Construction & siting issues  
The most significant consideration in the use of photovoltaics is in the siting of structures and their solar panels to take advantage of sun angles and solar insolation (Figure 2).  
   
 
Figure 2: Solar Insolation in the US - average insolation in units of kilo-watt per square meter per day (sun-hours) for a surface latitude tilt for December (Worst case solar resource month). (www.ttcorp.com/upvg/wh_sol.htm)
 
   

Figure 3: Trees and solar systems. (Derived from Zanetto J. LA 1978)

 Some systems include sun-tracking mechanisms which increase efficiency. The siting and selection of trees to avoid shading panels is critical, and growth habit of tree species must be considered for long-term efficiency (Figure 3). With site-specific design, PV systems can meet very exacting demands. PV systems also have the advantage of being silent, non-polluting, low-maintenance and do not cause visual clutter like that created by electric power lines and transformers. In public landscapes, however, vulnerability to vandalism is a consideration for the design and placement of solar panels (Sorvig, p.29).
 
When considering the construction of a PV system, many questions must be asked before determining which technology is appropriate to the specific situation, especially where meeting energy requirements at an acceptable cost is concerned.  
   
 

Any PV system provider will have the tools to trace the sun’s path at a given location and determine whether a home or business can benefit from a PV system. A south-facing roof is best, but west and east frontages may also work. Flat roofs are especially suitable, as PV modules can be mounted on frames tilted toward the south at the optimal angle. If the rooftop cannot be used, solar modules can be placed on the ground on a fixed mount or a tracking mount that follows the sun for maximum PV performance. Another option is to build structures that create covered parking, or structures that also function as window awnings.

   
     
  Wherever one chooses to place the modules, they must be unobstructed by trees, buildings, chimneys, etc., to have solar exposure for most of the day. One must also determine if the region receives enough solar energy to make a PV system worthwhile. If a region receives low but constant amounts of solar energy during daylight hours, a PV system may not be advisable. If one is building away from an established utility, however, one should take into account the cost of installing a utility line; solar energy may be cheaper than extending conventional power to a residence.