azimuth angles can be read off the acetate. The calculations can be used in
simulation programs. Computer programs can take into account the geometry of
the PV modules and their wiring for further evaluation of shading effects.
Shade Analysis Tools
Many shade analysis tools use digital cameras and computer software. Good soft-
ware tools are less prone to error. Make sure that the professional performing the
shade analysis is competent. Tools such as Solar Pathfinder or SunEye can calcu-
late shading in a manner of minutes. A shading analysis tool determines the
impact of nearby objects on the prospective site down to what hours and which
months that site will be shaded.
Roof Installation Options
Installing a PV system requires an in-depth understanding of solar power systems
and construction techniques. Installers must be able to convey facts, options, and
requirements to the customer. They must explain the shading analysis’s impact
and identify serious shading at the PV site. They also need to describe various
design factors that affect performance.
There are many varieties and types of mounting structures and systems. They
can be placed on the roof, used on building façades, or integrated into the building
itself. The most common are structures fixed on the roof. Other systems incorpo-
rate the PV modules into the roof or the outside of the building. Freestanding
roof rack structures for flat roofs, or to be used on the ground, also are available.
The mounting hardware is also elemental to a solidly placed PV system. Alu-
minum and stainless steel are the most commonly used mounting materials.
However, local environmental conditions need to be taken into account when
choosing mounting materials. Air pollution, desert temperatures, and ocean salt
can affect material longevity.
Roofs
Roofs perform a variety of tasks. The roof bears the brunt of the weather—wind,
rain, and snow. The roof keeps those weather conditions away from the inside of
the building. The roof provides shading and often insulation. Roofs keep noise
out or at least reduce it. And they protect against fire.
Roofs may be classified by their slope. Flat roofs have a slope less than
5 degrees. Sloping roofs have a slope between 5 and 22 degrees. Steep roofs have a
slope greater than 45 degrees.
Roof-Mounted PV Systems
A roofer may be needed for on-roof mounting systems. This depends on the PV
installer’s skill, the local requirements, or the specializations needed for the
mounting system. Structural integrity is crucial, and the installer may need
CHAPTER 4 Site Review, Layout, Mounting Systems, and Building Integration 77
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.