Active job

Photovoltaic

I'm having my roof replaced on my 1960's ex state house. I'm thinking I will look at the pro's and con's of having a photovoltaic system installed while the roof is off. The house floor area is 100m2; the roof area a little more. The house is pretty well exactly rectangular and faces north / south. I want someone who can tell me the detail of how it works ... power storage, selling to the grid, payback time, maintenance etc and of course,the costs