The new 'mantra' is to build "zero energy" homes or offices. This can be achieved by combining green-building techniques with active solar systems. A "zero energy" building is one that produces as much energy as it consumes over the course of a year. Making use of solar energy using Photovoltaic Panels is at the heart of sustainable building. But it is important to understand that where should these Photovoltaic Panels placed.
A small amount of shade covering the panel can reduce the panel performance by 80%. Therefore, the most important point to remember is that when choosing a location for your Array is shading obstacles.
Find out which month has the least amount of sun on average. Determining this month is particularly important if you intend to use or constructing a system that will be used year-round. Similarly, if you want to use it for summer or winter, you will have to find month with least sun during months that you will use the system.
It is also very important to estimate the availability of sun and the cloud cover. Obtaining this information may be little difficult. Sometimes you can get this information on the web otherwise you may contact concerned authorities in you town/city.
You want to choose a location that is on or near the place where you loads will be. The array should be free of shade (during each month in use) from 9 am to 3 pm. This is the optimum time-frame a panel has to receive light and is called the “Solar Window".