B. Large Commercial and Industrial Buildings
Efficient lighting and distributed energy technologies hold great promise
in large commercial and industrial buildings.
Current research also holds the promise for
improved wireless sensor technologies, along with advances in control technology such as neural networks
and adaptive controls. In the long term, these components will be combined into robust building manage
ment systems. Unlike today's simple thermostats and timers, these sophisticated systems will enable true
optimization of building energy services including the continuous recommissioning
of HVAC systems,
both reducing energy use and improving conditions for building occupants.
Lighting. Current lighting technologies are expected to benefit from incremental improvements
over the next 20 years, and two areas of research (hybrid solar lighting and solid state lighting) should be
able to deliver even greater savings. The efficiency of fluorescent lighting used in many larger commercial
and industrial buildings is expected to improve by about 10 percent by 2025.
This improvement, when
combined with more adaptive lighting arrangements, could increase savings by about another 15 to 20
percent. Incandescent lighting, although used less in commercial and industrial buildings (compared with
homes), is also predicted to increase in efficiency by about 10 percent.
One alternative lighting system for commercial buildings is called hybrid solar lighting. In this
system, a roof mounted solar collector sends the visible portion of solar energy into light conducting optical
cables, where it is piped to interior building spaces. Controllers supplement this light as necessary with
fluorescent lights to provide the desired illumination levels at each location. Early experiments show that
hybrid lighting is a viable option for lighting on the top two floors of most commercial buildings. It would
therefore be applicable to roughly two thirds of the commercial floor space in the United States. In retrofit
markets, hybrid lighting can be more readily incorporated than skylights into existing building designs, and
unlike skylights, the flexible optical fibers can be rerouted to different locations during renovations. This
technology is estimated to have a payback period of fewer than five years for some applications.
For the long term, research into solid state lighting shows great promise. Preliminary roadmaps
estimated that cumulative savings by 2020 could amount to 16.6 quads of electrical energy and 258
million metric tons, or 0.2 percent, of the projected total U.S. carbon emissions over that time period.
Today's light emitting diodes (LEDs) produce light at an efficiency only slightly higher than standard
Towards a Climate Friendly