
The amazing progress of LEDs - lesterbuck
http://www.vox.com/2014/10/7/6936361/the-amazing-progress-of-leds-in-one-chart
======
beloch
One interesting application for super-bright LED's is home theatre projectors.
Until very recently such projectors used lamp modules (usually metal-halide)
that typically have an operating lifespan of a few thousand hours at most.
That's a very rough estimate. Failures can happen sooner and they occasionally
implode. Also, brightness usually drops off gradually as lamps age. New lamp
modules usually cost a few hundred dollars. These lamps also produce a large
ammount of heat and require active cooling, which makes projectors noisy
unless carefully designed for quiet operation. For these reasons, home theatre
projectors probably remain more of a niche product than they might otherwise
be.

LED based lamps are starting to show up in this market sector. Current LED-
based projectors are mostly portable projectors that offer low brightness and
poor image quality, but some home theatre models of decent quality are
starting to appear. At present, they're expensive, less bright than most
projectors based on traditional lamps, and still require fans for active
cooling. However, as LED's become more power efficient and economical, these
projectors will hopefully become brighter, passively cooled, and significantly
cheaper.

Projectors are not appropriate in many environments, especially those with
high ambient light levels, but LED's may help them make major inroads into the
big-screen market.

~~~
patrickk
Another interesting application: growing vegetables very efficiently
(potentially in urban areas).

" _Plants mainly need blue and red light for photosynthesis and far-red, a
colour not even visible to the human eye but visible to the plant….._ "

This makes LEDs very interesting for this purpose - the ideal light spectrum
can be achieved with LEDs. This will make more and more sense over time as the
world urbanises further and LEDs get ever cheaper.

[http://www.bigpictureagriculture.com/2011/02/plantlab-
nether...](http://www.bigpictureagriculture.com/2011/02/plantlab-netherlands-
engineers-have.html)

~~~
ZoFreX
I can think of a large market for lighting suitable for growing vegetables in
your home that doesn't produce a lot of waste heat...

~~~
patrickk
It's already been done (LEDs for growing weed, impossible for cops to spot
growhouses using FLIR helicopters and much lower power usage so spikes in
energy consumption are far less dramatic).

I think in terms of impact, growing vegetables in a sustainable manner that
uses little water will be critical for the long term sustainability of cities
where water is scarce, such as Dubai or other cities in desert regions.

------
Scaevolus
Related: "Drowning in Light" from a few weeks ago:
[http://nautil.us/issue/11/light/drowning-in-
light](http://nautil.us/issue/11/light/drowning-in-light)
[https://news.ycombinator.com/item?id=8344769](https://news.ycombinator.com/item?id=8344769)

It makes the compelling argument that people are addicted to light. "Tsao
calculates that, as a result, light represents a constant fraction of per
capita gross domestic product (GDP) over time; the world has been spending
0.72 percent of its GDP for light for 300 years now. If there are other energy
markets that show a constant percentage of GDP expenditure over time, Tsao
doesn’t know of them."

------
jcampbell1
Certain things are cheap in the rich world that are expensive in the 3rd
world. Sewage, electricity, and water are so cheap in the 1st world, that we
don't think about the cost.

The first time I saw 100% adoption of compact fluorescents was in Cambodia.
They pay $.40/KWhr. That is insanely expensive (unless you live in Germany).

Lighting technology disproportionally benefits the poor rather than than the
rich. Anyone that works on it is my hero. My family bought power for $.04
KW/hr, so I could study at night.

~~~
witty_username
While Bangalore is not representative of India as a whole, the electricity
prices are similar to global figures.

------
seanalltogether
I'm genuinely curious whether new homes will start wiring lighting for DC to
accommodate all these new LED bulbs? I just don't have a good sense whether
its more efficient to transform AC to DC at a central hub in the home to
distribute to all rooms, or more efficient to do it at the bulb itself.

~~~
webignition
Interestingly, I'm looking to do exactly this in a new home (new to me, not
newly constructed).

I'll soon be moving to a park home (a relatively-permanent mobile home) that
is in need of a fair amount of renovation.

I'll be running all lighting, computers and the TV off 12v DV circuits powered
by bank of vehicle batteries and where the batteries are charged from 12v
solar panels.

~~~
ZoFreX
Converting voltages is trivial with AC, how do you handle devices that require
something other than 12v (lots of phones want 5, lots of laptops want 18) with
a DC system?

~~~
webignition
I'll be fitting some 12v-based USB wall sockets, much like the type you can
fit in a car. These can then provide power for phones.

Regarding computers, I've so far only considered my desktop. You can get ready
made DC to DC ATX power supplies quite easily [1].

[1] [http://www.mini-box.com/DC-DC](http://www.mini-box.com/DC-DC)

------
RoboTeddy
One problem with current popular LED bulbs:

They emit more blue light than incandescent bulbs [1]. If people light their
households with LED lights at night, it might shift their circadian rhythms
[2]. Screwed up circadian rhythms can have all sorts of negative
health/productivity effects.

[1] [http://www.designingwithleds.com/measuring-light-quality-
phi...](http://www.designingwithleds.com/measuring-light-quality-philips-cree-
led-bulbs-spectrometer/) [2]
[https://justgetflux.com/research.html](https://justgetflux.com/research.html)

~~~
peatmoss
I'll be trying my hand at some LED strip / arduino programming to build a dawn
alarm that goes from dim red to bright white progressively. I have a Philips
halogen dawn alarm which naturally goes from orange -> red as it ramps up, but
unfortunately doesn't get quite as bright as I would like for that "wake up at
the cabin" experience.

I'd love to see more applications of LEDs providing the right color
temperature and intensity for the time of day, as well as more applications
that avoid the bulb form factor. I'd love for my ceiling to emit light like
the sky...

~~~
RoboTeddy
The best thing I've found so far are these lights meant for growing coral:

[http://www.maxspect.com/index.php?option=com_content&view=ar...](http://www.maxspect.com/index.php?option=com_content&view=article&id=20&Itemid=21&lang=en)

One of the models puts out UV, so be careful.

Message me (email in profile) if you want to chat!

~~~
peatmoss
Those look like a very polished product! In my case, I'm looking to take
advantage of the availability of $15 for a 300 RGB LED strip, as well as for
the challenge writing my own control logic with an arduino. The SAD wake-up
alarm is more of a side-benefit.

~~~
RoboTeddy
I don't have any SAD issues, but I find that getting proper light in the
morning helps stop me from going to bed too late.

I like your project! How many watts is the LED strip?

~~~
peatmoss
At full intensity, it draws 6a @ 12v, so 72 watts if my mental arithmetic is
correct. With luck that will throw enough light to be useful.

------
montecarl
Exponential growth is awesome! However, I was curious about the maximum
theoretical lumens per watt to determine when the growth will fall flat. A
current LED bulb gives about 60 lumens per watt. While an ideal monochromatic
light source could give 683.[1] So it looks like there is _only_ one order of
magnitude left in efficiency gains.

1:
[http://en.wikipedia.org/wiki/Luminous_efficacy](http://en.wikipedia.org/wiki/Luminous_efficacy)

~~~
jzwinck
That 683 lumens per watt number is, as you say, for a monochromatic light.
This is not useful for humans to see with[1]; the actual limit for human
vision is about 300 lumens per watt[2]. That's an upper bound even ignoring
losses, and some LEDs are around 70 now, so the remaining efficiency gains we
can make seem limited to about 3x.

[1] [http://www.cool.conservation-us.org/byorg/us-
doe/color_quali...](http://www.cool.conservation-us.org/byorg/us-
doe/color_quality_of_white_leds.pdf)

[2] [http://phys.org/news202453100.html](http://phys.org/news202453100.html)

------
Yardlink
He makes some dubious efficiency claims. It's true the colored LEDs have
always been pretty efficient, but that's no use lighting your home. White LEDs
have surpassed incandescent bulbs but still have a way to go to reach
flourescent tubes and the grand-daddy of efficiency - gas discharge lamps.

One (the?) reason for low power levels is they generate so much heat and are
difficult to cool. LEDs are still primarily heaters - useful in the winter.

~~~
ghostly_s
I think you need to update your figures. High-end consumer luminaires have
been coming in above 100 lm/watt _total_ system efficiency for at least a year
or so now, and with CRI superior to fluorescents.

~~~
Yardlink
Great news. I guess efficiency is following a similar rapid growth to power.

------
robomartin
Several years ago I designed 1,500 W LED-based light source using extremely
tightly packed LED's. Thermal management was a huge challenge. It took over
three months of constantly running FEA thermal tests as well as physical tests
to zero-in on an innovative approach to cooling the array. Crazy project. The
surface of the emitter was measured at over 60,000 candelas per square meter.
You simply could not look at the thing directly, it was really dangerous,
almost like working with lasers.

------
johnm1019
I'm a bit disappointed they didn't include a legend on the giant chart they
put in the middle of the page.

------
jsilence
Why do I have to enable "whatsappsharing.com" in my NoScript filter to see the
graph?

~~~
jonathansizz
Because you're using a browser extension that breaks the web.

