Price paid per watt

[jgd108]

Hey Eleceng1979:

1. Thanks for your earlier response! I am just an end-consumer preparing for a solar install in a couple weeks. Answers such as yours help me evaluate whether my particular contractor is doing the "bare minimum" or doing a truly "professional" job. (Yes, as a consumer and the guy who writes the check paying for the product/service I personally see a difference between doing the bare minimum, or the minimum in accordance with code, or actually doing something that is above grade - that is what I label doing a "professional" job.)

2. Your comments about fading/cracking and the NEC is a good bit of information for a consumer like me. It gives me a chance to ask my contractor what he will be using, and if it seems "bare minimum" it will give me a chance to challenge the choice or materials, and demand something different.

3. Don't let the nay-sayers and trolls upset you. I did a while back. It wasn't worth it. Who knows why they write what they do - they may not even intend to be upsetting people or realize how they come across. You cannot control them. It is a waste of energy to try. No pun intended. Fortunately, 90-95% of the folks here are really helpful.

As messy as it often can be, even the back and forth nit-picking still helps folks like me that are watching from the sidelines... as long as you trust consumers to tell the difference between good advice/points/observations and snark.

entgegnen not sure how to PM you (tried everything) but was curious since you are in SoCal which installer you chose to go with? I saw in other posts you were aroud the $3 / W mark, the best I can do for now is 3.8 /W thanks! I've turned on private messages if it helps.

[DaveDE2]

Yes, photo was taken late in the day, 5pm or so. Shade comes in from a big pine tree on the west. It gradually creeps left to right (W to E). I tried to maximize output by configuring the four strings so that they are diced up into four blocks from east to west. I'm losing about 2-4% due to shading. Optimizers might have cut that down by 1% or so but I'm happy so far. My only slight regret is that I didn't put the Soladeck under a panel (you can see it on the left in the picture) for aesthetic reasons but no big deal. What I'm surprised at is *soiling* loss. Those big pine trees emit a lot of pollen and cover the panels with a film. I'm sure I'm losing 2-5% output or so from that. Hoping for rain to clean them off.

[SunEagle]

13kW diy system on shop building:

$18,392
$1.41/w before any incentives.

51ea Phono Solar 255w panels at $0.59/w (ACO solar)

Iron ridge racking at $0.23/w (Ressupply)

SMA Sunny Boy 6.0 inverters (2ea) at $0.29/w (The Power Store)

Misc @ $0.30/w: Structural analysis, Soladeck, SMA Rapid shutdown (2ea), permit fees, NEC 2014 manual, POCO new meter and connect fee, wire and connectors, AC disconnect, line side tap materials, PV labels, conduit, inverter cooling fans, tools, three high school students helped for panel installation labor @ $15/hr, etc.

System commissioned a few weeks ago. So far generating about 80kWhrs/day when it's not cloudy.

Photo taken by son's UAV:

Nice system. I hope that shade in the lower left corner is late in the day. Otherwise a pretty clean system. Keep us up to speed on how it performs.

[DaveDE2]

13kW diy system on shop building:

$18,392
$1.41/w before any incentives.

51ea Phono Solar 255w panels at $0.59/w (ACO solar)

Iron ridge racking at $0.23/w (Ressupply)

SMA Sunny Boy 6.0 inverters (2ea) at $0.29/w (The Power Store)

Misc @ $0.30/w: Structural analysis, Soladeck, SMA Rapid shutdown (2ea), permit fees, NEC 2014 manual, POCO new meter and connect fee, wire and connectors, AC disconnect, line side tap materials, PV labels, conduit, inverter cooling fans, tools, three high school students helped for panel installation labor @ $15/hr, etc.

System commissioned a few weeks ago. So far generating about 80kWhrs/day when it's not cloudy.

Photo taken by son's UAV:

[foo1bar]

As usual a person who didn't read the original post commented on my comment. Please read the original question and my comment and quit taking my post out of context. The question was...Question #2: Should conduit be inside the attic?

And if you had stated your response to the question asked and not said that metal conduit was required above the roof, I would not have replied.
But you stated (or at least strongly implied) that metal conduit is required on the roof, and NEC does not require it.

c. PVC is not approved for installation in locations subjected to direct sunlight. This is the comment from the majority of the AHJ'S in the usa with a good solar code amendment. Technically you are correct the NEC doesn't require it, but it is a minimum code.

It's used in many commercial installations on top of flat roofs for regular building wiring.
There may be locations where AHJ's have said it's not allowed - but that would be a local rule.
otherwise it generally IS approved for installation in direct sunlight. (I think most/all current PVC conduit available has UV inhibitors - if there's some that doesn't it'd probably be marked "underground only" or something and wouldn't be approved for direct sunlight.)

PVC does not belong on a roof in my opinion,

I have no argument with that.
I even agree with it.
But that is a personal opinion, and not a NEC requirement.

THE NEC IS A MINIMUM REQUIREMENT.

Yes - and that's why I was pointing out that it doesn't actually require what you said it does.
Even though it might be a best practice.

arm chair quarterbacks that have never been electricians, lecturing electricians on their iphone, all while sipping their Starbucks, while looking at their shaded sunpower panels feeling good about saving the planet while commuting to work in their 3 ton suv...i digress.

can't be talking about me, since I have never had an iphone, hate coffee, didn't use Sunpower, and don't have a large SUV.
(And are you an electrician or an Electrical Engineer? I assumed like me you are an engineer, and not an electrician based on your username.)

[entgegnen]

Hey Eleceng1979:

1. Thanks for your earlier response! I am just an end-consumer preparing for a solar install in a couple weeks. Answers such as yours help me evaluate whether my particular contractor is doing the "bare minimum" or doing a truly "professional" job. (Yes, as a consumer and the guy who writes the check paying for the product/service I personally see a difference between doing the bare minimum, or the minimum in accordance with code, or actually doing something that is above grade - that is what I label doing a "professional" job.)

2. Your comments about fading/cracking and the NEC is a good bit of information for a consumer like me. It gives me a chance to ask my contractor what he will be using, and if it seems "bare minimum" it will give me a chance to challenge the choice or materials, and demand something different.

3. Don't let the nay-sayers and trolls upset you. I did a while back. It wasn't worth it. Who knows why they write what they do - they may not even intend to be upsetting people or realize how they come across. You cannot control them. It is a waste of energy to try. No pun intended. Fortunately, 90-95% of the folks here are really helpful.

As messy as it often can be, even the back and forth nit-picking still helps folks like me that are watching from the sidelines... as long as you trust consumers to tell the difference between good advice/points/observations and snark.

[inetdog]

Well, Eleceng1979,

Us lowly moderators can only ban you. It would take an Admin to actually delete your account. And your posts would remain.

PS: The forum is, IMHO, quite congenial if you stick around and have a thick skin.

[Eleceng1979]

As usual a person who didn't read the original post commented on my comment. Please read the original question and my comment and quit taking my post out of context. The question was...Question #2: Should conduit be inside the attic?

c. PVC is not approved for installation in locations subjected to direct sunlight. This is the comment from the majority of the AHJ'S in the usa with a good solar code amendment. Technically you are correct the NEC doesn't require it, but it is a minimum code.

PVC does not belong on a roof in my opinion, many AHJ's opinions and despite proper ratings for such usage will deteriorate over time and look like $hit and will crack, bend, bow, etc... If you want to pick a fight about pvc and sunlight go talk to Mike Holt about it. The NEC also says you need more than one ground rod too for solar...

If you want to help this thread and answer questions than respond to this one. If you want to pick a fight with me over code compliance start a new thread. What I can tell you is my install passed 100% first time with a poco inspector, a local inspector, and a state inspector looking at it all at the same time. How about yours? THE NEC IS A MINIMUM REQUIREMENT.

This crap is why I have requested my account to be deleted....arm chair quarterbacks that have never been electricians, lecturing electricians on their iphone, all while sipping their Starbucks, while looking at their shaded sunpower panels feeling good about saving the planet while commuting to work in their 3 ton suv...i digress.

If anybody reads this crap, flag my post and get my account deleted...this place is like the hotel California. ..i have requested my account to be removed twice... if i post a sales link i get banned, if I'm stupid and post BS I'm stuck forever...WTF?

[foo1bar]

PV wiring is required to be in metallic conduit per the NEC. Metallic conduit should exist everywhere PV wires do, when on/in a house, period. Along the roof or inside the attic doesn't dictate safety. Where it can be cut by firefighters or wires fail inside the conduit without being noticed is my fears.

PV wiring only has to be in metallic conduit when INSIDE a structure per NEC (NEC 690.31(E))
On the roof it can be in PVC conduit OR even no conduit. (Usually it is no conduit when underneath the modules.)

Many people prefer metal conduit to PVC - but it is not required by NEC when outside the structure (ie. above the roof)

My *guess* at the reasoning is that if outside the structure it's obvious that it's a conduit with PV wires - and not going to be cut by firemen. As opposed to inside where it could look like "just another housewire - no reason not to take the ax to it to make a vent hole since the meter is pulled"

[Chris@SSE]

Hello, I'm from a UK company that manufactures solar panels and it is interested to see the cost that installers are paying per watt for their panels. We are currently offering a discount on all commercial silver framed panels. Our panels are high quality and TUV regulated and not cheap Chinese imports. We use the highest quality cells and materials and we can offer the following prices on our 260 watt Silver framed panel:
1-4 pallets : £0.48/watt or £124.80/panel

5-10 pallets : £0.46/watt or £119.60/panel

10-15 pallets : £0.45/watt or £117.00/panel

Multiples of 15 pallets : £0.44/watt or £114.40/panel.

If you would like to find out more or just fancy a chat we are available to help

[Eleceng1979]

Question #2: Should conduit be inside the attic? (I was just presuming it would be safer to have it along the roof because of the high voltage? And running it down through the roof and into the attic might give another possible place that roof is compromised?)

PV wiring is required to be in metallic conduit per the NEC. Metallic conduit should exist everywhere PV wires do, when on/in a house, period. Along the roof or inside the attic doesn't dictate safety. Where it can be cut by firefighters or wires fail inside the conduit without being noticed is my fears.

back on topic... 12.96kw Canadian solar cs6k-270m, ground mount, 360' from house, SMA 6.0 x 2, in ohio, with extended warranties, $3.10/watt installed prior to any incentives.

[DaveDE2]

I haven't weeded my way through this whole thread so I may be a bit off here but I just did a diy 13kW 51 panel system on my shop building. The inverters are inside the shop. The cleanest way I could see to do it was to get a Soladeck (roof penetration point) and run 1" EMT from it through the attic and down into the shop/garage space. Going over and around a soffit would be ugly, cause many more pipe bends and make the wire harder to pull. It is in no way unsafe to route the high voltage through the attic if the metal conduit is properly grounded.

[entgegnen]

Price seem good but you have to ask questions - will conduit be inside attic or along roof? Will inverters be inside or outside? Will conduit go around gutters or through soffit? There are lots of ways an installer can price low that may harm the value of your home by more than the price difference.

Question #1: Is there a best (or preferred) way of doing this? Is it better to go over/around/down the "soffit" or is is better to cut a route through the soffit and go straight down? Is this a matter of aesthetics vs structural integrity?

Question #2: Should conduit be inside the attic? (I was just presuming it would be safer to have it along the roof because of the high voltage? And running it down through the roof and into the attic might give another possible place that roof is compromised?)

PLEASE NOTE, I've reposted my questions on the part of the forum that specifically addresses installation (as opposed to here in he price per watt)

[TomP]

Sharp 250 W. cost me 1.07 a watt 3 years ago. Of course I think Sharp picked up and moved to Japan .

[jetsurgn]

Nice I self installed to down the road from you in San Pedro.