on 12/24/2007 11:35 AM HeyBub said the following:
willshak wrote:

on 12/24/2007 9:01 AM Pete C. said the following:

HeyBub wrote:


Tony Hwang wrote:


Hi,
Nearby town of Banff installed LED street lights with solar panels.
Very cool looking light and it is cool running, no bugs get
attracted kep them clean. Cost a lot initially but for the long
run, it's winner. LED bulbs now are expensive but with time the
price will come down. I have a few small ones in the house, they
use couple Watts per bulb.


My city, Houston, is retrofitting its traffic signals with LEDs.
They cost more initially, but since the bulbs won't have to be
replaced for, what, fifty years, they should recoup the expense
fairly soon.

I doubt the 50 yr thing since I've see LED signals failing. The good
thing is that they have a "soft" failure mode, losing a few strings
of LEDs rather than the whole thing at once like the old incandescent
signals. The power savings of the LED vs. the 300W incandescents they
replace becomes significant when multiplied by all the active
signals in a city.



Can you imagine what it takes to change the bulb on an overhead
traffic signal?


About an hour, a bucket truck and a cop to handle traffic.


If you include the time it takes for the truck to get there, perhaps.
Most times, the changing of a traffic signal bulb takes about as much
time as a few regular cycles of the light.
Take it from someone who used to have to handle traffic while the
change was done.


Hmm. Say an ordinary bulb lasts four years. Each signal has four bulbs (two
red, one yellow, one green). On average, then, the signal itself requires
attention once per year. My city has over 2,000 signalized intersections
with at least 4 signals per intersection (sometimes, it seems, as many as
ten!). That's a minimum of 8,000 signals or 8,000 maintenance visits per
year.

Think of the savings if those 8,000 maintenance visits could be cut to, say,
twelve total. Shucks, a fella could have a good time in Vegas with the
savings.

Yeah, your municipal taxes would go way down because of the savings in
labor and materials. You might even be able to save enough to pay for
the postage on a letter to Las Vegas.

--

Bill
In Hamptonburgh, NY
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