welcome to the science for the public lecture series science for the public is an organization committed to bringing science information to the general public this is our website for our program today is a time of enormous opportunity many many different processes are coming together converging to call for changes in the way that we use energy and fortunately we have a huge opportunity for change what this slide shows is the amount of energy that we use which is about thirty nine percent and the amount of energy that we waste so we waste the vast majority of the energy that we consume and this waste isn't just people who left their lights on or fell asleep watching television that even more waste that isn't included in here most of this waste actually comes as a function of the fundamental physical laws that govern burning and heat engines so this is an absolutely wonderful graph which is made by lawrence livermore laboratories and it summarizes all the energy use in the united states so at the far left is the graph i just showed you which is the overall use to waisted fraction below it is who is wasteful and if you look at transport you can see transport is terrible transport wastes about eighty percent of the energy whereas industry is quite good they are up at around eighty percent and residences are ok and electric power isn't very good the waste that you see in transport and electric power is a fundamental feature of the basic science of burning the only way to change this is to change fundamentally the technology that we use so i could give a five hour lecture on this graph it's a great thing to meditate on quietly and in private what you have at the very far left here is the different energy sources so we have solar petroleum coal natural gas and then as you go across the graph from left  right you go from the sources to the uses and there is also a part that goes off into the waste and that's where this waste fraction comes from the upper grey area is the waste of part and the lower part is what we actually use so if you want to know in detail where your energy comes and goes i strongly recommend this graph a brief summary here of what the major areas are petroleum is about third natural gas is about a third coal is about twenty percent nuclear is a little under ten and renewables account for the rest so if you wonder where the energy goes transport takes  third electric power is already a huge fraction about forty percent commercial and residential are only ten percent and industrials about twenty percent and if you look at those connections across the graph basically petroleum goes in to try sportin transport uses petroleum that's most of what we do with oil natural gas is evenly distributed coal all goes into generating electricity basically except for those couple people who are now powering their trucks with coal but basically it's just about power renewables are spread a little bit and nuclear is basically one hundred percent power except for the navy so as with in so many things the united states are not uniform if you look at energy use per capita it's very different spread across the united states there is a factor of five difference in energy consumption between the lowest state which is rhode island and the highest state which is wyoming and so you can see where you live has a very strong effect on what energy use is so this is an example where local matters so how did we get here how did we get in this state well this is a graph of historical energy use stuff starting roughly at the founding of harvard and then moving forward and you can see that early on most of the energy came from wood and then there was a transition where people began to mine coal and them and you can see energy use is just taking off wildly so with time we just use more and more and more then we hit a peak and it actually went down and that's the world financial crisis that you're seeing there so another way to look at it is to look at each individual source so no you can't see the total but you can see what is each particular and you can see that would rises and it falls a little bit coal rises during this era coal is clearly dominant so we had an age of would we had an age of coal and then we entered a diversified era where we actually use many different sources and i think that that's going to continue well into the future there is not going to be one energy source we're going to spread over many of them can see right now as the dominant source of petroleum but that's basically going into autos now if you look at the percentage that goes into each total you can see it was all about wood that it was all about coal and i can see the spread over all of them again petroleum dominates natural gas and coal are roughly equal nuclear has been rising and it's now flat and renewables are hovering down here so far so you ask can we change well for one thing we already have wood is no longer the dominant power source whale oil is no longer important many revolutions have already happened so having another one is not unprecedented it's in fact highly predictable a second question well can we afford it is it going to cost too much so one thing to do is look at what's happened recently so this is a graph which shows the energy project d p so the green line is the energy project d p and you can see it's been falling since about nine hundred seventy so that means that the economy is growing but the amount of energy being use per dollar has been shrinking so shrinking energy use need not shrink the economy and even the energy use per capita p reached a peak around nine hundred seventy and has been slowly going down so already we're now actually changing our energy consumption she use less obvious point is passive is good there are ways in which we don't have to consume any energy and so one thing is to improve insulation so this is a picture of one of the first buildings ever built in north america it's an early mission building and you can see this very very thick wall which provides good insulation it keeps the heat outside in the cold inside and this is a new high tech window it has triple paying it has all these fancy chambers it's filled with inert gas it's basically the modern version of this wall except you can see through it so this keeps energy in a second method is illustrated in this greek village the idea is as sun comes in  naturally keeps things up and if you've ever sat on a black car seat it's really really hot it's less hot if it's white because some of the energy reflects off so if we just changed our roofs from black to white we would actually have a lot less heating and cooling are killing that we'd have to do this is a picture from israel of solar water heating on a roof so now we're doing double duty you're having the heat not get to the roof where it makes the building uncomfortable and you're taking it away to provide light for showers but it's not just high tech in the developed world this is a really nice project from the developing world it's a two liter soda bottle filled with water and it functions as a forty to watt light bulb so it's completely passive it brings the solar energy in through a tin roof and provides very nice light and this is the cutting edge of about three thousand b c it's a refrigerator that's based on the evaporation of water so it's a way of keeping food cool without using any power at all so one fabulous strategy is not to consume any energy because you don't need it and these are various passive ways of doing man another option is to change the way that we actually use energy and there are two major options there's the evolution option and the revolution option and here's an illustration of them the evolution option  illustrated on the left it's looking at the energy consumed by cars and you can see that the miles per vehicle skyrocketed we drive a lot more but the fuel consumption per vehicle has gone way down and that's because the miles per gallon which went down a little bit initially from the forty's to the sixty's has then been rising steadily so cars now aren't worse than they were in the nine hundred sixty s they have and they can play m p three music and do other fabulous things and they use way less energy so this is an example of lifestyle and handsome and being accompanied by a big reduction in energy but this was a slow gradual process there are also sudden processes this is an old style charger so when you plugged in your cellphone or your camera or anything else that charge used to plug these things in the wall this is a big heavy object that used to have copper wire in a court in squirrels inside it wasn't very efficient this is the new style charger you can plug it in anywhere in the world though it's kind on the left only works in a particular country for example the one on the right will work anywhere in the world it's small light cheap an energy efficient it's a win on every front these are the things that i'm looking for what things can we do technologically that loop use less energy and make people happier so this is one example that i think everyone can embrace so what i'm basically going to advocate is the all electric revolution so i'm going to argue that what we want to do is switch our energy in some fashion from burning fossil fuels to completely electrically based system where that electricity is generated by renewables so this is a transition in how we get our energy and a transition and how we use our energy and that's what i'm going to talk about now so why do we want to make these changes well one reason is national security countries that export fossil fuels and use that as a source of national power it creates instability in places like europe in the middle east if we were less dependent not only the united states but the world on fossil fuels that would allow us to be a more stable and secure place a second is balance of payments when we pay to import fossil fuels that money is going away from the u s often to places with regimes of which we are not entirely fond another issue is the environment acid rain for example is a well known problem it causes a lot of issues in water supplies it can damage buildings there are a number of other problems associated with it we can eliminate that by changing how we use fuel then there's climate change which is probably the one people talk about most people are very concerned with increases in c o two levels and increases in temperature increases and instability and climate of storms and hurricanes and snow and so people are very concerned on a global level on a local level about climate and what we can do in the final concern is health and i mention that because people often talk about it less but in many ways it's the largest driver in the developing world and ultimately it's the developing world that's going to determine what happens so this is a discussion of air quality and health i have a picture of beijing on the left that small you simply cannot see the pollution is awful you may remember the beijing olympics they were very concerned about having athletes breathe the air particularly in the marathon and it's not just china india is even worse new delhi is on the right and to understand what our opportunities are you can look at the different emission sources so i've made a graph of pollutants in order here so this is in order of fuel combustion which is basically power plants so sulfur dioxide which is the cause of acid rain comes from power plants they reduce they produce less of the other  pollutants if we order them over here by mobile sources so this is transport cars carbon monoxide is a huge source from there and you can see it going down if we use electric cars we get rid of the mobile sources and if we generate electricity from renewables we get rid of the fuel combustion sources so we could have enormous improvements by making this transition to electric and the u s has already made huge progress this is what we have done in thirty years the reduction in lead has been almost ninety percent acid rain is improved a lot carbon monoxide is improved a lot even evolution can make a huge difference and we have a lot of opportunities to go even further so if i can have one slide to summarize my major point burning is bad when we consume fossil fuels it creates a lot of problems one is this fundamental karnow efficiency officials say of the system depends on the temperature of the engine and the temperature you dump outside which is usually room temperature and you can't do better than that no matter how good your engineering is so you are bound to waste enormous amounts of energy roughly fifty percent cited talked about on the previous slide or a problem carbon which is what causes a lot of climate change problem heat dumping which i didn't mention you have to have some way of cooling these things and that does heating in nearby rivers and lakes which can change the eco system substantially then their issues associated with extra ction there are oil wells and issues like deepwater horizon zx there mining accidents there are problems in santa barbara right now so getting the fossil fuels out is a problem and then the additional issues in transporting them the exxon valdez was a transport accident their pipeline issues so extract in fossil fuels to burn them has enormous amounts of bad consequences so going all electric allows us to get away from that if we convert our power sources to renewables like wind and solar so what does us electricity look like now this is how we use it at present so there's a large category here which is cooking refrigeration sort of a general catchall is about a third space cooling which is air conditioners are twenty one percent that's a large category lighting is fourteen percent and likely to go down rapidly as we change to l e d s and this isn't a particularly bad one most people don't know about color television set up boxes in the d v r is attached to them use on average more energy than your refrigerator so this is a big sort of hidden problem that people aren't aware of but it's also an opportunity and it highlights the challenges people know how to reduce that power by ninety five percent but it means that if you turn on your box you have to wait thirty seconds and most people don't want to wait thirty seconds so our technological opportunity is how to save that ninety five percent power without waiting thirty seconds so here's a map of electricity price which affects how we use it and again there's an enormous variation in price in hawaii it's thirty four cents per kilowatt hour in the wheezy and it's only seven so that's almost a factor of five difference in price and if you look at the map i did before of energy use per capita down here you can see that places with high electricity prices also have less overall energy use and i think there's probably a relationship there cost affects what people do with energy so one way to change energy use is to change cost so this is a look at just electrical power what i showed you before was all the energy in the u s this is just electrical energy and again it's divided into different categories which have been shifting so you see the trend overall increase financial crash in two thousand and eight which have things go down and you can see that coal rose in the fell natural gas has been expanding because of new techniques of extracting power so this is now a graph of each individual source coal you can see is how the rise and fall you can see the increase in natural gas as more sources have become available whereas nuclear has gone murrell us flat so this is renewables only they were small enough on the other graph that it was hard to see if you look at the electric power generation you can see there was a big growth in hydro power as people built more dams and then it's been flat since nine hundred sixty five there's been no significant increase in hydro and then very recently there's been a big increase in renewables with wind it cetera so because our power uses been increasing that constant amount of hydroelectric power has been shrinking in fractions in nine hundred forty five we used to generate roughly a third of our power from hydro and now it's down to about five percent so again we've already had revolutions it's happening whether we like it or not this is our opportunity to guide it and they could do what we want so here i've blown up an even tinier slice this is the non hydro renewables and you can see the huge growth in wind here which is taken off and solar is just beginning to rise and it could take off following wind in the next couple of years so a huge factor in determining whether people want to do something is costs and the hard thing about renewables is the cost is very different if you are consuming fossil fuels if you have a gas heater for example then you buy natural gas and you pay for it as you use it in contrast if you buy a solar panel for your roof you pay for it and you have it for thirty years so you pay  upfront say ten thousand dollars and then whether you make money on it depends on how much electricity you don't for the next thirty years and the problem with that is to figure out whether it's a good economic decision you have to know what electricity is going to be for the next thirty years and if you know that you don't need to worry about saving money on your roof because you already have a much better way of seeing into the future so if you look at prices of fossil fuels here's a graph of oil prices the gray is real dollars and then the red is inflation adjusted dollars you can see there was a big peak with the oil crisis it went down again and then it w going up so it was very hard to predict that who would predict the big middle east problems that gave rise to that oil crisis similarly the coal price has been falling and then rising and natural gas is up and down and up and down so it's very hard to predict the consumer electricity prices overall have been falling so it's really hard to estimate should you put a solar panel on your roof and of course it depends on where you live in hawaii it's pretty much always a good decision in the wheezy ana it's probably not and another important thing to think about in the next thirty years is not just the cost of the fossil fuels he would replace it's also the other associated costs there's the carbon cost and i took the obama administration's estimated carbon cost to make this graph so this is a graph from the energy information agency of the price in kilowatt in cents per kilowatt hour of different sources of electric power and then i added on the carbon cost for natural gas and coal so this magenta line is the carbon cost of natural gas added in and you can see then wind and geothermal and hydro are all fully comfortable but things like offshore wind are still way above coal was more expensive to begin with and it's carbon is more expensive that it's more expensive than any of the renewables but we don't really know what carbon policy is going to be is there going to be a tax are they going to include other pollutants we have no idea so the costs are very difficult here to estimate but it's important to understand that renewables are  cost you pay once upfront which is then amortized over thirty years whereas gas and oil you just keep consuming each time and then you add up how much you using so energy from renewables could we do it i say we should have a revolution but if you can't do it there is no point so is there enough sun to make this possible because it turns out renewables basically come from the sun so a useful way to think about this is to think about energy or power per meter squared because as the sun comes down it delivers energy and so you can look at how much energy we have to use so to compare how much we need i made a calculation of how much power the u s uses so the us total energy comes two point three four watts per meter squared so that's how much energy you'd have to harvest in order to provide the entire electricity for the entire energy for the u s the electricity is only point zero four five so if you look at the renewable sources if you look at hydro can't do it and i'll give you a discussion of why that's true there just is not enough hydro energy on the other hand there's plenty of wind and plenty of solar so it is going to be possible to do that but that depends on population density this map on the upper left  is population density green and yellow are lower so canada is low the us is pretty low europe is higher and many european countries will be challenge for that and india you'll know it has a very high population density so different countries have different challenges but fortunately most countries use much less energy than the us so they can potentially meet their needs with numbers that are lower than the numbers that i gave here so first hydro power everybody loves hydro power it makes keep graphics they're nice dams they're good for kayakers basically what happens is the sun shines it evaporates the water which does work to lift the water so in the way that if you want to lift a bucket of water you have to use energy in the case of the sun the heat of the sun does the energy to lift the water the rain then falls naturally back down and that's what's captured in hydro energy the water is put behind a dam which is nice because it stores the energy you have a rain storm that's a big delivery of water but you don't have to use it right away you can store it by accumulating it behind the dam in dams they don't usually flow over the top little dams do it sort of nice to look at but it's not very efficient what big dams do is use the pressure and you know if you go into a swimming pool and you dive down your ears start to hurt as you go lower and lower that's because the water pressure is increasing so as you make your dam higher and higher you get more pressure and that bigger pressure pushes harder on a generator so the higher your dam the more power you can generate so the important point here is that the increase in height of the dam gives you more energy so if you want to generate power you want to make a big d but if you figure out how much water put falls on the united states and you put it all behind hundred meter dams it just isn't enough so hydro power is great but we cannot have anymore so that brings us to wind power wind power been growing rapidly there has been enormous investment in it it's a well developed source one of the nice features as illustrated in this picture you can use land for wind and something else this is a picture of cows in germany they're happily grazing below these pictures of the wind turbines so if we say we're using some fraction of the united states for wind turbines you can also still grow soybeans or cattle or something else the amount of land actually used is only the part at the base of the tower which is very small so when power is very compatible with agriculture which is important so how does the wind turbine work basically wind in this diagram is blowing into the page if then pushes on the wind turbine and makes it go round it's exactly the same thing as children's pinwheels so if you have a bigger pinwheel how much more energy do you get well it goes as the area that the rotor occupies because that's how many air molecules you have so as the wind blows it delivers energy the bigger the area the bigger the energy so a circle has an area that's proportional to the radius squared so if you double the size you get four times the power so this is why you want to make a big wind turbine and higher when the speed is also important the power you generate goes is the cube of the wind speed so even if you have a time where there isn't often a lot of wind you still can have a peak power coming there because the power it generates is so much bigger so this red curve is the probability distribution for the wind and it peaks at around six miles an hour but the power peaks around twelve because even though twelve miles an hour is rarer it generates so much more power that you end up winning so this is a graph of wind speed in the united states and purple is good and you can see the entire center of the united states is this beautiful big purple band if we fill it with wind turbines we are good to go problem with wind is that it seasonal that you know let's go fly a kite you want to do that usually in the spring in most places in the summer there's very little wind so if you have enough wind in the big wind season  spring you may not have enough in summer and that's the challenge of renewables not only is it windy or some days than others there are seasonal factors but fortunately in the u s there's some distribution and it's possible to spread much more than it is in europe so this is a map of wind power capacity and you can see that we're pretty smart we put the wind turbines where the wind is and that we are doing pretty well so to generate wind power the lessons are citing is crucial you want to would build in a windy location because of that cube of the wind speed if you go to a place with double the wind so if you go from five miles an hour to ten miles an hour you get eight times the power so you want to put big wind farms in windy places you want to have large rotors to capture lots of wind and you want to go in a high tower because wind speed increases with height you know if you're stretched out on the beach on a nice lazy day and it's all nice and warm and then you get up to go and get a snack and suddenly it's much colder because it's windy  that that's an example where you feel the wind speed increasing with height so the lesson is he want to build big rotors on high towers in windy locations but you don't need a lot fifteen percent of the u s land area is enough and you say fifteen percent but remember it can co exist with agriculture you want losing that land you're sharing it with something else so when power can absolutely work solar power is another option slogan people have is thirteen sixty five so what is it it's not an address it's sounds like a bar in boston actually but it's not what it is in this case is the amount of power that the sun delivers if you are in a satellite facing the sun twenty four hours a day that's the number of watts that the sun delivers per meter squared unfortunately that's not what you get on earth for a number of reasons and the first one is the theory or terms so of course when it's night solar power is zero so that thirteen sixty five that you get if you have a satellite facing the sun is not what you get on earth as it's turning so you lose roughly a factor of two due to that and then there's another factor of two due to angles so you need to divide by four if your not at the equator the sun's rays don't come in perpendicular so you actually want to tilt your solar array but we're really lucky in boston a house roof is almost the perfect angle so if you put a solar panel on your roof you're absolutely golden so this is a map of solar power in the u s red is good green is less good but still not bad there's about a factor of two variation so you do better on solar power in arizona than you do in boston or seattle but it's not a huge difference the way it is with wind power so for solar power it makes sense for it to be local so the idea for solar power is you want to support solar panels on roofs roads deserts well why not put them in all those places we were putting wind power the answer is that solar power eats all the sunlight so it's not compatible with agriculture unless you're growing mushrooms you can't co exist with solar power so solar power constraints are different on the other hand what are you using the light on your roof for anyway it's making your a a big advantage to putting those solar panels in is that you are protecting the roof from overheating on hot days and you're deriving a lot of energy similarly roads deserts are places where the sunlight isn't used for something else anyway so it's advantageous for solar power to go local to put one on your roof and it turns out one percent of the u s land area would be enough and remember these are the figures for one hundred percent of the energy used in the us and you don't actually need anything like that for one thing you would share between solar wind and other sources for another that one hundred percent includes that sixty some percent you wasted from burning you don't need to generate that wasted energy either and so that's another win that i haven't included so far which is going to be important later so if you just put solar panels on suburban roofs you can put supply about thirty percent of the u s electricity which is roughly equivalent to everything used by residences so suburban roofs could power the electricity for residences as it's use now another option is geothermal power geothermal power again is site specific it comes in two different flavors one is trying to generate power from very warm areas and there are some areas in the us that are suitable for that but a second use of geothermal power is more subtle and that's to provide a little difference in temperature and that suitable everywhere portland maine for example has an airport which uses geothermal power to provide some heating so if you are trying to generate electricity there's a lot you can do with geothermal power so that's another renewable it's one that doesn't come from the sun so it follows slightly different rules than the others so one way to think about energy use is to look at what people do a fabulous feature of that we have now is a tremendous amount of opportunity that's posted on the web many many countries post their energy information in some form denmark posts the power it generates all the time germany also has a beautiful website showing the power it generates in the us california offers these graphs every day of how the state of california generates energy and you can see it varies from season to season obviously there is more sunlight in the summer than the winter because we are at a higher latitude in germany this is an even more dramatic effect because they're even more north on average than we are and the amount of sunlight that's generated becomes really impressive there was a sunny day in germany last year where solar power in a twenty four hour period generated more electricity than all of the other energy sources can bond so solar provided more alike then coal burning oil burning nuclear combined and that's a major industrial country even more impressive in denmark last year denmark's wind power generated more than one hundred percent of all of the electricity used by the country of denmark they went over one hundred percent so renewables are just a nice there are a lot of places where it's already quite large and there are several us states including iowa where the power generated by renewables exceeds thirty percent so generating large fractions is very possible and is increasing constantly so if you look at these graphs the first graph is the total power use on the big black is burning and that's the part that i would like to get rid of the part up here is cheating that's power that california imported from somewhere else so they aren't responsible for it and then there renewables are this section down here so here's a blow up over the renewables orange is so large and so you can see that there's no solar in the dark then the sun rises it peaks around noon and you get  energy that speaks peaks during the day it was about six gigawatts on this day the blue is hydro it is spaced out through the day it's not that they can't turn the dams on and off but they're balancing the changes in the solar with hydro and wind wasn't doing very much on this particular day so the average renewable power is shown in this gra in contrast on this summer day this was june nineteenth the total power use is still pretty similar they burned a little less than imported a little bit more but the total power numbers are the same on the other hand there's much much more power generated by the renewables now so one of the big contributions is wind wind was barely visible over here and it's now a very substantial fraction and that's partly seasonal in california and it's partly the day that i happened to pick so it's very useful to look at one of these if you're trying to understand what our potential for renewable energy is and california offers them germany offers them it gives you an idea of how people trade off energy fluctuations the winds blowing more the winds blowing less the sun shining more of the sun shining less that's one of the biggest challenges in renewable but one can cleverly mix things and in germany it happens that they beautifully balanced so in the winter it's much windier so they generate a lot of renewables from the wind in the summer they have those very long sunny days and they almost beautifully cancel if you look at the total actress city over twelve months it's almost even because the increase in sunlight in the summer compensates for the lack of wind whereas in california they're somewhat correlated so i've talked a lot about sources now but sources aren't the only way that electricity can change our lives the idea is to change from the way we do things now so right now we generate electricity by burning fuel and it suffers from that karnow efficiency i mention the efficiency fundamentally different depends on the temperature difference between the burnt burning furnace and the outside and you can only make the furnace so hot air is going to start to melt the metal and be destroyed so there isn't a lot you can do the numbers roughly fifty percent on bad days it can go up to sixty new gas plants that do multiple uses of the energy can go up to sixty percent efficiency but not a lot better whereas renewables are not much more efficient the wind power limit is roughly similar but not using all the wind is ok if the wind goes through when the wind turbine doesn't take some of it it's left over for the next wind turbine it's left over for your kite's it's not a problem simile the solar energy that you don't use in your solar power you can use to heat solar water it reflects off there aren't any bad consequences whereas the energy that you use to burn all the carbon emission associated with it the pollution associated with it means that energy loss is not only costing you the money to get it out but then it does all this emission you never use so by switching from fossil fuel burning plants to renewables you have these tremendous gains even though the efficiency itself isn't necessarily better what happens to the inefficient energy is much better and cars offer an even bigger opportunity you thought sixty percent energy use was better look at cars in city driving eighty four percent of the energy you buy in gasoline is wasted simply wasted even on the highway at seventy four percent hybrid cars are better there about sixty seven percent loss but that's still two thirds of the power that's terrible electric cars are much better their losses are only about forty percent so fruits  revolution can come by making a switch to all electric cars so the numbers we had from before for gasoline cars sixteen percent in the city twenty six percent on the highway electric cars are fifty nine to sixty two percent that's a huge advantage some people like to express these things in mpg electric cars are described typically as getting one hundred to one hundred thirty miles per gallon and that sounds absolutely fabulous but then you have to figure out where that electricity came from in this nice with the media picture you can see the tesla roadster in the front and all those windmills in the back which you are actually powering it if they're not if you're plugged into a fossil fuel burning plant then you still have that energy loss at the plant so you don't actually do much better if you plug in your electric car to your fossil fuel burning plant you still have a big energy loss you still have the carbon emissions you still have the pollution so what you really want to do is go to renewable energy you have fifty percent less energy you need which means all those numbers i gave you before for windmills and solar power generating one hundred percent of the energy you can have the amount of the us that we need you don't need one percent you need point five percent for solar power for example and you get rid of all the emissions so this is a huge advantage of going all electric and again there are inefficiencies in renewables but they don't matter letting the wind go free is not a bad thing so what are other opportunities that we have this opportunity is already occurring it's a picture of an l e d light bulb incandescent light bulbs are terrible there used to be an object called the easy bake oven you used to put an incandescent light bulb in there and you could bake cakes etc turns out about ninety percent of the energy that you have in a lightbulb goes to heating if you've ever had to turn a light bulb in a hot so that's not the way to go  d s are a fundamentally different technology which can allow you to be up to ninety percent efficient so this is already happening it is not possible in the u s now to buy a one hundred watt incandescent light bulb this revolution will occur but if you're a member of that previous graph even if we eliminated all energy use for lighting that's about fourteen percent of the electricity in the united states a second wonderful thing is this object here and these are heat pumps and right now if you have a furnace and it's a good gas furnace you can get efficiencies up to ninety eight percent wow ninety eight percent iraq but it turns out that one of these heat exchangers has an efficiency of over one hundred percent and you may say she's got problems over one hundred percent you can't do that but the trick of these heat exchangers is they take energy from the outside which is cold but not really cold and they take some of that energy and they bring it in so what you're paying is the transport cost and moving heat energy outside inside and that's how it can be more than one hundred percent efficient you're taking energy that's on the outside and you're moving it in so that outside energy was free to you you just had to pay the transport cost and it works the same in the other direction it also works as an air conditioner so you have a choice of running it either way it's both the heater and an air conditioner and you can get these fabulous more than one hundred percent efficiency so this is another w trick system this picture over here is an example of a thermal lecture cooler it's another heating and cooling technology that's typically used in refrigerators or coffee mugs if you have a plug in coffee mug it will often use this technology and the point is it's very different another different technology is stirling engine cryo coolers harvard now uses them in their bio labs because they're much much more  efficient other options are be smart and that means use energy in a different way and i've given three examples of that one is fission traffic lights so it's not the traffic light itself the going to l e d s helps a little bit there it's using computers to look at what the actual traffic patterns are in a city and use the traffic lights to make the traffic move faster so by using computation power you can lower the amount of time people sit in traffic fuming both literally and figuratively so that's a very nice advantage that's only recently come from computing power this is a picture of a heating system it's one of those heat pumps i showed on the previous page but it has a smart sensor that looks at where people are in the room and so it can direct the heat just to where you're sitting so you heat only the room you are warm and toasty you will get all the pets to be with you because they're not stupid and don't want to be cold and you don't want to heat the rest of the room so this is an example of directing energy where you use it and just park is an app which you use on your smartphone that tells you where the parking spaces are so you don't have to go around in traffic so that is reaching the end of my talk what i've tried to convince you of is that we have a tremendous opportunity that technology is offering us to change the way that we use energy and this isn't the case for people being asked to sacrifice to wear a big fleece and side to sweat away in the heat these are opportunities to change our consumption in ways where we are much happier nobody wants to sit in traffic nobody wants to look for parking places we have an opportunity to do these things that make everyone better and if we just stop burning fuel we can eliminate these dillard serious the facts that are of a big concern everywhere in the developing world health is the biggest concern because people just cannot breathe and that's very obvious to everyone who lives there and there's a movie that has come out in china called under the dome which talks about the situation in china the people of china are very aware of that and china is making a huge investment in this area in the u s we tend to be more worried about climate change and its resulting instabilities and renewables offer this tremendous opportunity to lower our carbon footprint and good things are already happening for the first time ever in twenty fourteen the world economy grew but carbon emission generated from energy did not they began to decouple offering us a path to a future where we can continue to be comfortable without having a dilatory asus act on the planet so i think that we have tremendous opportunities in many many different directions there are no silver bullets there is no one solution that's going to do everything but by moving more toward renewals by switching to electric cars by switching to electricity based heating and cooling by changing to more efficient technologies by taking advantage of passive opportunities those soda bottle lights are fabulous they bring power in without using any energy at all and more and more of these possibilities are emerging all of the time we have a tremendous opportunity for a future which is more comfortable and better for us and the planet and i'm very excited to have a chance to talk to you about it thank you