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Performance Boosting TIM
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Performance will not degrade
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* Lab testing compared to dry joint assembly
not need a one-for-one retrofit for two
reasons. The original lighting had been
installed on an ad hoc basis and the new
system would use a lighting design. And
some areas of the city have simply been
abandoned due to the financial crisis.
Initially, the PLA settled on 50,000 lights
but knew that plan would not be sufficient
to safely light the city. Ultimately, the number was raised to 65,000, although as we
will see, that number is also shy of ideal.
The consideration of LEDs compared
to legacy sources resulted in a simple
quick conclusion that more-efficient
SSL was the correct route. The compar-
ison of strictly the two luminaire types,
ignoring pole, wiring, and other costs,
was projected to payback in 2. 3 years just
for the LED luminaires and assuming the
remainder of the project would be under-
taken regardless. That projection did not
take into account the ultimate fact that
LED-based products enabled the city to
install lower-cost aluminum wiring.
Still, the project was a compromise. In
some residential neighborhoods on a typical 600-ft block, the city installed a light
on each corner and one in the middle of
the block. That design provided excellent
light levels in intersections but does not
meet IES RP- 8 guidelines in the middle of
the spans between poles. But the PLA correctly moved forward under the presumption that the wider pole spacing would be
a huge improvement relative to the system
with half the lights out.
As of August 2015, the city had com-
pleted installation of 48,000 LED street
lights and expects to complete all neigh-
borhood lighting by the end of the year. The
upgrade on thoroughfares will be handled
in 2016. The use of LEDs in 65,000 lights
compared to high-pressure sodium (HPS)
lamps will save $2.4 million annually.
Funding for the project came from
a short-term loan and issuance of lon-ger-term bonds. The PLA worked with the
Michigan Finance Authority on the bonds.
The debt service is being covered in part
by a $12 million annual allocation from a
utility user tax.
Citizen response has been mostly positive, especially given that many of the
older lights didn’t work at all. But the longer pole spacing has been at the center of
Detroit Mayor Mike Duggan addressed
those complaints at a DOE Workshop held
in Detroit in November 2014. Duggan said
some residents would say, “I had a light
in front of my house. As far as I was concerned, Detroit didn’t have a lighting
problem.” Duggan pointed out that such
complaints came primarily from people
who had not attended widely-promoted
Detroit from page 15