1) I think your panels are on your roof, right? What kind of roof structure do you have - is it rafters or trusses?
2) Were there any special challenges your installers had with your roof?
I paid to have my panels installed professionally, so I'm afraid I can't speak to the difficulties involved. It was a two day install job for 28 panels, with a two or three man crew. One day to put up the racking and run the wires while the electrician installed the inverters in the garage, and a second to lift all the panels on to the roof and connect them.
The racking system was installed over the shingles. Presumably it is anchored to studs but I haven't looked, sorry.
The panels stand about 4 inches off of the roof. The only change made to the roof was to shorten the sewer vent stacks so they would still be open, under the panels. Code here requires 14 inches of vent pipe above roof level to prevent clogging by very occasional snowfall, but that's not an issue under panels so we just shortened them. If the panels ever come off, I'll have to lengthen those pipes again. The panels were installed right over the top of my attic vents.
3) You have a net-meter, right? And did it have to be installed, by the power company, BEFORE your array came online? Do you have to pay a monthly base surcharge for that meter? My power provider requires a $3/month charge for the dual-reading net meter.
Yes, we have a net meter. Our regular meter measures net power consumption, so it runs backwards during the day. We had to have a second meter installed that measures just the power coming down from the roof and feeding into the net meter. That one only counts up to measure power generated, and that's the one the power company reads once per year to determine my production incentive payment ($4969 last year).
Yes, we had to have that meter installed and certified before we could start accruing production incentives, but the system was running for like three days before they got here to certify it. We just didn't earn any production incentives for those first three days, though we did effectively earn the retail rate for power by reducing our net meter total for the billing period.
We do not pay a monthly fee for the net meter specifically, but we do pay other monthly fees and I think it was like $200 up front (paid by my installer and figured into his cost to me) for the city to install the second meter.
Like every power customer here, we pay a $10/month grid connection fee, recently increased from $5/month when they lowered the retail cost of power a little bit. I suspect too many people like me were taking advantage of the incentive program, so the utility lowered per kWh rates and raised the fixed fee, which effectively penalized solar panel owners twice. I now pay more in fixed fees and get paid less for the power I provide to the grid. For most normal (non solar-producing) customers, this change was a slight to moderate cost savings, depending on their usage.