The first small photovoltaic (PV) predecessors to PV systems currently being installed on roofs were introduced during the early 1970s. Many of these systems were installed with little thought or planning; consequently, those who purchased the systems were disappointed, government incentives were discontinued and PV quickly fell out of public favor.
However, with energy costs constantly in flux, the recent extension of federal tax incentives and an overall trend toward environmental friendliness, more reliable PV products have been introduced and more building owners are looking at rooftop PV systems as a viable way to reduce energy costs.
We all have heard about "big box" building owners installing 50-kilowatt (kW), 100-kW and utility-sized PV systems on roof systems larger than 50,000 square feet. However, I believe PV roof system installations' future lies with small businesses and the residential sector where 1- to 25-kW systems will be installed on roof systems smaller than 50,000 square feet.
If you are interested in installing practical and efficient PV roof systems, there are numerous factors you must consider before and during each installation.