The end of Edison's light bulb - TechCentral

The end of Edison’s light bulb


The evolution of man-made light

The incandescent light bulb was birthed more than 200 years ago, when the first experiment saw chemist and inventor Humphry Davy pass electrical current through a thin strip of platinum. Seventy-five years later, Thomas Edison perfected the design for the light bulb and it became the viable lighting solution that we know today.

But light bulbs are inefficient. They use a lot of electricity, they produce heat, and they are still relatively fragile in terms of design and lifespan.

In contrast, light-emitting diodes (LEDs) have only been available since the early 1960s, when the first commercial product, the Texas Instruments SNX-100 infrared LED, was introduced. It was invented by Bob Biard and Gary Pittman and it is the same type of LED still used in infrared remote controls today.

It’s not just LEDs’ energy efficiency that make them so intriguing. Unlike incandescent lighting, LED is a digital technology that can do much more than simply light up a dark room.

Take the Philips Hue, for example. This wirelessly controlled lighting system can display 16m colours and can be controlled via a smartphone application, allowing users to select a display colour, or set it to change according to any number of parameters people can configure.

Those with a little technical savvy can even incorporate the popular IFTTT — If This Then That — protocol that allows one to set actions based on various conditions. For example, someone could set a rule that the LED light mimics the colours of the sunrise when their smartphone alarm is sounded.

Although they’ve been around for decades, LEDs have not, until recently, been able to provide the same light output of traditional 60W or 100W light bulbs. But in recent years, LED replacements have become available for almost any lighting requirement, even outdoor floodlighting.

A 100W light bulb produces around 1 600 lumens of light, while the equivalent LED consumes just 16W to 20W of electricity.

But replacing old light bulbs with new LED equivalents can be a costly exercise — at least for now.

The Philips Hue LED light can display 16m colours and is remotely controllable via a smartphone app

The Philips Hue LED light can display 16m colours and is remotely controllable via a smartphone app

An LED light meant to replace a traditional 60W light bulb can fetch anywhere between R200 and R400, depending on the quality. There are cheaper alternatives available, but these often don’t adhere to the same quality standards as more expensive products.

“South Africa may be lagging Europe and the US, but globally the market share for LEDs is growing fast,” says product manager for indoor lighting and large-scale projects at Philips Lighting Africa, Henk Rotman.

“While the technology for traditional lamps is mature, within the LED space there are huge differences in quality, specification and price.”

Consumers should measure the return on investment (ROI) of LEDs against incandescent and compact fluorescent bulbs when weighing up a purchasing decision, says Rotman.

The ROI for compact fluorescent bulbs against incandescent alternatives is currently about two months. For LEDs, the payback period is about two years. “However, we expect the payback time for LED lights to come down dramatically as the lamps become more efficient and as prices go down and electricity tariffs go up.”

It would also seem that the incandescent light bulb is doomed, regardless. In 2011, the South African government said it would be the first African nation to adopt a comprehensive policy to phase-out inefficient lighting.

The policy is linked to a global initiative aimed at helping combat climate change through a shift to energy-efficient lighting.

The initiative is called en.lighten and the idea is to halve the greenhouse gas emissions that lighting accounts for globally. The aim is to achieving a global phasing out of inefficient lighting by 2016.

Whether it’s through legislation, or through mass manufacturing of LEDs, Edison’s light bulb will soon be consigned to the scrap heap. It had a very good innings.  — © 2014 NewsCentral Media


  1. Greg Mahlknecht on

    Good riddance!

    A lot of people scoff at the “The policy is linked to a global initiative aimed at helping combat climate change through a shift to energy-efficient lighting” reason, but a quick calculation of how much power is saved by efficient lighting usually surprises.

    The Jasper Solar Array cost R2.3B to build, and produces 96MW. Take a conservative saving of 50W savings by converting a 60W incandescent to a 10W LED, and you get around 2mil light bulbs. At R200/bulb (conservative bulk price for a good one), that’s R400mil, or <20% of the price of the power plant that wouldn't have to be built if the changeover happened. If you work it out compared to building coal-powered capacity it still works out ridiculously cheap.

    The government/Eskom should actually ban incandescents ASAP and pay to replace every one with an LED and provide replacements for 10 years, even R350 for dimmable one would be very cost effective. I think it'd solve our immediate power problems in a matter of months, instead of decades.

  2. This is a good example on exactly how government causes pretty much all inflation. Regardless of the imagined or real effects of using the bulbs, the fact is a viable replacement, meaning one that works equally or better at a comparable price does not exist. The government passes their ridiculous laws all but outlawing the bulbs and taxing them to be as expensive as the next choices. The end result is people now get to pay anywhere for 4 to 12 times more for a light bulb. The choices being insanely expensive LED bulbs or almost insanely expensive toxic filled florescent bulbs. This 12 dollars per bulb works its way into the economy as inflation, because the real value of a light bulb is less than a dollar. Using laws and taxes to force people to pay for expensive bulbs is the cause of t he inflation. If this was done without government interference, eventually someone would have invented a true alternative, sold it and eventually incandescent would have gone away simply because they would have been undesired.

  3. You can put an incandescent bulb in your braai chimney but CAN you put a LED light bulb in there??

  4. tongue in cheek on

    of course you can, will it last is another question, as LEDS are constant current devices, and heat has an impact on their lifespan, braai= heat. I have LEDs all over the garden (not exposed to the elements) and they certainly last longer than CFL’s

  5. Your oven also has a light, but would never put a LED bulb there. In the fridge: yes
    CFLs and LED bulbs have electronics built in and they do not like heat.

  6. Greg Mahlknecht on

    I’ve had one in mine for about a year … so far so good.

    LED bulbs actually do get pretty hot over time, and a good bright one will have a large aluminium heatsink on the back, so it is well equipped to dissipate the heat.

    I’m using a 6W Osram, which has an aluminium heatsink on the back, and frosted glass on the front. The electronics are all buried in the core of the aluminium heatsink on the back, so I don’t see what the issue would be.

  7. Greg Mahlknecht on

    Yes. CFLs are terrible outside. In Durban you’re lucky to have them last more than a few months with the large day/night temperature swings.

  8. I guess you are talking about CFLs in an enclosed fitting exposed to the sun on daytime. The fitting might work as a kind of hothouse at day, and at night they heat produced by the CFL cannot escape properly. On the packages of the earlier CFL was a warning , they should not be used in a completely enclosed fitting. Surely because of heat.
    I have been using CFLs with day/night sensor, fitted on the rafters of my overhanging roof for over 13 years now, fitted with the simplest fitting possible, completely open, not exposed to direct sunlight and they last easily 4-5 years.
    And I am staying in one of the coldest parts of the country, Eastern FS, where day and night temps easily differ 20-25′ C. Much larger temp swings than in Durbs.
    Three days ago, 17/11 at 5 AM my car and fields were covered with a fat layer of frost.

  9. Greg Mahlknecht on

    Not totally enclosed, but the fitting is in direct sunlight at certain parts of the day, which is unavoidable as they’re in garden lights and lights on the side of my house. The ones that I use inside or don’t get direct sunlight last much much longer, which ties up with your experience.

    I’ve had some LEDs in similar circumstances for years and they just keep going. A good LED bulb is extremely rugged.

    The CFL’s I’m using advertise “6000 hours” on the box, while that seems like a lot, it’s about 2 years max expected lifespan at 8h/day which isn’t great.