Re: Daylight Saving Shift
On 11/01/2009 10:28 PM, Lew wrote:
The subject is politically controversial. Some claim energy savings due
to the use of DST. AFAIK there's no hard evidence to support this, at
least, not that takes into account the increase in costs due to air
conditioning and morning lighting. Certainly there are lots of claims
that DST saves energy, but for some reason no one ever seems to cite
studies or methodologies to support those claims. There is a vocal but
politically disadvantaged contingent that denies the validity of those
claims.
The recent research summaries I've seen all seem to indicate that the
impact of DST on energy use is somewhere around ??0.2% (it's a number
that's rarely put into full context, so I'm not exactly sure what the
percentage is of--probably average daily summer energy usage). The sign
is naturally hotly debated in political circles whenever tweaking DST is
bandied about.
*Performs some searching to find research papers*
The literature review I just finished reading seems to suggest that most
of the conclusions about the energy-saving nature of DST were formulated
about 25 years ago, when lighting in particular was much less efficient
than now (the hypothetical best-case scenario for energy savings would
be equivalent to replacing about 15% of your incandescent light bulbs
with compact fluorescents) and also fails to take into account the
modern shifts in habits. Its primary conclusion was "the stuff out there
sucks, we need modern comprehensive research on this topic."
Other papers recently published seem to suggest that DST may no longer
be saving energy. That may just be a manifestation of confirmation or
perhaps publication bias--I'd expect that people finding energy savings
due to DST would be less likely to publish their results nowadays. I'm
also not a big fan of DST myself.
Oh well, if humanity ever discovers interplanetary or even interstellar
travel (as well as sufficiently speedy communication to make
chronological synchronization across disparate settlements necessary),
the mess resulting from DST will be the least of our worries.
--
Beware of bugs in the above code; I have only proved it correct, not
tried it. -- Donald E. Knuth