[Pikachu_Dad]

A life of 20 years is probably about right - but verify based on the technology you intend to use.

You should include the cost of disposing of the cells when their useful life has expired.

On the other hand, all of the Solar bankruptcies may make obtaining solar panels at a steep discount possible. So you may be able to snag a lot of capacity for a song.

[UnBubba]

Believe it or not, an entire solar panel project's cost (soup to nuts, including planning, install, permits, service, etc...) has declined significantly over the past couple of years (from about $4.00/kWh to $2.80/kWH).

One of my big concerns is the general contractor's (GC) financial condition. I have seen many fly-by-night solar company's come and go over the past few years. Most of them have been in business for 5 years or less and have grown too quickly and have become over-leveraged.