Solar Array Issue?

This is a photo of a friend's very well designed and highly efficient solar electric array.  This array is designed to generate 5k of electricity at peak output which would happen in midday in mid-summer.  Being over-sized means it can deliver enough juice to power the house on an over-cast day in winter.

Is a solar array a good investment?  My friend, in order to take advantage of this free power has replaced his gas clothes dryer with an electric one and the same for his water heater. 

In our region, the utility (PG&E), will credit your solar generated electricity against your electric bill but not buy the excess generation.  Meaning the best you can do is zero-out your electric bill and reduce your gas bill by the amount of capital you put into converting gas equipment to electricity.

For many that means taking a hot shower and doing laundry only when the sun is out.

Is a solar array a good investment?  No.  Not based on my many professional calculations. 

If you can zero out your electric bill in my region, that is $1,000 to $1,500 a year in cost reductions.  Most solar arrays cost $18-$25,000 and last 7 to 12 years before replacement.  Regardless of the interest rate, or government tax subsidy, that doesn't pay.  Sorry. 

I'm especially sorry for you enviro-activists because you are supporting solar arrays at a time when natural gas prices are going to make natural gas nearly free.