There are many roof applications for solar installations, how do you know which racking solution applies to which roof type?
As long as there is enough space and enough
access to the sun, solar panels can be installed on just about any roof. The way the panels are attached to the roof
depends on the type of roof. And,
therefore, the cost to install the panels will vary as well. Solar panels will actually reduce some of the
weather-related wear on the parts of roof they cover. But they are not a substitute for a roof
replacement (unless one is using solar shingles). So if a roof has existing problems or is
approaching the end of its warranty, it should be replaced before installing
installing solar panels, it is important to consider both the angle of the roof
that the panels will be installed on and the direction that the roof
faces. To capture adequate amounts
of sunlight, panels should face south to the greatest extent possible and should
be mounted at an angle as close to the latitude of the site as possible. These two requirements generally do not
prevent buildings from installing solar panels; however, they do determine what
kinds of installations are possible on specific roofs and determine the
performance of the resultant installation.
roof types on homes include gable roofs, cross-gabled roofs, hipped roofs, and cross
hipped roofs. All of these have moderate
pitches and can be ideal for solar installations, provided that they have
sufficiently large south-facing surfaces. These roof types are amenable to
installations where photovoltaic shingles are desired rather than separate
roofs - which are commonplace on commercial buildings – and even more exotic
roofs such as Mansard-style roofs can actually provide a great starting point
for highly effective solar installations. On a flat roof, the solar panels
are typically installed on free-standing frames that can optimize array
performance by providing the ideal tilt and directional orientation. The same is true for Mansard roofs that include
relatively large flat spaces. The only
obstacles that cannot really be overcome are roofs that don’t have south-facing
surfaces (such as some shed-style roofs) and sites with unacceptable amounts of
shading from nearby trees or structures.
The cost and complexity of installing panels varies with
the design and the composition of the roof. Most roofs use composition shingles and solar
panels are attached to rails that are affixed to the roof through
bolting mounts into the roof rafters.
Flat roofs are typically covered with either tar and gravel or
polyurethane foam. The racks that hold
the panels generally don’t require drilling into the roof structure at all;
often some kind of ballast such as concrete blocks is used to keep the racking
stable. Roofs with wooden shake shingles
or ceramic tiles are the most expensive roofs to install PV
modules on. This is because the shingles
are fragile and difficult to walk on and drilling into them for mounting the
racking is delicate work and time-consuming.
There are, of course, more exotic roofs around
with complex curved surfaces and other unusual features. Such roofs present unique challenges to PV
installers but, provided that there is enough space, enough sunshine and enough
determination, solar panels can be installed on nearly any roof.