ir and water pollution. Furthermore, some lighting equipment is fairly short
lived and lighting equipment and components create a continuous waste stream, as raw materials are
extracted from the earth, delivered to factories, made into lighting equipment, installed in buildings,
and finally removed and disposed of. Section 3.1 and 3.2 discuss lighting's energy and environmental
impacts, respectively.
The importance of lighting to our livelihood and its impact on the environment has resulted in diverse
and overlapping policies, regulations, and standards. Section 3.3, Lighting Policies, Codes and
Standards, discusses these various policies and standards, including the IESNA recommended
practices and standards.
3.1 Energy
Impacts
Since its invention slightly over a century ago, electric lighting very quickly became the norm in this
country. However, we shouldnt forget that not all lighting is provided by electricity. Daylighting uses
none. Many remote locations in the United States and much of the developing world still use vastly
inefficient fuel sources. Compared to the candles, kerosene lanterns or whale oil lamps that
dominated the nineteenth century, electric lighting has offered huge improvements in cleanliness,
reliability, economy and efficiency.
Where light was once considered a nighttime supplement to daylight, now it has become the norm for
all our workplaces. Its use has vastly expanded the range and time of human activities. We can now
operate our workplaces 24 hours a day. Arctic locations can operate through the winter. Huge
buildings can be created without being limited in dimension by access to daylight. Enclosed spaces
like ships and airplanes can operate in a healthy environment.
With this expansion of uses, lighting energy use has become one of the major uses of energy in the
country. While efficiencies have improved dramatically, the use of electric lighting has also increased.

Currently, buildings consume over one-third of all sources of energy use in the United States
(Interlaboratory Working Group 1997, 1.5) and electricity accounts for almost 80% of the cost of that
building energy consumption (3.20).

Overall, lighting is estimated to account for 23% of national
electricity consumption. Of national lighting energy use, residential lighting is estimated to constitute
about 20%; commercial lighting, 60%; industrial 16%; and street lighting and other uses, 4%
(Atkinson et al. 1995, p 399-427). The Advanced Lighting Guidelines focuses on the commercial
9

lighting segment, which was estimated to consume 4 quads (365 billion kilowatt-hours) of energy in
1997 (Interlaboratory Working Group 1997, p 3.9).
These numbers are substantial, but only begin to describe the impacts of lighting energy use. In
addition to the direct energy used for lighting, there are other secondary effects. For example, all of
the electricity used for lighting eventually turns into heat, which is usually unwanted in commercial
buildings. Because of heat from internal sources such as lights, equipment and people, most
commercial buildings in the continental United States require some cooling even in the coldest
months of the winter. This excess heat must be removed from buildings via air conditioning. The
additional air-conditioning load created by electric lighting can add another 20% to the electricity use
attributable to electric lighting.
10


9
The term "commercial" is used throughout to designate all non-residential building uses in general, not just
those involved in commerce.
10
The degree of this effect is of course determined by both the specifics of each buildings design and operation,
and its local climate. See Rundquist et al. 1993. A
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Lighting use has substantial impacts on our electric generation systems. The majority of commercial
lighting use, and the associated added cooling loads, occur during periods of peak electricity demand,
and thus directly impact the need for additional generation and distribution facilities. Furthermore,
electricity used at a building site requires about three times as much energy consumption back at a
fossil fuel power plant. Thus, there is a substantial multiplier effect for each kilowatt used at a building
site, if we consider the total amount of energy consumed by lighting, including that needed to
generate it and transmit it from the power plant.
These energy impacts help to explain why lighting efficiency is so important. Efficiency improvements
in lighting technologies and practice have been dramatic in the past few decades. Indeed, in
California, with its aggressive energy-efficiency programs during the past decade, 75% of all building
energy savings have been found attributable to lighting efficiency measures (RLW 1999). In 1997 the
National Laboratories estimated that current national lighting energy can be reduced by 50% by the
year 2020, while simultaneously improving lighting quality (Interlaboratory Working Group 1997). The
same year, a study in California showed that if the most efficient lighting technologies then
commercially available were applied throughout the new and existing building stock, commercial
lighting energy savings for the state could total up to 7500 gigawatt-hours per year in 2010. This is
roughly equivalent to the annual output of one entire nuclear power plant.
The drive toward greater lighting system efficiency has been one of the principal motivators for recent
changes and improvements in lighting technology. Opportunities for more efficient electric lighting
sources, more effective design strategies, greater use of daylight, and use of controls to eliminate
unneeded light all promise substantial reductions in commercial lighting energy use in the future.
3.1.1 Lighting Energy Use by Building Type
Facility managers, energy service companies, and government program managers need to know
where to target their efforts to achieve the greatest improvement in lighting efficiency for the least
effort. Its helpful for lighting program managers and others to understand which building types use
the most lighting energy and where the greatest savings might be achieved with energy efficiency
improvements. Figure 3-1 shows estimated national lighting energy use by building type.
Other
32%
Storage
11%
School
6%
Grocery
store
2%
Office
25%
Retail
20%
Medical/
clinical
4%

Figure 3-1 National Lighting Energy Use by Building Type
Source: Lighting Source Book, Lawrence Berkeley National Laboratory 1997
Figure 3-1 is based on national commercial lighting energy use patterns researched by Lawrence
Berkeley National Laboratory (1992; 1997). While the researchers carefully analyzed the best data
available at the time, they were still forced to rely on considerable interpretation and educated
guesses, given the lack of detail that was available on the national level. National data is rapidly
aging, especially considering the rapid technological changes in the lighting industry. A number of
studies are underway to update national patterns of lighting energy use for different commercial
building types for different regions, but as of this edition of the Advanced Lighting Guidelines, none
were complete. A
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More complete data on energy use by building type is available for California as a result of utility
company research on the effects of their efficiency programs. California is probably the most studied
lighting market in the country, with seven major lighting studies conducted between 1994 and 1998
(Xenergy 1999). As a result, extremely reliable data is available on patterns of lighting energy use in
California buildings. Some of this information may apply to buildings in other parts of the nation, but in
general, California buildings are believed to be substantially more efficient than buildings in other
states, and the data should be used with caution if applied elsewhere.
11
California has had an
aggressive building energy code for over 20 years. In addition, the energy code has been reinforced
since the mid-1980s by utility programs that specifically reward projects that surpass code
requirements. Working together, the code and the utility programs have helped to create a large
population of relatively efficient buildings.
The detail on lighting energy use patterns by building type reported here is interesting in and of itself,
but also as a study of how building energy efficiency can improve over time. The average lighting
power density for existing commercial buildings in 1994 was 1.48 W/ft² (HMG 1997) while the
average for newly constructed buildings in 1998 had dropped to 1.22 W/ft² (RLW 1999).
Other
25%
Medical/clinical
6%
Grocery store
9%
School
8%
Storage
12%
Office
22%
Retail
18%

Figure 3-2 Commercial Lighting Energy Use in California, 1994, by Building Type
Source: Heschong Mahone Group, Lighting Efficiency Technology Report, Vol. 1, Baseline 1997.
Figure 3-2 shows the distribution of lighting energy use by existing California commercial buildings in
1994. Here, large offices and retail buildings have by far the greatest share of lighting energy use.
(The miscellaneous category includes a wide variety of buildings, which did not fit into the other
definitions.) Looking instead at the lighting energy use of newly constructed buildings, in Figure 3-3