Placeholder Image

字幕表 動画を再生する

  • [ 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 ]

[ Music ]

字幕と単語

ワンタップで英和辞典検索 単語をクリックすると、意味が表示されます

B1 中級

TEDx】照明--よりクリーンな空気への進化と効率的な道筋。TEDxPSUでのロバート・デイビス (【TEDx】Lighting -- an evolving and efficient pathway to cleaner air: Robert Davis at TEDxPSU)

  • 45 3
    richardwang に公開 2021 年 01 月 14 日
動画の中の単語