When I placed my order for a 6.02kW solar roof last Thanksgiving, the estimated price was $65K. For months there was no action on my order, in part because my roof has a projection over a bay window where the roof edge is angled other than 90°, which the PA said they could not do. Finally I did get a design proposal two weeks ago, so apparently they did implement a solution. Based on the experiences in this thread, I expected the actual price to be higher since my all-hip roof has a total of 21 ridge and valley line segments on an H-shaped house. And it was: $117K. I saw there was more space available on my roof so I asked the PA about the cost to increase the solar area and was told about $2K per kW. Therefore increasing the power by 2kW would reduce the cost per kW significantly, and since increasing the capacity of a solar roof later would be much harder than with panels, it makes sense to plan for future increased need due to conversion from gas to electric heat and appliances.
Imagine my (pleasant) surprise when the price of the revised design proposal for an 8.77kW system decreased to $107K, 9% less that the first design (these prices all before tax credit). Looking at where the cost reduction came from, I see that the non-solar roof material cost decreased more than the solar roof material cost increased -- are the metal tiles more expensive than the solar tiles? That seems unlikely. Similarly, the bulk of the reduced price came from the reduced non-solar roof labor cost. So I wonder if the calculations were incorrect in the earlier design (and I hope not in the new one).
Curiously, the new design includes a small line item for Alternative Roofing that the earlier design did not. I see in the Legend on the Your System Layout page that Alternative Roofing is indicated by areas in a light gray color. The only portion of the layout shown in that color is a triangle where we have a shade sail installed. I will take down the shade sail while this project is under construction, so it should not have any bearing on the cost. I just hope this line item does not imply that some alternative roofing method other than tiles will be used on some portion of my roof such as over the bay window. It would be nice if I could the newly assigned PA would answer the phone or email so I could find out.
My other concern is whether the larger PV size will be approved. The previous PA assured me that I could have any size my roof would support, but I've seen discussions in this forum regarding a limit of 120% of current usage. The 8.77kW design shows a 310% energy offset based on my utility bill, but that is not meaningful because I have an existing PV system that will be replaced. It would likely still be over 120%, though.