I have just come across an article in Wikipedia on the subject of
over-illumination (see below). I had never heard the term before. The
idea is that most commercial buildings use much more electricity than is
necessary to provide adequate illumination. This comes about in part
because the person responsible for paying for the electricity is not
involved in decisions regarding the design or operation of the lighting.
The short version is that almost half of commercial lighting may be
wasted. 

Regrettably, the article translates this into a stated number of barrels
of oil per day in the US instead of what the fraction of total energy
use in the US that represents. I haven't looked up the figure for total
energy use, but I assume that the amount of energy wasted by
over-illumination must be significant.

Therefore, this appears to me to be an overlooked opportunity to save a
substantial amount of energy. For those folks who believe that
anthropogenic CO2 contributes significantly to global warming, it's an
overlooked opportunity to reduce greenhouse gas emissions as well. The
following two paragraphs are an excerpt from the article; for more
information see http://en.wikipedia.org/wiki/Over-illumination. 

"Over-illumination is the presence of lighting intensity (illuminance)
beyond that required for a specified activity. Over-illumination was
commonly ignored between 1950 and 1995, especially in office and retail
environments; only since then has the interior design community begun to
reconsider this practice. Use of more artificial illumination than
required is expensive and energy-intensive. This includes consideration
both of the appropriate level of illumination when spaces are in use,
and when they are unoccupied. 

"Since lighting accounts for twenty to forty percent of commercial
electricity use, depending upon region, the toll of unneeded energy
consumption in the U.S. alone exceeds 700 million barrels of oil per
year, based upon estimates that almost half of commercial lighting may
be wasted (including unneeded overnight lighting of office buildings,
forsaking available natural light, underutilization of occupancy
sensors, and under-using discretionary light controls). In response to
these concerns, the design and architecture communities are making
greater use of indirect sunlight in modern commercial buildings." [End
of Wikipedia excerpt]

For existing buildings the obvious way to reduce unneeded illumination
would be to reduce the number of fluorescent lamps in fixtures used to
light an area. But here's another way. I didn't know about it until this
subject came up and it prompted my thinking. I have just found that it
is possible to have dimmer switches for fluorescent lights that don't
cause objectionable flicker. The next paragraph is from
http://www.fifthlight.com/. 

"At a time when most commercial buildings are over-lit and
under-managed, Fifth Light's patented Dimmable Lighting Technology
provides a key management tool that can be used to conserve energy,
customize lighting conditions and participate in demand
management/response programs in order to significantly reduce costs...
Fifth Light [has developed] a suite of DALI Dimmable Electronic
Ballasts, Networked ON/OFF and Variable Load Controllers and a
Management System that delivers sophisticated operating control of each
individual light fixture in a multi-building network anywhere an
internet connection is available."

It looks to me that this sophisticated technology would allow a simple
and practical way to reduce electricity use in areas that are needlessly
bright. 

Since most commercial buildings do not yet have the Fifth Light
technology installed, what options are available? Clearly, one way to
reduce energy use is to not light unused areas - turning off lights
either automatically or voluntarily. 

Automatically. Light switches that sense the presence of someone in an
office were installed here at my location for a while, but they were
later removed. I think they weren't accurate enough. When the lights go
out in your office just because you aren't moving around enough you will
find some way to bypass the switch. The sensor needs to be for infrared,
not motion. That way the lights go out in your office while you're in it
only after you die and your body temperature approaches ambient.

Voluntarily. Lack of the ability to monitor individual light fixture
usage has made attempts by management to get voluntary electricity usage
reduction depend on altruism. Given human nature that is a very weak
incentive indeed. Even among the conscientious, enthusiasm wanes within
months of the promotional program. People, some of whom are careless
about turning off lights at home, where the cost comes out of their
pocket, are not likely for very long to turn off lights at work, where
they will receive no recognition or reward.

The Fifth Light technology allows monitoring and controlling use of
lighting, fixture by fixture, from any computer with access to the
internet. Thus it offers management an opportunity to design an
incentive plan that rewards people for conserving electricity in their
own area. That way, if you have an office and you'd like to take a
snooze during lunchtime, you'd have a perfect excuse for turning off the
lights.

I can only wonder why environmental activists have not started picketing
the headquarters of companies that have over-illuminated buildings,
unless it is that they are concerned that they might antagonize (or at
least fail to win the sympathy of) people whom they need for support.
This isn't just global warming - it's sustainability. 

Maybe Fifth Light is missing a bet here in not contributing to activist
organizations. I hope they don't see this posting. I wouldn't want to be
blamed for companies being picketed - even if it is good for their own
bottom line.

Gordon Davy