The Other Arguments for LED.
This section covers the "other arguments" that I've seen get made against non-LED light sources. They can include glare shields, lack of availability, and a few others. There are a few reasons why they're made, and you might find that I make some new ways of thinking about ordinary things. Let's start!
Example: Why not use glare shields?
This one is mildly uncommon. To start, we need to take step back and see the "why" behind it. What's the problem being solved? Well, the whole use of a glare shield is to block glare from a streetlight.* Then why aren't they included with the fixtures? Well, I have a little theory. What makes a situation with a glare shield different than others? The light is shining in to where it shouldn't be. Why is it a problem? I wouldn't want light keeping me up at night. Now it's time for the first assumption: People don't like light trespass. I predict most people you would ask would agree with this new assumption, so let's go with it. The next step in the glare shield problem is, when does it happen? Depending on what the streetlight installation is like and how much foliage is present, it can vary from almost never needed to virtually necessary for a comfortable bedroom experience. Now let's make the second assumption: In a collection of houses, there will be an opportunity for light to enter a home. This one's simple enough, and it makes sense. Take a walk outside in a neighborhood and you'll probably see a situation that would allow for the assumption to take place. But why is it here? To make the next discovery, it's time to introduce yet another simple assumption: An intrinsically good design is better than one with a problem that needs a hack-job fix. Now that we've made the second-to-last assumption of this section, let's assemble it together. But before we do that, it's time for one more: Someone has to manually request a glare shield to get one.
Combined with the discoveries of the other pages in this site (look at Optics) we can say that, in most cases, an LED streetlight will make light trespass by assumption no. 2. Now, we know that people don't like this by assumption 1. By assumption 4, I can say that extra effort is needed to get a glare shield than if it were not needed. Why? It's because requesting a glare shield can involve calling the power company or city, and then hoping it gets installed. What about the third assumption? This one is what puts the metaphorical puzzle together, but it needs a little setup first. What does it need? It needs a hack-job fix. Where is this hack-job fix? It's in there with the micro-sized theorem talked about just six few sentences ago.** Depending on your definition, that extra effort qualifies the glare shield as being a hack-job fix. By assumption 3, the LED streetlight with a glare shield is now worse than a streetlight that didn't need a shield to begin with. And that's why glare shields are a bad idea. Also, these assumptions might be used in future arguments like this one, so be sure to remember them.
* For yardlights, the situation as a whole changes because the duties associated with yard lighting are different than that of streetlights.
** In case you're wondering, it really was 6-8 sentences ago that I talked about this micro theorem.
Corollary: Why not use blackout curtains?
This one's a slight variant of the example above. Instead of the streetlight's owner installing a glare shield, blackout curtains are used to block out the light. To start, you need to remember the assumptions I created earlier in this page. To start, let's see how the first assumption holds up. What's the definition of light trespass? Depending on who you would ask, it can be light entering a house, or yard. For this section, let's define it as light that isn't on the street. Now assumption 1 works, but there's more to be done. The fact that blackout curtains will sometimes be needed is held up by assumption 2. What's left? Well, let's see what you get with blackout curtains: No more light keeping you up. That's about it, as they don't work outside. (Unless you cover your yard with one!) Also, that light blocking could be a curse as well as a blessing. When it's sunrise and the sun overpowers the streetlights, there's no light entering your bedroom, keeping you in bed because of the lack of light. Plus, not everyone can afford blackout curtains. To add the cherry on top, this situation also is worse than one without the need for extra curtains because of assumption 3.
Example: Parts are hard to find!
This one I've seen at least once, and is likely a big reason why power companies want to do LED conversions. But like I've said a few other times here, there's more to the story. Where should I start? How about what the problem really is, which is a lack of availability of replacement parts. Why is this a problem? It's because when old streetlights get damaged or worn out, they can be fixed with a particular part, but if they're not available, then it can't be done. What causes this problem? There are many reasons, but one of them would be a low demand for them from the manufacturers. If there aren't enough people buying these replacements, then they might not want to make them anymore. But this is only half of the story, the supply side. On the demand side we have decision-makers who have a few options: 1, hope these parts aren't discontinued, 2, find new suppliers for aftermarket parts, and 3, quit ordering them. Let's go through 3, the most common option and see why it's a sub-par option. What happens when there are fewer orders? A lower demand. What happens when there's a lower demand? A larger temptation by the maker of them to not make them anymore. Why is it a problem? If these parts are not available, then other users of them (who didn't stop ordering) will be left without the first option. In other words, the actions of one group can affect others. Why else shouldn't the maker discontinue them? In economics, there's a thing called Say's Law. It says that when there's a supply, there's a demand. If the manufacturer doesn't discontinue this replacement part, then there will always be a demand for them by Say's Law.
So, let's say option 1 stops being a thing, and options 2 and 3 are left. Why should 2 be used? It's because unlike the LEDs, HID streetlights are (mostly) standardized. You've probably seen me talk about this in other pages on this site, but it's that important. This standardization allows for aftermarket parts to be used in a wide variety of different streetlights. For HPS, there are only 2 meaningful types of ignitor: Small and large. The differences between them are for another time, but the point still stands. With just a little effort, the decision makers at the power company can secure the future of current streetlighting.
Sometimes, options 1, 2, and 3 will not be available. An example of this would be the discontinuation of LPS/SOX lamps. In this case, there's a hidden fourth option, and it's to start back up manufacturing. Why should it be done? Like I talked about earlier in this page, Say's Law says that there will be a demand. How could it be done? With some effort, acquisition of factory equipment could be done. It is up to us to do this, and procrastination isn't your friend here.
Stay tuned for more juicy LED action!
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