Stacking Technology for Energy Efficiency
Holistic approach provides optimal
performance for net zero retrofit project
It started with Humanscale's
Director of Sustainability Jane Abernathy's vision to have
Humanscale's Piscataway, N.J., 110,000-square-foot facility
retrofitted to improve energy efficiency, with an ultimate goal of
a net zero carbon footprint.
Humanscale is the premier designer and manufacturer
of ergonomic products that improve health and comfort at work. The
company, based in New York City, has award-winning office solutions
including self-adjusting seating, sit/stand desks, monitor arms and
task lighting, which inspire movement and support the user in every
posture. Humanscale also has a strong corporate sustainability
philosophy which states "Everything we do has an impact. We're
aiming to make it a good one."
When she put the solar panel project out to bid, one
company came back with ideas for a "stacked" technology approach:
Energy, out of Hawthorne, N.J., a full-service energy company
that specializes in renewable energy systems.
As Wayne Pfisterer, president of Pfister Energy,
explains, "Although the initial bid was only for solar panels, we
took a holistic approach to the facility by looking at which
technologies we could 'stack' for optimal performance. We looked at
things like the client's objectives, ROI/payback period, state
incentives, permitting, engineering and so on. From there we made
recommendations on the right mix of technologies for Humanscale's
facility. Fortunately, [Abernathy] was open to our ideas."
After evaluating Humanscale's facility, Pfisterer
discovered that the roof had about only five years left before it
would need to be replaced, so they started there. "The existing
roof was a black tar surface that retained considerable heat, thus
making the facility hotter. We specified a 2-inch insulation board
with a white membrane roofing system with reflective properties,
thus providing a much cooler environment." The company also
specified a 775 KW solar array which comprised 2,585 solar panels.
The system generates enough energy to offset the facility's
electrical usage annually.
Humanscale's solar panels generate the power that the
facility uses during the day. During weekends and low-usage times
the excess power flows out to the power grid with the local utility
(rather than storing on-site, which would require large battery
cells). If additional power is needed, the company can access the
grid much like a big battery system. At the end of the year,
Humanscale and Pfister Energy will review the energy consumption
and make any adjustments.
Pfisterer also decided to introduce company
executives to Vista, Calif.-based Solatube
International Inc.'s Daylighting Systems, which integrate
easily with solar panels and would help Humanscale achieve energy
savings, a more productive work environment and reduced ecological
footprint, all driven by its corporate sustainability philosophy
and Abernathy's vision. "We knew that the production area would be
dramatically improved by having natural light from the Solatube
products to help employees with product assembly," Pfisterer
The project was originally specified with 300
Solatube 750 DS units. When Solatube International's new SkyVault
M74 Series was introduced, the project stood to benefit
tremendously from the use of the much-larger SkyVault units.
SkyVault units are designed for large spaces, particularly those
with ceiling heights of 18- to 40-plus feet.
SkyVault products require fewer roof penetrations
(since fewer are needed to daylight a given space), and increase
daylight output, which decreases lighting costs. The project used
87 SkyVault M74 with Amplifier units-the Amplifiers redirects
daylight to the visual task plane.
While the initial goal of using daylighting systems
was lighting energy savings, the daylighting noticeably impacted
quality control in the production area. Of the 110,000-square-foot
facility, approximately 38,500 square feet was daylit using
Solatube SkyVault units, with the remaining roof area over storage
racks dedicated exclusively to PV panels.
"An unexpected benefit is that the Solatube
Daylighting Systems reduce shadows and show color more accurately,
so workers can now detect small flaws they weren't able to before,"
says Willy Duran, production supervisor at Humanscale. "It's
positively impacted product quality."
"The reaction among Humanscale employees is that they
love the daylight. It's very apparent to them the difference in
brightness, quality and color of light from one side of the
facility to the other. They like their work environment better,"
according to Tim Neher, Humanscale facility maintenance
"With the Solatube units, we don't have task lighting
hanging down over each production area," Neher adds. "You can see
from one end of the floor to the other. It's a much cleaner, more
"During summer months, when power demands are at
their greatest in the hot weather, the energy grid is susceptible
to brown- or black-outs. One of the great things about the Solatube
SkyVault units is that no matter what is happening with the power
grid, daylight continues to flood into the space during the day,
even during a black-out," Pfisterer says.
Additionally, Pfister Energy added a new LED lighting
system, including daylight harvesting and motion control systems.
Pfisterer estimates the payback periods as:
- Solar panels: 4 years
- Solatube Daylight Systems: 7 to 8 years
- LED lighting: 1 year
- All of the above combined: 4 to 4.5 years
- All of the above combined with the new roof: 5 years
Phase two of Pfister Energy's "stackable energy
approach" for Humanscale will likely include rain harvesting and
containment tanks for use with irrigation and plumbing.
Pfisterer sums up by saying, "The Humanscale team has
embraced our vision of stackable solutions by incorporating
multiple technologies and optimizing them for their facility. In
America, we have to build energy plants and infrastructure for peak
power. In many areas we have an antiquated electrical grid that is
inefficient. Projects like this produce onsite power that is not
only much more efficient, but can also offset streams on the
electrical grid at critical times."
Neall Digert is vice president,
product enterprise, at Solatube International Inc., Vista, Calif.,
the worldwide manufacturer and marketer of tubular daylighting
devices. He can be reached at firstname.lastname@example.org. To learn more visit www.solatube.com.