A number of factors will affect the cost of your install. These factors include; energy consumption, the type of installation you want/need, the difficulty of your roof, and the permits needed per your homes location.
1. Your energy consumption, the type of solar application, your roof type, and the permits you need will affect the cost of your solar installation!
2. Common home additions that can impact your system size are: (bullet this list) electric cars, electric appliances such as dryers, hot tubs and pools.