University Place

Energy-Efficient Lighting and the Rebound Effect

[Liz Jesse, Media Specialist, Biotechnology Center, University of Wisconsin-Madison]

Welcome to Wednesday Nite at the Lab. I’m Liz Jesse, the media specialist for U.W. Science Outreach. On behalf of Wisconsin Alumni Association, Wisconsin Public Television, U.W.-Madison Science Alliance, U.W.-Madison Biotech Center, and U.W.-Extension and Cooperative Extension, thanks for coming out to Wednesday Nite at the Lab. We do this every Wednesday, 50 times a year.

Tonight, it is my pleasure to introduce Andrea Hicks. Andrea grew up in Dearborn, Michigan, which I just found out tonight is right outside of Detroit. I don’t know Michigan very well, apparently. She – she completed her PhD in civil engineering at the University of Illinois at Chicago and then completed a postdoc at the Institute of Environmental Science and Policy. Her research at the U.W., and maybe beyond, focuses on the environmental, economic, and social impacts of new technologies compared to conventional counterparts.

So, I kind of thought of this like, we don’t use Keurig at home because I know that conventional brewing is better. So, maybe that’s kind of what she talks about. Tonight, she’s going to be focusing, and we’re going to be talking a little bit about the history of artificial light and how it relates to sustainability of today’s emerging lighting technologies. So, here we go with the L.E.D. paradox. Please join me in welcoming Andrea Hicks.

[applause]

[Andrea Hicks, Assistant Professor, Department of Civil and Environmental Engineering, University of Wisconsin-Madison]

Thank you for that warm welcome. Can everyone hear me?

Nods? Okay.

So, first, I’d like to thank the organizers of Wednesday Night at the Lab for allowing me this platform to present some work, and to thank all of you for being here to learn about the L.E.D. paradox.

So, a little bit about what we’ll go over tonight. We’ll look in – what is artificial light? What’s the –

[slide titled – Outline – that features the following bulleted list – What is artificial light; History of Lighting in Chicago; Consumption; Technology Changes; Jevons Paradox; and Novel Consumption]

– history of lighting in Chicago? It’s a major city not so far from here. It’s a nice place to start. Our consumption of light, what technologies changes mean, Jevons paradox, and novel consumption.

[new slide titled – What is artificial light?]

So, what is artificial light? This is the point where everyone’s like, artificial light, it’s in this room. We have it.

[Andrea Hicks, on-camera]

I’ll point to it. So, to take it a more philosophical way, it renders the invisible visible.

It’s safety. It’s traffic control signals.

[return to the – What is artificial light? – slide now with two bullet points added – Renders the invisible visible, and Safety]

I’m from civil engineering, so I have to throw in some examples like that. It’s streetlights at night that encourage people to walk. It’s productivity.

[the slide animates in the bullet point – Productivity]

Without artificial light, there would be no night shift at hospitals. There would be no third shift at plants. And –

[the slide animates in the bullet point – Decoupling from the patterns of the Sun]

– it decouples us from the patterns of the Sun. We’re no longer dependent on the Sun as our sole source of light.

[the slide animates on a quote from Harold L. Platts The Electric City (1991) – The bright lights of the city quickly became both a status symbol and a physical manifestation of progress, wealth, and amenities.]

And here’s a quote from Harold Platt, who wrote The Electric City in 1991, and that centers on Chicago and its history of light. And we’ll talk a little bit about his book to give some background context. But The bright lights of the city quickly became both a status symbol and a physical manifestation of progress, wealth, and amenities.

[Andrea Hicks, on-camera]

So, light isn’t just light. It’s a symbol of progress. If you think about a cartoon, what happens when someone has an idea?

[Several audience members, off-camera]

Light bulb.

[Andrea Hicks, on-camera]

They get the light bulb. So, it’s more than just illumination.

So, this is a timeline of lighting in Chicago. In 1878, Barrett demonstrated Brush’s arc lamp.

[slide titled – Timeline of Lighting in Chicago – and featuring the point – 1878, John W. Barrett demonstrated Charles Brushes arc lamp – along with an illustration of an arc lamp lighting up a park and street from Harpers Weekly]

And within a decade –

[the slide animates on this bullet point underneath the first point – Within a decade, 6,800 arc lamps are built and operated at an annual cost of 1 million dollars]

– there are almost 7,000 arc lamps built and operated in the city of Chicago at an annual cost of a million dollars, which is a lot.

[the slide animates on the following quote under the last point – The electric suppliers faced a consumer market with not bounds to the demand for more of the lights in the lights in the citys shops, public buildings, and streets.]

“And so, the electric suppliers – this is also from Platt’s book – “faced a consumer market with no bounds. And this is a question that will permeate our talk tonight. What is saturation of light? When do we have enough light? How much light is too much light?

And – but there were some problems with this arc lamp. It was a fire hazard. It was big. You couldn’t use it in a residential setting.

[new slide with the following bullet point – 1879/1880 – Thomas Edison invents the first marketable incandescent bulb (lasting 600 hours)]

So, in 1880, or 1879 depending, Thomas Edison invented the first marketable incandescent bulb.

[the slide animates on the following quote – Chicagoans were suddenly offered unprecedented choices to meet their needs for more light, including arc lamps, incandescent bulbs, kerosene lamps, and gas options.]

And Chicagoans suddenly had this choice, what kind of light do I want? Do I want electric light? Do I want a kerosene lamp? Do I want to go by the old gas lighting standby? And so, these incandescent bulbs –

[Andrea Hicks, on-camera]

– were much safer than arc lamps and could be easily scaled to residential use.

But really, electric lighting was only for the wealthy at first. It wasn’t for the everyday person.

[return to the previous slide now with an additional quote – The first use of electricity by the well-to-do would also promote novel ideas about consumption and leisure that would help create an energy-intensive society in the 20th century.]

[new slide with the following quote – Equally important was a radical shift in psychological perceptions of interior lighting levels. What before had seemed adequate now appeared dark, gloomy, and depressing.]

But, at the same point, there was this radical shift in psychological perception of interior lighting levels. And this goes back to our question of how much light is enough light? How much light is too much light? So, what had seemed all right before was dark, gloomy, and depressing. So, already we’re craving more light, because we have more light.

[the slide animates on the new bullet point – 1893s Chicagos Worlds Fair City of Light]

Now, in nine – 1893, Chicago’s World Fair, Chicago was dubbed The City of Light. And –

[the slide animates on a new point – 1912, about half of Chicagos middle-class families has installed electricity in their homes]

– by 1912, about half of Chicago’s middle-class families had electricity in their homes and electric light.

[the slide animates in the following quote – the bright lights of the city quickly became both a status symbol and a physical manifestation of progress, wealth, and amenities.]

So, look at that quote again. It’s a status symbol. It’s progress, it’s wealth, it’s amenities. Light is more than just illumination. It means we’re moving forward.

[Andrea Hicks, on-camera]

And some photos from the World’s Fair. They’re not great, but, you know, early 1900s.

[slide featuring a photo of the 1893 Worlds Fair in Chicago with multiple buildings and fountains and attractions bright with light]

And it was amazing. We had all of this light.

So, before we start to talk about the actual consumption of light, some little background.

[new slide titled – Some Background – with the bullet Lumen and the sub-bullets – SI unit, measure of brightness, and 1 lumen = light of 1 candle 1 foot away. The slide also has an illustrated graph with Lumens on the x-axis and illustrations of three different wattages of lights (from left to right) – a 25 watt Christmas light, a 40 watt incandescent light, and a 60 watt incandescent light and showing the 25 watt light to be 23-270 lumens, the 40 watt light to be 440-460 lumens, and the 60 watt light to be 800-850 lumens]

One unit I’ll talk a lot about today is a lumen; and a lumen is an international standards unit – unit for the measurement of brightness. And another way to think about it, it’s the light of one candle one foot away. Although, I suspect most people don’t compare their light bulbs to candles at feet. Maybe people do, and that’s okay. And so, it’s a measure of light output, and it’s a nice way when we talk about different efficiencies of lighting to compare them. About 800 lumens is about a 60-watt incandescent, which translates into C.F.L.s and L.E.D.s.

[Andrea Hicks, on-camera]

So, this – we’re already using our lumen – this is teralumen hours per year of light consumed in the United Kingdom. It’s a study by Tsao et. al. in 2010 –

[slide featuring a graph of light consumed in the U.K. – on the x-axis is the year, from 1700 to 2000 and on the y-axis is teralumen hours per year – for Candles, Gas, Kerosene, Electricity, and Total Consumption. The graph shows overall increase in consumption year-over-year peaking at over 1,000 teralumen hours in 2000. Gas starts off in the early 1800s and peaks in the early 1900 before a steady decline in after the early 1900s. Kerosene starts at about the mid-18002 and peaks in the late-1800s and then steadily declines around 1900. Electricity starts in the late 1800s and grow exponentially to present day. Candle usage stays steady from early on until the early- 1900s]

– that looks at the consumption of light over time and changes in technology. So, here we are transitioning from candles to gas, to kerosene, and eventually to electricity.

And the whole time we’re consuming more light. Yes, the lines go up, consuming more light.

And it’s largely, this work by Tsao et al, was largely based on some earlier work by Fouquet and Pearson –

[new slide titled – Price of Lighting from Gas, Kerosene, and Electricity in the United Kingdom (per million lumen-hours), 1800-2000 – featuring a graph with the years 1800 to 2000 on the x-axis and the price of lighting for Gaslight, Kerosene, and Electric Light on the y-axis. The graph shows for all modes of lighting a large cost at the time that the lighting was introduced and then rapidly falling prices as new modes of lighting are introduced and overall reduction in costs over time]

– that looked at the price of lighting. So, how much per million lumen hours? We’re using those lumens again. So, what’s the cost of light, as we transition over time from gas light to kerosene light to electric light? And the point is, it’s been going down, over time in the U.K. during this study, which ends at about 2000.

I see people talking-

[Andrea Hicks, on-camera]

– this is a good sign, so.

So, okay, so we’ve been using more light and the cost of light has been going down, at least in the U.K. So, the Energy Information Administration very recently put together a chart of energy –

[slide titled – Energy consumption in the United States (1776-2015) – featuring a graph with the years 1776 to 2015 on the x-axis and Quadrillion BTUs on the y-axis for petroleum, natural gas, coal, nuclear, biomass, other renewables, and hydroelectric. The graph shows increase consumption of petroleum, natural gas, coal, and nuclear over time (with a slight decrease in coal around 2000) and steady but slow increases for all the other forms over time]

– consumption in the United States starting from 1776, which is nice. Usually you can’t find data, at least in engineering when I’m looking for something from the 1700s. And, okay, so we consume more energy. This is in quadrillion British Thermal Units. And our energy consumption broken down by what we’re consuming. And over time, we’ve transitioned from coal to more toward natural gas and petroleum products.

So, okay, the question is, how much energy do we use –

[Andrea Hicks, on-camera]

– for artificial light? Is it a lot? Is it a little? Would we even see it on this graph?

So, when I started studying this, and the first data is from maybe around 2001, we were using 8.2 quadrillion British Thermal Units of electricity for lighting in the United States. So, if you take a look, that is a little bit higher than nuclear energy consumption in 2015.

[return to the previous slide described above]

So, based on the premise of this talk, do you think it’s gone up or down? Some up? Shall we raise hands? Who thinks it’s gone up? Okay. Who thinks it’s gone down? –

[Male Audience Member, off-camera]

Are you asking input or output?

[Andrea Hicks, on-camera]

Total energy consumption.

[Male Audience Member, off-camera]

So, the – the energy input into it.

[Andrea Hicks, on-camera]

Right.

[Male Audience Member, off-camera]

Okay.

[Andrea Hicks, on-camera]

And who doesn’t know?

[laughter]

[Andrea Hicks, on-camera]

That’s okay. So, it’s actually gone down, which seems a little counterintuitive with a talk called, The L.E.D. Paradox and the Rebound Effect. But, in 2010, about 7.5 quadrillion British Thermal Units were devoted to electricity for lighting, and in 2013, 6.9 quads, which comprised about 18% of total U.S. electricity usage. So, it’s gone down. Why are we talking about energy rebound and the paradox? We’ll get there.

So, let’s think a little bit about efficiency. And, here, we’ve got a complact – compact –

[slide titled – Thinking about efficiency – featuring a photo of a compact fluorescent light bulb on the right-hand side of the slide]

– fluorescent lamp –

[the slide animates on the bullet point – 1973, Oil Crisis –

– which was invented or inspired in 1973 during the oil crisis –

[the slide animates on the second bullet point – 1974, G.E. Engineer made the first C.F.L.]

– and in 1974, maunfact – made by an engineer at General Electric.

[the slide animates on the third bullet point – 1980s -C.F.L. introduced to the public]

And in the 1980s, C.F.L.s were introduced to the public.

So, who remembers that?

Okay. Maybe half a dozen people, that’s a good start.

And, but there were some problems. They were expensive. They were about $25-$35 per light bulb, and that number is a little fuzzy, because they were often subsidized by the electrical utilities. They’re blue. They failed early, and they had inconsistent light input, output. Not well received.

So, as we talk about –

[new slide titled – Parts of a C.F.L. and featuring a diagram of all the parts of a compact fluorescent bulb from the cover to the lamp, to the Phosphor coating, Mercury vapor, and Argon (on the inside), to the ballast, ballast housing, and finally the base]

– lighting technologies, let’s talk a little bit about how they work. So, in an incandescent, which is sort of what we think of as the conventional technology, an electric current runs through the filament, heating it, and then it starts to glow and light is produced. But what about a C.F.L.? So, in a C.F.L., it has this curlicue shape, right? And an electric current goes through the argon and a small amount of mercury vapor, which is stored in the curlicue. That generates invisible ultraviolet light that excites a fluorescent coating, which is on the outside, and produces light. This is from the friendly folks at Energy Star.

[new slide titled – L.E.D. – Enabling Technology – featuring a graph with the years 1970 to 2010 on the x-axis and the Percent of L.E.D. Patent Application on the y-axis for these industries – L.C.D., Illumination, Novelty, Medicine, Manufacture, and Communication and showing the most applications in the above order with slight growth in each industry over time]

So, what about L.E.D.s?

So, L.E.D.s, or light emitting diodes, and we’ll talk about how they work in a second, are considered an enabling technology, because they enable other products and other technologies that would not be possible without them.

[Andrea Hicks, on-camera]

And this is a graph from – data mined from the U.S. patent database on the percentage of light emitting diode patents per year, applications per year, broken down by their application – the –

[return to the – L.E.D. – Enabling Technology – slide described above]

– application’s application. So, what is the goal of this? And you can see L.E.D.s for illumination are near the top. And illumination is what we primarily thought of of what we do with light. You light a candle to have light. You turn on an incandescent light bulb to have light. But with L.E.D.s, we start to have other options. We have liquid crystal displays. We have manufacturing, communication, military, medicine. There’s all, and novelties, which we’ll talk about later. There’s some exciting novelties.

And so, they have all of these properties. They don’t get really hot, they’re small.

[Andrea Hicks, on-camera]

You can enclose them, and they can get wet. And the first red L.E.D. came about in 1961. So, they’ve been around, but we’re now just starting to use them for residential lighting applications.

So, how do L.E.D.s work? And I enjoyed this. This is from –

[slide featuring an illustration of multiple diodes, some of which are red and have a positive charge and some of which are blue and have a negative charge and both of which are moving in opposite directions. The slide also states – When a current flows across a diode, negative electrons move one way and positive holes move the other way]

– howstuffworks.com. And forgive me if you’ve spent time studying quantum mechanics. This is just a very brief overview.

So, L.E.D.s are semiconductors, and current flows through the diode, and the electrons move.

[new slide with a new illustration of a negative blue electron falling to hit a red positively charged dot that in turn shines through a hole. The slide also states – The holes exist at a lower energy level than the free electrons, so when a free electron falls it loses energy]

There’s holes that exist at a lower energy and there’s free electrons, and when the electron moves –

[new slide with an illustration of the blue free electron hitting the red positive charge and emitting a yellow photon which produces light. The slide also states – This energy is emitted in the form of a light photon. The size of the electrons fall determines the energy level of the photon, which determines its color. A bigger fall produces a photon with a higher energy level and therefore a higher light frequency]

– to a lower energy level, it emits a photon, which is light.

Very brief overview.

[new slide which superimposes a cross-section of a red light emitting diode titled – Inside a Light Emitting Diode – showing the outside transparent plastic case of the diode and the diode at the end of two Terminal Pins on the inside with Emitted Light Beams bouncing from the diode to the plastic case]

And that is better, this a red L.E.D., but it doesn’t have to be a red L.E.D. You have your semiconducting material embedded in the lamp.

Okay, so we have L.E.D.s.

[Andrea Hicks, on-camera]

They work a little bit differently. Does anyone have an L.E.D.? At home?

[audience murmurs responses]

Okay. There’s a few folks. How about an L.E.D. with you right now?

Okay, so there’s people with L.E.D.s.

Are there people with smartphones right now? Okay. So, these exist, we have them. There are many in this room at this moment.

So, when we start to look at the con – at the lighting market, and this is from the U.S. Department of Energy in 2012 based –

[new slide titled – U.S. Lighting Electricity Consumption by Sector and Lamp Type in 2010 – and featuring a bar graph that has the different sectors (Residential, Commercial, Industrial, and Outdoor) and a total on the x-axis and the Annual Consumption in Terawatt hours per year on the y-axis. Additionally, each type of lamp type (Incandescent, Halogen, C.F.L., Linear Fluorescent, HID, and L.E.D.) is represented by a different color in each bar. The slide notes that the majority of Residential lighting was Incandescent, the majority of Commercial lighting is Linear Fluorescent, Industrial is 50/50 – Linear Fluorescent/HID, Outdoor lighting is mostly HID and in total most lighting is Linear Fluorescent, followed by HID, followed by Incandescent]

– on their 2010 data. This is annual electricity consumption in terawatt hours per year, broken down by sector. And the focus today will be residential. And residential, okay, so it’s primarily, in 2010, incandescents.

Do you think that’s changed?

Maybe?

[audience murmuring]

So, it has at some people’s houses for sure. And other people’s houses, we’ll talk about too. But, overall, in 2010, we used about 700 terawatt hours of electricity annually for lighting. And although residential isn’t the biggest sector, it’s interesting because you’re starting to deal with consumers and their individual behaviors.

Do you think people demand more light over time?

Maybe?

So, in 2001 –

[Andrea Hicks, on-camera]

– the average number of sockets per household was 43. Do you think that’s gone up?

[Female Audience Member, off-camera]

Yes.

[Andrea Hicks, on-camera]

Yeah. So, as of 2010, the average is 51. And that’s one way of consuming more light, that you have more light bulbs in your house.

Now, there’s been some evolutions in technology too.

[slide featuring three tables, one for each year – 2011, 2013, and 2016 – where the rows are – Light (lumens), Cost (dollars), Energy (watts), and Lifetime (hours) for each type of three lights – Incandescent, C.F.L., and L.E.D. The numbers are 2011 – Light: 830;824;800 – Cost: 1.20;1.60;33.90 – Energy: 60;13;12 – Lifetime: 1,500;8,000;25,000 – 2013 Light: 780;840;800 – Cost: .67;1.00;12.97 – Energy: 60;13;9.5 – Lifetime – 1,971;12,000;25,000 – 2016 Light: 780;900;800 – Cost – .80;1.00;4.50 – Energy – 60;13;8 – Lifetime – 1,000;10,000;25,000. The slide also shows photos of an incandescent bulb, a C.F.L. (both of which the formfactor has not changed), and four different versions of a L.E.D. bulb showing its differing formfactor over time]

And this starts at 2011 and goes through 2016. And we’ve got pictures of an incandescent and a C.F.L. and an L.E.D. And these are residential screw-in type replacements with a lumen output of about 800. So, 60-watt bulb equivalents.

So, we’re comparing apples to apples mostly. So, in 2011, an L.E.D. was $33.90, which seems like a lot for a light bulb. And if we go to 2013, okay, we’re at about $13, and today we’re at about $4.50. And incandescents have dropped a little bit. There’s some other factors at play that we’ll talk about. And C.F.L.s have dropped a little bit too. The energy consumption has gone down – has steadied for the conventional incandescent, and it’s gone down a bit for an L.E.D., going from 12 watts to about eight. There’s also a huge difference in the lifetimes of these bulbs. So, the lifetime of an incandescent is about 1,000 to 2,000 hours. And a C.F.L.? About 8,000 to 12,000. But an L.E.D. is about 25,000. So, in theory, you could have a light bulb that lasts a really long time –

[Andrea Hicks, on-camera]

– even if it costs a little more. And it should be more efficient to run because it consumes less energy. So, then everyone should buy them, right?

No? Maybe?

So, we talked a little bit about the cost, and this is a chart looking at ownership cost.

[slide featuring a graph with the years 1800 to 2011 on the x-axis and the ownership cost of 6 different types of lighting (Fire, Incandescent, Fluorescent, HID, L.E.D., and C.F.L) in dollars per Millilumens Per Hour) and showing a high cost for Fire from 1880-1850, a decreasing cost of incandescents from the late 1800s to 1980, a steady cost for both HID and Fluorescents, and a steep decline in costs for L.E.D. and C.F.L.]

So, the ownership cost is the purchase price plus the use price over the last – normalized over the lifetime. And, in this case, this is all in 2010 dollars. And it looks at the ownership cost of light from 1800 to about 2011, where we’re transitioning from fire, which are things like candles, kerosene lamps, to incandescents, fluorescents, high – high intensity discharge, L.E.D.s, and C.F.L.s. So, the ownership cost has been going down, much like we saw in that one chart looking at the United Kingdom, where they were transitioning from gas and kerosene to electricity.

[new slide titled – Energy Independence and Security Act of 2007 – featuring a photograph of a 16 pack of Ecosmart 60 watt incandescent bulbs along with the Lighting Facts Label for them (which is required by this law) showing Brightness, Yearly Energy Cost, Life, Color Temperature and Energy Used]

And there’s some other factors at play also. So, the Energy Independence and Security Act of 2007, who has heard of it?

Four people. Alright, we’re doing well.

[laughter]

Who has heard somewhere on television or the internet about someone trying to ban incandescent bulbs?

Alright, we’re talking about the same thing. So, the Energy Independence and Security Act of 2007 took effect between 2012 and 2014. And it’s not a ban, per se, on bulbs, but it requires increasing of the efficiency of incandescents. So, if you look, we’ve got this Ecosmart box, and it says it’s a better incandescent. So, it’s formerly a 60-watt incandescent, and what they mean is it produces about 800 lumens. But now it requires 43 watts, so we’ve made an efficiency gain. You also start to see things like the lighting facts per bulb, which, does this remind anybody else of food labels?

[laughter]

That’s why I’m like, calories or brightness. So, I can tell by looking at this, the brightness is about 800 lumens, so it’s a 60-watt equivalent bulb. And the energy used is about 13 watts, so it’s probably a C.F.L. Or it could be a really early L.E.D. And they rate the lifetime, and they say, Okay, I’ll use this for three hours a day, and it will last for nine years. So, it’s a way of distilling information. But here’s the question –

[Andrea Hicks, on-camera]

– when you heard about the ban on bulbs, did anyone start ordering incandescents?

[laughter]

It’s okay, two honest people. Alright.

So, this is David Brooks of Just Bulbs in Manhattan. And I got this from the New York Times –

[new slide featuring a photograph of David Brooks, owner of Just Bulbs in Manhattan standing beside a shelf in his store that is filled with light bulbs]

– where he’s commenting that he has one customer who’s ordering thousands and thousands of incandescents, because she never wants to be without them, and to please not tell her husband.

[laughter]

So, he’ll be surprised one day when he finds their storage unit of incandescent bulbs.

[laughter]

But – so, we have interesting behaviors that come about too that –

[Andrea Hicks, on-camera]

– I do not want a more energy efficient bulb, I’m going to use this incandescent forever. Okay. That’s part of evolutions of technology.

So, whenever I talk about C.F.L.s, the question of mercury comes up. Who –

[slide titled – What about the Mercury? – featuring a photo of a Compact Fluorescent Lightbulb]

– here knows that a C.F.L. has mercury?

Alright.

[Andrea Hicks, on-camera]

How much mercury do you think?

So, I see some people saying a little bit. So, it’s about, currently they have about five milligrams of mercury per bulb. And, okay, is that a lot? Is that a little? Should we care? So, there was one study that came out several years ago, where they said, Okay, so there’s five milligrams of mercury in the C.F.L., but it’s more efficient than an incandescent. So, what if I look at the life cycle and I burn coal to make my incandescent, power my incandescent throughout the lifetime? Is that – how does the mercury balance work out? And if you move to the C.F.L. even though it has mercury in it, you’re saving mercury through the gains in efficiency. So, you’re coming out ahead. Now, I’ve given talks similar to this enough times –

[slide still under the banner – What about the Mercury? – now featuring a photo of a bottle of red Mercurochrome]

– that there are some good anecdotes that come up.

Who here has heard of Mercurochrome?

[laughter]

Alright. So, I was giving this talk once and I always, almost always, got attacked by someone for the mercury content in C.F.L.s and they’re terrible and they’re going to kill us all and Minamata Bay. I was like, Okay. So, that’s what I was expecting. And he comes up and he starts telling me that he doesn’t think the mercury is a big deal. Okay. Good, someone’s finally not attacking me over this. And so –

[Andrea Hicks, on-camera]

– then he tells me about something called Mercurochrome, which, help me if I’m wrong, is something at one point we used to dab on cuts to sort of clean them and heal them? I was like, Oh, okay. So, then he proceeds to tell me that similar to our friend in New York hoarding the light bulbs, that he’s hoarded Mercurochrome.

[laughter]

And he has boxes and boxes full of this, that he still uses it today, mercury is not a big deal, and then he pulls out a bottle. So, okay, I – I guess mercury isn’t a big deal to everyone. And that’s a really great anecdote to keep next time I talk about this. So, just a side note.

So, one way to think about this, and I alluded to this a little bit when I was talking about the mercury in a C.F.L. versus if you burned coal for the lifetime of incandescent. So, something called life cycle assessment.

[slide titled – LCA – featuring a photo of 9 Coca-Cola bottles ranging from 1899 to 2007 and showing the stages of a life cycle assessment from Raw Materials to Manufacture to Use to End of Life]

Has anyone heard of it?

Okay, three or four people in the back. That’s a good start.

So, life cycle assessment is a systematic tool for looking at the environmental impact of a product or process throughout its lifetime. So, you’re breaking it down into components like raw materials. What’s the environmental impact of my raw materials? What is the environmental impact of my manufacturing? What about the use phase? So, in this case, when I take the light bulb home, I put it in the socket, I turn it on. And what about end of life? What happens when it’s done?

So, there’s some Coca-Cola bottles on this slide, and that’s because the first documented life cycle assessment was actually done by the Coca-Cola Company, I believe in the 1960s. And they were curious about the energy consumption for their packaging, because energy means money. And they wanted to know what kind of packaging should I use? What should I put my soda in? Or I could say pop because I’m from Michigan.

[laughter]

And so, the study results were never released, but that’s sort of what we herald as the first life cycle assessment.

[new slide titled – Incandescent – featuring a bar graph with nine categories on the x-axis (Ozone Depletion, Global Warming, Smog, Acidification, Eutrophication, Carcinogenics, Non-carcinogenics, Respiratory Effects, and Ecotoxicity) and percentage from 0 to 100 on the y-axis. Each bar all has the different phases (materials and manufacturing, use, and disposal) as part of the bar. And in all categories, the major effects of incandescent bulbs occur in the use phase. Also, in the bottom right of the slide are percentages of electricity generation mix – 45% coal, less than a percent petroleum, 24% natural gas, 20% nuclear, 6% hydroelectric, and 4% renewable]

So, to put that in perspective, we can look at one. This is from the U.S. Department of Energy for an incandescent light bulb. And I’ve got the electricity generation mix on the side, because that’s a valid point in this. And, okay, so you have your materials and manufacturing, it’s a very small part of the life cycle environmental impact. And the really big part is the use phase. So, when you take your light bulb home, and you use it. And on the bottom, we’ve got all of these categories. So, you see things like global warming. And global warming, has anyone heard of an environmental footprint?

Right, so these are different units to do. So global warming, you’re thinking about carbon dioxide emissions. Nitrification you’re worried about nitrogen. And we like to look at a suite, because you might find that while something is very good in one category, it is very bad in another. And you need to think about the environmental trade-offs.

So, it’s long been established that –

[Andrea Hicks, on-camera]

– the environmental impact for incandescent lighting is during the use phase. So, the question was, What about these new, more energy-efficient lights? They’re more energy efficient, so they should have less use phase impact, but they require more raw materials. So, how does this balance out?

So, we can look at a compact fluorescent –

[slide titled – C.F.L. – which is identical to the previously described slide with a new bar graph for all the same categories (from Ozone Depletion to Ecotoxicity) and each bar containing data from materials and manufacturing to disposal. The major difference between Incandescent bulbs and C.F.L. bulbs is that the material and manufacturing phase has more of an impact, but it is still the use phase has a majority of an impact]

– and the use phase is still dominant. Although, some phases like non-carcinogenics, we start to see more in materials and manufacturing. And –

[new slide titled – L.E.D. – which has a bar graph that is identical to the previous slide for C.F.L.s including more impacts during the material and manufacturing phase, but still the majority of impacts are still in the use phase]

– the same is true when we start to think about light emitting diodes. And in categories like non-carcinogenics, the bigger manufacturing and materials cost has to do with the heat syncs that go into making light emitting diodes. But –

[return to a previous slide that had the years from 1800 to 2011 on the x-axis and ownership costs on the y-axis for the different types of lighting – Fire, Incandescent, Fluorescent, HID, L.E.D., and C.F.L. – on the y-axis and described in more detail above]

– we’re going to go back. So, we know the use phase is dominant, and we know the ownership cost has been going down, so it costs less to use these.

[new slide titled – Jevons Paradox – featuring a photo of William Stanley Jevons on the right of the slide and the following information on the left-hand side of the slide – William Stanley Jevons, 1865 English Economist. Noticed that when the efficiency of coal usage increased, the more coal was actually used. Efficiency lowers cost, and consumption increases, because increases in efficiency that lower price look a lot like discounts to consumers]

So, who’s ever heard of William Stanley Jevons? Alright, I got like three or four people again. So, he is an economist from the 1800s, and he was looking at coal. And he said, When the efficiency of coal usage increases, we’re actually using more coal, which was this big revolutionary idea at the time. And some people would say it’s revolutionary today. If it’s more efficient, how are we consuming more? So, who thinks we do?

[Andrea Hicks, on-camera]

Discounting the title of this talk, of energy efficiency and the rebound effect and

So, there was a study out of M.I.T., that looked at multiple industries –

[slide featuring a table from the M.I.T. study with various activities in the rows from Pig Iron to freight rail travel to residential refrigeration, and the columns ranging from time period to region to units of quantity and efficiency, along with the results]

– over multiple time periods and geographic scales. And they said, Okay, we can look at the annual average change in efficiency. So that’s your delta E over E. And we can look at the change in consumption. And if the change in consumption is more than the change in efficiency, we’re going to out-consume our benefits of efficiency. So, if you look at the last column, with delta Q over Q and delta E over E, all of the numbers are bigger than one, which means that over the time scales they looked at, we out-consumed all the benefits of efficiency from an energy – from a consumption standpoint. And they qualified this though.

[Andrea Hicks, on-camera]

They said in the short-term, you might see savings because increased consumption hasn’t caught up with your increases in efficiency. But on the long-term, we haven’t seen this in any of these industries. And they took a large spread of things like passenger air travel, motor vehicles, refrigeration. So, one question would be, How do you consume more light? Do we buy more lights? So –

[slide titled – Consuming more light? – with the bullet point – Buying more lights]

– suddenly the cost of lighting has gone down, I’ll buy more?

[the slide animates on the next bullet point – Buying brighter lights]

I buy brighter lights. This goes back to when we were talking about electric lighting in Chicago, where they were saying what had once seemed adequate for indoor lighting, suddenly seemed dim and dark and hopeless and depressing. So, let’s have more light because we can have more light, and we think we need more light.

[the slide animates on the next bullet point – Leaving lights on longer]

You could leave the lights on longer. Maybe you never turn off your lights then, because they’re efficient. It’s an extreme example, but it’s possible. And the more times I’ve given a talk like this, someone will say, No, I would never ever, ever –

– leave my lights on longer, never. And then they’ll start telling me that, You know, I bought this L.E.D. I’m like, Great, you bought an L.E.D. And I decided to put in on my garage, and now I leave it on all night, because it’s so cheap to run. Okay. Well, that goes back to our safety, to What is light? And there’s some utility of light that you can’t really measure for lumens per watt. It’s What is safety, what is security?

So, there, this is results from a study that looked at –

[slide titled – Average hours of residential lighting used excluding nightlights – featuring a graph with Hours of Light Used Per Day from 1 to 24 on the x-axis and Percentage of Survey Respondents from 0 to 18 on the y-axis and showing the majority of people use lighting from 3 to 8 hours per day with the peak at 6 hours per day]

– how long do people leave their lights on. And this is a national survey that looked at five or six major metropolitan areas. So, there’s a spread. The average is 8.9 hours per day plus or minus 5.1. Okay.

[laughter]

And the most commonly occurring value was six. However, if you look, there are people who leave their lights on one hour per day, and people who leave their lights on 24 hours per day. So, looking at this, I would say the population is heterogeneous. And I get nods. So, they’re different.

[Andrea Hicks, on-camera]

And we can look at questions. This is a slightly older study. So, what’s the highest price you would pay for an L.E.D.? And at the time of the study, an L.E.D. was $33.99.

[slide titled – Highest purchase price for L.E.D. lamp adoption as indicated by respondents – and featuring a bar graph with various price points on the x-axis (from $33.99 to $2.12) and the Percentage of Survey Respondents on the y-axis and the results being the majority of respondents would pay $17.00 for an L.E.D. bulb]

And most people said they would pay about $17. Does anyone remember what we’re at now?

[Female Audience Member, off-camera]

$4.50

[Andrea Hicks, off-camera]

Right, about $4.50. So, in theory, based on this, we should see people buying a lot more L.E.D.s. But populations are heterogeneous, people interpret things differently.

[new slide titled – Responses to 3 scenarios comparing incandescent, C.F.L., and L.E.D. technologies – each purporting three different bulbs at three different price points and use lifetimes to see if these categories effected the choices of consumers in buying each type of lamp]

And this was a really interesting question from the survey, where we asked, we framed the same question three different ways, essentially. And we called it light bulb A, light bulb B, and light bulb C. So, A is an incandescent, B is a C.F.L., and C is an L.E.D. So, we framed asking people, So it costs so many dollars, and it lasts for so many hours, what would you pick? And then we asked the same question, It costs so much, and it would cost you this much to run per year, which would you pick? And then we also said, Okay, it costs this much to purchase, and for the same amount of money you could drive so many miles per year, which would you pick? So, across all three, about half the respondents said they would pick option B, the C.F.L., and they –

[Andrea Hicks, on-camera]

– didn’t know it was a C.F.L. I’m sure if they Googled it, they would have known it was the C.F.L. But you see this movement between question 18, and then when you look at question 19 and 20 of, L.E.D. versus incandescent. So, there’s some interesting issues of perception of What is efficient? What should I buy? How should we word things? So, how should we model this?

Has anyone heard of an agent-based model? Maybe a social scientist out there?

So, agent-based modeling is –

[slide titled – ABM – featuring three photos, one of a school of fish, one of geese flying in a V formation, one of a herd of sheep, and one illustration off a crowd of people dancing in silhouette]

– has roots in the social sciences. And it’s a method commonly used to model individuals. And it’s really good at that, and it’s been used to model things like fish, geese flying in a V, sheep, and people. But there’s more, those are just a few examples. And the idea is you have all these individuals following some set of rules, seeking to maximize some utility, and what do they do? So, there’s this question of, could we apply this to lighting? What do people do if they can pick energy efficient lighting?

[new slide featuring a decision chart with various activities and differing results depending on if the answer is yes or no as to whether people will uses more or less lighting based on factors such as efficiency, technology, and replacement of burned out bulbs]

So, the result is this nice chart for an agent-based model, where you’ve got some population that we informed with our survey data, and if their bulb is burned out, they go and buy a new light bulb. Okay, that’s a good assumption. If it burns out, I’ll buy a new one. They use some probabilistic utility to decide which light bulb based on the fact they’re a heterogeneous population. So, different people value things differently. And then, if their bulb is more efficient, they have this question of, do they consume more light? And I was informed with the survey data that some people will consume more light. And the question of how much, is sort of this interesting tipping point we looked at.

So, okay, we’ve got some sort of model.

[Andrea Hicks, on-camera]

What do we know about the data we put in the model? So, one question on the survey that went to this model, was your environmental –

[slide titled – Correlations with Attitude – featuring a table from her study in which the columns range from Extremely Mindful to Not Very Mindful and the rows are – Respondent Age, Daily Energy Consumption, C.F.L. Mercury Content, Save Energy, Environmental Friendliness, Quality of Light, and Lifetime of Bulb]

– mindfulness, or your environmental attitude. How environmentally friendly do you think you are? Do you care?

[the slide highlights the Extremely Mindful column by drawing a red rectangle around those responses]

And this is looking at statistically significant correlations, for people who thought they were extremely mindful. And, okay, so they want to save energy. They’re concerned about environmental friendliness of what they buy. They apparently were not that interested in the quality of light, or how long their light bulbs lasted, which I thought was interesting because you would worry about, well I’m throwing it out – Im. In the survey, more than 50% of the people threw them out and did not recycle, so.

[the slide highlights the results of the Average Mindful respondents by placing a blue rectangle around their responses]

Then we have our average mindfulness. They’re actually worried about the lifetime of the bulb. So, it’s just interesting to think about the heterogeneity of the population.

[new slide featuring a new table with the rows being rank 1-7 and the columns being decision factors (saving money as a result of increased efficiency, saving energy as a result of increased efficiency, environmental friendliness of product, influence of others, initial purchase cost, quality of light, and lifetime of bulb. The slide also notes that 50% would use more by leaving current lights on longer (33%) or purchasing more lights (31%)]

And, okay, so one way you can think about making these agents in a model, is they were trying –

[the slide highlights the number 1 rank by drawing a red rectangle around that row]

– how would they pick a light bulb? So, in order to use a probabilistic utility, the question was, What do you think is most important, when you pick a light bulb? Because we all go and buy a light bulb and we think about this internally, maybe not formally. But there’s trade-offs. And so, 36% of the respondents thought saving money as a result of increased efficiency was most important. Only 12% ranked environmental friendliness as the first. So, yet again we have a spread of data. We also said –

[Andrea Hicks, on-camera]

– Would you use more if you adopted a more energy efficient light bulb? Which its – its crude and surveys are never perfect. Every time I talk about something like this, people tell me surveys are never perfect. And I say, Yes, they’re not, I know. So, about 50% said they would use more light. And we said, Okay, well, howll we use more light? So, of that, 33% would leave current lights on longer, 31% would purchase more lights. And you could do both.

So, we have this model. We have some scenarios, predicated on the rebound effect or Jevons’ paradox. The idea –

[slide featuring a table with Scenario and Scenario Description as the columns and with the rows being 1 – no rebound (no rebound and 5% spontaneous adoption), 2 – rebound (time [25%] and bulb [25%] rebound, 5% spontaneous adoption), 3 – rebound subsidy (same as #2 with 50% L.E.D. purchase subsidy), 4- rebound C.F.L. Disposal tax (same as #2, $3 C.F.L. disposal tax), 5- rebound early failure (same as #2, 5% of L.E.D.s fail early), 6 – more rebound (time [50%] and bulb [50%} rebound, 5% spontaneous adoption), 7 – backfire (time [60%] and bulb [60%] rebound, 5% spontaneous adoption), and 8 – extreme backfire (time [75%] and bulb [75%] rebound, 5% spontaneous adoption)]

– that people will consume more. So, there’s scenarios with varying degrees of, If you consume more, how much more light would you consume? Cause the question is, When are you going to erode the savings gained by efficiency? So, it varies from no rebound, and we have some spontaneous adoption where people say, I don’t care that my light bulb’s not burned out. This L.E.D. is so cool, I must go buy one right now, which happens. We’re all guilty of that sometimes with some thing. To scenario eight, which is extreme rebound. If you buy a more energy efficient bulb and you’re that 50% of the population, you will leave your lights on 75% longer and buy 75% more.

[new slide titled – Light – featuring a graph with the years 2013 to 2075 on the x-axis and Average Household Light Consumption on the y-axis and graphing the eight different scenarios and showing that under scenarios 1 and 2 (no rebound and rebound) the amount of lighting will increase substantially over time]

So, the results aren’t that surprising. We have our average annual household light consumption in megalumen hours. So, in the extreme scenarios, the respondent, you consume a lot more light. You’d expect this. So, the question was really –

[new slide titled – Energy – with the same years as the above slide on the x-axis but now substituting Average Household Energy Usage for Lighting on the y-axis and showing increased energy costs over time in scenarios 1 and 2 again]

– What does energy consumption look like? And in the extreme scenarios, you consume a lot more energy, more energy than you were consuming initially.

So, what does this mean?

[new slide titled – Household energy consumption for light comparison between the U.S. Department of Energy and her study – featuring a line graph with the years 2013 to 2075 on the x-axis and average household energy consumption of light on the y-axis and showing an inverted bell curve for the survey results as opposed to the small decrease as shown by the Department of Energy data]

So, this is comparing with some data from the U.S. Department of Energy. In their earlier studies, they didn’t consider the rebound effect, but they did consider a 1.75% annual growth in lit spaces, due to bigger houses and expansion of lit spaces. So, this is comparing their data, the Navigant U.S. D.O.E., with the non-extreme rebound scenarios. So, in the study we found that, okay, we can predict that energy consumption for light will drop a lot. And then eventually it’ll inch back up, which is what the paper by Dahmus out of M.I.T., that looked at all the sectors, said. Unless we come up with something new, or we come up with a policy, we’re eventually going to out-consume.

[Andrea Hicks, on-camera]

So, this brings up an interesting question called the saturation of light. So, what is the limit for light?

[slide titled – Saturation of Light? – featuring a satellite photo of the United States at night with the lights from all the cities visible]

Is it constant daylight? Everywhere, all the time, outside even? Is it light of a certain brightness? Does the saturation for light in a room change depending on who’s designing it? So, we don’t know. And there was a paper a few years ago by Tsao et al, that said, it was a controversial paper. They got lots of comments. That said using some – a Cobb-Douglas framework, we don’t think we’ve reached saturation of light anywhere in the world.

Okay. So, going on that, there’s this question of, What is saturation of light?

[Andrea Hicks, on-camera]

What does it look like? But there’s this question because L.E.D.s are an enabling technology. So, what if we start using light and lighting, for things we never have before? Or what if we start using bigger things we haven’t thought of? So, this is looking at television screens.

[slide titled – TV Screens Are Getting Bigger and Bigger – featuring a bar graph titled – percentage of global television unit sales accounted for by 40 inch plus TVs – and having the years 2009 to 2019 on the x-axis and percentage of screens 40 to 49 inches and percentage of screens greater than 49 inches on the y-axis. The graph shows and increasing percentage of television screens larger than 49 inches over time]

So, the new flat screens commonly have L.E.D.s or all L.E.D.s. TV screens are getting bigger. In 2015, 52% of television sales were between 40 and 49 inches, and 20% was greater than 49 inches. So, it’s an enabling technology, we can make bigger televisions. We’re consuming in ways we hadn’t thought.

What –

[new slide featuring a photo of the old scoreboard at County Stadium in Milwaukee in the 1950s]

– about this? Does anyone recognize this?

So, County Stadium and circa 1950s, I believe. So, this is a scoreboard. And County Stadium no longer exists. But does the scoreboard in Miller Park look like this? No. So, okay, this might have had some light, but it’s not some brightly lit television display.

[the slide animates on the first scoreboard at Miller Park over the top of the photo of the old scoreboard]

And here we go. This is a scoreboard at Miller Park. And we’ve got these black – this black and orange lighting.

[the slide animates on the newest scoreboard at Miller Park with a video capture of Clay Matthews above the score]

And what about today? We seem to have caught Clay Matthews. So, we’re using light in ways we wouldn’t have thought to in the past. If you would ask –

[Andrea Hicks, on-camera]

– someone in the 1950s, Is this the scoreboard of the future? I don’t know that they would have known. So, it’s hard to come up with a saturation for light and a limit if we have all these new ways to use it.

And another example is a book. So –

[new slide featuring a photo of the book cover and spine of Silent Spring by Rachael Carson]

– Silent Spring by Rachel Carson, a very famous book credited with the environmental movement, talking about the dangers of chemicals, which isn’t really a topic of this. But, okay, is this the only way to read books today?

No. Alright.

[the slide animates on a photo of the first amazon Kindle]

So, this is the first Kindle in, I believe, 2007. So, only 11 years ago. And both of these are not backlit, you need light, but light comes from external sources, light for illumination in the room. But then we go –

[the slide animates on a photo of the newest Kindle Fire HD]

– to something like the Kindle Fire, which you can buy today, or many people probably bought on Prime Day yesterday. And you still need light, but you’ve got this backlit screen. So, we’re using light in new ways that we haven’t thought of before. And I mentioned –

[new slide featuring ten photos of new devices that are now using L.E.D. lighting – a wall panel, remote controlled L.E.D. candles, glasses, rope lighting, showerheads, balloons, two types of L.E.D. dresses, a music player, and outdoor lighting]

– that L.E.D. is an enabling technology and novelties. So, we’re using ways, we’re lighting things that we wouldn’t have lit before also. So, we’ve got L.E.D. screens, but how about some pretend candles that change color? Or light-up glasses? Or rope lighting, which, on the way in, someone told me they bought for their garage. Or what about a light-up shower? You can buy it with an L.E.D. And light-up balloons and snuggly children’s nightlights that don’t get hot. So, it’s hard to come up with this saturation of light –

[Andrea Hicks, on-camera]

– if we have all of these new enabled technologies coming about.

So, just to think about conclusions a little bit. Historically –

[slide titled – Conclusions – with the following point – Historically artificial light has been about more than just illumination]

– artificial light has been about more than just illumination. It’s progress. It’s wealth. It’s a status symbol.

[the slide animates on the next point – The potential exists to save energy due to the consumption of energy efficient lighting technologies]

And there’s a potential to save energy, if we adopt energy efficient technology for a while. But eventually they either need to come up with a policy, or we need to come up with a more efficient technology, if we’re considering the rebound effect.

[the slide animates on the next point – What is the saturation of light?]

What is the saturation of light? That’s a good question. It depends what we’re coming up with next.

[the slide animates on the next point – novel uses of light]

And there are many novel uses of light, from children’s toys to light-up showers, which I don’t have.

[laughter]

But maybe someone does and that’d be very exciting.

[new slide featuring the logos for the University of Wisconsin-Madison and the University of Illinois Institute for Environmental Science and Policy]

So, with that, I need to thank the University of Illinois Institute for Environmental Science and Policy, and the Civil and Environmental Engineering Department, here at the University of Wisconsin-Management – Madison.

[Andrea Hicks, on-camera]

And I enjoy this for questions.

[applause]