10kW grid-tie microFIT in NW Ontario

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johnl
johnl Solar Expert Posts: 30 ✭
in Grid Tie and Grid Interactive Systems #1
Hi All - new member here. First post so please don't be too surprised at how clueless I am. :confused:

I'm considering putting up a 10kW or so roof-mount grid-tie system in North-Western Ontario to take advantage of the new microFIT 80.2 cents per kwh pricing being offered by our province. I have an unobstructed 52' by 20' area facing 160 degrees SSE that looks suitable for mounting the panels. The roof has about a 30 degree pitch, 2x6 rafters spaced 24" on centre, and asphalt shingles that are likely about 15 years old and will need replacement within the next 5 years.

Here's my proposed configuration (so far):
- 45 Canadian Solar C6P-230P 230 watt poly-silicon panels (3 rows of 15 panels)
- Unirack Solarmount or Dyco Solar racking system (racks must be "Ontario-manufactured" to comply with microFIT rules)
- either 45 Enphase M-190s or 2 SMA 5000s for the inverters

So does that rate a Thumbs-Up or a Thumbs-Down?

I'm guessing I need to re-shingle the roof before putting up the racks and panels instead of doing that 3 or 4 years from now. I'll let a roofer tackle that part of the job, and I'll be hiring a qualified electrician handle to pull the electrical permits and to connect the system up to my home's main breaker box and the new generator meter that will be installed. But I'm thinking of installing the racks and panels myself (with a little help from friends and family). Is DIY realistic for that part of the job, or is it beyond the average homeowner's skills?

I'm undecided about whether the Enphase or SMA inverters would be the better choice. The last 5 feet at one end of the roof gets a little shading late in the afternoon from some trees, and I'm running into opposition about cutting the trees down. I could configure the system into 3 strings of 11 across in the unshaded areas, and make the last 4 columns by 3 rows in the area that gets some shading into a 4th string of 12. That would limit the shading to just one string. Or I could use the Enphase inverters and not worry at all about shading. Any opinons around here about that choice?

I'm also not sure what little bits and pieces I need to get to tie this whole system together. DC cables with MC4 connectors? Combiner boxes? Lightning protectors? DC and/or AC disconnects and breakers? Some strange thing called a WEEB? Is there a good sticky or link around here that would point out all the items needed (like a bill of materials) to create a complete grid tie system?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,443 admin
    #2
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    Re: 10kW grid-tie microFIT in NW Ontario

    Regarding the trees--they do grow over time... If you cannot "address" them now--what will happen in 5 years?

    -Bill "Trees are just tall asparagus" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • johnl
    johnl Solar Expert Posts: 30 ✭
    #3
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    Re: 10kW grid-tie microFIT in NW Ontario
    BB. wrote: »
    Regarding the trees--they do grow over time... If you cannot "address" them now--what will happen in 5 years?

    -Bill "Trees are just tall asparagus" B.

    Good point. They are 50+ year old mature pine trees. I don't think they have grown much in the 10 years we've owned the house. The tips of the trees cast a little shade on one part of the roof after about 3 PM. While I'd be glad to get the chainsaw out now and make some extra firewood for next winter, other family members think it would be "terrible" to cut these trees down. I could scale back to about 36-39 panels and avoid the shaded area altogether. I'm not sure if it makes more sense to scale back to 39 C6P-230W panels (8.9kw), or get the full complement of 45 CSI panels knowing that some will be shaded in the late afternoon, or pay a little more overall for 39 SunTech STP-270W panels to keep close to 10kw and avoid the shading.
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  • drees
    drees Solar Expert Posts: 482 ✭✭✭
    #4
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    Re: 10kW grid-tie microFIT in NW Ontario

    I really like the concept of Enphase inverters - should be installing 18 of them on my own roof this weekend if the weather cooperates. That said - if you can avoid the shade, a convential inverter will work just as well and be a bit less expensive. Pruning the trees back so they don't shade your roof should be feasible - everyone likes big pine trees, don't they? :)

    As for your roofing - if you can work out the penetrations you will need to mount the panels, I would suggest installing your roof anchors while the roof is getting redone so that the roofer can properly seal them instead of poking new holes in your brand new roof.
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  • johnl
    johnl Solar Expert Posts: 30 ✭
    #5
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    Re: 10kW grid-tie microFIT in NW Ontario

    I'm still pondering roofing options while I wait for my project approval/conditional contract from the Ontario Power Authority. Does it make more sense to replace my 15-year old asphalt shingles with more of the same to go under the solar panels? Should I follow the advice of both Dad and Dad-in-law and go with metal roofing? Or should I go with some sort of continuous rubber-roofing membrane like a commercial building would have, as my neighbour suggested? (This is a standard residential sloped roof, with a pitch that is a touch less than 30 degrees).

    For racking, I'm looking at a company called Dyco (http://www.dyco.ca/solar/products-solar.html) that makes a product that complies with Ontario's domestic content rules. The L-bracket feet are intended to be mounted with lag-bolts drilled through the roof and into the rafters (with generous amounts of sealant in each roof penetration).

    I've been lucky enough to find a local installer that I'll be working with, and I think I've gotten some good advice on many of the installation details. The trees have to go, if I want to have any chance of producing power after 1PM in the wintertime. It looks like I'll be using two Solectria PVI 5000 inverters and 48 Kyocera KD-210-GX-LPU in strings of 12. (Products much preferred by the installer over the CSI panels and Enphase or SMA inverters I was considering). The one thing I'm not sold on with the Kyocera panels is that their lower voltage makes them incompatible with the Enphase inverters. But I suppose that as long as I'm using a traditional inverter, that won't matter.
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  • jdair101
    jdair101 Registered Users Posts: 5 ✭
    #6
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    Re: 10kW grid-tie microFIT in NW Ontario

    Hi
    I just yestertday reshingled my 11 year old south facing roof in preporation for my microfit install. (supose to be intalled in 2 weeks) I moved several of the roof vents to different locations to make it clean for the install.
    I did ice&watershield the entire surface just as a preventative measure against leaks.
    I wish I had room for a 10kw system but can only fit 5kw without loosing my solar thermal system.
    Jim
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