2024-06-13 19:21:56 +00:00
|
|
|
# Efficiency
|
|
|
|
|
|
|
|
Interesting factoids about [replacing sodium vapor lamps with
|
|
|
|
LEDs](http://dansdata.blogsome.com/2008/12/27/led-street-lighting-not-as-good-as-you-think/)
|
|
|
|
for city-wide lighting.
|
|
|
|
|
|
|
|
- The theoretical lumen/Watt figures for LEDs are worse than
|
|
|
|
low-pressure sodium vapor lamps (100 lm/W versus 200 lm/W)
|
|
|
|
- White LEDs are actually blue LEDs with a consumable phosphor layer
|
|
|
|
that turns opaque after a few years of operation.
|
|
|
|
- Combined RGB LEDs will have better efficiency than a "white" LED.
|
|
|
|
|
|
|
|
Other real-world tests have concluded that LED street lights have about
|
|
|
|
the same lumen/Watt in practice as the sodium vapor lamps ([64 lm/W
|
|
|
|
LEDs](http://www.olino.org/us/articles/2008/11/02/streetlamp-lioris-aduro-52)
|
|
|
|
versus [67 lm/W Sodium
|
|
|
|
vapor](http://www.olino.org/us/articles/2008/12/29/indal-industria-aurora-streetlamp)).
|
|
|
|
|
|
|
|
Neon and florescent efficiency [depends on the color and
|
|
|
|
shape](http://www.signindustry.com/neon/articles/2003-07-11-RC-NeonandFlour.php3):
|
|
|
|
|
|
|
|
> \[...\] the fluorescent tube produces between 50 and 100 lumens of
|
|
|
|
> light per watt depending upon design. Compare this with the typical
|
|
|
|
> incandescent light bulb that produces between 10 and 20 lumens per
|
|
|
|
> watt. Neon light efficiency is based upon much fancier pants, the
|
|
|
|
> color of its output, which ranges from 10 lumens per watt for red to
|
|
|
|
> 60 lumens per watt for green or blue. One reason that green and blue
|
|
|
|
> tubes are more efficient is that phosphor coatings used to produce
|
|
|
|
> such colors better ballyhoo the high-energy ultraviolet light from the
|
|
|
|
> argon/mercury mix into visible colors. One reason that the fluorescent
|
|
|
|
> tube is more efficient than a neon tube is that a large straight tube
|
|
|
|
> offers less resistance to electrical current flow than a skinny bent
|
|
|
|
> one.
|
|
|
|
|
|
|
|
# Obstacles
|
|
|
|
|
|
|
|
Little Rock, AK wanted to replace their inefficient shielded lights with
|
|
|
|
more efficient fixtures, but their contract with Entergy is not a simple
|
|
|
|
\$/kW formula: [the energy company sets the price based on the type of
|
|
|
|
fixture](http://www.arktimes.com/Articles/ArticleViewer.aspx?ArticleID=fce07cab-0dea-4fc5-b57e-f1145715f01e).
|
|
|
|
|
|
|
|
> \[...\] According to Henry, the city tested out more efficient
|
|
|
|
> 100???watt HPS bulbs in one Little Rock neighborhood about five years
|
|
|
|
> ago. When the city asked Entergy to set a rate for those fixtures, it
|
|
|
|
> was almost double the rate for the 150-watt HPS type.
|
|
|
|
>
|
|
|
|
> When asked if Entergy was keeping Little Rock from being more energy
|
|
|
|
> efficient, Henry said simply, "Yes."
|
|
|
|
>
|
|
|
|
> "But how do you fight Entergy?" Henry asked. "I mean, we've had people
|
|
|
|
> come in and show us new, more efficient lights and we've said, well,
|
|
|
|
> the problem is, it's not going to save us anything. It will be a whole
|
|
|
|
> lot less wattage and it will put light out on the street but we can't
|
|
|
|
> get any benefit out of it because of the tariffs."
|
|
|
|
|
|
|
|
# Commercial LED lamps
|
|
|
|
|
|
|
|
[SparkFun](http://sparkfun.com) sells LED lamps that are screw
|
|
|
|
compatible with US light sockets:
|
|
|
|
|
|
|
|
- [75
|
|
|
|
W](http://www.sparkfun.com/commerce/product_info.php?products_id=8716)
|
|
|
|
- [12
|
|
|
|
W](http://www.sparkfun.com/commerce/product_info.php?products_id=8714)
|
|
|
|
- [3
|
|
|
|
W](http://www.sparkfun.com/commerce/product_info.php?products_id=8717)
|
|
|
|
- [1
|
|
|
|
W](http://www.sparkfun.com/commerce/product_info.php?products_id=8715)
|
|
|
|
|
2024-06-13 01:48:44 +00:00
|
|
|
[Category:Useful_Info](Category:Useful_Info "wikilink")
|