the desert dust. I clean them as I see a need, visual scum on the panels, a simple ladder climb and hose off is enough.
  • migrainemigraine Registered Users Posts: 1
    Re: Illustration of 8 KW (DC) GT Solar PV System Install for Dallas Area Urban Residence

    I'm new here and spent some time perusing the site, including 28 pages of this thread. I commend you on the time you spent chronicling your installation and your ability to take input/criticism. Many people immediately take a defensive position, which IMO, you did not.

    I'm starting to consider that a system is in our future and after reading what you went through, I have confirmed some of my reluctance in jumping in without obtaining more knowledge.

    I'm from a construction background and because of that, many of your first photos that were posted sent up red flags as to the installer's qualifications. Too many shortcuts on the installation process that seemed to have not been caught by the AHJ/inspector(s)... only time will tell.
    In many of the responses you received, it was demonstrated that others are here to help out by streamlining your project with proper materials/installation procedures, not have baked. This is a sign of a group of skilled/knowledgeable people helping to promote this industry.

    I, myself, am dealing with 2 issues. These are purchasing a time proven power system and a installation from someone that is reputable. Either together or separate. One cannot compensate for the other and failure of either side will result a high cost to correct. IE: roof repairs, wiring issues, diminished efficiency and longevity.

    In the past, I have been against leasing, but, some of your experiences have made me more open to the option. It would probably make our project happen sooner than later and allow for some of the current tax/rebate benefits.

    Here, in NorCal(Sacramento), there are a few big players in the industry that have really made me cautious. Seems that when ever you have that much money spent in advertising/sales, the money is coming from some where. The construction industry is riddled with sub par work and I've witnessed the fallout too many times to want to get into bed with them. At least, until proven wrong.

    Now, it's time for me to jump into the deep end...

    thanks for the read.
    -Brian
  • GodsprovisionGodsprovision Registered Users Posts: 8
    Re: Illustration of 8 KW (DC) GT Solar PV System Install for Dallas Area Urban Residence

    Do you have updates on this system? I had some questions and am also in the area near you. Thank you.
  • GodsprovisionGodsprovision Registered Users Posts: 8
    Re: Illustration of 8 KW (DC) GT Solar PV System Install for Dallas Area Urban Residence

    Not sure where my post went. I will send you a PM and maybe you can help me locally on my system. I am not far from Plano. Thank you.
  • GodsprovisionGodsprovision Registered Users Posts: 8
    Re: Illustration of 8 KW (DC) GT Solar PV System Install for Dallas Area Urban Residence

    Well, I guess I cannot send a PM to you. Please let me know if we can talk. Thank you again. I know I have said that each time.
  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭

    Feel free to ask questions here.  Others may benefit.

    The system is in it's 6th year.  It's performance is carefully measured, and can be publicly viewed here:

    http://www.welserver.com/WEL0043 .

    These charts range from real time to historical rolling last 13 month charts.

    Key learnings have been:

    1. The best sustained energy performance my system (36 Astronergy 225W panels mounted with 2 roof orientations and connected as 3 strings into a 7000W Sunny Boy inverter) is currently capable of is about 35 kWh per day.  It is right now, early Aug., that I get this sustained performance, annually.  While it's hot here (over 100 degree days continuously) at the moment, the days are still long and the weather has few clouds.

    2. The period of best one day energy performances my system is currently capable of long ended 3 months ago.  In the early May time frame days are still long, and temperatures are cooler.  Best one day performance this year is about 42 kWh.

    3. What you see is with no maintenance since 2010 installation.  Since I don't own the panels I'm reluctant to sweep ice off of them in the winter (scratching) or spray them with potable, chlorinated drinking water (spots). 

    4. One of the charts has the monthly PV Watts numbers for my exact location.  It's in the month of August that I actually come close to producing what PV Watts predicts.  For the rest of the months I always produce less than PVWatts estimated performance.  December is the worst month, where I only produce about half of what PVWatts says I should be.  All of this less than PVWatts predicted performance is due to design deficiencies of my system long discussed in this thread.

    5. On another chart, my utility, in 2009, paid a lot of incentive money to my installer.  In return, they're requirement was that the array had to produce at least 62% of PVWatt's estimate.  On an annual basis, it does (it's about 68% - blue line).  On a monthly basis, it does not general for the months of Nov., Dec., Jan. and Feb.

    6.  My leasing arrangement was no up front money required of me.  All components were installed, and are owned by the solar installer.  Every year now I am approximately $250 cash flow positive per year, from day one.  This is net of the three cash flows that influence the subject:  The savings of kWh I'd otherwise have to pay, the payments from the utility for kWh I put on to the grid, and the monthly lease payment to the installer.  Through 2015 I have saved $1500 for an investment of $0.  Not big numbers but always cash flow positive, and, I'm doing good for the environment.

    Hope this helps.

    Best regards,

    Bill



  • a0128958a0128958 Solar Expert Posts: 316 ✭✭✭
    edited August 2016 #280

    Sometimes I get asked about long term performance and degradation.

    The online measurement system referenced earlier is configured to be real time to about 13 months.  To analysis numbers all the way back to installation I have to do it with a 'batch' process.

    Here's the chart for annual performance.  It shows 'Year Beginning' numbers - i.e. 2011, 12, 13, 14 and 15 - six years of annual numbers (ignore the months on the x axis).

    While the chart suggests that annual deterioration is significant, I don't have annual kWh output rationalized to weather conditions, and thus I believe it's too soon to make any conclusion on long term performance.

    Best regards,

    Bill

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