Page 14 - North American Clean Energy May June 2015

solar energy

Solar Rooftop

Installations

Demand Safety

by Joe Camarota, Mike Wessner, and Chris Baralus

Solar power systems have experienced widespread popularity and growth in recent years. In 2010, less than 2,000 MW

of solar power was installed and in 2014 it was projected that over 7,000 MW would be installed . As solar becomes more
afordable, more businesses are utilizing it as a way to “go green” and reduce electricity costs. However, installing a solar

power system in a place of business may not be as easy as it seems. In fact, one aspect of installation - safety - is critical, not

only to ensuring long-term output of the array but also to keeping the building and workers out of harm’s way.

The following safety issues should be accounted for before any When the decision has been made to put a solar array on the roof, it is critical that a full
construction begins:
analysis of the roof be completed. his analysis should include a review of the existing roof,

• Is the roof strong enough to support the array?
a structural analysis of the building and roof, and which racking method works best for the
• How should the solar panels be arranged to maintain accessibility?
structure. his analysis should answer questions such as:
• What is Arc Fault Technology and why is it necessary?
• How old is the roof?
• Can power be shut of from the array to the building from the electrical service to prevent
• Will it sustain for the life of the solar array?

electrical shock hazards?
• If the system requires roof penetrations, how will this afect the integrity of the roof?
• Do the solar panels remain energized even after power has been disconnected?
Without a structural analysis, customers risk problems as minor as a roof leak to as severe
here are three main locations that solar arrays are installed: rooftop, ground, and parking as a roof collapse. A structural analysis of the additional roof loading should be performed

canopy. A ground or parking canopy system is not attached to a building and generally by a professional engineer, including the new load imposed by the modules, possible snow
poses little risk to the building or occupants. However, the opposite is true of roof-top drift, and additional wind loading which transfers to the structure.
mounted systems and safety issues related speciically to these must be addressed.
Why is it important to arrange the

solar panels properly? From a ire
safety standpoint, aisles and walkways
A highly secure safety system
should be incorporated for emergency

responders. For example, if a rooftop
penetration is required for ventilation
in order to ight a ire, it may not be
possible if the roof is entirely covered

with solar panels. Arranging the panels
in arrays which are wired separately
also allows for individual sections to
be isolated. his reduces the number of

live conductors which are exposed to
emergency personnel.

Arc Fault Technology allows the system

to operate while simultaneously monitor-
ing the direct current (DC) conductors
coming from the panels for arc fault, re-
ducing the possibility that a ire will start.

his new technology is now available and
Greeneye Smart PV Switch
required by the National Electrical Code
(NEC) for all solar array wiring installed
on or in a building. he Arc Fault Circuit
• Failsafe safety system
• Individual shutdown feature per PV module
Interrupter (AFCI) capability is tested
• Protection for ireighters or PV installers and electricians
as part of a system’s commissioning
and thereafter as part of a maintenance
package. When implemented correctly,
Ferraz Shawmut is Mersen
ep.mersen.com the Arc Fault Technology will not only
de-energize the photovoltaic (PV) circuit,

14 nacleanenergy.com
MAY/JUNE 2015