SOLAR TODAY - May 2011 - Innovative Design

As a result of the upgrades, the shop floor is well-lit with new Orion Apollo light pipes and lighting
fixtures. Because of supplemental daylighting, each fixture had only two of six lamps lit when this
photo was shot.
electricity to power electric lights. For now, we
took a more direct, less expensive approach.
Last April BAAC hired Beltsville, Md.-based
Hawkins Electric to replace each of the 22 metal
halide, 455-watt fixtures with a corresponding
Orion 192-watt fixture having six T8 fluorescent
lamps. Hawkins also installed a Watt Stopper
open-loop daylight- and occupancy-sensing
system (wattstopper.com). Depending upon
available daylight, the control system
keeps all lights off, or lights two, four
or all six lamps in each fixture. In addition
to daylight controls, occupancy
controls ensure that the lights in each
of the four work sections are switched
off when that section is vacant.
In other interior areas of the building,
Hawkins installed occupancysensing
lighting controls, except where
Copyright © 2011 by the American Solar Energy Society Inc. All rights reserved.
the use of manual controls was effective. For most
rooms, passive infrared sensors worked well, as
there is a straight line of sight between sensor and
occupant. Areas with obstacles (such as a parts
rack) required more expensive ultrasonic sensors.
For corridors, just removing two of three lamps
effectively reduced energy use, while maintaining
adequate lighting.
Upgrades Generate Savings,
Public Kudos
The daylighting and energy-efficiency
upgrade resulted in some significant benefits:
• Greater productivity due to higher lighting levels
and natural light;
• Immediate and automatic lighting response;
• Lower energy bills, as lamps are off when daylighting
is adequate or an area is vacant, BAAC
has more efficient lamps and fixtures, and
unneeded lamps have been removed;
• Less demand on the electric grid, especially
during bright, sunny days, when the grid may
be stressed due to high temperatures and high
air-conditioning loads; and
• Recognition for BAAC’s environmental stewardship.
The chart below illustrates the direct effect
of our conservation efforts. Annual energy use
decreased from 121 megawatt-hours (MWh) average
in 2007 through 2009 to a projected 74 MWh.
That represents a savings of 47 MWh per year,
or $6,980 at 15 cents per kilowatt-hour. Under
the governor’s EmPOWER Maryland initiative
to reduce statewide enerwwgy consumption,
the local utility granted $2,860 for the upgrades,
lowering BAAC’s material and installation costs
from $29,452 to $26,592. As mentioned, these
upgrades will pay off in less than four years.
Because most of the electricity in the mid-
Atlantic region comes from burning coal,
BAAC’s reduced energy demand means less
coal-fired power, reducing emissions of greenhouse
gases and other pollutants. The upgrade
will decrease carbon dioxide emissions by nearly
600 tons during the 20-year life cycle of the
upgrade. (Based on 0.675 tons of carbon dioxide
per megawatt-hour for electricity generation in
Maryland, eia.doe.gov/pub/oiaf/1605/cdrom/
pdf/gg-app-tables.pdf, table C.1.)
“The energy-efficiency efforts of British
American Auto Care are important for the environment
and are reducing their carbon footprint,”
said Orion CEO Neal Verfuerth. “While
the company is doing its part to
help the environment, they received
better light and substantial cost savings,
which make this project a winwin
for everyone.”
Brian England’s commitment to
and actions for the environment led
to BAAC’s selection as one of five
Maryland Green Registry Leadership
Award winners last July. ST
solartoday.org SOLAR TODAY May 2011 49