Page 204 - Alternative Energy Systems in Building Design
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180 ENERGY CONSERVATION
global warming will increase the national expenditure to such a degree that govern-
ments will be prevented from meeting society’s needs for transportation, irrigation,
heating, and many other energy-dependent services. On the other hand, environmen-
talists argue that protection of nature and the prevention of global warming warrant the
required expenditure to prevent inevitable climatic deterioration.
Advances in technology, the increased output efficiency of solar photovoltaic (PV)
modules, and the reduction in cost of PV modules that would result from mass pro-
duction will make solar power installation quite economical within the next decade.
National policies should take into consideration that technologies aimed at reducing
global warming indeed could be a major component of the gross national income and
that savings from decreased fossil-fuel consumption could be much less than the
expenditures for research and development of solar power and sustainable-energy
technologies.
In the recent past, some industry leaders, such as DuPont, IBM, Alcan, NorskeCanada,
and British Petroleum, have expended substantial capital toward the reduction of
carbon dioxide and greenhouse gas emissions, which has resulted in billions of
dollars of savings. For example, British Petroleum has reduced carbon dioxide emissions
by 10 percent in the past 10 years and, as a result, has cut $650 million over 10 years
of expenses. DuPont, by reducing 72 percent of its greenhouse gas emissions, has
increased its production by 30 percent, which resulted in $2 billion per year of savings.
The United States at present uses 47 percent fewer energy dollars than it did 30 years
ago, which results in $1 billion per day of savings.
Computerized Lighting Control
In general, conventional interior lighting control is accomplished by means of hard-wired
switches, dimmers, timers, lighting contactor relays, occupancy sensors, and photoelec-
tric eyes that provide the means to turn various light fixtures on and off or to reduce lumi-
nescence by dimming. The degree of interior lighting control in most instances is
addressed by the state of California Title 24 energy regulations, which dictate specific
design measures required to meet energy-conservation strategies, including
■ Interior room illumination switching
■ Daylight illumination control or harvesting
■ Duration of illumination control by means of a preset timing schedule
■ Illumination level control specific to each space occupancy and task environment
■ Lighting-zone system management
■ Exterior lighting control
Figures 5.2 through 5.10 depict various wiring diagrams and lighting-control equip-
ment used to increase illumination energy-consumption efficiency.
In limited spaces such as small offices and commercial retail and industrial envi-
2
ronments (where floor spaces do not exceed 10,000 ft ), lighting control is undertaken