solar installations
With an IRS
allowance for
white roofs used
with Solyndra’s
technology,
the contractor
stands to pocket
tax incentives
worth nearly
half the total
system and
roof cost.
By GInA R. JOHnSOn
Mark Bell, Empower Energy Technology president (right), demon- strates the Solyndra panels’ easy installation with Choate Construc- tion’s director of sustainability, Michael Swick, LEED AP BD+C.
choAte coNStRuctioN co.
Choate Construction Co.
Headquarters
Solar was an obvious option as Choate Con- struction Co. pursued LEED for Existing Buildings certification at its Atlanta headquarters last year. Sun is plentiful year-round in
Georgia, and state and federal incentives are generous. But for Choate, an IRS ruling extending
the 30 percent federal solar tax credit to reflective roofing, when installed with an innovative
photovoltaic (PV) technology, made the deal too
good to pass up. Empower Energy Technology
commissioned the 74-kilowatt (k W) Solyndra
PV system in October.
According to Michael Swick, LEED AP
BD+C, director of sustainability at Choate, “We
project less than a five-year ROI with solar panels that have a 25-year warranty. That’s a good
investment.” Choate based the payback estimate
on projected system generation, offset electric
utility rates and a 6 percent capitalization rate.
The fast payback relates to Solyndra’s technology. Its systems, comprising panels and
mounts, use proprietary cylindrical modules
with thin-film copper indium gallium diselenide,
or CIGS, technology. The 360-degree surface
allows it to capture more light than traditional
flat panels early and late in the day, with broad
42 April 2011 SOLAR TODAY solartoday.org
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PV System highlights
Atlanta’s Climate
Average Solar Resource: 4. 37 kilowatt-hours/square meter/day
Average High/Record Low Temps:
53°F–90°F ( 12°C- 32°C)/- 8°F (- 22°C)
System Details
Designer and Installer: Empower Energy
Technology
Array Capacity: 74 kilowatts (k W)
Annual AC Production: 106 megawatt-
hours
Panels: 405 of Solyndra’s 182-watt panels
Inverters: Nine 7-k W SMA Sunny Boy
inverters
Array: 29 arrays of 10-15 panels each.
Each array’s homerun circuit is brought
directly to the inverters, thereby avoiding combiner boxes.
System Monitoring: Advanced Green
Technologies’ Solar Monitor Dashboard
Commissioned: Late October 2010
Cost and Incentives
Solyndra system: $350,000
White membrane roof: $175,000
Misc. and overhead: $50,000
Pre-incentive total: $575,000
Estimated federal tax credit for the
Georgia corporate tax credit on PV
system cost*: ($122,500)
Total cost after incentives: $295,000
shoulders and less peak during the day, says the
manufacturer. A reflective roof helps the system
capture more sunlight, thereby increasing efficiency. It’s this complementary arrangement
that the IRS has recognized.
“The IRS issued a private letter ruling on a
similar project that included the costs of a reroof
in with the system costs calculated for the tax
credits because the Solyndra system produces 18
percent of its power off the reflection of a white
roof,” Swick explained. Choate’s ballasted black
roof was a decade old. “This was a great opportunity for us to reroof with a new, white ‘cool roof’
and get it rolled in with the tax credit,” he said.
Because the IRS requires that at least 70 percent of the roof be covered with the Solyndra
product in order to qualify, Empower installed
405 panels, a total of 8,748 square feet (813
square meters).
Design Accommodates Quick, Dense
Installation. The Choate installation was
Empower’s second Solyndra project, and the
four-year-old firm has installed a third since
then. According to Chuck Clarke, Empower’s
vice president of engineering, the roof incentive
made Solyndra the clear technology recommendation for a client that also needed to replace
the roof. Ease of installation was another factor
that gave Solyndra an edge over more-proven,
less-expensive crystalline modules. According
