It's recommended solar panels are placed on the roof and face true south for optimal sunlight absorption. True south is slightly different from magnetic south, which is the direction a compass will provide you. To achieve optimal conversion of solar energy, it is essential to know the solar path, the profile of the needs, and the conditioning factors of the location of the solar panels. Choosing the right spot isn't just about finding a sunny patch—it's about making sure your investment works as efficiently as possible. Shading by nearby (or distant) trees, building, mountains, etc. California residents don't need to concern themselves with whether the climate is. Solar panel installation costs range from $15,000 to $30,000 for an average American home, with a payback period of 6 to 10 years depending on your state's incentives and sun exposure.