NJ newbie here! Saying hello!

[flowing]

So finally installed, not active... But fully installed.

[macaddict]

@macaddict I see that yous install was done via GPE. How close was their estimate to the actual production you have been getting?

Thanks!

Just saw this, sorry for taking so long.

GPE's estimate was 11,284 kWh / year. I created two other estimates, one using the Solar Edge Designer app and gave me an estimate of 12,470 kWh/yr. The other estimate I created was with PVWatts and that one was 11,890 kWh/yr.

In 2018, which was my first full year with the system, it made 11,285 kWh so it was right in line with GPEs estimate but we also had a lot of rainy days. So I would say, at least for me, the GPE estimate was on the low range.

I'm using the PVOutputPro app to visualize my production and as you can see, I ended up -5% from my highest estimate last year. But this year, I'm up 7% since we have had much better weather. Ignore 2017 as that's when I got my system installed as it is a partial year.
Image-1.jpg
Here you can really see the difference. February was horrible last year but this year, I did great:

Image-2.jpg

[Mike90250]

Stop it fellas. I've pulled some posts, and if I have to pull more, I'll close the thread and nobody wins

[J.P.M.]

All good ideas. But, you'll end up taking a project which was barely cost effective at $3.23 / W and turning it into a boat by the time you are done. You know what a boat is right? "A boat is a hole in the water surrounded by wood into which you pour money."

I'm not in construction, but here in NJ, I've found a good rule of thumb to estimate the cost of trade's people. $1200 per person per day. It doesn't matter whether its electrical, plumbing, roofing, sprinkers, deck repair, fencing -- I've had them all. $1200 per person per day.

Given the proximity of your garages and the need for clearance when pulling in and out, I'd wager your up in the $6+/W territory just to get started. Saving all of that money, investing it, and using it to pay your electric bill for years to come would be a much more prudent investment.

FWIW, +1. Overall, and IMO only, this is not a good application for PV.

[JSchnee21]

All good ideas. But, you'll end up taking a project which was barely cost effective at $3.23 / W and turning it into a boat by the time you are done. You know what a boat is right? "A boat is a hole in the water surrounded by wood into which you pour money."

I'm not in construction, but here in NJ, I've found a good rule of thumb to estimate the cost of trade's people. $1200 per person per day. It doesn't matter whether its electrical, plumbing, roofing, sprinkers, deck repair, fencing -- I've had them all. $1200 per person per day.

Given the proximity of your garages and the need for clearance when pulling in and out, I'd wager your up in the $6+/W territory just to get started. Saving all of that money, investing it, and using it to pay your electric bill for years to come would be a much more prudent investment.

[Ampster]

Structurally that is not that difficult. You have the house for sheer strength. The calculation are going to be primarily for wind. As you found out it will probably involve several trades, a srructural engineer, a contractor/carpenter and the solar company. A cantilever design would be expensive but a short shed roof design supported by a header and posts set in concrete for uplift load could work.in your area you might need snow load calcs as well. A design build contractor with acess to an engineer would be perfect.

[flowing]

Ampster yes it is. Thats what I originally wanted to do. Build off-roof.... but was scared away by costs.
If I could fit some panels on the little roof on the side. Or extend that roof two fit 2 rows I would be very happy.

Capture.JPG

This is a bit too optimistic. But If I could do it. I think it would make a difference.

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[Ampster]

Is it a two story house? I am asking because there is a great opportunity for a lot of south facing panels above the cars parked in the driveway. I know that has probably been ruled out earlier and maybe you keep it for future expansion.

[flowing]

JSchnee21

Yeah North is up.

I would be placing panels on the "red" squiggly lines. I definitely will not be placing them on the east/front of the home. I too doubt the amount of panels they think they can fit on my roof. Lets see when they do the survey.

The trees dont cast shadows on my home. The angle of that shot is weird. The trees to the left are very far from the home. The willow at the bottom of the screen is gone due to lasts years storms.

What is this "clipping" I heard you mention.

Thanks again!

[JSchnee21]

Hi flowing

Based on your image above, am I correct to assume that North is up? So you essentially have three possible faces. ENE (which you would prefer not to use), WSW (preferred face), and SSE (possible/preferred face). Is that correct?

It's always hard to judge scale in these satellite images, but I'm doubtful you will fit ~40 panels using just the WSW and SSE faces, Additionally, production from the WSW face will not be very good. I'm having some doubts about a 20 MWh estimate given a mostly WSW array.

I know you would rather not, but using all 3 faces would be ideal. Not quite a good as all facing South, but having a large East and West contingent would enable you to capture a lot of sun in the morning and afternoon. and the SSE would be a nice bonus. Given the different orientations, using two 7600H inverters would likely be fine, even with 18kW to 20kW of panels (per SE's requirements) as production is spread out throughout the day.

Shade may also be an issue. You seem to have a lot of trees (as do I). They can cast surprising long shadows 9 months of the year, and, they grow

[Ampster]

I reread this thread and it looks like you may be evolving to a roof mount system. If I understand your site your main roof surfaces may face south west and north east. I also understand that you have two EVs.

If your goal is to generate as much power as possible, or at least up to your consumption of 2,000 Watts per day then you may want to look at what bcroe did with multiple orientations. That could include roof mount and ground (carport or pergola). While others my suggest you would want to optimize panel productivity only, my opinion is that you may want to optimize site productivity. That may mean a higher DC to AC ratio overall. With proper design of strings that high ratio may not have to penalize you with any mid day clipping. Essentially you might be able to capture more morning and afternoon light without losing the best mid day light.

Bruce had the advantage of doing some of his install himself and with a ground mount that may be easier to adjust during the build. The key will be your site survey and how innovative the designer is. Of course if you do get an innovative design that looks too aggressive you may want to ask for a production guarantee.

[J.P.M.]

J.P.M.

They estimate 20,670 kWh a year.
I'm on 07059
Thanks for the link to PV Watts this is what they estimated: 22,944 kWh/Year*

I'm unsure of the angles. Once they do the survey I should have a better idea.

Thanks again for all the help.

You're welcome. Two points:

1.) PVWatts is not an estimator of annual performance. It's a design tool whose output is representative of a long term average output. It's no better than the inputs used (GIGO). Any actual year is most likely to be no better than +/- 10 % of the model's output, mostly due to weather variation. Folks think that if they have a month or a year that's very different from PVWatts, they either got screwed or made out like a bandit.

2.) Note 20,670/22,944 = 0.901. Looks about like that 10 % I wrote about in my last post, huh ? maybe just coincidence.

Peddlers who (mis)use PVWatts or other models to provide "estimates" routinely manipulate the input or simply lie about the output to underestimate the output of the system they're peddling by about 10% or more. A couple of reasons:

- To give some false but authoritative looking backup for their low performance performance estimates. That makes their estimate more believable and makes it easier to sell larger a larger system than needed.

- Keep in mind that no peddler ever got fired for selling the customer more than was needed, especially if the customer is clueless and will only think that the system is outperforming the estimate by 10 % or so which is what it can look like to the solar ignorant buyer. Bigger system with more profit and a happy customer who thinks their system is doing 10 % better than expected. Win/win - for the peddler ( the customer just got screwed and lied to).

One trick of many.

Just sayin'

[flowing]

JSchnee21 You can see I'm definitely not oriented the best for solar. Its hard to tell from this image. There's a 6' roof that runs on the side on the home that I'm hoping to fit 7 panels along with that roof next to the driveway.


Capture.JPG

[flowing]

J.P.M.

They estimate 20,670 kWh a year.
I'm on 07059
Thanks for the link to PV Watts this is what they estimated: 22,944 kWh/Year*

I'm unsure of the angles. Once they do the survey I should have a better idea.

Thanks again for all the help.

[hiya]

I hate to interrupt this thread but not sure what else to do. I am a new member and for some reason cant start a new thread, i can only reply to a thread. Sorry for butting in to this conversation.