we are so pleased to have mara printers here to discuss a renewable energy i also want to think of on staff who is right over there from science for the public she the belmont media center and the library are all starting something we're trying to start something called citizen literacy this particular event is science literacy  so i would love to welcome yvonne up here to introduce myra good evening and mary thank you very much for introducing the project and thank you for the library hosting this joint project with belmont media the library and science for the public on civic literacy tonight we are specially delighted to present mera apprentice and professor of physics at harvard university and author of energy revolution the physics and promise of efficient energy and i am told that all of the library copies are out thank you dr premise is a fellow of the american physical society and she has collaborated with at least four nobel prize laureates and we are lucky to get her before she gets a  nobel prize so we thank her for that her research is largely concerned with the application of physics to understanding complex processes say in biology and in her book though for the general public energy revolution she brings her physics expertise to a major issue of our time and presents a very clear argument for energy  much today i come to bring you a message of hope that there is a lot of gloom and doom going around but i think it's not true and so i want to talk to you about things that are already going extremely well and opportunities that we have to make them go even better so i'm going to take a broad approach here what i'm going to talk about is changing where we get our energy how we use our energy and general aspects of our lifestyle where we can make a lot of changes without sacrificing our comfort that famously dick cheney discuss not being a big fan of energy conservation but i'm going to discuss cases where even he would be a fan and so the idea is not the sacrifice it's not to wear a cardigan sweater in the winter it's to figure out how to live better and live well the von mentioned we waste an incredible amount of the energy we consume and this wasted energy does not represent when my daughter forgets and leaves the lights on when she goes or leaves the television on  that's not it this is a fundamental loss most of it due to burning there is a theorem called karnos theorem that says the amount of energy you can get out is limited by the temperature difference between the hot region and the cold region and you just can't do better than that no matter what you do and so when you burn you just have to waste a lot of energy for very fundamental scientific reasons this isn't because people are stupid or bad engineers so if you can get rid of this the amount of energy you need is actually much smaller and if my daughter can remember not to leave her lights on we can do even better than that so there's a huge opportunity here and i'd like to give you some examples of how we can take advantage of this so what's our current fuel situation this is the our division of energy the bad news is eighty three percent of it is fossil fuel burning so it divides the biggest source of energy we have is petroleum and that's almost all cars so this is basically transportation natural gas is used for a variety of things for heating and electricity coal is almost all electricity and it's plummeting the for a very long time and it's going to continue to plummet whatever anyone does because it economically can't compete with natural gas so that's really good news because coal emits the most c o two it emits the most other particulates it's the dirtiest fuel and coal is disappearing because it's not economically viable not because of anything in policy that people are doing and then the remainder is divided to non burst burning sources nuclear hydro wind cetera so how did we get to this place well this is a history of energy use in the united states so at the beginning of time which is to say the founding of harvard virtually everything that we consumed in energy was wood burning so we burned wood we burned wood and then people discovered you could burn coal and then around the second world war things really took off it was covered we could burn everything and we did and so there's this huge increase in energy consumption and you know it is this dip here and as you probably realize this dip was the depression so that's an economic dip this dip is the oil crisis there was a huge increase in energy here so these were political economic events you see this dip out here that's changing our lifestyles that event is very different that's a change in how we live and i think that that's permanent and that's a huge event that i want to emphasize a bit more so this is the same graph as before only instead of showing all the energy i've shown the different types so there is wood peaking around the civil war call goes up up and then notice it's plummeting and it's keeping going down petroleum also is going down natural gas is going up because it's cheap fracking has made natural gas much cheaper and that's absolutely transform the economics of energy generation the good news is that natural gas generates much less c o two than coal does it's much cleaner so we have been dropping our c o two emissions for some long time just from the economics of switching from coal to natural gas so that's really good news and that's purely economic that's not driven by any political consideration so i said i have a lot of good news for you this is some of that good news people worry well if we use less energy then our economy is going to go to crud but the truth is that if you look at the energy per dollar it's been going down for a long time we are no longer an energy intensive economy so the fact that we're losing using less energy doesn't mean we have less economy the world economy grew last year and the energy use worldwide went down so this is a transformation is not about economic catastrophe and if you look at the energy use per capita it's been more or less flat for a very long time it peaked somewhere in the mid seventy's and it's been going steadily down so energy use is going down and it's going to continue to go down the trends that drive this our energy efficiency changes technology in ology and these are going to be lasting changes so this is really good news for us so can we change well we already have what i've shown you is that we've already had a series of transformations we were once a wood economy that we became coal then we became grouped we are now making a new transformation which is moving in the short term toward natural gas and in the long term toward renewables and that's a purely economic argument but it's having huge positive consequences on the climate health he's using less energy because he's insulated himself so he's not changing anything he's doing he's just wasting last because he's better insulated so i regard that as passive the alternative is active this is the way the high jump used to work then follows very hand with the fosbury flop and that's how it works now humans don't have that much more energy despite great nautilus equipment and dubious doping practices that the dominant change between this high jump and this one was a change in how the energy was used they make more efficient use of the energy to get over that bar so i'm going to talk about both of these kinds of changes passive is awesome but i'm only going to talk about it for one slide so these are some examples greek houses look really cool they're white but that also means that they reflect the heat back so you're less hot inside steve chu who won a nobel prize in energy and gave me my first job went on to be secretary of energy for obama and one of the things he said is why on earth to people in hot climates have black roofs that is the dumbest design we need to to convince people that white roofs are cool so literally and  figuratively so he pointed out there's a lot you can do along these lines you know people are generally bright nuff to plant trees in hot climates to shield them so they simply get less heat in their house you don't need so much air conditioning if you have the brains to put your house in the shade on things like closing windows this is a very common practice in most european cities here i confess my shutters are screwed on the little plastic things they never move in europe they actually move them which allows you to change temperature that's very useful this is the cutting the sixteen hundreds it's a big adobe wall thickness helps to keep you in this is cutting edge of two thousand bunch of windows this is a really neat thing that i love it's a coke bottle light it's simply a coke bottle that contains water and the water spreads the light so you put it in the roof of your show back and it has about the light of a sixty watt light bulb and so it's a very elegant little thing my point is it doesn't have to be high tech it doesn't have to be wonderful it doesn't have to be invented in a big laboratory some mechanic came up with that i think in brazil and so there are a huge amount of opportunities to live better without sacrificing comfort and so i want to think about this as things that we're going to be happier because we do them so active options there are two choices evolution and revolution evolution means you don't notice it's changing like when your children grow like oh well they were here they're there how did that happen that you know  o they were changing all the time but you didn't notice as opposed to when you see other people's children three years like you're going to taunt and so i'm going to discuss both sorts of changes an example of evolutionary change is change in gas mileage car gas mileage has gone up tremendously over time so even though we drive many more miles per vehicle you can see a huge increase here we actually are using less fuel because the fuel economy has gone up tremendously the change in fuel economy standards had a huge impact but it wasn't any one moment it's a whole series of things over time that have done this so this is evolutionary this is revolutionary this is one i would argue that vice president cheney would have loved because this is an old style charger and if you ever picked one up there very heavy what's inside is a big oil of copper wire actually several of them and the copper wire is heavy and it only works to change volts for example so if you plug it in the u s you're good you plug it in the u k and you blow your shaver so it was very limited and it was not very energy efficient this is the new style of charger it actually is electronic contains a little switch which turns the voltage on and off so you can go from any voltage to any other voltage it works in the u s japan india anywhere in the world you just plug it in and you go and it's much more energy efficient it's more than three times as energy efficient as the other one so it's smaller cheaper more convenient and much more energy efficient so that's an example of a completely different technology this is based on two copper coils talking to each other this is based on a switch that goes on and off very rapidly so it's completely different but it does the same thing from the point of view of wanting to plug in your shaver or your camera or your computer so this was an this was a revolution that w so i'm going to argue that we should switch all of our energy to renewables and that we can and i'm going to go over that here so to to do that we need to change our sources and we need to change how we consume things so we need to change to basically an all electric economy jet planes can't be electrical but you can use biofuels to do it you can use corn ethanol to make biofuel so that with the exception of jet planes everything else can be made electrical so we can have an all electric all economy and much of europe is moving toward that so why would we want to do this national security we send a lot of money particularly f to places of which we are unfun and we would prefer to defund them as rapidly as possible we also send money to them that hurts our balance of payments the environment is negatively affected by burning i've been talking about c o two but there's also sulfur dioxide niter sachs carbon monoxide spar to kill it so you're up there right now is very concerned with particulates from diesel fuel paris has had trouble breathing and so they had to ban cars and people got very upset i was there over christmas last year and people were leaving for vacation and they shut down the cars and they were not happy so it's a big problem in germany is banning older diesel so there's a lot of environmental issues climate tomorrow we will be reminded of how fun that is health effects are a big driver in the developing world in places like beijing and bombay very rich people's children cannot breathe and that's really important to them so they're going to do something about that even if they don't care about anything else and this final one of flexibility and fungibility if i have a certain amount of energy in my gas tank that does not help me power my computer i have all these different forms of energy that don't talk to each other if all of my energy is interchangeable i don't have to store as much of it and it's easier to share it with other people so burning is bad if you go into a coma for the rest of this talk so one thing i want you to remember burning is bad it's bad because of the carno efficiency i explained to you the temperature between the engine in the outside means that efficiency is poor you have pollutants carbon heat dumping simply warmer because we're admitting all this heat there's a thermal effect in cities they're warmer just because of the heat we dump extraction bad things happen with things like deepwater horizon as there was that enormous methane leak in california that people hadn't known about and transport there was the exxon valdez for example which was an unfortunate adventure so these are all reasons not to do fossil fuels so stop burning and do something else as i said the dominant reason the developing world is they can't breathe these are real unadapted photos and the us used to have much more of this problem i had a friend who is a pilot and used to fly into los angeles in the fifty's and he said it was seriously dangerous to land because he actually didn't have visibility and how much our pollution control has really improved things and this is just a graph of how much we have improved things a lot of things have gone down by as much as ninety percent so we have made huge changes and the developing world wants to do that too because they don't like living that way either and so when people say well the developing world doesn't care they're just destroying everything they want to breathe and the desire to breathe means they're changing to renewables and lowering their burning and that has all these other positive effects as well so there are three issues one is do you want to change this is way above my pay grade i'm going to stay away from this i leave that to people who do that sort of thing for a living technology i argue that we can in my book i do a very detailed calculation and i show it so you can do it yourself to one of the reasons i wrote the book is i go on the internet  read stuff and it was so very much like who on earth do i believe so i gave you spreadsheets if i screwed it up you can find out and so it's your chance to figure out how we did this and cost i'm going to talk a little bit about and basically my answer is yes so the first thing is change the sources nuclear nuclear is not burning in the traditional sense and so i visited france as the core country for nuclear energy they generate seventy five percent of their electricity from nuclear and it's relatively cheap five point five cents per kilowatt hour if you look at what the u s prices are that's a cheap price and that's the generated pr not the retail price that's their wholesale price they've had no serious accidents in forty years they've got twenty plants here they are but they have problems they have no permanent storage either not only are we still trying to decide what to do with mountain or wherever we're going to put these things but they don't know either so they have this many cubic meters of high level waste and no place to put it so that's a problem noble and fukushima obviously were disasters and you could argue well france hasn't had a serious accident but you have that kind of serious accident and you notice and so people have to evaluate risk for themselves nuclear is a topic in which i like to say as little as possible scientifically nuclear energy absolutely works it generates electricity fine the issues are how risk conscious are you how risk averse how much do you worry about these things and what else do you worry about the price in the us is poor and i'll show you the cost nuclear is terrible it's one of the most costly options and there are a lot of reasons for that i don't want to go into u s and french nuclear policy but i did want to briefly present nuclear hydro the good news is hydro is that effective renewable energy source and include storage hydro is the only renewable energy we can control the bad news is we're using all the rain that falls in the united states if you do a back of the on below calculation you can get much more hydro than we have and if you look at detailed calculations from the bureau of land management and mines they argue there is no more hydro power in the us so we have all the hydro power we're going to get and so it's awesome but it's limited but you can have pumped hydro power all you want if you want to pump water up and let it fall down during the night you can do it all you want we just can't harness much more rain wind power wind power has the good feature of being compatible with agriculture people say it sounds terrible but i've walked under the wind turbines that they have in medford and they didn't sound bad to me the cows looked pretty happy there so what are our wind potential the thing about wind is some places are windier than others so this is a wind map of the united states purple is good so there's this huge belt right down the center of the country and usually this is a political map when you see something like this and this represents voting patterns and the good news is they've got a lot of wind and in fact wind is incredibly popular there it's actually a bipartisan thing iowa is the state that gets the most energy from wind thirty five percent of iowa's energy comes from wind so this is a bipartisan happy thing there's a lot of energy there and they are eager to export it this is all good here there is no wind power putting some wind turbine there is not going to get you anything and the coasts have a lot of wind which is why they're special but the big wind in the u s is right down that central corridor and i have a map of where wind farms are people aren't stupid that's where the wind farms also are so brief scientific interlude if it's traumatic you can cover your ears and close your eyes the important thing is that the power you get scales as the cube of the wind speed so if you double your wind speed you get eight times as much power so it's really useful to put wind farms in windy places the same wind mill generates much much more energy in a windy place so the political translation is you want to build really big rotors on really tall towers in really windy places and the good news of the calculation is that we have more than enough wind along that central band to give one hundred percent of the energy for the united states not just electricity every bit of energy we use without even taking into account that burning bonus to just get the energy we have now including all the petroleum if you say well we're going to be smarter and be like belmont and go for electric cars etc then you need even less energy so we have more than enough wind we are good so solar a number that's really popular is thirteen sixty five then go back to your history and wonder who invaded whom or executed whom it's actually the amount of watts that fall on a one meter squared panel in space in a day so if you had a satellite and it was always facing the sun you would get this much power but in reality on earth we only get about thirty five watts so what's the difference well one difference is that the satellite always faces the sun far as the sun rises and sets and the total factor you get is a factor of four you get a factor of two for darkness and a factor of two for your solar panel facing the wrong direction so you end up losing a factor of four for that so this is a picture of solar panel efficiency and now you can afford to put solar panels everywhere the difference between the most efficient and the least efficient isn't large phoenix is thirty two to forty three boston is twenty two to twenty nine watts per meter squared so if you have a one meter squared solar this is what you're going to get an average power out of that so wind farms you want to put in windy places it's really important you want to make them big solar panels go anywhere there's a little difference in efficiency but it's not large so  you want to put solar panels everywhere and this is a local solar panel here so if we just put a solar panel on every suburban roof that would be thirty percent of the u s electrical power indeed and we have to not do questions three start so i so geothermal works fabulously but again you have to have geothermal power where you are so this is where there is geothermal power in the u s again people aren't stupid they put the geothermal power where it is so this is my big science slide we have more than enough renewable energy to supply one hundred percent of the u s power our u s energy that we use now and if we have the burning bonus if we take out the car no efficiency these numbers are even better so no problem have enough renewable energy but this is average and averages are important these are a bunch of people with an average age of forty five these are two this is a reminder that average is don't necessarily tell the entire story and so we have to say well average power isn't the same as instantaneous if i want the lights to go on in my bathroom i want them to go on i don't want to be told that i can wait five years like no i cannot wait five minutes i want light now so how do we make it instantaneously match and there are two obvious big options one is control demand to match supply this is a place where they had a problem i guess the lights went out in ecuador and so this is ecuador having no electricity at all all they had was their car lights so we want to avoid this we want people to get as much electricity as they want so it's a question of how to do this intelligently and of course storing energy if you store it it's not a problem and the averages become the true value and it turns out that not only does energy supply from renewables for example change but the man does too we don't have a constant demand what power companies would like was a constant demand all the time and that's most economically valuable for them so it turns out renewables change in time is actually useful this is actual data from the state of california so this is the total energy consumed by california as they get up in the morning the sun rises so as the energy demand increases solar power does too so you actually automatically match so the demand goes up at the supply does also so people say well renewables are terrible because they change but in the morning they change in a really good way they say well what about at night it's not so good so at night you have to figure out what to do but one helpful thing is to have solar panels faced west so another question is is this too costly and we spend a lot of money on things this is our fossil fuel subsidy per year this is what hurricane sandy cost these we can't really place a cost on very well the health effects are really hard to place it's you that living in beijing is like smoking thirty cigarettes a day it's not easy to say how bad that is and it's really not easy to say how bad that is but it's not good so we want we want not to send more money to that particular charity so when we want to be more dependent on ourselves and more renewable and so one of the issues with cost is we say well what's the cost of electricity well there isn't a cost first there's a big regional variation so you can see massachusetts has a very high cost california has a high cost there's less cost in the center this gives you an idea of the variation but look at iowa the place that's more than thirty five percent when it's the third chiefest energy electricity in the united states so arguing renewables are going to drive your costs through the roof are not true in the very existence very real very american state of iowa and people say well don't tell me about denmark and i want to hear about denmark i don't want to live in denmark like ok how about iowa i was good they've got you know farms and pigs and corn dogs and they get more than thirty five percent of their energy from wind and cheap electricity so this is a real american example that renewables are awful and the other example of what energy cost is electricity is charged differently depending on the season depending on the hour depending on in california how much money you make so there is a very complicated pricing structure so all this graph is giving you is different prices for energy depending on demand so california really socks it t us fifty cents a kilowatt hour at peak demand and alabama has a really really low minimum price but the point is those at that map i showed you was average prices but you can do fairly well if you can balance your energy consumption and storage by for example having solar and storage and sell it back at times when it costs more so it's important to remember there is no given cost so i think about renewables as you pay now and then it's a capital expense that goes over time it's hard to know what the future is going to be this is oil prices gas prices i don't think anyone could have predicted how these things are going to go up and down so to predict your revenue over thirty years is hard but even now the prices are pretty good right now wind is comparable to natural gas can and substantially cheaper than coal even without a c o two penalty or a tax subsidy with those things of course it's even better and it's not just the fuel you use here all the purple bars are natural gas plants but it depends on how you burn your gas do you recycle it do you do it one cycles or t so all of these purple things is almost a factor of to burn natural gas they're just different ways of using it and onshore wind is right here it's one of the cheapest power sources without a tax subsidy so economic that's why they do so well in iowa that it's actually a pretty good energy source so that's the sources we want to change consumption and i want to argue that what belmont does is fabulous electric cars are really really good idea that's because thermal losses and engines are bad we talked about the car no efficiency if you're in city driving sixty three percent of your energy goes to heat your hood you know when you put your hand on the top and it's all warm that's not good that was energy you didn't use to go anywhere and when you can fry an egg on there it's even less good so the heat loss is terrible with electric cars you do much better because you don't have this heat loss you you use roughly a quarter of the energy so by switching to an electric car you use much much less energy because you aren't wasting it by burning it in the highway it's a little less good but it's still a significant increase is still in a factor of two so what you win by doing this you get much less energy loss and you don't have the burning problem and so it's a tremendous win as long as you get your electricity from renewables if you get your electricity for your electric car from a coal plant that is very old and very dirty it's possible you're doing worse than a and car so it matters where you get your electricity but if you get your electricity from a good source the subtle windmills that someone nicely put back there then that it's actually good and my last thing we have enough energy storage right now today in the united states the gas tanks in our cars store between one in three days worth of total energy use in the united states so that's enough if those cars were all electric there would be no energy storage problem that just by having all lecture cars then the average renewable energy that i talked about would even out and we wouldn't even have to do anything else special and so this is an example of the port of rotterdam they've put a lot of these things together i compress the science in my talk to not send you too much into a coma but there's a lot of computer science things you can do to make the lights intelligent to find parking spaces to control how you use the electricity in your house and if you put that together with solar energy and new technologies like  pumps to replace regular heaters we can lower our current energy consumption to something like fifteen percent of what we're doing now without having a lifestyle loss and somebody is being much more cheerful like those on power supplies that i showed you so that is the end of my talk t