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[ Music ]
[ Applause ]
>> Good afternoon.
I have just turned on the standard electric light bulb,
which has been unchanged, except for the filament
and the gas within the bulb,
since Edison patented it in 1880.
Sam Taylor, what do you think the efficiency
of this bulb is?
>> Pretty lousy.
>> Give me between 1 and 100 percent.
>> 40 percent.
>> Melissa Marshall, what do you think the efficiency is
[laughter] between 1 and 100 percent?
>> 30 percent.
>> 30 percent.
Well, actually, believe it or not, this light bulb,
which we've used for so long and which is
in everybody's home and, and workplace,
is only 5 or less percent efficient.
What this means is that we have,
we're spending about 55 billion dollars a year
on electricity for which we use 20 percent
of all the electricity generated in the United States,
and most other developed countries, just for lighting.
So if you're going to have something this inefficient,
you've got to have a lot of energy.
And 20 percent of our energy is being used for this.
If you're going to have a lot of energy,
you've got to have a lot of fuel.
And in the United States, and most other places, in fact,
most of our electricity is still generated
by coal-fired power plants.
The emission from these coal-powered plants,
in terms of CO2, is on the order of 110 million tons of CO2.
An equivalent weight to our family automobile,
if you took our, if you took,
the equivalent weight is 73 million automobiles.
So if you line those automobiles up end to end,
they would encircle the diameter of the earth 9 times.
You see on this map now, the bright areas,
the bright areas are where people are connected
to a grid, like you and I.
This is where we use that 20 percent
of our electrical-generating capacity for just lighting.
But you'll see on that slide,
that the one-third of the population
of the globe has no access to electricity.
You have no access to electricity,
there's still light there,
they still have to provide lighting in some way.
So let's see how they do that.
Candles, very familiar with that, diesel fuel, kerosene,
whale oil, seal oil, particularly in the northern latitudes,
cheese, and my favorite, yak butter [laughter].
Alright, so.
Interestingly enough though,
all of those sources spread throughout the world provide 1
percent of the global lighting,
and yet they produce 20 percent
of the CO2 in the atmosphere.
That amounts to 210 million tons of CO2,
which is equivalent to 93 million vehicles today,
if you tied them end-to-end, would go to the moon
and more than halfway back.
The takeaway from this, takeaway number from this,
is that 30 percent of CO2 put
into the atmosphere throughout the world,
30 percent of the CO2 put in the atmosphere
around the world is only, is generated only for lighting.
Do we have alternatives?
Yes we do.
Interestingly enough, the legislatures of many
of the developed countries have already pushed us into this
by legis, by saying, passing laws bipartisanly, actually,
that say after, in the United States, after January 1, 2014,
we will, the, the 40-watt bulb, the 75-watt bulb,
60-watt bulb, and 100-watt bulb will no longer be for sale.
You cannot, after inventories are depleted,
you will not be able to go to your source of light
of bulbs and buy them.
They won't be there.
I was in my Lowe's in Pittsburgh two weeks ago,
not a single incandescent light bulb was for sale.
Alright, so, I think we can cut this one out.
Other possible sources of light
for us are the fluorescent light,
the compact fluorescent introduced in 1995,
and the light-emitted diode, which is here enveloped
in a standard glass shell, and, and also with an Edison end
on it, so you can screw it into your lamp.
I had these up here, let's take a look at some
of the properties of these new sources,
which you're going to have to buy.
First of all, efficiency.
I'm going to emphasize the LED at this point,
because I think that the fluorescent light has pretty much
reached the end of its innovation.
The light, light-emitting diode has not reached the end
of its innovation, it's still coming, it's still being more,
made more efficient.
Notice that it's 10 times more efficient in a, a unit,
which you're going to have to look
at when you go to buy them.
Lumens is the light output.
Watt is the power input.
They're going to give you both those numbers,
you'll have to do the division,
to see how the efficiency is.
So the efficiency of the LED is 10 times
that of the Edison bulb.
CO2 emissions, 10 times less for a 30-bulb equivalent,
for the, than the incandescent light,
but the fluorescent light, I'm not shutting that out,
that is also quite an efficient light.
But here's where the big difference is, in life span.
Notice that the incandescent light
and the fluorescent light go up to about 10,000,
1,000 hours and 10,000 hours respectively,
but the LED starts about 50,000 hours, in fact,
when you buy your house,
you'll probably sell it before you change your light bulb,
okay?
That's important, because as we improve the lighting,
as we improve the efficiency of the lighting,
it also improves our visibility.
What about the other areas, those black areas on the map?
LEDs are also making their way into there,
they're much simpler than what we're using,
they're tied to solar cells, notice on your right-hand side,
they're tied to solar cells and storage facilities,
such as batteries or fuel cells, but they're able to bring,
they're able to provide light without tying to a source
of electricity, that is grid wise.
This is Kenya.
This is Nepal, from where we saw some of the candles
and other fuel oil being used.
Nepal and Sri Lanka, notice
in the upper left-hand corner there, the LED,
or the LED set, they're providing light for kids to be able
to study more and more, and to go to further
and further education in their schools.
There's another source coming.
This is called quantum dots.
And you'll notice that the size appears 5 nanometers
in diameter, you're looking at the atoms of this thing.
These things can be made either by changing their size
or changing their composition to emit light
at very sharp wavelengths,
and I'll give you an example of this.
I have vials here of quantum dots,
and I can excite them all the way
from the visible red to green to blue.
And to give you an idea of how small these things are,
within each vial, there's 300 trillion quantum dots.
Alright, now, they are already starting to enter your life.
You see here, Sony, this is the reason you can have a
ultra-high definition TV.
They're now using quantum dots, excited by other LEDs,
to produce these very pure reds, very pure greens,
and very pure blues at very high resolution for your TV
and you'll notice the big guys are stepping in,
other big guys are stepping in to start
to adopt them as well.
So quantum dots are going to be and are, perhaps,
in your life very soon.
Now these are optically activated.
In other words, it took another light,
this is photo-optically activated,
this took another light to activate it.
Can we use electricity to activate it?
And that's still in the laboratory for these quantum dots.
These are quantum dot light-emitting diodes.
They're not your, yet very efficient,
but the early LEDs weren't very efficient either,
but these will be upwards of 80 percent efficient.
These lights, 80 to 85 percent efficient.
This trumps the LEDs that we have now,
which are 60 to 65 percent efficient.
So in summary, this time, this is both a timeline,
and a line of increasing efficiency,
a line of decreasing the amount of CO2,
and the evolution of the ability to evolve to produce light
in ever more efficient
and less polluting ways is now happening.
In fact, we've had more rapid change in lighting
in the last 20 years, then we had in the previous 100.
Remember the takeaway,
30 percent of all CO2
in the atmosphere currently is produced,
or globally, by lighting.
Thank you!
[ Applause ]
コツ:単語をクリックしてすぐ意味を調べられます!

読み込み中…

【TEDx】Lighting -- an evolving and efficient pathway to cleaner air: Robert Davis at TEDxPSU

1536 タグ追加 保存
richardwang 2014 年 5 月 6 日 に公開
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