> FOCUS ALLURE OF DC POWER
“Berkeley Labs received a DC-to-DC grant,”
said Brent Moss, training director for the Elec-
trical Training Institute, a joint venture of
the International Brotherhood of Electrical
Workers Local No. 11 and Los Angeles County
Chapter of the National Electrical Contractors
Association. “We are now partnering with them
using our the Net Zero Plus Electrical Training
Institute as a setting for what DC-to-DC power
could provide in terms of additional energy
efficiency. Right now the project is in the talk-
Moss described how five of the training
center’s classrooms would be retrofitted for
“We want to find how DC-to-DC pencils out as we use it for
our LED lighting and other straight DC loads, including classroom computers, audiovisual and projection systems,” he said.
“We would draw from the solar inverter as our solar panels
already produce DC energy. The inverter will smooth and condition the power. We would compare against five classrooms
operating on AC.
“DC-to-DC is certainly evolving. If the industry moves this
way, we should be prepared. On the energy side, it’s another
way to do more with less,” Moss said.
Other DC explorers
EMerge has worked to network with national organizations
such as the U.S. Green Building Council and local ones like
the Alliance for Sustainable Colorado. Sustainable Colorado
is interested in transforming its 40,000-square-foot Alliance
Center into its own solar-powered DC microgrid. The effort
has been named the “dcProject.”
The center underwent a major redesign two years ago in
an effort to make the office building as energy efficient as pos-
sible. Its energy use intensity was reduced from 89 kBtu per sq.
ft. per year to 37 kBtu per sq. ft. per year using passive lighting
and other tactics before adding alternative energy and storage.
Sustainable Colorado’s founder, John Powers, advanced the
idea of adding DC-to-DC power.
“We’re now experimenting with what energy reduction
we can gain through DC power based on where can presently
apply it,” said Mark Reiner of Non Sequitur, a consultant for the
Alliance. “We’ve increased efficiency with our solid-state, elec-
tronic-based operation in much of our equipment, eliminating a
7 percent energy loss at each point they would normally be fed
AC power. This helps as we attempt to create a local distribu-
tion of power within the building.”
“Our DC power is first delivered from a battery bank of
solar-power storage,” said Sandy Vanderstoep, special projects
director, Alliance for Sustainable Colorado. “We also still con-
nect to the AC power grid, but optimized our power through this
hybrid approach. DC-to-DC loads we can tackle today include
heating and air conditioning demand, lighting and plug loads.”
Other efforts to improve building performance include high
levels of daylighting and energy-management controls working
with occupancy sensors.
“We don’t view ourselves so much as a demo project but a
laboratory for DC-to-DC,” Vanderstoep said. “The dcProject is
proof of feasibility. Instead of projecting energy saving, we are
measuring. Our goal is to establish that DC-to-DC really works
but with refinement.”
The dcProject is expected to switch more mechanicals to
DC-to-DC over the next two years. Increasing the amount solar
power for a viable solar/DC microgrid is also at work. Vertical
PV panel arrays have been installed to the building’s exterior
walls. Photovoltaic cabling is also being used.
Also, the alliance is investigating the performance of used
storage batteries, which are cheaper to purchase. The building’s current 60-kilowatt battery storage unit uses advanced
lithium-ion. Other batteries being tested include nickel-metal
hydride, aqueous hybrid ion and super-charge ion.
In the end, market adoption of DC-to-DC will need public
policy affirmation to take off.
“A DC-to-DC market seems ridiculous until it’s ubiquitous,”
Savage said. “It’s a cross-cutting technology that can also play
in the electrical generation and delivery industry. We need to
build support at the federal, state and local levels. Large devel-
opers are coming to the NextHome to see what it is, what’s
there and who’s involved. That’s encouraging. It will take some-
one with the big order to take this concept to the next level in
marketability and exposure.”
Savage is encouraged by finding DC-to-DC referenced as
an energy tactic within the U.S. Department of Energy’s quad-
rennial report. He also emphasized IEEE’s consideration
of EMerge standards is a major milestone for the DC-to-DC
movement. For its part, Sustainable Colorado has won local and
state code backing for its use of DC and solar-energy storage in
its building renovation.
GAVI N, LEED Green Associate, is the owner of Gavo
Communications, a sustainability-focused marketing services firm
serving the energy, construction, and landscaping industries. He can
be reached at email@example.com. D I
A ceiling grid is one DC-to-DC
configuration used to power
lights and other electronics.
DC supplied by solar energy
adds to power efficiency.