IEEE Spectrum September, 2007 - 6

Power: David Kaneda shows off the solar panels and skylights of his new building [left].
The skylights are sometimes supplemented with efficient fluorescent lights [top].
Meanwhile, water in underground pipes keeps things cool [bottom].

MIkE	kAhN/GrEEN	STock	MEdIA	(2)

Washington, D.C. At that time, global
climate change was not in the forefront
of public consciousness, and the council's
standards were not much in the public
eye. So Kaneda thought he was being
very forward-thinking when he proposed
to renovate the bank to meet the council's specifications for building materials,
water use, indoor air quality, and-most
important-energy use.
But when Kaneda hired architect Scott
Shell, from EHDD Architecture, in San
Francisco, to work on the project, Shell
went even further, suggesting they design
a building with no net electricity usage
and no carbon dioxide emissions.
"It was a shock to me when he said that,"
Kaneda recalls. He didn't know of any commercial buildings that had gone that far.
The idea appealed to Kaneda, and the
two decided they would disconnect the
natural gas pipes running to the building
and find heating alternatives. They would
stay on the electric grid but install enough
photoelectric panels to cover the entire
energy load-about 30 kilowatts, generating more electricity than the building uses
during the day but pulling a small amount

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off the grid at night. Since they'd be limited by the size of the roof, they'd have to
be clever about energy use.
"To cut down on energy use, you've
got three areas to address," Kaneda says,
"lighting, heating and cooling, and plug
load-that is, the computers, printers,
microwave ovens, and other things you
plug into the wall."
To reduce the amount of energy used for
lighting, Kaneda's builders sawed through
the concrete perimeter of the building to
install windows and skylights. Special
window glass lets visible light through but
blocks infrared and ultraviolet light, keeping the office cool. An overhang on the
south side shades the windows from direct
sun; on the east side, electrochromic glass
controlled by a sensor darkens the windows when sun hits them directly and
makes them transparent the rest of the day.
Because the ceilings are high, the skylights
bathe much of the office space in a diffuse
light; in areas where the skylight illumination is too strong, Kaneda is experimenting
with different types of diffusers.
The building also uses low-energy
f luorescent bulbs, some of which are

hooked up to switched circuits, while
others are on dimmers. Kaneda wasn't able
to get any good data on which method is
more energy efficient, so he plans to collect his own data, which will be invaluable
to others embarking on similar projects.
For heating and cooling, Kaneda
chose a geothermal heat pump, which
takes advantage of the fact that at some
point below the surface, the ground
remains a constant 10 °C all year round.
In Northern California, this point is only
about 1.8 meters below ground level;
Kaneda installed water pipes that snake
throughout the property, an area that will
eventually have a landscaped courtyard
and a bocce court. When the water flows
into the building, it goes through a heat
exchanger that collects the heat from the
ground in winter and pulls heat out of the
building in summer.
Designers of energy-efficient buildings
often stop at this point, but for Kaneda,
once the first two areas of energy use had
been addressed, the amount of energy
allocated to computers and other plug-in
devices looked huge. All the appliances
he purchased for the common room meet
the U.S. Department of Energy efficiency
goals, and all his employees' computers
will have LCD screens, the lowest-power
option. Light and motion sensors will
turn on electric lights when daylight
gives way to evening and employees
are still working, but employees will be
able to adjust their personal light levels
from their desktop computers. Arming
the building security system, which is
supposed to happen when the last person
leaves for the night, will automatically
cut off the power-sucking printers-
Kaneda's own large-format printer, the
worst power vampire, draws 40 watts in
standby mode.
Kaneda won't know for sure just how
efficient the building will be until he and
other tenants-yet to be determined-
move in later this fall, but he's confident
he'll be putting more energy into the grid
than he takes out. Though he has yet
to set a policy for tenants, he hopes to
attract companies that are equally concerned about the environment.
If Kaneda wins the Green Building
Council's approval, his will be among
the few Platinum buildings in Northern
California (only about 40 exist in the
United States as a whole). But whether
his will truly be a z-squared building is a
matter of debate, since no official definition exists.
Is simply producing more energy than
a building consumes enough to call it

September	2007	|	IEEE	Spectrum	|	NA							13
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Table of Contents for the Digital Edition of IEEE Spectrum September, 2007
