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  • 1.  Decommissioning Existing Solar Array

    Posted 12-10-2021 08:46 PM

    Hi there,

    I'm curious if folks could share their experience with decommissioning existing ground mount residential solar arrays? 

    Do you typically cover the panels with blankets or tarps while doing this to ensure very low voltage? I'm just curious what the best practices are!

    Thank you,

    Riley



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    Riley Neugebauer
    Project Manager & Installer
    Colorado
    rileyneugebauer@gmail.com
    ------------------------------


  • 2.  RE: Decommissioning Existing Solar Array

    ASES Life Member
    Posted 12-14-2021 02:31 PM
    Blankets and such would be for a fire if the switch could not be located. You'll need to know where the man breaker is, stop the meter, get an electrician. It takes and electrician to turn a system on so, best beware asking a question online as opposed to taking a course or being an installer? No bueno in MHO

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    Wyldon Fishman
    Bronx NY
    wyldon1@gmail.com
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  • 3.  RE: Decommissioning Existing Solar Array

    ASES Life Member
    Posted 12-15-2021 12:49 PM

    Hi Riley,

    The key thing to check before working on any system is if there are any faults. Check all strings.

    If you find no faults, you can safely work without covering the array. But never touch any frames, metallic structures, etc. before you have first checked for ground faults, etc. (this goes for any array you are working on for whatever reason). 

    If there are faults, then you may want to cover the array with black plastic or make key array electrical disconnections after dark.

    A lot of older PV systems that were installed 20+ years ago were never code compliant, so decommissioning can be a bit more sketchy for these older systems and you should be extra cautious.

    Generally PV systems are going to work ~30 to 40 years before they need to be decommissioned.

    Stay safe



    ------------------------------
    Robert Foster
    Assistant Professor
    New Mexico State University, College of Engineering
    Las Cruces NM
    rfoster@ases.org
    ------------------------------



  • 4.  RE: Decommissioning Existing Solar Array

    Posted 12-15-2021 08:05 PM
    Thanks Robert, I appreciate the information. 

    We were able to successfully take everything apart this week. We ended up using tarps to cover the array as an extra precaution, turned off all disconnects, and then tested the voltage on the DC and AC sides before moving forward. This system was from 2007, so it wasn't too bad as far as compliance, but I can imagine some of the systems from decades ago can be concerning to work on! 

    Riley

    ------------------------------
    Riley Neugebauer
    Project Manager & Installer
    SoCo Solar
    Bayfield CO
    rileyneugebauer@gmail.com
    ------------------------------



  • 5.  RE: Decommissioning Existing Solar Array

    ASES Life Member
    Posted 12-15-2021 09:44 PM
    Great Riley, glad to hear it all worked out.

    The scariest system I was involved with decommissioning back when I was a young pup was replacing the 100 kWp PV array and 600 kWh battery bank at Natural Bridges National Monument in 1991.

    The system was installed in 1980 and was the largest PV array in the world at that time. It was also the world's first PV-diesel mini-grid. It used early days Block III PV modules (refers to the 3rd qualification of PV modules by JPL ~1978). It even had lightning rods set up throughout the array field (early designers used to think that was necessary). The highly degraded modules had brown EVA oozing out and dripping down the sides that looked like something out of a horror movie. See this early system at

    https://en.wikipedia.org/wiki/Natural_Bridges_National_Monument_Solar_Power_System

    But it was a pioneering system with lots of lessons learned that helped pave the way for today's mini-grids.

    Fortunately I've never seen a PV system in such bad shape ever since.

    By ~1993 the industry figured out how to use UV inhibitors in PV modules to reduce degradation.

    They are still running Natural Bridges off of (modern) solar today.

    Mucha suerte




    ------------------------------
    Robert Foster
    Assistant Professor
    New Mexico State University, College of Engineering
    Las Cruces NM
    rfoster@ases.org
    ------------------------------



  • 6.  RE: Decommissioning Existing Solar Array

    Posted 12-16-2021 07:45 AM

    Robert,

    Wow! That's incredible to hear about. I just read the Wikipedia article as well and was impressed with all the entities that came together to pull that off. And the fact that each battery was 1200 pounds! Things really have advanced quickly in the last 40 years, that becomes clear when I read stories like that one. I definitely would have been afraid of decommissioning that as well - I find the little systems a little scary, let alone the ones with big battery banks. 

    You've had quite a career in solar it sounds like - and have gotten to see a lot of things. 

    I don't think I know what EVA is also.

    And, UV inhibitors are some sort of chemical additive in the PV cell creation process I take it?

    Interesting stuff, I appreciate you sharing.

    Riley



    ------------------------------
    Riley Neugebauer
    Project Manager & Installer
    SoCo Solar
    Bayfield CO
    rileyneugebauer@gmail.com
    ------------------------------



  • 7.  RE: Decommissioning Existing Solar Array

    ASES Life Member
    Posted 12-19-2021 04:22 PM
    Hola Riley,

    EVA is for Ethylene Vinyl Acetate, which is a traditional thermoplastic polymer encapsulant used between the PV cells and glass. It needs to have high transmissivity and durability, and thus be UV stabilized. See more at

    https://www.sciencedirect.com/science/article/pii/S235284782100068X

    I see from your profile that you are interested in getting more women into solar. That's really great and I share that vision. I had the privilege to help train and work with some of the first women PV installers and engineers in Latin America, Africa, and Asia. I still occasionally teach solar classes at NMSU, and encourage our women engineering students to go into solar.

    I hope you have the opportunity to attend Solar 2022 in Albuquerque in June. Maybe you might be interested to submit an abstract on some of your solar projects / activities? I hope to see you there.

    Happy Holidays!

    ------------------------------
    Robert Foster
    Assistant Professor
    New Mexico State University, College of Engineering
    Las Cruces NM
    rfoster@ases.org
    ------------------------------



  • 8.  RE: Decommissioning Existing Solar Array

    Posted 12-23-2021 04:37 PM
    Hi Robert!

    Thanks again for explaining the EVA, and sending along the article. I just read through it, finally, and understood some of it haha, but it did help me get a better sense of all that has gone into figure out the best way to encapsulate the cells for longevity since they are in rough conditions for their lifespan! 

    And yes, indeed, I have a great interest in helping support more equitable representation of women in the solar industry, particularly on the installation side, but definitely engineering and design as well. I think more women would enjoy installing, if they ever had the opportunity to learn about it and try it, etc. There aren't a lot of good pathways for women into solar on the trades side in the U.S. is my opinion, whereas many other countries seem to be creating more opportunities. 

    That's great that you have had the chance to train a lot of women. I've done a little volunteering with Remote Energy because I love the work that they do, and they are training a lot of women in Africa and elsewhere. I hope to get some additional opportunities to learn how to be an effective trainer, so I can do more of it on my own or with other groups, and with a particular emphasis on women! If you have ideas, let me know! I want to understand what SEI requires in order to be an instructor there. I'm trying to get NABCEP PVIP in the next year, I'm qualified to take the exam, but I'm not ready to take the exam yet. I think that will help.

    And I've spoken with Carly about the event in June. It sounds like there is already the women's forum, but I am interested to possibly host a discussion or do something related to women in solar, or maybe specifically about another idea - forming a women's installer network in the U.S. possibly. If you know any female installers that might like to be involved in that conversation or in another session at the conference, let me know, maybe I could co-present something with other ladies. I did ask Alison (who I met via the ASES community forums as well recently and who has done trainings for women in Puerto Rico) if she'd like to try and do something. It would be great to meet you as well if I'm able to make it!

    Riley




    ------------------------------
    Riley Neugebauer
    Project Manager & Installer
    SoCo Solar
    Bayfield CO
    rileyneugebauer@gmail.com
    ------------------------------