WEBVTT 00:01.800 --> 00:03.900 align:left position:22.5%,start line:83% size:67.5% - Welcome to Wednesday Nite at the Lab. 00:04.000 --> 00:05.866 align:left position:25%,start line:83% size:65% I'm Liz Jesse, the media specialist 00:05.966 --> 00:07.500 align:left position:20%,start line:89% size:70% for UW Science Outreach. 00:07.600 --> 00:10.033 align:left position:22.5%,start line:83% size:67.5% On behalf of Wisconsin Alumni Association, 00:10.133 --> 00:14.133 align:left position:12.5%,start line:5% size:77.5% Wisconsin Public Television, UW Madison Science Alliance, 00:14.233 --> 00:15.800 align:left position:15%,start line:5% size:75% UW Madison Biotech Center, 00:15.900 --> 00:18.933 align:left position:22.5%,start line:5% size:67.5% and UW Extension and Cooperative Extension, 00:19.033 --> 00:21.300 align:left position:12.5%,start line:5% size:77.5% thanks for coming out to Wednesday Nite at the Lab. 00:21.400 --> 00:25.000 align:left position:12.5%,start line:5% size:77.5% We do this every Wednesday, 50 times a year. 00:25.100 --> 00:29.166 align:left position:15%,start line:5% size:75% Tonight, it is my pleasure to introduce Andrea Hicks. 00:29.266 --> 00:31.133 align:left position:22.5%,start line:5% size:67.5% Andrea grew up in Dearborn, Michigan, 00:31.233 --> 00:33.600 align:left position:12.5%,start line:5% size:77.5% which I just found out tonight is right outside of Detroit. 00:33.700 --> 00:36.266 align:left position:25%,start line:5% size:65% I don't know Michigan very well, apparently. 00:36.366 --> 00:39.766 align:left position:25%,start line:5% size:65% She completed her PhD in civil engineering 00:39.866 --> 00:41.833 align:left position:22.5%,start line:5% size:67.5% at the University of Illinois at Chicago 00:41.933 --> 00:43.466 align:left position:12.5%,start line:5% size:77.5% and then completed a postdoc 00:43.566 --> 00:46.433 align:left position:22.5%,start line:5% size:67.5% at the Institute of Environmental Science and Policy. 00:46.533 --> 00:49.066 align:left position:25%,start line:5% size:65% Her research at the UW, and maybe beyond, 00:49.166 --> 00:51.233 align:left position:20%,start line:5% size:70% focuses on the environmental, economic, 00:51.333 --> 00:53.166 align:left position:22.5%,start line:5% size:67.5% and social impacts of new technologies 00:53.266 --> 00:55.033 align:left position:20%,start line:5% size:70% compared to conventional counterparts. 00:55.133 --> 00:56.466 align:left position:22.5%,start line:5% size:67.5% So I kind of thought of this like, 00:56.566 --> 00:57.800 align:left position:12.5%,start line:5% size:77.5% we don't use Keurig at home 00:57.900 --> 00:59.900 align:left position:10%,start line:5% size:80% because I know that conventional brewing is better. 01:00.000 --> 01:02.533 align:left position:22.5%,start line:5% size:67.5% So maybe that's kind of what she talks about. 01:02.633 --> 01:04.100 align:left position:22.5%,start line:5% size:67.5% Tonight, she's going to be focusing, 01:04.200 --> 01:07.866 align:left position:15%,start line:5% size:75% and we're going to be talking a little bit about 01:07.966 --> 01:09.766 align:left position:12.5%,start line:5% size:77.5% the history of artificial light 01:09.866 --> 01:12.000 align:left position:25%,start line:5% size:65% and how it relates to sustainability 01:12.100 --> 01:13.900 align:left position:22.5%,start line:5% size:67.5% of today's emerging lighting technologies. 01:14.000 --> 01:16.900 align:left position:22.5%,start line:5% size:67.5% So, here we go with the LED paradox. 01:17.000 --> 01:19.533 align:left position:22.5%,start line:5% size:67.5% Please join me in welcoming Andrea Hicks. 01:19.633 --> 01:21.633 align:left position:25%,start line:5% size:65% [audience applauding] 01:24.366 --> 01:25.800 align:left position:25%,start line:5% size:65% - Thank you for that warm welcome. 01:25.900 --> 01:27.800 align:left position:25%,start line:5% size:65% Can everyone hear me? 01:27.900 --> 01:29.333 align:left position:32.5%,start line:5% size:57.5% Nods? Okay. 01:29.433 --> 01:31.633 align:left position:22.5%,start line:5% size:67.5% So, first, I'd like to thank the organizers 01:31.733 --> 01:34.500 align:left position:22.5%,start line:5% size:67.5% of Wednesday Night at the Lab for allowing me 01:34.600 --> 01:36.466 align:left position:25%,start line:5% size:65% this platform to present some work, 01:36.566 --> 01:38.700 align:left position:22.5%,start line:5% size:67.5% and to thank all of you for being here 01:38.800 --> 01:41.966 align:left position:12.5%,start line:5% size:77.5% to learn about the LED paradox. 01:42.066 --> 01:45.466 align:left position:12.5%,start line:5% size:77.5% So, a little bit about what we'll go over tonight. 01:45.566 --> 01:48.466 align:left position:22.5%,start line:5% size:67.5% We'll look at what is artificial light? 01:48.566 --> 01:50.566 align:left position:25%,start line:5% size:65% What's the history of lighting in Chicago? 01:50.666 --> 01:52.433 align:left position:25%,start line:83% size:65% It's a major city not so far from here. 01:52.533 --> 01:54.033 align:left position:12.5%,start line:89% size:77.5% It's a nice place to start. 01:54.133 --> 01:55.433 align:left position:15%,start line:89% size:75% Our consumption of light, 01:55.533 --> 01:57.933 align:left position:12.5%,start line:89% size:77.5% what technologies changes mean, 01:58.033 --> 02:01.266 align:left position:22.5%,start line:83% size:67.5% Jevons paradox, and novel consumption. 02:02.266 --> 02:04.766 align:left position:15%,start line:89% size:75% So, what is artificial light? 02:04.866 --> 02:06.200 align:left position:22.5%,start line:83% size:67.5% This is the point where everyone's like, 02:06.300 --> 02:07.500 align:left position:27.5%,start line:83% size:62.5% artificial light, it's in this room. 02:07.600 --> 02:08.700 align:left position:32.5%,start line:5% size:57.5% We have it. 02:08.800 --> 02:10.266 align:left position:25%,start line:5% size:65% I'll point to it. 02:10.366 --> 02:13.433 align:left position:25%,start line:5% size:65% So, to take it a more philosophical way, 02:13.533 --> 02:16.300 align:left position:25%,start line:5% size:65% it renders the invisible visible. 02:17.300 --> 02:18.533 align:left position:32.5%,start line:5% size:57.5% It's safety. 02:18.633 --> 02:20.433 align:left position:15%,start line:5% size:75% It's traffic control signals. 02:20.533 --> 02:21.666 align:left position:12.5%,start line:5% size:77.5% I'm from civil engineering, 02:21.766 --> 02:24.200 align:left position:20%,start line:83% size:70% so I have to throw in some examples like that. 02:24.300 --> 02:28.066 align:left position:12.5%,start line:83% size:77.5% It's street lights at night that encourage people to walk. 02:28.166 --> 02:29.866 align:left position:25%,start line:89% size:65% It's productivity. 02:29.966 --> 02:31.100 align:left position:15%,start line:89% size:75% Without artificial light, 02:31.200 --> 02:33.133 align:left position:22.5%,start line:83% size:67.5% there would be no night shift at hospitals. 02:33.233 --> 02:36.466 align:left position:22.5%,start line:83% size:67.5% There would be no third shift at plants. 02:36.566 --> 02:39.300 align:left position:20%,start line:83% size:70% And it decouples us from the patterns of the sun. 02:39.400 --> 02:41.433 align:left position:22.5%,start line:83% size:67.5% We're no longer dependent on the sun 02:41.533 --> 02:43.266 align:left position:12.5%,start line:89% size:77.5% as our sole source of light. 02:43.366 --> 02:45.433 align:left position:25%,start line:83% size:65% And here's a quote from Harold Platt, 02:45.533 --> 02:47.566 align:left position:22.5%,start line:83% size:67.5% who wrote The Electric City in 1991, 02:47.666 --> 02:50.633 align:left position:12.5%,start line:83% size:77.5% and that centers on Chicago and it's history of light. 02:50.733 --> 02:53.066 align:left position:22.5%,start line:83% size:67.5% We'll talk a little bit about his book 02:53.166 --> 02:55.100 align:left position:10%,start line:89% size:80% to give some background context. 02:55.200 --> 02:56.633 align:left position:25%,start line:83% size:65% "But the bright lights of the city 02:56.733 --> 02:58.800 align:left position:22.5%,start line:83% size:67.5% quickly became both a status symbol 02:58.900 --> 03:00.800 align:left position:15%,start line:83% size:75% and a physical manifestation of progress, 03:00.900 --> 03:03.100 align:left position:22.5%,start line:89% size:67.5% wealth, and amenities." 03:03.200 --> 03:05.166 align:left position:12.5%,start line:5% size:77.5% So, light isn't just light. 03:05.266 --> 03:07.200 align:left position:15%,start line:5% size:75% It's a symbol of progress. 03:07.300 --> 03:09.233 align:left position:15%,start line:5% size:75% If you think about a cartoon, 03:09.333 --> 03:12.466 align:left position:22.5%,start line:5% size:67.5% what happens when someone has an idea? 03:12.566 --> 03:14.400 align:left position:20%,start line:5% size:70% They get the light bulb. 03:14.500 --> 03:17.500 align:left position:27.5%,start line:5% size:62.5% So it's more than just illumination. 03:18.666 --> 03:22.400 align:left position:22.5%,start line:5% size:67.5% So, this is a timeline of lighting in Chicago. 03:22.500 --> 03:26.433 align:left position:15%,start line:5% size:75% In 1878, Barrett demonstrated Brush's arc lamp. 03:28.200 --> 03:31.533 align:left position:15%,start line:83% size:75% And within a decade, there are almost 7,000 arc lamps 03:31.633 --> 03:33.733 align:left position:25%,start line:83% size:65% built and operated in the city of Chicago 03:33.833 --> 03:36.833 align:left position:22.5%,start line:83% size:67.5% at an annual cost of a million dollars, 03:36.933 --> 03:38.166 align:left position:32.5%,start line:89% size:57.5% which is a lot. 03:40.133 --> 03:41.966 align:left position:22.5%,start line:83% size:67.5% "And so the electric suppliers..." 03:42.066 --> 03:44.500 align:left position:12.5%,start line:89% size:77.5% This is also from Platt's book. 03:44.600 --> 03:48.033 align:left position:22.5%,start line:83% size:67.5% "...faced a consumer market with no bounds." 03:48.133 --> 03:50.300 align:left position:10%,start line:83% size:80% And this is a question that will permeate our talk tonight. 03:50.400 --> 03:52.433 align:left position:12.5%,start line:89% size:77.5% What is saturation of light? 03:52.533 --> 03:54.233 align:left position:15%,start line:89% size:75% When do we have enough light? 03:54.333 --> 03:57.800 align:left position:25%,start line:83% size:65% How much light is too much light? 03:57.900 --> 04:00.133 align:left position:12.5%,start line:83% size:77.5% But there were some problems with this arc lamp. 04:00.233 --> 04:02.233 align:left position:25%,start line:89% size:65% It was a fire hazard. 04:02.333 --> 04:03.500 align:left position:32.5%,start line:89% size:57.5% It was big. 04:03.600 --> 04:05.966 align:left position:22.5%,start line:83% size:67.5% You couldn't use it in a residential setting. 04:06.066 --> 04:07.066 align:left position:32.5%,start line:89% size:57.5% So, in 1880, 04:08.300 --> 04:09.800 align:left position:25%,start line:89% size:65% or 1879 depending, 04:11.033 --> 04:12.466 align:left position:10%,start line:89% size:80% Thomas Edison invented the first 04:12.566 --> 04:14.966 align:left position:15%,start line:89% size:75% marketable incandescent bulb. 04:16.133 --> 04:18.566 align:left position:22.5%,start line:83% size:67.5% And Chicagoans suddenly had this choice, 04:18.666 --> 04:20.900 align:left position:15%,start line:89% size:75% what kind of light do I want? 04:21.000 --> 04:22.300 align:left position:15%,start line:89% size:75% Do I want electric light? 04:22.400 --> 04:23.766 align:left position:15%,start line:89% size:75% Do I want a kerosene lamp? 04:23.866 --> 04:27.266 align:left position:15%,start line:83% size:75% Do I want to go by the old gas lighting standby? 04:27.366 --> 04:29.200 align:left position:12.5%,start line:5% size:77.5% And so these incandescent bulbs 04:29.300 --> 04:30.766 align:left position:12.5%,start line:5% size:77.5% were much safer than arc lamps, 04:30.866 --> 04:34.033 align:left position:15%,start line:5% size:75% and could be easily scaled to residential use. 04:34.133 --> 04:35.266 align:left position:15%,start line:5% size:75% But really, electric lighting 04:35.366 --> 04:38.100 align:left position:25%,start line:5% size:65% was only for the wealthy at first. 04:38.200 --> 04:40.966 align:left position:25%,start line:5% size:65% It wasn't for the everyday person. 04:43.533 --> 04:46.533 align:left position:12.5%,start line:83% size:77.5% But, at the same point, there was this radical shift 04:46.633 --> 04:50.166 align:left position:15%,start line:83% size:75% in psychological perception of interior lighting levels. 04:50.266 --> 04:51.400 align:left position:25%,start line:83% size:65% And this goes back to our question 04:51.500 --> 04:53.466 align:left position:25%,start line:83% size:65% of how much light is enough light? 04:53.566 --> 04:55.833 align:left position:25%,start line:83% size:65% How much light is too much light? 04:55.933 --> 04:57.166 align:left position:25%,start line:83% size:65% So what had seemed all right before 04:57.266 --> 05:00.000 align:left position:25%,start line:83% size:65% was dark, gloomy, and depressing. 05:00.100 --> 05:02.966 align:left position:22.5%,start line:83% size:67.5% So already we're craving more light, 05:03.066 --> 05:05.366 align:left position:12.5%,start line:89% size:77.5% because we have more light. 05:05.466 --> 05:08.800 align:left position:25%,start line:83% size:65% Now, in 1893, Chicago's World Fair, 05:08.900 --> 05:11.700 align:left position:25%,start line:83% size:65% Chicago was dubbed the city of light. 05:11.800 --> 05:15.266 align:left position:10%,start line:83% size:80% And, by 1912, about half of Chicago's middle class families 05:15.366 --> 05:19.533 align:left position:15%,start line:83% size:75% had electricity in their homes and electric light. 05:22.033 --> 05:24.566 align:left position:15%,start line:89% size:75% So, look at that quote again. 05:24.666 --> 05:25.833 align:left position:25%,start line:89% size:65% It's a status symbol. 05:25.933 --> 05:28.400 align:left position:22.5%,start line:83% size:67.5% It's progress, it's wealth, it's amenities. 05:28.500 --> 05:30.566 align:left position:25%,start line:83% size:65% Light is more than just illumination. 05:30.666 --> 05:33.233 align:left position:12.5%,start line:5% size:77.5% It means we're moving forward. 05:33.333 --> 05:36.866 align:left position:22.5%,start line:5% size:67.5% And some photos from the World's Fair. 05:36.966 --> 05:40.766 align:left position:22.5%,start line:5% size:67.5% They're not great, but, you know, early 1900s. 05:41.900 --> 05:43.133 align:left position:22.5%,start line:89% size:67.5% And it was amazing. 05:43.233 --> 05:45.300 align:left position:15%,start line:89% size:75% We had all of this light. 05:47.700 --> 05:50.433 align:left position:15%,start line:83% size:75% So, before we start to talk about the actual consumption 05:50.533 --> 05:53.466 align:left position:25%,start line:83% size:65% of light, some little background. 05:53.566 --> 05:56.900 align:left position:20%,start line:83% size:70% One unit I'll talk a lot about today is a lumen, 05:57.000 --> 06:00.100 align:left position:12.5%,start line:83% size:77.5% and a lumen is an international standards unit 06:00.200 --> 06:02.600 align:left position:22.5%,start line:83% size:67.5% for the measurement of brightness. 06:02.700 --> 06:04.666 align:left position:25%,start line:83% size:65% And another way to think about it, 06:04.766 --> 06:08.366 align:left position:25%,start line:83% size:65% it's the light of one candle one foot away. 06:09.500 --> 06:10.966 align:left position:20%,start line:83% size:70% Although, I suspect most people don't compare 06:11.066 --> 06:13.666 align:left position:22.5%,start line:83% size:67.5% their light bulbs to candles at feet. 06:13.766 --> 06:17.066 align:left position:30%,start line:83% size:60% Maybe people do, and that's okay. 06:17.166 --> 06:19.333 align:left position:25%,start line:83% size:65% And so it's a measure of light output, 06:19.433 --> 06:21.233 align:left position:22.5%,start line:83% size:67.5% and it's a nice way when we talk about 06:21.333 --> 06:24.100 align:left position:15%,start line:83% size:75% different efficiencies of lighting to compare them. 06:24.200 --> 06:28.166 align:left position:15%,start line:83% size:75% About 800 lumens is about a 60-watt incandescent, 06:28.266 --> 06:31.266 align:left position:22.5%,start line:83% size:67.5% which translates into CFLs and LEDs. 06:35.333 --> 06:38.600 align:left position:22.5%,start line:5% size:67.5% So, this we're already using our lumen. 06:40.000 --> 06:42.866 align:left position:10%,start line:5% size:80% This is teralumen hours per year 06:42.966 --> 06:45.233 align:left position:22.5%,start line:5% size:67.5% of light consumed in the United Kingdom. 06:45.333 --> 06:48.566 align:left position:25%,start line:5% size:65% It's a study by Tsao et al in 2010 06:48.666 --> 06:52.400 align:left position:22.5%,start line:5% size:67.5% that looks at the consumption of light 06:52.500 --> 06:55.566 align:left position:25%,start line:83% size:65% over time and changes in technology. 06:55.666 --> 06:57.966 align:left position:15%,start line:83% size:75% So here we are transitioning from candles 06:58.066 --> 07:02.300 align:left position:15%,start line:83% size:75% to gas, to kerosene, and eventually to electricity. 07:03.466 --> 07:07.166 align:left position:20%,start line:83% size:70% And the whole time we're consuming more light. 07:08.366 --> 07:11.800 align:left position:25%,start line:83% size:65% Yes, the lines go up, consuming more light. 07:13.733 --> 07:16.066 align:left position:22.5%,start line:83% size:67.5% And it's largely, this work by Tsao et al, 07:16.166 --> 07:18.533 align:left position:22.5%,start line:83% size:67.5% was largely based on some earlier work 07:18.633 --> 07:21.133 align:left position:22.5%,start line:89% size:67.5% by Fouquet and Pearson, 07:21.233 --> 07:24.600 align:left position:25%,start line:83% size:65% that looked at the price of lighting. 07:24.700 --> 07:28.166 align:left position:22.5%,start line:83% size:67.5% So, how much per million lumen hours? 07:28.266 --> 07:30.500 align:left position:12.5%,start line:89% size:77.5% We're using those lumens again. 07:30.600 --> 07:32.466 align:left position:12.5%,start line:89% size:77.5% So what's the cost of light, 07:32.566 --> 07:35.066 align:left position:25%,start line:83% size:65% as we transition over time from gas light 07:35.166 --> 07:37.866 align:left position:27.5%,start line:83% size:62.5% to kerosene light to electric light? 07:37.966 --> 07:40.233 align:left position:25%,start line:83% size:65% And the point is, it's been going down, 07:40.333 --> 07:43.600 align:left position:22.5%,start line:83% size:67.5% over time in the UK during this study, 07:43.700 --> 07:45.800 align:left position:15%,start line:89% size:75% which ends at about 2000. 07:49.233 --> 07:52.800 align:left position:25%,start line:83% size:65% I see people talking, this is a good sign. 07:54.700 --> 07:56.600 align:left position:25%,start line:83% size:65% So okay, so we've been using more light 07:56.700 --> 07:58.533 align:left position:25%,start line:83% size:65% and the cost of light has been going down, 07:58.633 --> 08:00.433 align:left position:22.5%,start line:89% size:67.5% at least in the UK. 08:00.533 --> 08:04.300 align:left position:12.5%,start line:83% size:77.5% So, the Energy Information Administration very recently 08:04.400 --> 08:06.800 align:left position:25%,start line:83% size:65% put together a chart of energy consumption 08:06.900 --> 08:10.233 align:left position:22.5%,start line:83% size:67.5% in the United States starting from 1776, 08:11.766 --> 08:13.266 align:left position:32.5%,start line:89% size:57.5% which is nice. 08:13.366 --> 08:15.633 align:left position:12.5%,start line:83% size:77.5% Usually you can't find data, at least in engineering 08:15.733 --> 08:18.833 align:left position:15%,start line:83% size:75% when I'm looking for something from the 1700s. 08:18.933 --> 08:22.366 align:left position:22.5%,start line:83% size:67.5% And, okay, so we consume more energy. 08:22.466 --> 08:26.000 align:left position:22.5%,start line:83% size:67.5% This is in quadrillion British thermal units. 08:26.100 --> 08:29.400 align:left position:15%,start line:83% size:75% And our energy consumption broken down by 08:29.500 --> 08:30.866 align:left position:25%,start line:89% size:65% what we're consuming. 08:30.966 --> 08:32.833 align:left position:22.5%,start line:83% size:67.5% And over time, we've transitioned from coal 08:32.933 --> 08:36.766 align:left position:15%,start line:83% size:75% to more toward natural gas and petroleum products. 08:36.866 --> 08:38.866 align:left position:15%,start line:89% size:75% So, okay, the question is, 08:38.966 --> 08:42.833 align:left position:15%,start line:5% size:75% how much energy do we use for artificial light? 08:44.100 --> 08:45.100 align:left position:32.5%,start line:5% size:57.5% Is it a lot? 08:45.200 --> 08:46.366 align:left position:32.5%,start line:5% size:57.5% Is it a little? 08:46.466 --> 08:48.866 align:left position:25%,start line:5% size:65% Would we even see it on this graph? 08:48.966 --> 08:51.733 align:left position:25%,start line:5% size:65% So, when I started studying this, 08:53.666 --> 08:56.633 align:left position:22.5%,start line:5% size:67.5% and the first data is from maybe around 2001, 08:56.733 --> 09:01.233 align:left position:15%,start line:5% size:75% we were using 8.2 quadrillion British thermal units 09:01.333 --> 09:04.466 align:left position:12.5%,start line:5% size:77.5% of electricity for lighting in the United States. 09:04.566 --> 09:05.966 align:left position:22.5%,start line:5% size:67.5% So, if you take a look, 09:06.066 --> 09:08.433 align:left position:12.5%,start line:5% size:77.5% that is a little bit higher 09:08.533 --> 09:11.866 align:left position:25%,start line:5% size:65% than nuclear energy consumption in 2015. 09:13.333 --> 09:14.933 align:left position:25%,start line:83% size:65% So, based on the premise of this talk, 09:15.033 --> 09:17.866 align:left position:25%,start line:83% size:65% do you think it's gone up or down? 09:19.033 --> 09:20.600 align:left position:40%,start line:89% size:50% Some up? 09:20.700 --> 09:21.766 align:left position:25%,start line:89% size:65% Shall we raise hands? 09:21.866 --> 09:24.133 align:left position:20%,start line:89% size:70% Who thinks it's gone up? 09:24.233 --> 09:25.666 align:left position:45%,start line:89% size:45% Okay. 09:25.766 --> 09:28.600 align:left position:15%,start line:89% size:75% Who thinks it's gone down? 09:28.700 --> 09:31.300 align:left position:12.5%,start line:83% size:77.5% - [Audience Member] Are you asking input or output? 09:31.400 --> 09:33.633 align:left position:12.5%,start line:89% size:77.5% - Total energy consumption. 09:35.033 --> 09:37.033 align:left position:15%,start line:83% size:75% - [Audience Member] So the energy input into it. 09:37.133 --> 09:38.833 align:left position:40%,start line:89% size:50% - Right. 09:38.933 --> 09:40.500 align:left position:25%,start line:89% size:65% And who doesn't know? 09:40.600 --> 09:41.733 align:left position:22.5%,start line:89% size:67.5% [audience chuckling] 09:41.833 --> 09:43.833 align:left position:32.5%,start line:89% size:57.5% That's okay. 09:45.066 --> 09:48.000 align:left position:12.5%,start line:89% size:77.5% So it's actually gone down, 09:48.100 --> 09:50.566 align:left position:22.5%,start line:77% size:67.5% which seems a little counterintuitive with a talk called, 09:50.666 --> 09:53.766 align:left position:22.5%,start line:83% size:67.5% The LED Paradox and the Rebound Effect. 09:53.866 --> 09:54.933 align:left position:35%,start line:89% size:55% But, in 2010, 09:56.866 --> 09:59.900 align:left position:25%,start line:83% size:65% about 7.5 quadrillion British thermal units 10:00.000 --> 10:02.800 align:left position:15%,start line:83% size:75% were devoted to electricity for lighting, 10:02.900 --> 10:04.833 align:left position:22.5%,start line:89% size:67.5% and in 2013, 6.9 quads, 10:06.800 --> 10:10.966 align:left position:12.5%,start line:83% size:77.5% which comprised about 18% of total US electricity usage. 10:13.133 --> 10:14.466 align:left position:25%,start line:89% size:65% So it's gone down. 10:14.566 --> 10:18.566 align:left position:10%,start line:83% size:80% Why are we talking about energy rebound and the paradox? 10:18.666 --> 10:20.000 align:left position:30%,start line:89% size:60% We'll get there. 10:21.666 --> 10:25.800 align:left position:20%,start line:83% size:70% So, let's think a little bit about efficiency. 10:25.900 --> 10:29.900 align:left position:15%,start line:83% size:75% And, here, we've got a compact fluorescent lamp, 10:31.633 --> 10:34.800 align:left position:22.5%,start line:83% size:67.5% which was invented or inspired in 1973 10:36.133 --> 10:37.800 align:left position:22.5%,start line:89% size:67.5% during the oil crisis, 10:37.900 --> 10:42.000 align:left position:15%,start line:83% size:75% and in 1974, made by an engineer at General Electric. 10:43.566 --> 10:47.100 align:left position:12.5%,start line:83% size:77.5% And in the 1980s, CFLs were introduced to the public. 10:47.200 --> 10:49.100 align:left position:22.5%,start line:89% size:67.5% So, who remembers that? 10:50.266 --> 10:51.600 align:left position:45%,start line:89% size:45% Okay. 10:51.700 --> 10:54.800 align:left position:15%,start line:83% size:75% Maybe half a dozen people, that's a good start. 10:54.900 --> 10:57.633 align:left position:22.5%,start line:83% size:67.5% And, but there were some problems. 10:57.733 --> 10:58.966 align:left position:22.5%,start line:89% size:67.5% They were expensive. 10:59.066 --> 11:02.766 align:left position:22.5%,start line:83% size:67.5% They were about $25-$35 per light bulb, 11:02.866 --> 11:04.966 align:left position:25%,start line:83% size:65% and that number is a little fuzzy, 11:05.066 --> 11:06.200 align:left position:25%,start line:83% size:65% because they were often subsidized 11:06.300 --> 11:08.733 align:left position:12.5%,start line:89% size:77.5% by the electrical utilities. 11:08.833 --> 11:10.366 align:left position:35%,start line:89% size:55% They're blue. 11:10.466 --> 11:11.800 align:left position:25%,start line:89% size:65% They failed early, 11:11.900 --> 11:15.366 align:left position:15%,start line:83% size:75% and they had inconsistent light input, output. 11:15.466 --> 11:16.966 align:left position:25%,start line:89% size:65% Not well received. 11:18.333 --> 11:21.900 align:left position:22.5%,start line:83% size:67.5% So, as we talk about lighting technologies, 11:23.200 --> 11:27.366 align:left position:22.5%,start line:83% size:67.5% let's talk a little bit about how they work. 11:27.466 --> 11:28.933 align:left position:22.5%,start line:89% size:67.5% So in an incandescent, 11:29.033 --> 11:30.633 align:left position:30%,start line:83% size:60% which is sort of what we think of 11:30.733 --> 11:32.300 align:left position:12.5%,start line:89% size:77.5% as the conventional technology, 11:32.400 --> 11:35.533 align:left position:10%,start line:83% size:80% an electric current runs through the filament, heating it, 11:35.633 --> 11:39.733 align:left position:15%,start line:83% size:75% and then it starts to glow and light is produced. 11:39.833 --> 11:41.533 align:left position:25%,start line:89% size:65% But what about a CFL? 11:42.933 --> 11:46.733 align:left position:15%,start line:83% size:75% So, in a CFL, it has this curlicue shape, right? 11:48.533 --> 11:51.433 align:left position:22.5%,start line:83% size:67.5% And an electric current goes through the argon 11:51.533 --> 11:53.200 align:left position:25%,start line:83% size:65% and a small amount of mercury vapor, 11:53.300 --> 11:56.300 align:left position:10%,start line:89% size:80% which is stored in the curlicue. 11:56.400 --> 11:58.800 align:left position:20%,start line:83% size:70% That generates invisible ultraviolet light 11:58.900 --> 12:01.700 align:left position:22.5%,start line:83% size:67.5% that excites a fluorescent coating, 12:01.800 --> 12:05.466 align:left position:20%,start line:83% size:70% which is on the outside, and produces light. 12:07.533 --> 12:11.700 align:left position:15%,start line:83% size:75% This is from the friendly folks at Energy Star. 12:11.800 --> 12:13.466 align:left position:22.5%,start line:89% size:67.5% So, what about LEDs? 12:16.833 --> 12:19.033 align:left position:25%,start line:83% size:65% So, LEDs, or light emitting diodes, 12:19.133 --> 12:20.833 align:left position:20%,start line:83% size:70% and we'll talk about how they work in a second, 12:20.933 --> 12:23.600 align:left position:22.5%,start line:83% size:67.5% are considered an enabling technology, 12:23.700 --> 12:26.233 align:left position:10%,start line:83% size:80% because they enable other products and other technologies 12:26.333 --> 12:29.233 align:left position:22.5%,start line:5% size:67.5% that would not be possible without them. 12:29.333 --> 12:30.900 align:left position:22.5%,start line:5% size:67.5% And this is a graph 12:32.366 --> 12:35.966 align:left position:22.5%,start line:5% size:67.5% from data mined from the US patent database 12:36.066 --> 12:40.066 align:left position:10%,start line:5% size:80% on the percentage of light emitting diode patents per year, 12:40.166 --> 12:41.766 align:left position:22.5%,start line:5% size:67.5% applications per year, 12:41.866 --> 12:45.600 align:left position:15%,start line:5% size:75% broken down by the application's application. 12:47.400 --> 12:49.833 align:left position:15%,start line:89% size:75% So, what is the goal of this? 12:51.200 --> 12:54.266 align:left position:12.5%,start line:83% size:77.5% And you can see LEDs for illumination are near the top. 12:54.366 --> 12:55.866 align:left position:20%,start line:83% size:70% And illumination is what we primarily thought of 12:55.966 --> 12:57.700 align:left position:15%,start line:89% size:75% for what we do with light. 12:57.800 --> 13:00.700 align:left position:25%,start line:83% size:65% You light a candle to have light. 13:00.800 --> 13:04.066 align:left position:12.5%,start line:83% size:77.5% You turn on an incandescent light bulb to have light. 13:04.166 --> 13:07.166 align:left position:22.5%,start line:83% size:67.5% But with LEDs, we start to have other options. 13:07.266 --> 13:10.400 align:left position:10%,start line:89% size:80% We have liquid crystal displays. 13:10.500 --> 13:14.733 align:left position:22.5%,start line:77% size:67.5% We have manufacturing, communication, military, medicine. 13:14.833 --> 13:17.700 align:left position:15%,start line:83% size:75% There's all, and novelties, which we'll talk about later. 13:17.800 --> 13:20.466 align:left position:10%,start line:89% size:80% There's some exciting novelties. 13:21.666 --> 13:25.233 align:left position:22.5%,start line:83% size:67.5% And so they have all of these properties. 13:25.333 --> 13:28.033 align:left position:25%,start line:5% size:65% They don't get really hot, they're small. 13:28.133 --> 13:30.833 align:left position:25%,start line:5% size:65% You can enclose them, and they can get wet. 13:30.933 --> 13:35.000 align:left position:25%,start line:5% size:65% And the first red LED came about in 1961. 13:35.100 --> 13:36.266 align:left position:22.5%,start line:5% size:67.5% So they've been around, 13:36.366 --> 13:37.933 align:left position:22.5%,start line:5% size:67.5% but we're now just starting to use them 13:38.033 --> 13:40.533 align:left position:22.5%,start line:5% size:67.5% for residential lighting applications. 13:42.866 --> 13:44.633 align:left position:25%,start line:5% size:65% So, how do LEDs work? 13:46.266 --> 13:47.600 align:left position:22.5%,start line:5% size:67.5% And I enjoyed this. 13:47.700 --> 13:50.300 align:left position:12.5%,start line:5% size:77.5% This is from howstuffworks.com. 13:51.833 --> 13:54.500 align:left position:25%,start line:83% size:65% And forgive me if you've spent time 13:54.600 --> 13:55.800 align:left position:12.5%,start line:89% size:77.5% studying quantum mechanics. 13:55.900 --> 13:59.466 align:left position:22.5%,start line:83% size:67.5% This is just a very brief overview. 13:59.566 --> 14:02.466 align:left position:12.5%,start line:89% size:77.5% So, LEDs are semiconductors, 14:02.566 --> 14:06.733 align:left position:15%,start line:83% size:75% and current flows through the diode, and the electrons move. 14:11.633 --> 14:14.366 align:left position:22.5%,start line:83% size:67.5% There's holes that exist at a lower energy 14:14.466 --> 14:16.433 align:left position:12.5%,start line:89% size:77.5% and there's free electrons, 14:16.533 --> 14:20.933 align:left position:12.5%,start line:83% size:77.5% and when the electron moves to a lower energy level, 14:21.033 --> 14:23.833 align:left position:25%,start line:83% size:65% it emits a photon, which is light. 14:25.000 --> 14:26.666 align:left position:22.5%,start line:89% size:67.5% Very brief overview. 14:27.900 --> 14:29.033 align:left position:32.5%,start line:89% size:57.5% And that is, 14:29.133 --> 14:30.400 align:left position:32.5%,start line:89% size:57.5% this a red LED, 14:31.533 --> 14:33.800 align:left position:22.5%,start line:83% size:67.5% but it doesn't have to be a red LED. 14:33.900 --> 14:37.900 align:left position:12.5%,start line:83% size:77.5% You have your semiconducting material embedded in the lamp. 14:38.900 --> 14:40.966 align:left position:22.5%,start line:89% size:67.5% Okay, so we have LEDs. 14:41.066 --> 14:43.066 align:left position:25%,start line:5% size:65% They work a little bit differently. 14:43.166 --> 14:45.366 align:left position:20%,start line:5% size:70% Does anyone have an LED? 14:45.466 --> 14:46.866 align:left position:40%,start line:5% size:50% At home? 14:46.966 --> 14:48.366 align:left position:25%,start line:5% size:65% [audience murmurs responses] 14:48.466 --> 14:49.733 align:left position:45%,start line:5% size:45% Okay. 14:49.833 --> 14:51.866 align:left position:22.5%,start line:5% size:67.5% There's a few folks. 14:51.966 --> 14:54.966 align:left position:22.5%,start line:5% size:67.5% How about an LED with you right now? 14:58.600 --> 15:01.033 align:left position:25%,start line:5% size:65% Okay, so there's people with LEDs. 15:01.133 --> 15:05.166 align:left position:25%,start line:5% size:65% Are there people with smartphones right now? 15:05.266 --> 15:06.966 align:left position:45%,start line:5% size:45% Okay. 15:07.066 --> 15:09.733 align:left position:12.5%,start line:5% size:77.5% So, these exist, we have them. 15:09.833 --> 15:13.433 align:left position:22.5%,start line:5% size:67.5% There are many in this room at this moment. 15:14.900 --> 15:18.966 align:left position:20%,start line:5% size:70% So when we start to look at the lighting market, 15:19.066 --> 15:21.400 align:left position:12.5%,start line:5% size:77.5% and this is from the US Department of Energy in 2012 15:21.500 --> 15:23.300 align:left position:15%,start line:89% size:75% based on their 2010 data. 15:23.400 --> 15:25.366 align:left position:22.5%,start line:83% size:67.5% This is annual electricity consumption 15:25.466 --> 15:28.433 align:left position:12.5%,start line:89% size:77.5% in terawatt hours per year, 15:28.533 --> 15:30.800 align:left position:22.5%,start line:89% size:67.5% broken down by sector. 15:30.900 --> 15:34.466 align:left position:25%,start line:83% size:65% And the focus today will be residential. 15:34.566 --> 15:35.733 align:left position:30%,start line:89% size:60% And residential, 15:35.833 --> 15:39.600 align:left position:20%,start line:83% size:70% okay, so it's primarily, in 2010, incandescents. 15:40.700 --> 15:43.000 align:left position:12.5%,start line:89% size:77.5% Do you think that's changed? 15:43.833 --> 15:45.500 align:left position:42.5%,start line:89% size:47.5% Maybe? 15:46.633 --> 15:48.133 align:left position:25%,start line:89% size:65% [audience responds] 15:48.233 --> 15:50.633 align:left position:15%,start line:83% size:75% So it has at some people's houses for sure. 15:50.733 --> 15:55.233 align:left position:15%,start line:83% size:75% And other people's houses, we'll talk about too. 15:55.333 --> 15:57.166 align:left position:22.5%,start line:89% size:67.5% But, overall, in 2010, 15:58.766 --> 16:02.233 align:left position:15%,start line:83% size:75% we used about 700 terawatt hours of electricity 16:02.333 --> 16:04.733 align:left position:22.5%,start line:89% size:67.5% annually for lighting. 16:04.833 --> 16:08.300 align:left position:15%,start line:83% size:75% And although residential isn't the biggest sector, 16:08.400 --> 16:09.800 align:left position:22.5%,start line:83% size:67.5% it's interesting because you're starting 16:09.900 --> 16:14.066 align:left position:12.5%,start line:83% size:77.5% to deal with consumers and their individual behaviors. 16:14.166 --> 16:18.166 align:left position:15%,start line:83% size:75% Do you think people demand more light over time? 16:20.166 --> 16:21.333 align:left position:42.5%,start line:89% size:47.5% Maybe? 16:22.333 --> 16:24.600 align:left position:12.5%,start line:5% size:77.5% So, in 2001, the average number 16:24.700 --> 16:27.366 align:left position:10%,start line:5% size:80% of sockets per household was 43. 16:29.200 --> 16:30.366 align:left position:12.5%,start line:5% size:77.5% Do you think that's gone up? 16:30.466 --> 16:33.100 align:left position:15%,start line:5% size:75% - [Audience Member] Yeah. 16:33.200 --> 16:36.566 align:left position:25%,start line:5% size:65% So, as of 2010, the average is 51. 16:36.666 --> 16:39.633 align:left position:25%,start line:5% size:65% And that's one way of consuming more light, 16:39.733 --> 16:43.166 align:left position:20%,start line:5% size:70% that you have more light bulbs in your house. 16:43.266 --> 16:48.066 align:left position:15%,start line:5% size:75% Now, there's been some evolutions in technology too. 16:48.166 --> 16:51.933 align:left position:22.5%,start line:83% size:67.5% And this starts at 2011 and goes through 2016. 16:52.033 --> 16:53.400 align:left position:22.5%,start line:83% size:67.5% And we've got pictures of an incandescent 16:53.500 --> 16:55.533 align:left position:25%,start line:89% size:65% and a CFL and an LED. 16:55.633 --> 16:58.900 align:left position:17.5%,start line:83% size:72.5% And these are residential screw-in type replacements 16:59.000 --> 17:01.466 align:left position:22.5%,start line:83% size:67.5% with a lumen output of about 800. 17:01.566 --> 17:04.233 align:left position:15%,start line:89% size:75% So, 60-watt bulb equivalents. 17:04.333 --> 17:07.933 align:left position:20%,start line:83% size:70% So we're comparing apples to apples mostly. 17:10.133 --> 17:11.133 align:left position:32.5%,start line:89% size:57.5% So, in 2011, 17:12.266 --> 17:13.766 align:left position:25%,start line:89% size:65% an LED was $33.90, 17:17.133 --> 17:20.366 align:left position:25%,start line:83% size:65% which seems like a lot for a light bulb. 17:20.466 --> 17:24.166 align:left position:15%,start line:83% size:75% And if we go to 2013, okay, we're at about $13, 17:24.266 --> 17:27.200 align:left position:12.5%,start line:89% size:77.5% and today we're at about $4.50. 17:27.300 --> 17:29.100 align:left position:22.5%,start line:83% size:67.5% And incandescents have dropped a little bit. 17:29.200 --> 17:32.500 align:left position:15%,start line:83% size:75% There's some other factors at play that we'll talk about. 17:32.600 --> 17:35.700 align:left position:25%,start line:83% size:65% And CFLs have dropped a little bit too. 17:35.800 --> 17:37.633 align:left position:22.5%,start line:89% size:67.5% The energy consumption 17:39.266 --> 17:43.433 align:left position:15%,start line:83% size:75% has steadied for the conventional incandescent, 17:43.533 --> 17:45.566 align:left position:25%,start line:83% size:65% and it's gone down a bit for an LED, 17:45.666 --> 17:48.600 align:left position:22.5%,start line:83% size:67.5% going from 12 watts to about eight. 17:48.700 --> 17:49.900 align:left position:12.5%,start line:89% size:77.5% There's also a huge difference 17:50.000 --> 17:52.500 align:left position:10%,start line:89% size:80% in the lifetimes of these bulbs. 17:52.600 --> 17:54.033 align:left position:25%,start line:83% size:65% So the lifetime of an incandescent 17:54.133 --> 17:56.633 align:left position:12.5%,start line:89% size:77.5% is about 1,000 to 2,000 hours. 17:57.466 --> 17:58.633 align:left position:35%,start line:89% size:55% And a CFL? 17:59.633 --> 18:01.533 align:left position:22.5%,start line:89% size:67.5% About 8,000 to 12,000. 18:02.400 --> 18:05.333 align:left position:12.5%,start line:89% size:77.5% But an LED is about 25,000. 18:05.433 --> 18:07.333 align:left position:22.5%,start line:83% size:67.5% So, in theory, you could have a light bulb 18:07.433 --> 18:09.733 align:left position:12.5%,start line:5% size:77.5% that lasts a really long time, 18:09.833 --> 18:12.066 align:left position:12.5%,start line:5% size:77.5% even if it costs a little more. 18:12.166 --> 18:14.300 align:left position:25%,start line:5% size:65% And it should be more efficient to run 18:14.400 --> 18:17.566 align:left position:10%,start line:5% size:80% because it consumes less energy. 18:17.666 --> 18:20.600 align:left position:22.5%,start line:5% size:67.5% So then everyone should buy them, right? 18:20.700 --> 18:22.700 align:left position:35%,start line:5% size:55% No? Maybe? 18:24.700 --> 18:28.200 align:left position:22.5%,start line:5% size:67.5% So, we talked a little bit about the cost, 18:28.300 --> 18:31.366 align:left position:15%,start line:5% size:75% and this is a chart looking at ownership cost. 18:31.466 --> 18:33.566 align:left position:25%,start line:83% size:65% So the ownership cost is the purchase price 18:33.666 --> 18:37.633 align:left position:15%,start line:83% size:75% plus the use price normalized over the lifetime. 18:37.733 --> 18:41.366 align:left position:22.5%,start line:83% size:67.5% And, in this case, this is all in 2010 dollars. 18:41.466 --> 18:43.900 align:left position:22.5%,start line:83% size:67.5% And it looks at the ownership cost of light 18:44.000 --> 18:46.000 align:left position:20%,start line:89% size:70% from 1800 to about 2011, 18:48.133 --> 18:49.733 align:left position:20%,start line:83% size:70% where we're transitioning from fire, 18:49.833 --> 18:53.000 align:left position:20%,start line:83% size:70% which are things like candles, kerosene lamps, 18:53.100 --> 18:55.266 align:left position:12.5%,start line:89% size:77.5% to incandescents, fluorescents, 18:55.366 --> 18:58.766 align:left position:15%,start line:83% size:75% high intensity discharge, LEDs, and CFLs. 19:00.933 --> 19:03.966 align:left position:25%,start line:83% size:65% So the ownership cost has been going down, 19:04.066 --> 19:06.266 align:left position:25%,start line:83% size:65% much like we saw in that one chart 19:06.366 --> 19:08.500 align:left position:12.5%,start line:89% size:77.5% looking at the United Kingdom, 19:08.600 --> 19:12.633 align:left position:15%,start line:83% size:75% where they were transitioning from gas and kerosene 19:12.733 --> 19:13.966 align:left position:32.5%,start line:89% size:57.5% to electricity. 19:18.100 --> 19:21.566 align:left position:22.5%,start line:83% size:67.5% And there's some other factors at play also. 19:21.666 --> 19:26.400 align:left position:12.5%,start line:83% size:77.5% So, the Energy Independence and Security Act of 2007, 19:26.500 --> 19:28.166 align:left position:22.5%,start line:89% size:67.5% who has heard of it? 19:29.166 --> 19:30.600 align:left position:32.5%,start line:89% size:57.5% Four people. 19:30.700 --> 19:31.700 align:left position:12.5%,start line:89% size:77.5% All right, we're doing well. 19:31.800 --> 19:33.833 align:left position:22.5%,start line:89% size:67.5% [audience laughing] 19:33.933 --> 19:37.933 align:left position:15%,start line:83% size:75% Who has heard somewhere on television or the internet 19:38.033 --> 19:41.733 align:left position:22.5%,start line:83% size:67.5% about someone trying to ban incandescent bulbs? 19:41.833 --> 19:44.600 align:left position:20%,start line:83% size:70% All right, we're talking about the same thing. 19:44.700 --> 19:48.466 align:left position:12.5%,start line:83% size:77.5% So, the Energy Independence and Security Act of 2007 19:48.566 --> 19:51.833 align:left position:22.5%,start line:83% size:67.5% took effect between 2012 and 2014. 19:51.933 --> 19:55.733 align:left position:22.5%,start line:83% size:67.5% And it's not a ban, per se, on bulbs, 19:55.833 --> 19:58.966 align:left position:15%,start line:83% size:75% but it requires increasing of the efficiency 19:59.066 --> 20:00.466 align:left position:25%,start line:89% size:65% of incandescents. 20:01.833 --> 20:05.066 align:left position:22.5%,start line:83% size:67.5% So, if you look, we've got this EcoSmart box, 20:05.166 --> 20:08.433 align:left position:22.5%,start line:83% size:67.5% and it says it's a better incandescent. 20:08.533 --> 20:11.766 align:left position:25%,start line:83% size:65% So it's formerly a 60-watt incandescent, 20:11.866 --> 20:15.833 align:left position:15%,start line:83% size:75% and what they mean is it produces about 800 lumens. 20:15.933 --> 20:18.366 align:left position:15%,start line:89% size:75% But now it requires 43 watts, 20:19.933 --> 20:22.533 align:left position:30%,start line:83% size:60% so we've made an efficiency gain. 20:22.633 --> 20:24.966 align:left position:12.5%,start line:89% size:77.5% You also start to see things 20:26.166 --> 20:28.466 align:left position:25%,start line:83% size:65% like the lighting facts per bulb, 20:28.566 --> 20:32.300 align:left position:12.5%,start line:83% size:77.5% which, does this remind anybody else of food labels? 20:32.400 --> 20:33.533 align:left position:22.5%,start line:89% size:67.5% [audience laughing] 20:33.633 --> 20:36.966 align:left position:22.5%,start line:83% size:67.5% That's why I'm like, calories of brightness. 20:37.066 --> 20:38.700 align:left position:30%,start line:83% size:60% So I can tell by looking at this, 20:38.800 --> 20:41.033 align:left position:25%,start line:83% size:65% the brightness is about 800 lumens, 20:41.133 --> 20:44.566 align:left position:25%,start line:83% size:65% so it's a 60-watt equivalent bulb. 20:44.666 --> 20:46.933 align:left position:22.5%,start line:83% size:67.5% And the energy used is about 13 watts, 20:47.033 --> 20:48.966 align:left position:22.5%,start line:89% size:67.5% so it's probably a CFL. 20:51.666 --> 20:54.466 align:left position:25%,start line:83% size:65% Or it could be a really early LED. 20:54.566 --> 20:56.566 align:left position:12.5%,start line:83% size:77.5% And they rate the lifetime, and they say, okay, 20:56.666 --> 20:59.066 align:left position:27.5%,start line:83% size:62.5% I'll use this for three hours a day, 20:59.166 --> 21:02.166 align:left position:10%,start line:89% size:80% and it will last for nine years. 21:02.266 --> 21:05.600 align:left position:22.5%,start line:83% size:67.5% So it's a way of distilling information. 21:07.133 --> 21:08.366 align:left position:20%,start line:5% size:70% But here's the question, 21:08.466 --> 21:10.433 align:left position:22.5%,start line:5% size:67.5% when you heard about the ban on bulbs, 21:10.533 --> 21:13.600 align:left position:22.5%,start line:5% size:67.5% did anyone start ordering incandescents? 21:13.700 --> 21:15.566 align:left position:22.5%,start line:5% size:67.5% [audience laughing] 21:15.666 --> 21:17.666 align:left position:15%,start line:5% size:75% It's okay, two honest people. 21:17.766 --> 21:19.766 align:left position:35%,start line:5% size:55% All right. 21:21.200 --> 21:26.066 align:left position:12.5%,start line:5% size:77.5% So, this is David Brooks of Just Bulbs in Manhattan. 21:26.166 --> 21:28.533 align:left position:22.5%,start line:5% size:67.5% And I got this from the New York Times, 21:28.633 --> 21:31.333 align:left position:20%,start line:83% size:70% where he's commenting that he has one customer 21:31.433 --> 21:34.500 align:left position:12.5%,start line:83% size:77.5% who's ordering thousands and thousands of incandescents, 21:34.600 --> 21:37.200 align:left position:22.5%,start line:83% size:67.5% because she never wants to be without them, 21:37.300 --> 21:39.500 align:left position:25%,start line:83% size:65% and to please not tell her husband. 21:39.600 --> 21:40.766 align:left position:22.5%,start line:89% size:67.5% [audience laughing] 21:40.866 --> 21:42.766 align:left position:22.5%,start line:83% size:67.5% So, he'll be surprised one day when he finds 21:42.866 --> 21:44.833 align:left position:25%,start line:83% size:65% their storage unit of incandescent bulbs. 21:44.933 --> 21:47.233 align:left position:22.5%,start line:89% size:67.5% [audience laughing] 21:47.333 --> 21:49.533 align:left position:25%,start line:83% size:65% But, So we have interesting behaviors 21:49.633 --> 21:51.566 align:left position:15%,start line:89% size:75% that come about too that, 21:51.666 --> 21:53.800 align:left position:22.5%,start line:5% size:67.5% I do not want a more energy efficient bulb, 21:53.900 --> 21:55.900 align:left position:25%,start line:5% size:65% I'm going to use this incandescent forever. 21:56.000 --> 21:57.333 align:left position:45%,start line:5% size:45% Okay. 21:57.433 --> 22:00.766 align:left position:15%,start line:5% size:75% That's part of evolutions of technology. 22:00.866 --> 22:03.200 align:left position:12.5%,start line:5% size:77.5% So whenever I talk about CFLs, 22:03.300 --> 22:06.100 align:left position:25%,start line:5% size:65% the question of mercury comes up. 22:06.200 --> 22:09.366 align:left position:22.5%,start line:5% size:67.5% Who here knows that a CFL has mercury? 22:10.200 --> 22:12.200 align:left position:35%,start line:89% size:55% All right. 22:14.066 --> 22:17.066 align:left position:12.5%,start line:89% size:77.5% How much mercury do you think? 22:18.066 --> 22:20.766 align:left position:25%,start line:83% size:65% So, I see some people saying a little bit. 22:20.866 --> 22:22.466 align:left position:32.5%,start line:89% size:57.5% So, it's about, 22:22.566 --> 22:24.166 align:left position:25%,start line:83% size:65% currently they have about five milligrams 22:24.266 --> 22:26.200 align:left position:22.5%,start line:89% size:67.5% of mercury per bulb. 22:26.300 --> 22:28.900 align:left position:15%,start line:89% size:75% And, okay, is that a lot? 22:29.000 --> 22:30.066 align:left position:25%,start line:89% size:65% Is that a little? 22:30.166 --> 22:31.333 align:left position:32.5%,start line:89% size:57.5% Should we care? 22:31.433 --> 22:34.666 align:left position:12.5%,start line:83% size:77.5% There was one study that came out several years ago, 22:34.766 --> 22:36.166 align:left position:22.5%,start line:89% size:67.5% where they said, okay, 22:36.266 --> 22:38.666 align:left position:15%,start line:83% size:75% so there's five milligrams of mercury in the CFL, 22:38.766 --> 22:41.300 align:left position:22.5%,start line:5% size:67.5% but it's more efficient than an incandescent. 22:41.400 --> 22:44.766 align:left position:25%,start line:5% size:65% So what if I look at the life cycle 22:44.866 --> 22:47.833 align:left position:25%,start line:5% size:65% and I burn coal to make my incandescent, 22:47.933 --> 22:50.100 align:left position:20%,start line:5% size:70% power my incandescent throughout the lifetime? 22:50.200 --> 22:53.566 align:left position:15%,start line:5% size:75% Is that, how does the mercury balance work out? 22:53.666 --> 22:59.100 align:left position:10%,start line:5% size:80% And if you move to the CFL even though it has mercury in it, 22:59.200 --> 23:02.233 align:left position:15%,start line:5% size:75% you're saving mercury through the gains in efficiency. 23:02.333 --> 23:04.100 align:left position:12.5%,start line:5% size:77.5% So you're coming out ahead. 23:04.200 --> 23:05.366 align:left position:42.5%,start line:5% size:47.5% Now, 23:06.533 --> 23:09.533 align:left position:20%,start line:5% size:70% I've given talks similar to this enough times, 23:09.633 --> 23:13.100 align:left position:20%,start line:5% size:70% that there are some good anecdotes that come up. 23:14.733 --> 23:16.433 align:left position:25%,start line:83% size:65% Who here has heard of Mercurochrome? 23:16.533 --> 23:17.600 align:left position:22.5%,start line:89% size:67.5% [audience laughing] 23:17.700 --> 23:19.533 align:left position:35%,start line:89% size:55% All right. 23:19.633 --> 23:22.833 align:left position:12.5%,start line:89% size:77.5% So, I was giving this talk once 23:22.933 --> 23:26.766 align:left position:12.5%,start line:83% size:77.5% and I always, almost always, got attacked by someone 23:26.866 --> 23:29.066 align:left position:15%,start line:83% size:75% for the mercury content in CFLs and they're terrible 23:29.166 --> 23:33.300 align:left position:15%,start line:83% size:75% and they're going to kill us all and [muffled]. 23:33.400 --> 23:34.433 align:left position:25%,start line:89% size:65% I was like, okay. 23:34.533 --> 23:36.066 align:left position:12.5%,start line:89% size:77.5% So that's what I was expecting. 23:36.166 --> 23:37.466 align:left position:32.5%,start line:89% size:57.5% And he comes up 23:37.566 --> 23:40.266 align:left position:20%,start line:83% size:70% and he starts telling me that he doesn't think 23:40.366 --> 23:42.100 align:left position:15%,start line:89% size:75% the mercury is a big deal. 23:42.200 --> 23:43.366 align:left position:45%,start line:89% size:45% Okay. 23:43.466 --> 23:45.733 align:left position:12.5%,start line:83% size:77.5% Good, someone's finally not attacking me over this. 23:45.833 --> 23:47.600 align:left position:22.5%,start line:5% size:67.5% And so then he tells me 23:47.700 --> 23:48.800 align:left position:25%,start line:5% size:65% about something called Mercurochrome, 23:48.900 --> 23:50.633 align:left position:12.5%,start line:5% size:77.5% which, help me if I'm wrong, 23:50.733 --> 23:54.066 align:left position:15%,start line:5% size:75% is something at one point we used to dab on cuts 23:54.166 --> 23:56.566 align:left position:22.5%,start line:5% size:67.5% to sort of clean them and heal them? 23:56.666 --> 23:58.066 align:left position:25%,start line:5% size:65% I was like, oh, okay. 23:58.166 --> 24:00.233 align:left position:12.5%,start line:5% size:77.5% So then he proceeds to tell me 24:00.333 --> 24:02.800 align:left position:22.5%,start line:5% size:67.5% that similar to our friend in New York 24:02.900 --> 24:04.000 align:left position:15%,start line:5% size:75% hoarding the light bulbs, 24:04.100 --> 24:05.233 align:left position:10%,start line:5% size:80% that he's hoarded Mercurochrome. 24:05.333 --> 24:06.500 align:left position:22.5%,start line:5% size:67.5% [audience laughing] 24:06.600 --> 24:09.033 align:left position:22.5%,start line:5% size:67.5% And he has boxes and boxes full of this, 24:09.133 --> 24:11.400 align:left position:12.5%,start line:5% size:77.5% that he still uses it today, 24:11.500 --> 24:15.033 align:left position:12.5%,start line:5% size:77.5% mercury is not a big deal, and then he pulls out a bottle. 24:15.133 --> 24:16.266 align:left position:25%,start line:5% size:65% I was like, okay, 24:16.366 --> 24:19.600 align:left position:22.5%,start line:5% size:67.5% I guess mercury isn't a big deal to everyone. 24:19.700 --> 24:22.433 align:left position:22.5%,start line:5% size:67.5% And that's a really great anecdote 24:22.533 --> 24:25.300 align:left position:27.5%,start line:5% size:62.5% to keep next time I talk about this. 24:25.400 --> 24:27.166 align:left position:25%,start line:5% size:65% So, just a side note. 24:29.033 --> 24:31.166 align:left position:12.5%,start line:5% size:77.5% So one way to think about this, 24:31.266 --> 24:33.100 align:left position:25%,start line:5% size:65% and I alluded to this a little bit 24:33.200 --> 24:36.333 align:left position:20%,start line:5% size:70% when I was talking about the mercury in a CFL 24:36.433 --> 24:40.366 align:left position:15%,start line:5% size:75% versus if you burned coal for the lifetime of incandescent. 24:40.466 --> 24:43.600 align:left position:22.5%,start line:5% size:67.5% So, something called life cycle assessment. 24:43.700 --> 24:45.600 align:left position:22.5%,start line:5% size:67.5% Has anyone heard of it? 24:46.800 --> 24:48.600 align:left position:22.5%,start line:83% size:67.5% Okay, three or four people in the back. 24:48.700 --> 24:50.100 align:left position:22.5%,start line:89% size:67.5% That's a good start. 24:50.200 --> 24:52.900 align:left position:20%,start line:83% size:70% So life cycle assessment is a systematic tool 24:53.000 --> 24:55.466 align:left position:22.5%,start line:83% size:67.5% for looking at the environmental impact 24:55.566 --> 24:58.700 align:left position:22.5%,start line:83% size:67.5% of a product or process throughout its lifetime. 24:58.800 --> 24:59.900 align:left position:15%,start line:89% size:75% So you're breaking it down 25:00.000 --> 25:01.833 align:left position:22.5%,start line:83% size:67.5% into components like raw materials. 25:01.933 --> 25:04.433 align:left position:12.5%,start line:83% size:77.5% What's the environmental impact of my raw materials? 25:04.533 --> 25:07.500 align:left position:12.5%,start line:83% size:77.5% What is the environmental impact of my manufacturing? 25:07.600 --> 25:09.000 align:left position:15%,start line:89% size:75% What about the use phase? 25:09.100 --> 25:11.166 align:left position:15%,start line:83% size:75% So in this case, when I take the light bulb home, 25:11.266 --> 25:13.900 align:left position:25%,start line:83% size:65% I put it in the socket, I turn it on. 25:14.000 --> 25:15.233 align:left position:12.5%,start line:89% size:77.5% And what about end of life? 25:15.333 --> 25:17.333 align:left position:12.5%,start line:89% size:77.5% What happens when it's done? 25:17.433 --> 25:20.966 align:left position:15%,start line:83% size:75% So there's some Coca-Cola bottles on this slide, 25:21.066 --> 25:23.900 align:left position:12.5%,start line:83% size:77.5% and that's because the first documented life cycle 25:24.000 --> 25:27.300 align:left position:12.5%,start line:83% size:77.5% assessment was actually done by the Coca-Cola Company, 25:27.400 --> 25:29.300 align:left position:22.5%,start line:89% size:67.5% I believe in the 1960s. 25:30.666 --> 25:32.533 align:left position:12.5%,start line:83% size:77.5% And they were curious about the energy consumption 25:32.633 --> 25:34.333 align:left position:22.5%,start line:89% size:67.5% for their packaging, 25:34.433 --> 25:37.066 align:left position:12.5%,start line:89% size:77.5% because energy means money. 25:37.166 --> 25:40.200 align:left position:10%,start line:83% size:80% And they wanted to know what kind of packaging should I use? 25:40.300 --> 25:42.566 align:left position:15%,start line:89% size:75% What should I put my soda in? 25:42.666 --> 25:46.400 align:left position:15%,start line:83% size:75% Or I could say pop because I'm from Michigan. 25:47.766 --> 25:50.033 align:left position:20%,start line:83% size:70% And so the study results were never released, 25:50.133 --> 25:51.300 align:left position:25%,start line:83% size:65% but that's sort of what we herald 25:51.400 --> 25:54.300 align:left position:25%,start line:83% size:65% as the first life cycle assessment. 25:58.666 --> 26:00.666 align:left position:12.5%,start line:89% size:77.5% So, to put that in perspective, 26:00.766 --> 26:01.933 align:left position:22.5%,start line:89% size:67.5% we can look at one. 26:02.033 --> 26:03.866 align:left position:25%,start line:83% size:65% This is from the US Department of Energy 26:03.966 --> 26:06.400 align:left position:12.5%,start line:89% size:77.5% for an incandescent light bulb. 26:06.500 --> 26:10.900 align:left position:12.5%,start line:83% size:77.5% And I've got the electricity generation mix on the side, 26:11.000 --> 26:13.533 align:left position:22.5%,start line:83% size:67.5% because that's a valid point in this. 26:13.633 --> 26:16.333 align:left position:15%,start line:83% size:75% And, okay, so you have your materials and manufacturing, 26:16.433 --> 26:17.966 align:left position:22.5%,start line:83% size:67.5% it's a very small part of the life cycle 26:18.066 --> 26:19.566 align:left position:25%,start line:89% size:65% environmental impact. 26:19.666 --> 26:21.700 align:left position:22.5%,start line:83% size:67.5% And the really big part is the use phase. 26:21.800 --> 26:24.533 align:left position:12.5%,start line:83% size:77.5% So when you take your light bulb home and you use it. 26:24.633 --> 26:26.633 align:left position:12.5%,start line:83% size:77.5% And on the bottom we've got all of these categories. 26:26.733 --> 26:29.100 align:left position:22.5%,start line:83% size:67.5% So you see things like global warming. 26:29.200 --> 26:30.700 align:left position:22.5%,start line:89% size:67.5% And global warming, 26:30.800 --> 26:35.366 align:left position:20%,start line:83% size:70% has anyone heard of an environmental footprint? 26:35.466 --> 26:38.266 align:left position:22.5%,start line:83% size:67.5% Right, so these are different units to do. 26:38.366 --> 26:39.733 align:left position:25%,start line:89% size:65% So global warming, 26:39.833 --> 26:42.033 align:left position:15%,start line:83% size:75% you're thinking about carbon dioxide emissions. 26:42.133 --> 26:44.700 align:left position:22.5%,start line:83% size:67.5% Nitrification you're worried about nitrogen. 26:44.800 --> 26:46.700 align:left position:12.5%,start line:89% size:77.5% And we like to look at a suite, 26:46.800 --> 26:48.366 align:left position:22.5%,start line:83% size:67.5% because you might find that while something 26:48.466 --> 26:51.600 align:left position:15%,start line:83% size:75% is very good in one category, it is very bad in another. 26:51.700 --> 26:54.433 align:left position:15%,start line:83% size:75% And you need to think about the environmental trade-offs. 26:54.533 --> 26:56.100 align:left position:12.5%,start line:89% size:77.5% So, it's long been established 26:56.200 --> 26:58.366 align:left position:15%,start line:5% size:75% that the environmental impact for incandescent lighting 26:58.466 --> 27:00.366 align:left position:20%,start line:5% size:70% is during the use phase. 27:00.466 --> 27:02.700 align:left position:25%,start line:5% size:65% So the question was, what about these new, 27:02.800 --> 27:04.966 align:left position:15%,start line:5% size:75% more energy-efficient lights? 27:05.066 --> 27:06.200 align:left position:12.5%,start line:5% size:77.5% They're more energy efficient, 27:06.300 --> 27:08.300 align:left position:22.5%,start line:5% size:67.5% so they should have less use phase impact, 27:08.400 --> 27:10.900 align:left position:22.5%,start line:5% size:67.5% but they require more raw materials. 27:11.000 --> 27:13.666 align:left position:15%,start line:5% size:75% So how does this balance out? 27:13.766 --> 27:17.333 align:left position:22.5%,start line:5% size:67.5% So, we can look at a compact fluorescent, 27:17.433 --> 27:19.500 align:left position:27.5%,start line:83% size:62.5% and the use phase is still dominant. 27:19.600 --> 27:22.800 align:left position:22.5%,start line:83% size:67.5% Although, some phases like non-carcinogenics, 27:22.900 --> 27:26.200 align:left position:12.5%,start line:83% size:77.5% we start to see more in materials and manufacturing. 27:26.300 --> 27:28.300 align:left position:15%,start line:83% size:75% And the same is true when we start to think about 27:28.400 --> 27:30.600 align:left position:22.5%,start line:89% size:67.5% light emitting diodes. 27:30.700 --> 27:33.833 align:left position:22.5%,start line:83% size:67.5% And in categories like non-carcinogenics, 27:33.933 --> 27:36.466 align:left position:20%,start line:83% size:70% the bigger manufacturing and materials cost 27:36.566 --> 27:38.233 align:left position:15%,start line:89% size:75% has to do with the heat syncs 27:38.333 --> 27:41.966 align:left position:22.5%,start line:83% size:67.5% that go into making light emitting diodes. 27:42.066 --> 27:43.933 align:left position:12.5%,start line:89% size:77.5% But we're going to go back. 27:44.033 --> 27:45.766 align:left position:25%,start line:83% size:65% So we know the use phase is dominant, 27:45.866 --> 27:49.100 align:left position:15%,start line:83% size:75% and we know the ownership cost has been going down, 27:49.200 --> 27:51.700 align:left position:12.5%,start line:89% size:77.5% so it costs less to use these. 27:52.900 --> 27:57.266 align:left position:22.5%,start line:83% size:67.5% So, who's ever heard of William Stanley Jevons? 27:57.366 --> 28:00.366 align:left position:12.5%,start line:83% size:77.5% All right, I got like three or four people again. 28:00.466 --> 28:03.700 align:left position:22.5%,start line:83% size:67.5% So, he is an economist from the 1800s, 28:05.000 --> 28:06.833 align:left position:12.5%,start line:89% size:77.5% and he was looking at coal. 28:06.933 --> 28:10.700 align:left position:10%,start line:83% size:80% And he said when the efficiency of coal usage increases, 28:10.800 --> 28:13.333 align:left position:12.5%,start line:89% size:77.5% we're actually using more coal, 28:13.433 --> 28:16.166 align:left position:10%,start line:83% size:80% which was this big revolutionary idea at the time. 28:16.266 --> 28:19.333 align:left position:15%,start line:83% size:75% And some people would say it's revolutionary today. 28:19.433 --> 28:22.700 align:left position:15%,start line:83% size:75% If it's more efficient, how are we consuming more? 28:22.800 --> 28:24.466 align:left position:22.5%,start line:89% size:67.5% So who thinks we do? 28:25.600 --> 28:28.200 align:left position:22.5%,start line:5% size:67.5% Discounting the title of this talk, 28:28.300 --> 28:31.966 align:left position:22.5%,start line:5% size:67.5% of energy efficiency and the rebound effect. 28:33.700 --> 28:36.666 align:left position:25%,start line:5% size:65% So, there was a study out of MIT, 28:36.766 --> 28:39.600 align:left position:22.5%,start line:5% size:67.5% that looked at multiple industries 28:41.000 --> 28:44.866 align:left position:15%,start line:83% size:75% over multiple time periods and geographic scales. 28:44.966 --> 28:47.900 align:left position:22.5%,start line:83% size:67.5% And they said, okay, we can look at 28:49.200 --> 28:52.533 align:left position:25%,start line:83% size:65% the annual average change in efficiency. 28:54.166 --> 28:56.066 align:left position:12.5%,start line:89% size:77.5% So that's your delta E over E. 28:56.166 --> 28:58.866 align:left position:22.5%,start line:83% size:67.5% And we can look at the change in consumption. 28:58.966 --> 29:01.366 align:left position:10%,start line:89% size:80% And if the change in consumption 29:01.466 --> 29:03.533 align:left position:25%,start line:83% size:65% is more than the change in efficiency, 29:03.633 --> 29:06.833 align:left position:12.5%,start line:83% size:77.5% we're going to out-consume our benefits of efficiency. 29:06.933 --> 29:09.500 align:left position:25%,start line:83% size:65% So, if you look at the last column, 29:09.600 --> 29:12.833 align:left position:22.5%,start line:83% size:67.5% with delta Q over Q and delta E over E, 29:14.000 --> 29:16.466 align:left position:22.5%,start line:83% size:67.5% all of the numbers are bigger than one, 29:16.566 --> 29:18.933 align:left position:12.5%,start line:83% size:77.5% which means that over the time scales they looked at, 29:19.033 --> 29:21.766 align:left position:22.5%,start line:83% size:67.5% we out-consumed all the benefits of efficiency 29:21.866 --> 29:24.366 align:left position:12.5%,start line:89% size:77.5% from a consumption standpoint. 29:25.400 --> 29:27.966 align:left position:12.5%,start line:5% size:77.5% And they qualified this though. 29:28.066 --> 29:30.400 align:left position:12.5%,start line:5% size:77.5% They said in the short-term, 29:30.500 --> 29:33.166 align:left position:15%,start line:5% size:75% you might see savings because increased consumption 29:33.266 --> 29:37.600 align:left position:15%,start line:5% size:75% hasn't caught up with your increases in efficiency. 29:37.700 --> 29:38.900 align:left position:25%,start line:5% size:65% But on the long-term, 29:39.000 --> 29:41.766 align:left position:22.5%,start line:5% size:67.5% we haven't seen this in any of these industries. 29:41.866 --> 29:43.633 align:left position:25%,start line:5% size:65% And they took a large spread of things 29:43.733 --> 29:47.900 align:left position:12.5%,start line:5% size:77.5% like passenger air travel, motor vehicles, refrigeration. 29:50.000 --> 29:54.466 align:left position:12.5%,start line:5% size:77.5% So, one question would be, how do you consume more light? 29:54.566 --> 29:56.400 align:left position:22.5%,start line:5% size:67.5% Do we buy more lights? 29:57.833 --> 30:00.333 align:left position:20%,start line:83% size:70% So, suddenly the cost of lighting has gone down, 30:00.433 --> 30:02.300 align:left position:32.5%,start line:89% size:57.5% I'll buy more? 30:02.400 --> 30:04.300 align:left position:22.5%,start line:89% size:67.5% I buy brighter lights. 30:04.400 --> 30:07.166 align:left position:22.5%,start line:83% size:67.5% This goes back to when we were talking about 30:07.266 --> 30:09.333 align:left position:15%,start line:89% size:75% electric lighting in Chicago, 30:09.433 --> 30:12.033 align:left position:12.5%,start line:83% size:77.5% where they were saying what had once seemed adequate 30:12.133 --> 30:13.566 align:left position:22.5%,start line:89% size:67.5% for indoor lighting, 30:13.666 --> 30:17.400 align:left position:12.5%,start line:83% size:77.5% suddenly seemed dim and dark and hopeless and depressing. 30:17.500 --> 30:20.066 align:left position:10%,start line:83% size:80% So let's have more light because we can have more light, 30:20.166 --> 30:23.233 align:left position:10%,start line:89% size:80% and we think we need more light. 30:23.333 --> 30:26.166 align:left position:22.5%,start line:83% size:67.5% You could leave the lights on longer. 30:26.266 --> 30:29.000 align:left position:25%,start line:83% size:65% Maybe you never turn off your lights then, 30:29.100 --> 30:31.033 align:left position:15%,start line:89% size:75% because they're efficient. 30:31.133 --> 30:33.500 align:left position:20%,start line:89% size:70% It's an extreme example, 30:33.600 --> 30:34.800 align:left position:25%,start line:89% size:65% but it's possible. 30:34.900 --> 30:37.733 align:left position:22.5%,start line:83% size:67.5% And the more times I've given a talk like this, 30:37.833 --> 30:42.133 align:left position:22.5%,start line:5% size:67.5% someone will say, no, I would never ever ever 30:42.233 --> 30:45.700 align:left position:25%,start line:5% size:65% leave my lights on longer, never. 30:45.800 --> 30:47.000 align:left position:22.5%,start line:5% size:67.5% And then they'll start telling me that, 30:47.100 --> 30:48.400 align:left position:12.5%,start line:5% size:77.5% you know, I bought this LED. 30:48.500 --> 30:50.400 align:left position:25%,start line:5% size:65% I'm like, great, you bought an LED. 30:50.500 --> 30:54.300 align:left position:22.5%,start line:5% size:67.5% And I decided to put in on my garage, 30:54.400 --> 30:55.933 align:left position:10%,start line:5% size:80% and now I leave it on all night, 30:56.033 --> 30:58.566 align:left position:15%,start line:5% size:75% because it's so cheap to run. 30:58.666 --> 31:00.066 align:left position:45%,start line:5% size:45% Okay. 31:00.166 --> 31:04.800 align:left position:12.5%,start line:5% size:77.5% Well, that goes back to our safety, to what is light. 31:04.900 --> 31:06.366 align:left position:30%,start line:5% size:60% And there's some utility of light 31:06.466 --> 31:09.133 align:left position:12.5%,start line:5% size:77.5% that you can't really measure for lumens per watt. 31:09.233 --> 31:12.433 align:left position:22.5%,start line:5% size:67.5% It's what is safety, what is security? 31:16.366 --> 31:19.066 align:left position:22.5%,start line:5% size:67.5% So, there, this is results from a study 31:19.166 --> 31:23.333 align:left position:15%,start line:5% size:75% that looked at how long do people leave their lights on. 31:24.233 --> 31:26.600 align:left position:15%,start line:89% size:75% And this is a national survey 31:26.700 --> 31:30.800 align:left position:15%,start line:83% size:75% that looked at five or six major metropolitan areas. 31:30.900 --> 31:33.066 align:left position:22.5%,start line:89% size:67.5% So there's a spread. 31:33.166 --> 31:37.333 align:left position:15%,start line:83% size:75% The average is 8.9 hours per day plus or minus 5.1. 31:38.166 --> 31:39.233 align:left position:45%,start line:89% size:45% Okay. 31:40.966 --> 31:44.966 align:left position:20%,start line:83% size:70% And the most commonly occurring value was six. 31:45.066 --> 31:46.333 align:left position:25%,start line:83% size:65% However, if you look, there are people 31:46.433 --> 31:48.766 align:left position:22.5%,start line:83% size:67.5% who leave their lights on one hour per day, 31:48.866 --> 31:52.833 align:left position:12.5%,start line:83% size:77.5% and people who leave their lights on 24 hours per day. 31:52.933 --> 31:54.666 align:left position:10%,start line:89% size:80% So, looking at this, I would say 31:54.766 --> 31:57.433 align:left position:10%,start line:89% size:80% the population is heterogeneous. 31:58.266 --> 31:59.833 align:left position:32.5%,start line:89% size:57.5% And I get nods. 31:59.933 --> 32:01.833 align:left position:22.5%,start line:89% size:67.5% So, they're different. 32:03.066 --> 32:05.466 align:left position:15%,start line:5% size:75% And we can look at questions. 32:06.666 --> 32:08.833 align:left position:12.5%,start line:5% size:77.5% This is a slightly older study. 32:08.933 --> 32:12.766 align:left position:12.5%,start line:5% size:77.5% So, what's the highest price you would pay for an LED? 32:12.866 --> 32:16.866 align:left position:15%,start line:5% size:75% And at the time of the study, an LED was $33.99. 32:18.433 --> 32:22.266 align:left position:15%,start line:83% size:75% And most people said they would pay about $17. 32:24.000 --> 32:27.766 align:left position:22.5%,start line:83% size:67.5% Does anyone remember what we're at now? 32:27.866 --> 32:29.500 align:left position:22.5%,start line:89% size:67.5% Right, about $4.50. 32:29.600 --> 32:30.966 align:left position:15%,start line:89% size:75% So, in theory, based on this, 32:31.066 --> 32:33.866 align:left position:22.5%,start line:83% size:67.5% we should see people buying a lot more LEDs. 32:33.966 --> 32:36.566 align:left position:25%,start line:83% size:65% But populations are heterogeneous, 32:36.666 --> 32:39.666 align:left position:22.5%,start line:83% size:67.5% people interpret things differently. 32:39.766 --> 32:43.166 align:left position:25%,start line:77% size:65% And this was a really interesting question from the survey, 32:43.266 --> 32:46.266 align:left position:20%,start line:83% size:70% where we asked, we framed the same question 32:46.366 --> 32:48.833 align:left position:25%,start line:83% size:65% three different ways, essentially. 32:48.933 --> 32:51.833 align:left position:12.5%,start line:89% size:77.5% And we called it light bulb A, 32:51.933 --> 32:54.200 align:left position:12.5%,start line:89% size:77.5% light bulb B, and light bulb C. 32:54.300 --> 32:58.466 align:left position:15%,start line:83% size:75% So A is an incandescent, B is a CFL, and C is an LED. 32:59.566 --> 33:02.066 align:left position:12.5%,start line:89% size:77.5% So, we framed asking people, 33:02.166 --> 33:04.433 align:left position:12.5%,start line:89% size:77.5% so it costs so many dollars 33:04.533 --> 33:05.733 align:left position:12.5%,start line:89% size:77.5% and it lasts for so many hours, 33:05.833 --> 33:07.500 align:left position:22.5%,start line:89% size:67.5% what would you pick? 33:07.600 --> 33:09.733 align:left position:27.5%,start line:83% size:62.5% And then we asked the same question, 33:09.833 --> 33:11.200 align:left position:30%,start line:89% size:60% it costs so much 33:11.300 --> 33:14.666 align:left position:15%,start line:83% size:75% and it would cost you this much to run per year, 33:14.766 --> 33:16.766 align:left position:25%,start line:89% size:65% which would you pick? 33:16.866 --> 33:18.700 align:left position:12.5%,start line:89% size:77.5% And then we also said, okay, 33:18.800 --> 33:20.233 align:left position:12.5%,start line:89% size:77.5% it costs this much to purchase, 33:20.333 --> 33:21.600 align:left position:10%,start line:89% size:80% and for the same amount of money 33:21.700 --> 33:25.366 align:left position:22.5%,start line:83% size:67.5% you could drive so many miles per year, 33:25.466 --> 33:27.633 align:left position:25%,start line:89% size:65% which would you pick? 33:27.733 --> 33:30.866 align:left position:15%,start line:83% size:75% So across all three, about half the respondents 33:30.966 --> 33:33.233 align:left position:22.5%,start line:83% size:67.5% said they would pick option B, the CFL, 33:33.333 --> 33:35.766 align:left position:25%,start line:5% size:65% and they didn't know it was a CFL. 33:35.866 --> 33:37.666 align:left position:12.5%,start line:5% size:77.5% I'm sure if they Googled it, 33:37.766 --> 33:40.200 align:left position:25%,start line:5% size:65% they would have known it was the CFL. 33:40.300 --> 33:42.733 align:left position:15%,start line:5% size:75% But you see this movement between question 18, 33:42.833 --> 33:46.233 align:left position:15%,start line:5% size:75% and then when you look at question 19 and 20 of, 33:46.333 --> 33:47.466 align:left position:20%,start line:5% size:70% LED versus incandescent. 33:47.566 --> 33:49.633 align:left position:12.5%,start line:5% size:77.5% So there's some interesting issues of perception 33:49.733 --> 33:52.200 align:left position:25%,start line:5% size:65% of what is efficient, what should I buy, 33:52.300 --> 33:53.900 align:left position:15%,start line:5% size:75% how should we word things. 33:55.766 --> 33:58.200 align:left position:15%,start line:5% size:75% So, how should we model this? 34:00.566 --> 34:03.966 align:left position:25%,start line:5% size:65% Has anyone heard of an agent-based model? 34:04.066 --> 34:07.000 align:left position:22.5%,start line:5% size:67.5% Maybe a social scientist out there? 34:08.000 --> 34:10.000 align:left position:20%,start line:5% size:70% So, agent-based modeling 34:11.766 --> 34:13.566 align:left position:30%,start line:83% size:60% has roots in the social sciences. 34:13.666 --> 34:17.833 align:left position:15%,start line:83% size:75% And it's a method commonly used to model individuals. 34:19.900 --> 34:21.033 align:left position:15%,start line:89% size:75% And it's really good at that, 34:21.133 --> 34:23.800 align:left position:22.5%,start line:83% size:67.5% and it's been used to model things like fish, 34:23.900 --> 34:27.633 align:left position:22.5%,start line:83% size:67.5% geese flying in a V, sheep, and people. 34:27.733 --> 34:30.666 align:left position:22.5%,start line:83% size:67.5% But there's more, those are just a few examples. 34:30.766 --> 34:32.900 align:left position:20%,start line:83% size:70% And the idea is you have all these individuals 34:33.000 --> 34:34.400 align:left position:12.5%,start line:89% size:77.5% following some set of rules, 34:34.500 --> 34:39.200 align:left position:15%,start line:83% size:75% seeking to maximize some utility, and what do they do. 34:39.300 --> 34:40.533 align:left position:12.5%,start line:89% size:77.5% So there's this question of, 34:40.633 --> 34:42.666 align:left position:10%,start line:89% size:80% could we apply this to lighting? 34:42.766 --> 34:43.866 align:left position:25%,start line:89% size:65% What do people do 34:43.966 --> 34:46.400 align:left position:22.5%,start line:83% size:67.5% if they can pick energy efficient lighting? 34:46.500 --> 34:50.666 align:left position:10%,start line:83% size:80% So the result is this nice chart for an agent-based model, 34:51.900 --> 34:53.866 align:left position:10%,start line:89% size:80% where you've got some population 34:53.966 --> 34:57.300 align:left position:25%,start line:83% size:65% that we informed with our survey data, 34:57.400 --> 34:59.166 align:left position:10%,start line:89% size:80% and if their bulb is burned out, 34:59.266 --> 35:01.466 align:left position:25%,start line:83% size:65% they go and buy a new light bulb. 35:01.566 --> 35:03.500 align:left position:12.5%,start line:89% size:77.5% Okay, that's a good assumption. 35:03.600 --> 35:05.333 align:left position:22.5%,start line:83% size:67.5% If it burns out, I'll buy a new one. 35:05.433 --> 35:08.300 align:left position:12.5%,start line:83% size:77.5% They use some probabilistic utility to decide 35:08.400 --> 35:09.933 align:left position:25%,start line:83% size:65% which light bulb based on the fact 35:10.033 --> 35:12.533 align:left position:22.5%,start line:83% size:67.5% they're a heterogeneous population. 35:12.633 --> 35:16.900 align:left position:15%,start line:83% size:75% So, different people value things differently. 35:17.000 --> 35:19.400 align:left position:22.5%,start line:83% size:67.5% And then, if their bulb is more efficient, 35:19.500 --> 35:21.466 align:left position:15%,start line:83% size:75% they have this question of, do they consumer more light? 35:21.566 --> 35:24.166 align:left position:22.5%,start line:83% size:67.5% And I was informed with the survey data 35:24.266 --> 35:26.533 align:left position:25%,start line:83% size:65% that some people will consume more light. 35:26.633 --> 35:28.533 align:left position:15%,start line:89% size:75% And the question of how much, 35:28.633 --> 35:31.933 align:left position:12.5%,start line:83% size:77.5% is sort of this interesting tipping point we looked at. 35:32.033 --> 35:34.666 align:left position:22.5%,start line:83% size:67.5% So okay, we've got some sort of model. 35:34.766 --> 35:38.766 align:left position:15%,start line:83% size:75% What do we know about the data we put in the model? 35:38.866 --> 35:42.533 align:left position:12.5%,start line:83% size:77.5% So, one question on the survey that went to this model, 35:42.633 --> 35:43.900 align:left position:22.5%,start line:83% size:67.5% was your environmental mindfulness, 35:44.000 --> 35:45.266 align:left position:12.5%,start line:89% size:77.5% or your environmental attitude. 35:45.366 --> 35:48.000 align:left position:12.5%,start line:83% size:77.5% How environmentally friendly do you think you are? 35:48.100 --> 35:49.266 align:left position:32.5%,start line:89% size:57.5% Do you care? 35:51.200 --> 35:52.900 align:left position:22.5%,start line:89% size:67.5% And this is looking at 35:53.000 --> 35:55.466 align:left position:15%,start line:83% size:75% statistically significant correlations, 35:55.566 --> 35:58.233 align:left position:12.5%,start line:83% size:77.5% for people who thought they were extremely mindful. 35:58.333 --> 36:00.866 align:left position:22.5%,start line:83% size:67.5% And, okay, so they want to save energy. 36:00.966 --> 36:02.633 align:left position:15%,start line:83% size:75% They're concerned about environmental friendliness 36:02.733 --> 36:04.866 align:left position:25%,start line:89% size:65% of what they buy. 36:04.966 --> 36:06.233 align:left position:22.5%,start line:83% size:67.5% They apparently were not that interested 36:06.333 --> 36:08.066 align:left position:20%,start line:89% size:70% in the quality of light, 36:08.166 --> 36:10.900 align:left position:22.5%,start line:83% size:67.5% or how long their light bulbs lasted, 36:11.000 --> 36:12.366 align:left position:12.5%,start line:89% size:77.5% which I thought was interesting 36:12.466 --> 36:15.900 align:left position:12.5%,start line:83% size:77.5% because you would worry about, well I'm throwing it out. 36:16.000 --> 36:18.833 align:left position:22.5%,start line:83% size:67.5% In the survey, more than 50% of the people 36:18.933 --> 36:21.833 align:left position:25%,start line:83% size:65% threw them out and did not recycle. 36:23.866 --> 36:26.066 align:left position:22.5%,start line:83% size:67.5% Then we have our average mindfulness. 36:26.166 --> 36:27.833 align:left position:12.5%,start line:83% size:77.5% They're actually worried about the lifetime of the bulb. 36:27.933 --> 36:29.666 align:left position:20%,start line:83% size:70% So it's just interesting to think about 36:29.766 --> 36:32.766 align:left position:27.5%,start line:83% size:62.5% the heterogeneity of the population. 36:34.400 --> 36:37.800 align:left position:25%,start line:83% size:65% And, okay, so one way you can think about 36:37.900 --> 36:40.333 align:left position:12.5%,start line:89% size:77.5% making these agents in a model, 36:40.433 --> 36:41.966 align:left position:22.5%,start line:89% size:67.5% is they were trying, 36:42.066 --> 36:44.700 align:left position:25%,start line:83% size:65% how would they pick a light bulb? 36:44.800 --> 36:47.533 align:left position:25%,start line:83% size:65% So, in order to use a probabilistic utility, 36:47.633 --> 36:51.300 align:left position:12.5%,start line:83% size:77.5% the question was, what do you think is most important, 36:51.400 --> 36:52.900 align:left position:12.5%,start line:89% size:77.5% when you pick a light bulb? 36:53.000 --> 36:54.700 align:left position:22.5%,start line:83% size:67.5% Because we all go and buy a light bulb 36:54.800 --> 36:58.600 align:left position:10%,start line:83% size:80% and we think about this internally, maybe not formally. 36:58.700 --> 37:01.033 align:left position:22.5%,start line:89% size:67.5% But there's trade-offs. 37:01.133 --> 37:04.500 align:left position:15%,start line:89% size:75% And so 36% of the respondents 37:04.600 --> 37:06.433 align:left position:10%,start line:89% size:80% thought saving money as a result 37:06.533 --> 37:09.300 align:left position:22.5%,start line:83% size:67.5% of increased efficiency was most important. 37:09.400 --> 37:13.500 align:left position:15%,start line:83% size:75% Only 12% ranked environmental friendliness as the first. 37:13.600 --> 37:16.600 align:left position:22.5%,start line:83% size:67.5% So yet again we have a spread of data. 37:16.700 --> 37:19.566 align:left position:22.5%,start line:5% size:67.5% We also said, would you use more if you adopted 37:19.666 --> 37:22.666 align:left position:25%,start line:5% size:65% a more energy efficient light bulb? 37:22.766 --> 37:26.233 align:left position:15%,start line:5% size:75% Which is crude and surveys are never perfect. 37:26.333 --> 37:27.933 align:left position:22.5%,start line:5% size:67.5% Every time I talk about something like this, 37:28.033 --> 37:30.133 align:left position:22.5%,start line:5% size:67.5% people tell me surveys are never perfect. 37:30.233 --> 37:33.166 align:left position:22.5%,start line:5% size:67.5% And I say yes, they're not, I know. 37:34.500 --> 37:37.566 align:left position:22.5%,start line:5% size:67.5% So about 50% said they would use more light. 37:37.666 --> 37:40.566 align:left position:12.5%,start line:5% size:77.5% And we said, okay, well, how would we use more light? 37:40.666 --> 37:45.133 align:left position:12.5%,start line:5% size:77.5% So, of that, 33% would leave current lights on longer, 37:45.233 --> 37:46.933 align:left position:12.5%,start line:5% size:77.5% 31% would purchase more lights. 37:47.033 --> 37:48.866 align:left position:22.5%,start line:5% size:67.5% And you could do both. 37:50.233 --> 37:51.500 align:left position:22.5%,start line:5% size:67.5% So, we have this model. 37:51.600 --> 37:53.400 align:left position:22.5%,start line:5% size:67.5% We have some scenarios, 37:53.500 --> 37:56.100 align:left position:17.5%,start line:5% size:72.5% predicated on the rebound effect or Jevons' paradox. 37:56.200 --> 37:58.366 align:left position:22.5%,start line:5% size:67.5% The idea that people will consume more. 37:58.466 --> 38:01.466 align:left position:20%,start line:83% size:70% So there's scenarios with varying degrees of, 38:01.566 --> 38:05.000 align:left position:15%,start line:83% size:75% if you consume more, how much more light would you consume? 38:05.100 --> 38:06.466 align:left position:22.5%,start line:83% size:67.5% Because the question is, when are you 38:06.566 --> 38:10.833 align:left position:15%,start line:83% size:75% going to erode the savings gained by efficiency? 38:10.933 --> 38:12.900 align:left position:15%,start line:89% size:75% So it varies from no rebound, 38:13.000 --> 38:14.500 align:left position:22.5%,start line:83% size:67.5% and we have some spontaneous adoption 38:14.600 --> 38:16.233 align:left position:15%,start line:89% size:75% where people say I don't care 38:16.333 --> 38:17.733 align:left position:22.5%,start line:83% size:67.5% that my light bulb's not burned out. 38:17.833 --> 38:21.466 align:left position:15%,start line:83% size:75% This LED is so cool, I must go buy one right now, 38:21.566 --> 38:22.933 align:left position:32.5%,start line:89% size:57.5% which happens. 38:23.033 --> 38:26.600 align:left position:12.5%,start line:83% size:77.5% We're all guilty of that sometimes with some things. 38:26.700 --> 38:29.966 align:left position:20%,start line:83% size:70% To scenario eight, which is extreme rebound. 38:30.066 --> 38:32.466 align:left position:25%,start line:83% size:65% If you buy a more energy efficient bulb 38:32.566 --> 38:34.033 align:left position:22.5%,start line:83% size:67.5% and you're that 50% of the population, 38:34.133 --> 38:38.300 align:left position:15%,start line:83% size:75% you will leave your lights on 75% longer and buy 75% more. 38:41.933 --> 38:45.500 align:left position:22.5%,start line:83% size:67.5% So, the results aren't that surprising. 38:45.600 --> 38:47.733 align:left position:12.5%,start line:83% size:77.5% We have our average annual household light consumption 38:47.833 --> 38:49.900 align:left position:22.5%,start line:89% size:67.5% in mega lumen hours. 38:50.000 --> 38:52.800 align:left position:15%,start line:89% size:75% So, in the extreme scenarios, 38:52.900 --> 38:55.633 align:left position:15%,start line:83% size:75% the respondent, you consume a lot more light. 38:55.733 --> 38:57.833 align:left position:25%,start line:89% size:65% You'd expect this. 38:57.933 --> 38:59.666 align:left position:12.5%,start line:89% size:77.5% So the question was really, 38:59.766 --> 39:02.666 align:left position:22.5%,start line:83% size:67.5% what does energy consumption look like? 39:02.766 --> 39:07.533 align:left position:15%,start line:83% size:75% And in the extreme scenarios, you consume a lot more energy, 39:07.633 --> 39:11.533 align:left position:15%,start line:83% size:75% more energy than you were consuming initially. 39:11.633 --> 39:13.933 align:left position:20%,start line:89% size:70% So, what does this mean? 39:14.033 --> 39:16.266 align:left position:25%,start line:83% size:65% So, this is comparing with some data 39:16.366 --> 39:18.733 align:left position:25%,start line:83% size:65% from the US Department of Energy. 39:18.833 --> 39:20.233 align:left position:15%,start line:89% size:75% In their earlier studies, 39:20.333 --> 39:23.200 align:left position:22.5%,start line:83% size:67.5% they didn't consider the rebound effect, 39:23.300 --> 39:27.466 align:left position:15%,start line:83% size:75% but they did consider a 1.75% annual growth in lit spaces, 39:28.666 --> 39:32.366 align:left position:20%,start line:83% size:70% due to bigger houses and expansion of lit spaces. 39:32.466 --> 39:36.233 align:left position:22.5%,start line:83% size:67.5% So, this is comparing their data, the US DOE, 39:38.600 --> 39:42.033 align:left position:22.5%,start line:83% size:67.5% with the non-extreme rebound scenarios. 39:42.133 --> 39:44.600 align:left position:22.5%,start line:83% size:67.5% So, in the study we found that, okay, 39:44.700 --> 39:47.166 align:left position:15%,start line:83% size:75% we can predict that energy consumption for light 39:47.266 --> 39:48.766 align:left position:30%,start line:89% size:60% will drop a lot. 39:48.866 --> 39:51.833 align:left position:22.5%,start line:83% size:67.5% And then eventually it'll inch back up, 39:51.933 --> 39:54.233 align:left position:22.5%,start line:83% size:67.5% which is what the paper by [muffled] out of MIT, 39:54.333 --> 39:56.033 align:left position:25%,start line:83% size:65% that looked at all the sectors, said. 39:56.133 --> 39:57.666 align:left position:22.5%,start line:83% size:67.5% Unless we come up with something new, 39:57.766 --> 40:00.300 align:left position:12.5%,start line:89% size:77.5% or we come up with a policy, 40:00.400 --> 40:03.633 align:left position:25%,start line:83% size:65% we're eventually going to out-consume. 40:03.733 --> 40:07.166 align:left position:22.5%,start line:5% size:67.5% So this brings up an interesting question 40:08.100 --> 40:11.200 align:left position:12.5%,start line:5% size:77.5% called the saturation of light. 40:11.300 --> 40:14.566 align:left position:12.5%,start line:5% size:77.5% So what is the limit for light? 40:14.666 --> 40:17.066 align:left position:20%,start line:89% size:70% Is it constant daylight? 40:17.166 --> 40:20.066 align:left position:22.5%,start line:83% size:67.5% Everywhere, all the time, outside even? 40:20.166 --> 40:23.166 align:left position:22.5%,start line:83% size:67.5% Is it light of a certain brightness? 40:24.400 --> 40:26.400 align:left position:22.5%,start line:83% size:67.5% Does the saturation for light in a room 40:26.500 --> 40:29.666 align:left position:22.5%,start line:83% size:67.5% change depending on who's designing it? 40:29.766 --> 40:31.366 align:left position:25%,start line:89% size:65% So we don't know. 40:31.466 --> 40:34.966 align:left position:25%,start line:83% size:65% And there was a paper a few years ago 40:35.066 --> 40:37.366 align:left position:15%,start line:89% size:75% by Tsao et al, that said, 40:38.533 --> 40:40.300 align:left position:15%,start line:89% size:75% it was a controversial paper. 40:40.400 --> 40:42.266 align:left position:15%,start line:89% size:75% They got lots of comments. 40:43.433 --> 40:45.766 align:left position:22.5%,start line:83% size:67.5% That said using a Cobb-Douglas framework, 40:46.766 --> 40:49.466 align:left position:12.5%,start line:83% size:77.5% we don't think we've reached saturation of light 40:49.566 --> 40:50.633 align:left position:22.5%,start line:89% size:67.5% anywhere in the world. 40:50.733 --> 40:51.900 align:left position:45%,start line:89% size:45% Okay. 40:53.233 --> 40:54.733 align:left position:15%,start line:83% size:75% So, going on that, there's this question of, 40:54.833 --> 40:57.266 align:left position:12.5%,start line:89% size:77.5% what is saturation of light? 40:57.366 --> 40:58.433 align:left position:22.5%,start line:5% size:67.5% What does it look like? 40:58.533 --> 41:01.633 align:left position:25%,start line:5% size:65% But there's this question because LEDs 41:01.733 --> 41:04.433 align:left position:12.5%,start line:5% size:77.5% are an enabling technology. 41:04.533 --> 41:08.500 align:left position:15%,start line:5% size:75% So what if we start using light and lighting, 41:08.600 --> 41:10.966 align:left position:10%,start line:5% size:80% for things we never have before? 41:11.066 --> 41:14.766 align:left position:22.5%,start line:5% size:67.5% Or what if we start using bigger things 41:14.866 --> 41:16.533 align:left position:22.5%,start line:5% size:67.5% we haven't thought of? 41:16.633 --> 41:19.900 align:left position:25%,start line:5% size:65% So this is looking at television screens. 41:21.066 --> 41:26.333 align:left position:10%,start line:83% size:80% So the new flat screens commonly have LEDs or all LEDs. 41:27.500 --> 41:29.800 align:left position:12.5%,start line:89% size:77.5% TV screens are getting bigger. 41:30.966 --> 41:32.133 align:left position:40%,start line:89% size:50% In 2015, 41:33.300 --> 41:34.966 align:left position:22.5%,start line:89% size:67.5% 52% of television sales 41:35.066 --> 41:37.766 align:left position:12.5%,start line:89% size:77.5% were between 40 and 49 inches, 41:37.866 --> 41:41.033 align:left position:22.5%,start line:83% size:67.5% and 20% was greater than 49 inches. 41:41.133 --> 41:43.333 align:left position:10%,start line:89% size:80% So, it's an enabling technology, 41:43.433 --> 41:45.600 align:left position:12.5%,start line:89% size:77.5% we can make bigger televisions. 41:45.700 --> 41:48.900 align:left position:22.5%,start line:83% size:67.5% We're consuming in ways we hadn't thought. 41:49.000 --> 41:50.266 align:left position:30%,start line:89% size:60% What about this? 41:53.266 --> 41:55.600 align:left position:12.5%,start line:89% size:77.5% Does anyone recognize this? 41:57.466 --> 41:58.966 align:left position:25%,start line:89% size:65% So, County Stadium 42:00.666 --> 42:02.966 align:left position:12.5%,start line:89% size:77.5% and circa 1950s, I believe. 42:05.566 --> 42:07.566 align:left position:20%,start line:89% size:70% So this is a scoreboard. 42:09.100 --> 42:12.300 align:left position:25%,start line:83% size:65% And County Stadium no longer exists. 42:12.400 --> 42:16.500 align:left position:12.5%,start line:83% size:77.5% But does the scoreboard in Miller Park look like this? 42:16.600 --> 42:18.100 align:left position:42.5%,start line:89% size:47.5% No. 42:18.200 --> 42:20.933 align:left position:22.5%,start line:83% size:67.5% So, okay, this might have had some light, 42:21.033 --> 42:24.700 align:left position:15%,start line:83% size:75% but it's not some brightly lit television display. 42:24.800 --> 42:25.900 align:left position:32.5%,start line:89% size:57.5% And here we go. 42:26.000 --> 42:28.233 align:left position:22.5%,start line:83% size:67.5% This is a scoreboard at Miller Park. 42:28.333 --> 42:32.100 align:left position:20%,start line:83% size:70% And we've got this black and orange lighting. 42:33.066 --> 42:35.000 align:left position:25%,start line:89% size:65% And what about today? 42:35.100 --> 42:38.700 align:left position:25%,start line:83% size:65% We seem to have caught Clay Matthews. 42:38.800 --> 42:40.133 align:left position:12.5%,start line:89% size:77.5% So we're using light in ways 42:40.233 --> 42:42.366 align:left position:22.5%,start line:83% size:67.5% we wouldn't have thought to in the past. 42:42.466 --> 42:44.866 align:left position:25%,start line:5% size:65% If you would ask someone in the 1950s, 42:44.966 --> 42:47.000 align:left position:22.5%,start line:5% size:67.5% is this the scoreboard of the future, 42:47.100 --> 42:49.533 align:left position:22.5%,start line:5% size:67.5% I don't know that they would have known. 42:49.633 --> 42:51.733 align:left position:12.5%,start line:5% size:77.5% So it's hard to come up with a saturation for light 42:51.833 --> 42:55.300 align:left position:12.5%,start line:5% size:77.5% and a limit, if we have all these new ways to use it. 42:55.400 --> 42:57.900 align:left position:12.5%,start line:5% size:77.5% And another example is a book. 42:59.533 --> 43:01.800 align:left position:25%,start line:5% size:65% So, Silent Spring by Rachel Carson, 43:01.900 --> 43:06.666 align:left position:10%,start line:83% size:80% a very famous book credited with the environmental movement, 43:06.766 --> 43:09.000 align:left position:25%,start line:83% size:65% talking about the dangers of chemicals, 43:09.100 --> 43:10.466 align:left position:25%,start line:83% size:65% which isn't really a topic of this. 43:10.566 --> 43:14.633 align:left position:12.5%,start line:83% size:77.5% But, okay, is this the only way to read books today? 43:16.666 --> 43:17.800 align:left position:42.5%,start line:89% size:47.5% No. 43:18.633 --> 43:19.800 align:left position:35%,start line:89% size:55% All right. 43:19.900 --> 43:22.166 align:left position:12.5%,start line:89% size:77.5% So this is the first Kindle 43:23.733 --> 43:25.400 align:left position:22.5%,start line:89% size:67.5% in, I believe, 2007. 43:26.700 --> 43:28.433 align:left position:25%,start line:89% size:65% So only 11 years ago. 43:29.866 --> 43:34.000 align:left position:15%,start line:83% size:75% And both of these are not backlit, you need light, 43:34.100 --> 43:36.433 align:left position:22.5%,start line:83% size:67.5% but light comes from external sources, 43:36.533 --> 43:39.766 align:left position:25%,start line:83% size:65% like for illumination in the room. 43:39.866 --> 43:42.533 align:left position:12.5%,start line:83% size:77.5% But then we go to something like the Kindle Fire, 43:42.633 --> 43:43.966 align:left position:20%,start line:89% size:70% which you can buy today, 43:44.066 --> 43:48.433 align:left position:12.5%,start line:83% size:77.5% or many people probably bought on Prime Day yesterday. 43:48.533 --> 43:49.633 align:left position:15%,start line:89% size:75% And you still need light, 43:49.733 --> 43:52.133 align:left position:22.5%,start line:83% size:67.5% but you've got this backlit screen. 43:52.233 --> 43:53.533 align:left position:10%,start line:89% size:80% So we're using light in new ways 43:53.633 --> 43:56.533 align:left position:25%,start line:83% size:65% that we haven't thought of before. 43:56.633 --> 43:58.566 align:left position:32.5%,start line:89% size:57.5% And I mentioned 43:58.666 --> 44:03.000 align:left position:15%,start line:83% size:75% that LED is an enabling technology and novelties. 44:03.100 --> 44:04.666 align:left position:22.5%,start line:89% size:67.5% So we're using ways, 44:04.766 --> 44:07.366 align:left position:15%,start line:83% size:75% we're lighting things that we wouldn't have lit before also. 44:07.466 --> 44:09.666 align:left position:15%,start line:89% size:75% So we've got LED screens, 44:09.766 --> 44:13.366 align:left position:15%,start line:83% size:75% but how about some pretend candles that change color? 44:13.466 --> 44:15.166 align:left position:22.5%,start line:89% size:67.5% Or light-up glasses? 44:15.266 --> 44:16.733 align:left position:25%,start line:83% size:65% Or rope lighting, which, on the way in, 44:16.833 --> 44:19.366 align:left position:20%,start line:83% size:70% someone told me they bought for their garage. 44:19.466 --> 44:21.966 align:left position:10%,start line:89% size:80% Or what about a light-up shower? 44:22.066 --> 44:24.533 align:left position:12.5%,start line:89% size:77.5% You can buy it with an LED. 44:24.633 --> 44:25.900 align:left position:25%,start line:89% size:65% And light-up balloons 44:26.000 --> 44:30.166 align:left position:10%,start line:83% size:80% and snuggly children's nightlights that don't get hot. 44:31.533 --> 44:33.366 align:left position:15%,start line:5% size:75% So, it's hard to come up with this saturation of light 44:33.466 --> 44:35.000 align:left position:12.5%,start line:5% size:77.5% if we have all of these new 44:35.100 --> 44:37.933 align:left position:22.5%,start line:5% size:67.5% enabled technologies coming about. 44:39.333 --> 44:42.100 align:left position:15%,start line:5% size:75% So just to think about conclusions a little bit. 44:42.200 --> 44:43.966 align:left position:20%,start line:5% size:70% Historically, artificial light has been about 44:44.066 --> 44:45.033 align:left position:12.5%,start line:89% size:77.5% more than just illumination. 44:45.133 --> 44:46.200 align:left position:32.5%,start line:89% size:57.5% It's progress. 44:46.300 --> 44:47.666 align:left position:32.5%,start line:89% size:57.5% It's wealth. 44:47.766 --> 44:49.500 align:left position:25%,start line:89% size:65% It's a status symbol. 44:50.633 --> 44:53.400 align:left position:22.5%,start line:83% size:67.5% And there's a potential to save energy, 44:53.500 --> 44:57.200 align:left position:12.5%,start line:83% size:77.5% if we adopt energy efficient technology for a while. 44:57.300 --> 44:59.766 align:left position:12.5%,start line:83% size:77.5% But eventually they either need to come up with a policy, 44:59.866 --> 45:02.666 align:left position:12.5%,start line:83% size:77.5% or we need to come up with a more efficient technology, 45:02.766 --> 45:05.533 align:left position:22.5%,start line:83% size:67.5% if we're considering the rebound effect. 45:05.633 --> 45:07.333 align:left position:10%,start line:89% size:80% What is the saturation of light? 45:07.433 --> 45:09.233 align:left position:22.5%,start line:89% size:67.5% That's a good question. 45:09.333 --> 45:12.733 align:left position:25%,start line:83% size:65% It depends what we're coming up with next. 45:12.833 --> 45:15.133 align:left position:22.5%,start line:83% size:67.5% And there are many novel uses of light, 45:15.233 --> 45:18.233 align:left position:22.5%,start line:83% size:67.5% from children's toys to light-up showers, 45:18.333 --> 45:20.100 align:left position:22.5%,start line:89% size:67.5% which I don't have. 45:20.200 --> 45:24.466 align:left position:12.5%,start line:83% size:77.5% But, maybe someone does and that'd be very exciting. 45:24.566 --> 45:25.900 align:left position:12.5%,start line:89% size:77.5% So, with that, I need to thank 45:26.000 --> 45:27.366 align:left position:27.5%,start line:83% size:62.5% the University of Illinois Institute 45:27.466 --> 45:29.466 align:left position:22.5%,start line:83% size:67.5% for Environmental Science and Policy, 45:29.566 --> 45:31.733 align:left position:10%,start line:83% size:80% and the Civil and Environmental Engineering Department, 45:31.833 --> 45:35.900 align:left position:22.5%,start line:83% size:67.5% here at the University of Wisconsin, Madison. 45:36.000 --> 45:38.566 align:left position:12.5%,start line:89% size:77.5% And I enjoy this for questions. 45:39.533 --> 45:42.700 align:left position:25%,start line:5% size:65% [audience applauding]