This is a presentation that I put together for a group of building design professionals who has heard about - but knew very little about - the Rise and Rise of the LED.

1. The Life and Times of the LED . . .
and why it ain’t that Simple

2. In the beginning was the FLAME …

3. which came at quite a price …

4. It began simply enough

5. gained a
solid
reputation

6. threatened
a species

7. became
draught-
proofed

8. achieved a
brighter
future

9. got
turned
upside-
down in
the

10. But it was
still just
a flame in
a bulb

12. And then there was the lightning …

13. The long light had arrived

14. With all
kinds of
results

15. and scale

16. and story-
telling

17. Until
energy
started
costing
more than
was
comfortable

19. Until … this came along

20. In 1907, Henry Joseph
Round discovered the
principle of the semi-
conductor – but no one
knew what to do with it.

22. In 1927, Oleg V. Losev, in
the USSR published a
paper on light emission
using Silicon Carbide
(carborundum).
No one outside of the
USSR read it for thirty
years.

23. LED technology kicked-
off in 1961 when Bob
Baird and Gary Pittman,
working for Texas
Instruments developed the
infra-red LED – by
‘accident’.

25. Their LED was built using
s substrate of Gallium
Arsenide GaAs – a
compound still is
commercial use in LED
technology.
It is classed as a
carcinogen in California

26. Gallium Nitride. (GaN)
. . . while the dust from
GaN is an irritant to
skin, eyes and lungs, it
is non-toxic and bio-
compatible in its bulk
form.

27. . . . and the preferred
source of Gallium is
Trimethylgallium, which
has the tendency is catch
fire on contact with air.
Its also a by-product of
bauxite mining.

28. This is bauxite mining . . .
. . . in Guyana

29. though this is the Guyana
that we get told about

30. and bauxite makes aluminium . . .
. . . oh, oh

31. Anyway: eventually we got this …

32. Which became these … amongst many
others

33. And which has introduced us to a whole new
world of lighting opportunities …

35. Bulb
s:
Reflector
(light)
(heat)
LEDs: 90°-140° viewing angle
(light)
(heat)
(light)
The fundamental differences:
– Directionality of generated
light
• Omni-directional vs.
directional
– Means of evacuating
generated heat
• Convection vs.
conduction
Here’s the thing …

36. LED technology introduced us to a whole
new way of looking at our old familiar friends
…

37. But the LED has also changed the shape of lighting

38. This is a conventional (energy-saving) CFL downlight

39. And this is a comparable LED downlight

40. Lightweight structure with minimal metalwork

41. Almost 50% of the weight of the downlight is in
the aluminium heatsink mounted on the back

42. whereas the working part is very small indeed

43. whereas the working part is very small indeed

44. But what happens when we want to get rid of it?

45. But how do we get rid of it?
Electronic waste is the fastest-
growing part of the world’s
garbage stream. Improperly
disposed of, the lead, mercury
and other toxic materials inside e-
waste can leak from landfills.
75% of the aluminium produced
since the 19th century is still in use.
The demand for aluminium is set to
increase from 40M tonnes to 70M
tonnes by 2020, over two-thirds of
that demand will have to come from
primary sources,

46. But how do we get rid of it?
For every ton of aluminum produced,
the process generates approximately
24 kg of waste. In most cases it’s
only partially reused and the rest of
cases it’s discharged, contributing to
the problem of saturation in landfills
A lot of exported e-waste ends up
in Guiyu, China, where peasants
heat circuit boards over coal fires
to recover lead, while others use
acid to burn off bits of gold. Guiyu
has the highest level of cancer-
causing dioxins in the world and
elevated rates of miscarriages.

47. SO … what do we want from the LED?

48. Much of what the lighting designer wants is
consistency across all of the available sources
….
But can the LED deliver on
Energy efficiency ?
Colour quality ?
Light performance ?

49. Much of what the lighting designer wants is
consistency across all of the available sources
….
And what about ….
Cost effectiveness ?
Long life expectancy ?

50. Much of what the lighting designer wants is
consistency across all of the available sources
….
But can the LED deliver on
Energy efficiency ?
Colour quality ?
Light delivery ?
Cost effectiveness ?
Long life expectancy ?

51. The benchmark for energy efficiency is provided by
Building Regulations: Part L.
Energy efficiency

52. Energy efficiency

53. LED light quality is varied – much of it poor.
The commercial market for LEDs is enormous and
the most profitable fixtures are the ones that can
be bought cheap and sold dear.
Poor colour is a major factor in that cheapness.
Colour quality

54. Colour quality
Sunlight
Spectral Power Distribution
(~100 numbers)
CIE 1931
Chromaticity (xy or HSB)
(2-3 numbers)
Black Body Curve
Color Temperature
(1 number)

55. Colour quality
David MacAdam – a scientist at
Kodak – performed the first basic
research in the late 1940’s
Found a JND (Just Noticeable
Difference) in color varied
statistically by observer, size, and
orientation in CIE 1931

56. Colour quality
• CIE 1931 diagram, focused on the 3000K point.
• Data points represent color points of
approximately 1000 XSM 3080-01 modules,
manufactured in January 2009. All units
produced are shown.
• All modules are within 3 MacAdam Ellipses
• 99% of the modules are within 2 MacAdam
Ellipses

57. How good a light beam does the LED produce?
This performance factor is often ignored.
typical tungsten halogen a good LED
Light performance

58. Light performance
•By using different phosphor
mixes CRIs of 80+ or 95+
are available
•80 + modules have a 20%
higher efficacy
•90+ modules have industry
best colour-rendering
properties, including vivid
red portrayal (R9>90)

59. Light performance

60. Light performance
Ra R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15
Standard 81 80 85 89 81 78 80 86 66 16 64 79 58 81 93 75
Artist 98 98 99 98 98 98 97 98 98 98 99 98 88 98 98 98

61. Cost effectiveness is more than energy efficacy.
The cost of an LED fixture supports the overall
performance of its Longevity and its Colour Quality.
Cost effectiveness

62. Cost effectiveness
Ø Halogen, 3khrs life and 16 replacements
Ø CFL / CMH, 12khrs life and 4
replacements
Ø LED, 50khrs life and 1 replacement
Cumulative maintenance required over 50khrs

63. LED technology comes at a price.
There is a commercial balance that has to be achieved
re. cost v. life to justify energy savings.
Long life expectancy

64. Long life expectancy

65. Long life expectancy

66. The answer is certainly
YES
the LED can deliver on all these issues …
Energy efficiency
Colour quality
Light delivery
Cost effectiveness
Long life expectancy

67. But not every LED …….. Sorry.

69. Thank you for your time