(Updated March 8th 2020)
Hindsight is a wonderful thing. But we don’t usually realize how ineffective the products and solutions of the past truly were, until we’re presented with something better.
Consider the first automobile. Clocking in at around 10mph, it was actually slower than a horse and carriage.
But imagine if everyone, the designer included, had decided to give up on the idea then and there. Many of us already have long enough commutes, without having to worry about riding a horse and carriage to work!
Without the first, albeit slow, car: would we ever have got to the top speeds we are used to? Or the fully electric, driverless cars of the near future? Probably not.
The same goes for lighting.
Long before Edison, long before even gas, homes were lit with fire light. And this was far from a sustainable option. In fact, to produce the same amount of light a 100 watt bulb produces in one hour, they would have needed to chop wood for 60 hours!
And that’s not even to mention the environmental impact of using up so much wood.
The breakthrough came with the invention of electricity in 1802. As a safer energy source with limitless potential, inventors across the world saw a huge commercial opportunity to make a safer, cheaper and more reliable light.
This is where the path to the LED begins, with the lighting industry’s version of the first car: the incandescent light bulb.
A timeline of light bulb development
1840-1880: The Race to Patent the Incandescent Light Bulb
In 1840, Warren de la Rue invented the first recognizable incandescent light bulb, which used an expensive coiled platinum filament.
It was not until decades later, that a British scientist named Joseph Swan overcame the cost-effectiveness problem by using a carbonized cotton thread filament in a vacuum. For his efforts, he was awarded a patent in 1878.
But at the same time in Menlo Park in California, Thomas Edison started his exploration of the incandescent light bulb. Already a household name, famous for inventing the phonograph and the quadruplex telegraph, he used his significant resources to research alternative filaments.
On December 31st, 1879, Edison demonstrated the first modern incandescent bulb, announcing: "We will make electricity so cheap that only the rich will burn candles."
Fast forward to 2020, and not much has changed with the incandescent light bulb.
True, there are now more reliable filaments, and some refinements have been made to the manufacturing process, but the bulb still works in the same way. Electricity passes through a filament. And as this filament heats up, it begins to glow.
Just like log fires, candles, oil or gas, the light comes from heat, meaning incandescent bulbs waste more than 90% of their energy.
1896: The Fluorescent Bulb Takes Things A Step Further
Waste heat leads to more energy usage, which means higher energy bills and higher carbon emissions. Designers, experts and inventors knew a different approach to lighting was desperately needed.
This came in 1896 when Edison filed a patent for a lamp that used fluorescence to produce light. Edison’s early fluorescent bulbs used x-rays — a risky design flaw which ultimately led to one of his assistants being affected by radiation poisoning.
But if you have any fluorescent bulbs in your home or workplace, there’s no reason to panic.
Modern fluorescent bulbs use short-wave ultraviolet light, which is then filtered by a phosphor coating inside the lamp, to produce visible light. (Remember this coating, as its discovery made LEDs possible over 20 years later!).
Fluorescent lighting was more energy-efficient than incandescent bulbs. But it was also harsher. Despite government programs and product development, fluorescents failed to sell as well as was anticipated.
Luckily, in the background, new technology was emerging — the light-emitting diode or LED.
1960s to 1980s: The LED Starts To Gain Attention
Enter the LED or light-emitting diode, powered by electroluminescence.
But just like the incandescent light bulb, the LED light bulb wasn't a sudden invention. It came from the inventions of dozens of people, accumulating into the modern LED.
And you might be surprised to learn how LEDs were first used. For a light source now used in millions of homes across the world, the early applications of the LED were limited, to say the least.
It started in 1962, when Nick Holonyak invented the first visible-spectrum red LED. This invention was then commercially mass-produced by Monsanto in 1968.
These red LEDs were popular as backlighting in expensive watches and calculators through the 1970s and early 1980s. As costs of producing LEDs reduced and more colors became available, they were also added to information displays in VHS machines, televisions and HiFi systems. Being vastly superior to the bulbs they replaced, which failed regularly and produced excess heat, LEDs had found a good home.
At this time, nobody thought an LED light bulb would be possible nor desirable — who would want an alien red, sickly green or bright yellow bulb in their home, particularly for such a high cost?
1994: The LED Bulb Gets Its Time To Shine
The radical step required to make LEDs a useful lighting technology came with the invention of the blue LED light. The first commercially viable blue LED was created by Nobel Prize winner Shuji Nakamura in 1994, who invented the ultra-bright blue Gallium Nitride LED.
This was a critical invention because there are only 2 ways to produce white light with an LED.
You can mix red, blue and green to create a white light. This produces a bulb with a highly configurable lighting color, but requires three costly LEDs types in one package. As the color is produced by blending, it is also affected by the environment, leading to poor color rendering.
Phosphor Conversion Method
Thanks to the prior development of the fluorescent bulb, we already knew how to convert blue light to useful white light via phosphor conversion.
This method filters a blue LED light through a yellow phosphor coating. When blue and yellow light is combined, a white light is produced. This offers much improved color rendering versus the RGB method.
Launching the LED bulb
The final step was to place this LED into a casing that was compatible with common bulb fittings (like GU10, B22, B15, E27, and E14).
From then, the LED bulb began to take over the world.
In the last 10 years, LEDs have become dramatically more affordable and even more energy-efficient. Refinements have also been made to the quality of the light produced, with LED bulbs now able to produce a warm light similar to the incandescent bulb.
Comparing the costs of lighting — how did LEDs become so affordable?
Remember how we said it would have taken 60 hours to chop the wood required to create the same amount of light emitted from a 100 watt bulb in a single hour?
We know this staggering fact thanks to a man named William Nordhaus, and his series of experiments comparing the cost of lighting in different eras throughout history.
To establish exactly how much more efficient the LED bulb is, Nordhaus calculated the lumen-hours of an open fire Neolithic lamp, a Babylonian-style sesame oil lamp (yes, people really used to light their homes with sesame oil!), a candle, town gas, a kerosene lamp, an electric lamp, and a number of modern light bulbs.
Nordhaus found an extraordinary decrease in the cost per lumen-hour — that is, the quantity of light (in lumens) radiated for 60 minutes — even between the more contemporary lighting solutions.
- The first Neolithic lamp would have cost around 40 cents per lumen hour
- Edison’s first electric lamp would have cost 9 cents per lumen hour
- The modern compact fluorescent lamp (CFL) light bulb costs 0.124 cents an hour
- But today’s LED light bulbs slash even that figure, costing just 0.0008 cents per lumen hour!
To put that into perspective: a 19th Century worker, like Edison himself, would have had to labor for over 3 hours to afford one lumen-hour of illumination. Today, it takes less than a second for the average worker to earn enough to cover the same amount of light.
So how did LEDs become so affordable, especially considering the prohibitively high price tag of the 80s?
Essentially, as LEDs grew in application and popularity, the cost of producing them decreased.
It’s a common pattern seen in many innovations. After all, the first commercial cell phone cost $4,000 — and now you can buy a brand new, internet-enabled smartphone with just a 100-dollar bill.
Before the mid 90s, LEDs were made in small batches, with very little economy of scale. But as production volumes increased, the per-unit cost went down, making the bulbs more affordable, encouraging higher demand as a result.
This increased demand then spurred more competitors to enter the market, which led to an even more dramatic price decrease, and so on.
The cost of LEDs has dropped more than 85% in the last decade. In turn, sales have tripled — with LEDs reaching a market share of 40% in the USA and 31% in Europe.
So where now?
What's next for the LED Bulb?
With no obvious successor to the LED bulb, innovation will continue until LED replace older lighting technologies in almost every application.
However, we could go beyond mere replacement.
We’re starting to see LEDs be promoted from a retrofit alternative to an entirely new way to light residential and commercial spaces. This enables innovative lighting systems such as our LED flush mounts, which take full advantage of the strengths of LEDs, unhindered by existing fittings.
With these new lighting systems, we can now control our lighting with incredible precision.
This means we can choose the right lighting for the right situation, leading to improved productivity, comfort, and health. Read more about this in our article, the "Beginner’s Guide to Color Temperature".
We can even control LEDs electronically, thanks to their solid-state nature, leading to the emergence of smart light bulbs. Never before has it been possible to change the color of a lightbulb from your phone on the other side of the world — but watch this space!