Page 16 - North American Clean Energy July August 2015

solar energy

Above: Ajo Solar, 6 MW in Ajo, AZ

Left: Centinela Solar, 249 MW in Imperial Valley, CA

How to Design to Code

Compliance Considerations for Ground Mounted Solar

by John Williamson

AS THE SOLAR MARKET CONTINUES TO MATURE, regulators are taking an increased interest Many individual jurisdictions have their own codes, so when building a site, the installer
in ensuring installation safety compliance and long-term reliability. Especially in areas of must be aware of international, national, state, county, city, and even customer code require-
high solar activity, such as the state of California, and other authorities having jurisdiction ments. Most of these are derived from certain standards organizations and often defer sec-
(AHJs) in the southwest, code oicials have learned the hard way that not all solar installa- tions of their codes to these agencies. hough the names of the codes may be diferent, most

tions are equally sound. Since many codes surrounding solar installations are either brand other countries have very similar requirements to the United States. he codes in North
new, or still in development, there is not often a clear standard for solar equipment provid- America and Europe are typically the most developed and stringent, though other countries
ers to follow. Structural guidelines that have been designed for skyscrapers and bridges are may have developed more code requirements around subjects speciic to their regional issues.
being applied to mounting structures in certain jurisdictions. he environmental require- In the United States, it is typical for most structures to be designed according to codes

ments, such as high winds, excessive snowfall, and wet environments, may be excessively from certain manufacturing and construction code entities, such as the ICC (Interna-
conservative, or not enough so. Electrical safety and grounding code requirements must tional Code Council), American Institute for Steel Construction (AISC), American Society
also be met for AHJs to allow systems to be energized and connected to the grid. It takes a for Testing and Materials (ASTM), and AISI (American Iron and Steel Institute), and the
broad understanding of all of these subjects to ensure that solar components will comply Aluminum Association to name some of the most recognized. Most of these organiza-

with code requirements, and continue to be reliable over the typical 25- to 30-year design tions have all been established for around 100 years or more, and were mostly organized
lifetime of a solar ield.
to provide some level of standardization for building design and material safety for steel
buildings and bridges. Because steel com-
ponents are mainly used in mounting solar

panels, they fall under the same code re-
quirements since they are deined as a “steel
structure”. he original intent of these
codes was to standardize design, but also to

strengthen U.S. industry. Most of the code
requirements make it diicult to incor-
porate non-standard or foreign materials
including structural steel and hardware,

and rely on the engineer of record (EOR)
code enforcement oicial’s judgement as to
whether these materials are allowed to be

used. While there has been some efort to
standardize codes for solar structure design
(ICC AC428), these guidelines have yet to
be accepted into most jurisdictions. In sum-

mary, most of these resources are excellent
guidelines for design, but may be prohibi-
tive to innovation if they are required to be
followed to the letter.

Environmental design requirements vary
considerably from one AHJ to another, and
often the most local authority (typically
city or county) has established rules for

their regional environment that all struc-
tures, including solar, must be designed to
accommodate. At a national level, in the
United States, most of these requirements

16 JULY/AUGUST 2015
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