re: Solar Panels on houses

I made this spreadsheet a while back when I was looking into solar panels:

LINK

I've hightlighted the cells that require input.

Cell B1: Input your average annual electricity usage (in KWH)
Cell B2: Input how much you spent on electricity in that 1 year period
B5: I have a 3% inflation rate per year. Could be 2, could be 4, who knows.
E1: Average sun hours per day. Use the link to the right side of this to determine this value.
E2: Total output of the solar panel system you're looking at. Locally, companies are advertising 7kw systems for the $25,000.

Off to the right, it shows how munch you would normally spend on electricity over the next 30 years without solar panels, next column shows how much money you would save with the inputted Solar System per year, and last column shows what your new electricity cost would be with solar panels (assuming you don't have a 100% solar system)