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Washington’s largest solar array, a 782-kilowatt (k W), 2.5-acre PV array, is on the rooftop of an event center adjacent to CenturyLink Field.
installer Surmounts Snags at Seattle Stadium
FiRST & GoAL
Bono, or a non-compliant disconnect switch? Seattle-based McKinstry, contractor for the solar photovoltaic (PV) system on the rooftop of CenturyLink Field Event Center, isn’t saying which
made for the more memorable installation experience.
CenturyLink Field (formerly Qwest Field) is the home of the NFL’s Seahawks and Major League Soccer’s Sounders, and the location of frequent
large-scale events. As of late June, it’s also the site of a 782-kilowatt (k W),
2.5-acre PV array. The Solyndra system, on the rooftop of an event center
adjacent to the stadium, hit the grid as Washington’s largest.
Besides a space-themed U2 concert, McKinstry had to accommodate
for a number of other events during the nine-day panel installation. The
Seahawks cheerleaders — the “Sea Gals” — held a function, and there
were shows at the WaMu Theater and soccer and baseball games to be
worked around. “At times, the site was very busy with traffic and people
coming and going to events,” said John McBride, project manager at
McKinstry. “It did extend the actual delivery of the panels by around
four or five days.
McBride worked closely with First & Goal, the field operator, to work
out a delivery schedule based around everything going on. “We took our
deliveries as early in the morning as we could — by about 6:00, 6: 30 a.m.
By noon, we were pretty well offloaded from the truck, with the product
up on the roof,” he said.
The crew, consisting of two install teams of three people, four panel
transporters, a crane operator, bell man and two flaggers, averaged 375
panels delivered and installed per day, with a peak delivery of 468. The self-ballasted, non-penetrating Solyndra panels, chosen because of the freshly
renovated white “cool roof,” simplified the installation, allowing for half the
team to be comprised of apprenticeship labor.
Approximately a month into the project, but before the panels arrived,
McKinstry became aware of compatibility issues with the disconnect switches. As originally designed and approved, the system featured a 1,200-amp
switch for each of its two Power-One inverters. McBride came
across a white paper that suggested the planned design could
fail to break the DC power from
the inverter — a potential safety
hazard to maintenance crews. By using multiple 600-amp, three-pole disconnect switches per inverter, which increased the DC arc gap, the redesign
corrected the issue. Without compromising the construction schedule, it
was approved by the city of Seattle within days.
Completion of the system gives Seahawks’ owner and Microsoft co-founder Paul Allen another green stadium under his belt. In 2010, the Rose
Garden, the arena of Allen’s NBA team, the Portland Trail Blazers became
the first pro-sports stadium to achieve LEED Gold certification.
The CenturyLink Field system will output 830,000 kilowatt-hours of
electricity annually. That offsets 380 tons of carbon emissions, equivalent
to planting about 71 football fields of trees. — MikE koShMrl
CL Join the Seahawks and
Sounders in a video walk-through
of CenturyLink Field: