Page 180 - Solar Power in Building Design The Engineer's Complete Design Resource

150 ENERGY CONSERVATION

and many other energy-dependent services. On the other hand, environmentalists
argue that protection of nature and the prevention of global warming warrant the
required expenditure to prevent inevitable climatic deterioration.
With advances in technology, the increased output efficiency of solar PV modules
and the reduction in the cost of PV modules, which would result from mass produc-
tion, will within the next decade make solar power installation quite economical.
National policies should take into consideration that technologies aimed at reducing
global warming could indeed be a major component of the gross national income and
that savings from fossil fuel consumption could be much less than the expenditure 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 of expenses. DuPont by reduc-
ing 72 percent of greenhouse gases has increased its production by 30 percent, which
resulted in $2 billion of savings. The United States at present uses 47 percent less
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
photoelectric eyes that provide the means to turn various light fixtures on and off or to
reduce luminescence 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 6.2 through 6.10 depict various wiring diagrams and lighting control equip-
ment used to increase illumination energy consumption efficiency.
In limited spaces such as small offices, commercial retail, and industrial environ-
2
ments (where floor spaces do not exceed 10,000 ft ), lighting control is undertaken by
hardwiring of various switches, dimmers, occupancy sensors, and timers. However, in
large environments, such as high-rise buildings and large commercial and industrial