DIY grid-tie? Any other parts needed?

HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
Since my installer is dragging his feet (2 weeks since we finalized the design, still no diagrams ready to submit for permits)...I've been reading and learning a lot and wondering if I could tackle this myself. I don't have much experience with electrical but at the same time it doesn't really seem like rocket science either. Plus I love DIY stuff (I've rebuilt car engines, reassembled transmissions...did all the backyard landscaping plumbing and electrical...installed breakers into the main panel, stuff like that).
I haven't decided if I'm going this route, guess I'll see how the installer moves in the next week or so but it's tempting.

Being that I'd be using SolarEdge equipment, I don't have the concern of having equal strings and figuring all that out, plus until the inverter is switched on, the optimizers put out a safe 1V DC so I feel it's pretty safe.
I would get an electrician to do some of the items I'm thinking if I don't feel comfortable.

The roof mounting seems pretty straight forward using this QuickMount Flashing Tile Hook: http://www.renvu.com/Racking/Pitched-Roof/QUICKMOUNT-QMFTH-A-1-Flashing-with-Flat-Tile-Hook-Mill-Finish-Qty-1

If my calculations are right, the cost savings are pretty big. For the same configuration system, my installer is charging $34,500 whereas I calculate I'd be under $21,000.

This is the parts list and prices I came up with, what else would be needed? I am probably over estimating on the railing and tile mount so the total might even be lower.

DIY.jpg

Comments

  • KozmoKKozmoK Solar Expert Posts: 42
    Re: DIY grid-tie? Any other parts needed?

    Hey There!

    Sorry to hear about your guy! If it wasn't already 106+ degree's out I'd be helping you as it sounds like a fun project. Check with APS and Peoria and see if they will allow it first, then also check to see if you still qualify for the tax credits.

    You could also do all the mounting on the roof, and leave the final connection to be completed by a licensed electrician...

    If you don't feel like getting up on the roof when its 110+ out (by the time you get your equipment and ok from city) I have a guy that does it on the side - he wont do the permits, but knows how to mount and hook up the panels :)

    Oh, you will need a 2nd disconnect switch on the inside of the garage - and outside prior it going to breaker panel, Metal conduit, and placards/Labeling that rivets into the metal on the Inverter, disconnects etc.
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    Hey! Thanks for the feedback. If I do do this, it wouldn't be until sometime in September so you still have a chance to help. ;):D

    I would be putting the inverter outside, so I don't think a second disconnect is needed. Even if it is though, they aren't too expensive so it should fit in the "misc" I allocated for.

    I know APS allows it for sure, I hope City of Peoria does as well.

    The tax credit still applies on all parts purchased...I guess not on the labor, though technically you should still get fair market credit for the labor you do yourself. :P

    Do you know if City of Peoria requires the panels to be grounded to the railing? Someone told me that differs from city to city code. If it is required, then I would need some of these...little suckers are not cheap! http://www.renvu.com/Racking/IronRidge/IRONRIDGE-Iron-Ridge-Mid-Clamp-C-D-J-E-Kit-2-25-Mill-4-pcs-_11
  • KozmoKKozmoK Solar Expert Posts: 42
    Re: DIY grid-tie? Any other parts needed?

    Those are for the railing splices - I didn't have those on each panel. You will need to run a solid copper wire clamped onto them.

    I can go up top and look to see if I even have them on the rail splices I have now.
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    Hmm, someone else locally who is doing a DIY project said they are for grounding the panels to the rails, which is required by some city codes.
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    Can anyone comment on if it's ok to run the racking parallel to the rafters like this? Is it better to do it one way vs the other (perpendicular to the rafters)?

    If I could run the racking parallel to the rafters, I would need 249' of racking vs 384' if I were to run it perpendicular.

    The red circles are the posts and the yellow squares the the panel clamps.

    Full size image: http://nitnelav.com/racking.jpg

    racking.jpg
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    Talked to the guys over at Renvu.com and while the racking can be installed parallel on top of the rafters, that is not how they were designed or tested. Also talked to the city who said they can allow a homeowner to install their own system but the homeowner has to write a letter explaining why they feel they are qualified and what kind of experience and training they have. Seems a bit strange but ok.

    With the racking perpendicular to the rafters, it would look like this:

    387' of racking
    110 pcs flashed tile mounts
    56 pcs end clamps
    46 pcs middle clamps

    Price is now estimated $21,156.


    Full size image: http://nitnelav.com/racking2.jpg
    racking2.jpg
  • BB.BB. Super Moderators, Administrators Posts: 30,177 admin
    Re: DIY grid-tie? Any other parts needed?

    Many (some/most/all?) solar panel mfg. require their panels to be mounted "across" the racks (i.e., horizontal racks, portrait panels) to meet structural design requirements.

    Most vendors do not say anything on the data sheet--you have to check their install/warranty documents to find these little "details".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    Thanks BB, I have verified that the Canadian Solar CS6X series can be mounted in landscape mode with horizontal racking.

    http://www.civicsolar.com/sites/default/files/documents/canadian-solar-installation-manual-ul-154727.pdf

    From the install PDF:
    canadian.jpg

    For the SolarWorld panels, it does look like they can only be mounted with the racking running parallel to the short side, so they wouldn't work in my install. Guess that makes that decision easy.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: DIY grid-tie? Any other parts needed?

    Regarding mounts going parallel with roof rafters: it depends on what they hit (or don't).

    If the lugs/bolts go into/through the rafters it's okay, providing said rafters are not split (structurally compromised). But the rafters may not line up with where the panel mounts need to fasten down. Then you have a different situation. If the sheathing is not strong enough to support the weight it can't be done this way (hence going perpendicular to the rafters placing the weight across them even if the fasteners are not on 2x material). You really need to check both the roof structure and the particular panel mounts in question.

    On the up side it is not too difficult to install additional 2x material between rafters so that the panel mounts will have thick material to bolt to and the weight gets distributed to the rafters on either side regardless of the parallel/perpendicular issue. Us 2x6 at least (to give yourself plenty of 'landing space') and fasten with screws (to avoid jarring existing structure).
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    Thanks for the input Cairboocoot. I actually calculated for that...if you look at my diagram, each blue/light blue rectangle represents space between the rafters. I would actually be able to place the mounts on a rafter at all points and it would work ok with the panels, the mounting points would fall within the specs required (between 7.5" from the edge to 22" from the edge on the long side).

    Full size image: http://nitnelav.com/racking.jpg

    racking.jpg
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: DIY grid-tie? Any other parts needed?

    I'm sure they are fine drawings, but to my old eyes they are a blur of colour spots. :blush:
  • BB.BB. Super Moderators, Administrators Posts: 30,177 admin
    Re: DIY grid-tie? Any other parts needed?

    Many building departments will require a structural engineer to review your roof structure and racking, and sign off the plans.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    I've checked into that and I think it would be ok...this is what the city's solar guide says:

    roof.jpg
  • HX_GuyHX_Guy Solar Expert Posts: 296 ✭✭✭✭✭✭
    Re: DIY grid-tie? Any other parts needed?

    If I can in fact run the rails vertical (parallel with the rafters...a rail on each other rafter), it would save $1415 vs running the rails horizontally.
    That's also if I can cut the rails, not sure if that's easy or ok.

    Each railing would fall right on top of a rafter. There would be a lot less posts/flashing required (90 vs 110).
    Vert.jpg

    This looks cleaner but it would be quite a bit more money and labor.
    Horz.jpg
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