Don't forget that there is also an added equity value to your home.

Ah to dream. 

The ROI I speak of is not the same as a valuation and yield of a security or increase in equity by appreciation of a stock.

My cost was based on the  number of panels required, support equipment, battery replacement and installation costs and a simple cost projection Rate hikes by SPP would decrease that.

I do have a system by Sentinel that provides emergency lighting

With 40% cells the panel size would be smaller, generating hours longer. The cost would be the determining factor.I would assume as the 40% cell hit the market, cost would drop for the old technology.

There are intangibles involved. The idea of being independent of the grid plus the ability to locate a home on less than optimal land are some.

Before me things create were none, save things Eternal, and eternal I endure.

All hope abandon ye who enter here.