Light is Cheap

 

Light is Cheap

In India, light is cheap. How else can you understand the Light Emitting Diodes (with gallium arsenide, gallium phosphide, or gallium nitride as their constituents) that are seen in profusion in Indian urban, suburban, peri-urban, and semi-urban areas? As LEDs have become the status symbol of an aspiring nation, even one-signal towns–to go smaller still, hamlets, too– are creating intersections merely to put up an LED signal, no matter that there are no more than a dozen motorized vehicles. (My paternal ancestral village has become such a hamlet, but with a temple, and no traffic signals of any kind.)

First, let me talk about the invisible pollutions. Gallium is, as I understand, is not mined; then, whence the pollution?

Gallium is a by-product of making aluminium from bauxite ore, quite the model for extractive pollution, and semiconductor fabrication waste. Therefore, gallium creates a second order pollution. So, merely a second order pollution that we can live with!

Not so fast.

In Madurai, sacred for and famous among Hindus as the abode of Goddess Meenakshi, in the public procurement process, authorities concerned have gone crazy adopting LEDs for public lighting and traffic signals. Recently I saw more or less the same in other cities/towns in Tamil Nadu–Palani, Thiruchirappalli, and many nearby towns thereof.

They dominate street lighting (provided by public authorities) and it definitely appears that they are cheap in operation; cost-effective, to avoid the misinterpretation of cheap to mean gaudy or unsophisticated. The irony is, the LED luminaire assemblies are indeed gaudy.

Some photographs, from the Net, are in order here, with my adverse comments thereon

 

Seeing the above pictures, you cannot but agree that the road signals signal gaudiness. If you wish to be gaudy, follow these signals.

Street-cart vendors and kirana stores in Srirangam, a suburb of Tiruchirappalli, use bright LED bulbs, offering high RoI of lumens over life time money invested. At least some of them must be “stealing” power from the street-light poles, I suspect. Yet, in my reckoning this is micro-corruption as the imposition on the power generation companies is minimal. Even large commercial establishments and office space are lit by LEDs, and many residences too (mine included).

Again, a picture.

LED luminaires deliver higher luminosity; yet, they are highly directional. That is, if you have a longish hall in your house to be lit, you would rather go in for a couple of wall-mounted fluorescent or CFL tube lights rather than LEDs (unless these are clusters of LEDs hung from the ceiling, each sub-luminaire oriented randomly individually).

The next time you visit a shop for your house lighting needs, make it a point to spend time looking at LED luminaires; you would observe that a decorative  light to be hung from the ceiling when looked at from close quarters reveals the cluster of LEDs I referred to earlier.

 Cluster LEDs may be good in a seminar hall, in a room for ministerial briefing, reasonably spaced for the seated attendees to receive sufficient illumination, commercial establishments like jewellery or clothing stores, and of course for surgical procedures. Ask the lighting experts on this.

It is not that LEDs cannot be used for street lighting, or in parking lots, but the luminaires have to be configured to achieve the desired spread of light.

Why all of the above details?

The attractive feature is LEDs are light on your wallet/purse on a longer time frame, typically life-time costing. They consume a lot less energy than tungsten, fluorescent or CFLs, as I understand. This automatically means that the consolidated energy consumption for lighting is less. We are going Green!

Look at the first two photos in this post. They create unnecessary and uncomfortable visual imposition on you. One has to squint her eyes to see the actual signals among the rest of the luminaires and drive or stop the vehicle accordingly. I know what I am talking about. Sitting in the front seat (not driving) I am, for the sake of my comfort, forced to turn away from the light; the driver cannot afford to do this, you understand.

The photographs below showing a pedestrian crossing must engage people interested in public safety and light pollution.

I grant that whoever posted the above has the prerogative to voice his appreciation as he did. But look at it from my perspective: is it clear to you–it was not to me–by who the lights on the carriageway are to be taken note of. If you look at the lights from the platform it would look like it is advising you to stop; if you are driving the vehicle, you too would stop! That is not as bad as compared if the lights are green, the top picture!

Were the regular signal lights (just four or five of them, circular and of normal size, on a signal post) so information-deficient that we need to overdo cram so much information that it becomes meaningless at best and dangerous at worst?

The only reason LEDs are coming to dominate road signals should have been that these are cheap and someone thought they added to the beauty of the urban landscape. Let her be informed that outdoor lighting should be limited to what is absolutely necessary and not a lumen greater. And LEDs are the worst form of outdoor lighting for three reasons: 1. Because it is cheap, it is easily overdone; 2. Because it is directional, it lights up only a narrow patch on the road, but does it too intensely, both negative aspects of provision for public safety; 3. It harms the viewer, vehicle users and pedestrians, both short-term (accidents) and long-term (effect on sight).

I sincerely hope this falls on the ears of those who care for public provision for public safety and for public safety.

LED luminaires are cheap, in terms monetary and aesthetics of public space. Yet, they should be shunned.

It is better to be more effective than be more efficient.

Raghuram Ekambaram