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Planning:
This was a DIY project - so I went with a simple design with well supported elements. Enphase micro-inverters do not require a complicated (to me anyway) DC wiring system, or load matching - panel matching - inverter designs. Each panel pairs with an inverter, the panels do not need to match in make, size, or wattage. Plus I could install 1 or 20, the design stays the same. I went with clicksys mounting - I have no experience with other hardware - but clicksys was VERY easy to use.
Permit:
For Brevard County, Fl - there is a handy web site where most of the information can be found and forms downloaded: http://www.brevardcounty.us/onestop/home/
Questions sent to the "Contact us by e-mail" were answered surprisingly quick - and some of the permitting actions like requesting the final is done via email - VERY helpful.
What was not readily available was a list of paperwork that is required for solar install - mainly because it is still new and not a lot of people are doing it themselves. The list I was given and initially turned in was missing 90% - the checklist at Permit Checklist lists everything I eventually submitted for an approved permit.
Electical Inter-Connect:
For my area - an application and agreement is submitted to the utility. After the work is complete and the permit signed - a copy is submitted. Within 30 days they will swap out the meter with a bi-directional meter. It is free to do, and very simple to accomplish from this web site:
Electrical:
The ONLY requirement for a federal rebate, state incentives, or FPL interconnect is that the system is installed by a licensed solar contractor OR a master electrician. To save money I went with a local electrician. I consulted with him on what I could do, what he had to perform, and an hourly price. It worked out for all - he was more than happy to come out for a few hours to make the connections - I mounted the sub panel, ran the wire and conduit in the attic, etc (all the time consuming - but menial tasks). You will need an electrical diagram similar to the example for the permit process, show circuit breakers, wire size, panels, etc.
Mounting:
Find, mark, and triple check the center lines of rafters. I took the vents off my eaves so I could see the ends of the gable, and used the end wall, plubming vents pipes, and exhausts inside the attic to pinpoint the rafters.
There are lots of mounts on the market ranging from $20 flashings that slip under the shingles, to flange footings that screw down right over them. Since I used clicksys I went for the latter, but I slid the mounting hole under the shingle above, used 35-year silicone under the flange and all over the stainless steal lag screw, and glued the shingle back down with roofing cement.
Rails:
Brackets:
The shingles are parallel to the roof line - so butting the flange up to the shingle ensures they are parallel as well. I put one every 24", and the rails are laid out so that the panel will be supported about a third from the top and bottom evenly.
The panels will be spaced 1" apart - so remember to account for it in the rail spacing.
The rails are aluminum I-beams. Each bracket comes with a "slider", stainless steel bolt and nut, and the bracket. The bolt goes up through the slider, which then "slides" over the top of the I-beam. WEEB grounding clips slip over the bolt, the ends of the WEEB will sit between the panel and the rail. A bracket (either and END or MIDDLE) slips over the bolt along with the nut (smear anti-sieze around the top of the bolt first). Once the panel is in place, the DC wires snapped into the inverter, and everything squared up - you tighten the bolt. After 2 panels are in place you tighten the first panel to 10-inch/lbs. A torque wrench should not be optional - you want the panel to be evenly torqued.
Inverters:
Grounding:
Enphase micro inverters are installed under each panel. The first inverter connects to an outdoor rated J-box via a supplied cable. The location of the first inverter is not critical - as the AC cable and the inverter "OUT" pigtail together is over 10'. The rest of the inverters need to be thought out - the inverter "IN" pigtail is 6", the "OUT" is 70" - so as you go from the top row to the next row - make sure the cable reaches.
With Clicksys - the mounting kits come with 2 sliders, set screws, regular nut and flange nut. The set screw is loosely screwed into the regular nut which goes up through the slider like a bolt. When in position, tighten the 2 set screws into the I-beam, then torque a flange nut over the bolt to 20 in/lbs.
Thread a continuous ground through each inverter back to the AC J-box ground.
Here is a link to another install using the same inverters - the gounding process is explaing and shown in really good detail. Actually the entire install process it very detailed - a great additioanl reference site.
My system is grounded 3 ways - every rail has a splice near the left hand side - at every splice I have a copper lug nut connected with a WEEB washer to the rails. #6 copper wire connects all the rails down the roof and into a 8' copper rod pounded into the ground.
The panels are secured with clips to the rails, every clip has a WEEB washer that bond 2 panels and the rail together.
Finally each inverter is connected via a continuous ground to the AC electrical service ground.
First Panel:
Pre-Cautions:
The first panel determines the placement of the entire array. I spent extra time ensuring that it was square to the railings.
The 2x4 contraption on the left was an easy way to move the panels. They are only 44 lbs - but at 4' x 6' a little awkward. There are stops screwed into the top - lay the panel on the rails, push over the first set of stops, use the small ladder to stand on while pushing over second stops.
I worked very early and very late due to the heat, but even then the panels produce power - I taped cardboard from the shipping boxes over the glass untill they were connected. There are warnings on the panel NOT TO CONNECT under power. I am not sure why, but sparks and shocks while you hold a 44 lb panel on the roof, or blowing a diode on a few hundred $$ panel would not be worth finding out.
I screwed 1'x4's against the eaves to support the first row, you can not tighten the mounting hardware, plug cables in, or adjust while the panel is sliding down the roof. For the next row - some scrap railing is exactly 1" and works great for spacing and securing the panel while you work.
Completion:
Where / What to buy:
Going by the time stamps on the images you would think 8 days total. In reality this size of array is a 3 day weekend project in terms of time. I spent more time double checking the location of the rafters than I did bolting them down. The bulk of the work was done after 5:30 at night - June 2010 in central Florida experienced 100+ heat index temps - that is bearable in the shade sipping tea - but not on the roof with power tools and 44lb panels (My hat off to ANY roofer out there!!). So I probably got 3 hours in at a time.
I have room for 3 more panels, the beauty of micro inverters is that a cheap, blemished panel I get can be added any time - with a single DC inverter system I am positive you can not just throw another panel in the mix.
I did quite a bit of research and price comparisons. Going with micro-inverters is a little more expensive, but in my opinion well worth it when you consider ease of design, no single point of failure, ease of modifying and expanding in the future. Buying the entire system from a single source will save money as well, shipping, handling, etc can be combined. I found an excellent and hard to beat price with DMSolar out of Fort Lauderdale, Fl. Do not discount shipping in figuring price - the most expensive line item for my project was shipping. The panels and rails are shipped via truck - if you buy panels from CA, and live in FL - you can easily pay $800- $1000 shipping. DMSolar is out of Florida - so shipping was a little less painful.
Email David Li with questions, requests for quotes, etc as you shop around - you will be happy with the pricing.
Inverters: Enphase M190-72-240-S12
Panels: Brightwatts BWI-60_M230 (230watts)
Mounting: Clicksys (Unirac)
Master Electrician: MJM Electrical Service (also a certified contractor)
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