In my 1AM stupor, I mistakenly noted those panel/inverter connectors were Tyco when they are in fact MC4 (now that I compared the two). I edited my post above to correct that.

Day to day, year to year PV output has so many variables that I cannot see any degredation. I'm sure it's there, because I believe the textbook science that says the output degrades 1% per year, but the palm tree that shades my array part of the day also grows taller each year. You'll note when I post my monthly data on the 12.5kW thread, I provide previous years data for comparison.

My house came with one of those Carlon boxes buried in the front yard as a junction box, it takes on water. I used a similar carlon box in my attic out of the weather, but for the roof I wanted something more robust. I drilled the Wiegmann box where I needed cable gland entrances, that's not a problem. They're uniform thickness fiberglass side walls and a forstner or spade bit went right through them.

There is a torque specification for the main lugs, sub-panel lugs, and the terminal leads coming off the breakers in most UL panels. However, most everyone seems to overlook that, and torque "to feel" without a measuring device. When I pulled out my torque wrench with the appropriate end bits and asked my AHJ inspectors if they wanted to check the torque of any of the bolts or lugs during my final inspection, they chuckled, said "If you a) know they are supposed to be torqued, and b) are offering us a tool to check them, then we expect you have torqued every one of the connectors to spec. Most homeowners don't know there's a spec, and most contractors develop a 'feel' for what's right and don't actually use a tool. Kudos for reading the NEC and knowing there's a specification for that." I had purchased the micro-torque wrench to torque the panel mount nuts on the racking to properly ground the WEEBs, it only made sense to torque the wiring connections if I already had the tool. I have heard electricians say they occasionally see lugs loosen over time, especially in areas with drastic temperature variations. The intense heat developed by arcing from a loose lug or loose meter blade terminal connection has been one of the concerns as smart meters were rolled out to consumers in my power utility. When the arcing caused a fire, consumers automatically blamed the "new smart meter" for the fire. I'm sure a fire marshal would properly diagnose the origination point for the fire if an inspection were performed.

What do you know about electrical work.
Because going from not being able to add a circuit to your home or replacing a switch or receptacle to building a diy solar system sounds like a recipe for disaster.

Roostre,

I believe you need to have the system installed and OPERATING by Dec 31 of this year to get the 2016 tax credit.

There is always GTA (good until audited), but I like to get things done "cleanly" for the IRS. No sense waving any red flags in front of bulls . . . . .

You have a lot to do - but we can help you. First off, we need your month by month kWhr consumption for past year and the associated costs for kWhrs in the varying seasons and for differing consumption levels. This allows us to figure out how many kW system. Then we figure number of panels. Then we look at roof to see how panels can go up and where. That determines amount of racking and wiring.

Not trying to be scary, but old man winter is puffing up . . . . .


Steve

An 8 year payback is a 12+% return on investment, which is pretty good in my experience. That's ~1.5x the real return of the S&P 500 over the past century.

:thumbup:

It wouldn't be 1.5x the return.
I considered this when I bought my solar system and mine doesn't beat the stock market.
If I consider a conservative average annual return for the total US stock market to be about 7%, that means the value would double every 10 years.
If I figure a lower cost solar system is $10,000(mine was slightly more) after the tax credit, ignore the delay in getting the tax credit money back, and consider the idea that the money put into the solar system is sunk until it comes back out, this is what my math looked like based on my own expected payback.

Solar installed(figuring 8 year payback, but mine is actually over 10) -$10,000
$-8750 Year 1
$-7500
$-6250
$-5000
$-3750
$-2500
$-1250
$0 Year 8
$1250
$2500 Year 10
$8750 Year 15
$10000 Year 16 (Took 16 years to double)
$15000 Year 20
$27500 Year 30

Of course, this isn't accounting for changes in electricity cost or net metering factors specific to your region or electric provider.

Stock market starting with $10,000 with 7% annual return
$10,700 Year 1
$14,025 5
$19,671 10
$27590 15
$38696 20
$76122 30

Compounding returns is powerful. You could take the returns you get from the solar system and invest those in the stock market, but even if you do that, you still need to consider that the price paid for the system is not going to be in the stock market and you've lost the opportunity cost for that initial potential principal. The idea that the original poster is about to otherwise lose the cash and is willing to DIY the install, I'd say that it's still a good move to do.

For what it's worth, the financial component of solar was a factor but I still wanted the solar and I figured it was better than spending the money on a couch, a car, or some other depreciating asset. It is fun for me to look my eGauge power graphs and see the power the system is generating and what the house is using.

I work in the power business. (Generation/transmission/distribution) 17 years mostly instrumentation and controls. Have friend that is a master electrician who is willing to help as I take good care of him when he does. I'm probably more comfortable with the project than most would be. It's actually the mechanical part (roof racking, shingle modification, snow load, wind load) stuff that I have blind spot in.

No pressure!! Right?? :D

We only recently moved into this house, so my data is limited.

July-1581 kWh August-1455 kWh September-1260 kWh

Yesterday was actually step 1 in this process. We rented a lift and took down 3 large trees. One of these completely shaded our southern side of the house, but it needed to go. I will add pictures of the roof in a separate post.

Roof2
 

Roof3