dgpcolorado
high altitude member
Are you including the federal tax credit and any local power company rebates that apply?It's a lot more in California, too.
$4/watt installed is a pretty good deal. Bids I've received recently are in the $4.3-$4.5/watt range. $4/watt would make an 8kW system cost around $32k. $1/watt is not something I've heard anyone achieve even through self-installation. Maybe @Topher can help us out with what we're missing.
I put in my second array before panel prices dropped to the current $1/watt or so. Even so, my cost for 1470 watts installed was $8142 before the federal tax credit and $5699 after tax credit ($3.88/watt). [Unless changed by the incoming administration — a distinct possibility — the 30% solar PV federal tax credit runs though 2019, I believe.] My installation would have been significantly less if I had qualified for a rebate from my local power co-op, but I had already used the one-per-household rebate on my previous installation.
And that cost was for more expensive pole-mounted panels; it would have been lower for roof-mounted panels due to less expensive hardware, but I didn't want holes in my roof and ground-mounted panels have significant advantages. I did my own trenching, post-hole digging, and concrete work but all the rest was done by the local solar company at $70/hr IIRC.
My tiny PV system is less cost-effective than the big ones that you mentioned, and that most people seem to favor, due to economies of scale. If you can't get way below $4/watt installed after tax credit and rebate (if any), you aren't trying very hard. An extreme example: my sister and brother-in-law put in a 4500 watt array in central Oregon, doing most of the work themselves, for an out-of-pocket cost of $1000, thanks to generous rebates from their state and utility company.
I believe that a large roof-mounted array would price out at significantly less than $4/watt with today's lower panel prices, the tax credit, and economies of scale. Why people need such large arrays and use such large amounts of electricity is another question. Before electric car and solar panels I was using about 4.8 kWh/day. It might be a bit higher than that today but not by much, except for fueling the Model S. I guess I am glad I live in a climate that doesn't need air conditioning! My 2170 watts of solar panels covers all of my household and EV fueling needs.