 I'm so happy to introduce Professor Sally Benson. She is the pre-court family professor and also the co-director of the pre-court institute for energy at Stanford. Sally was also the director of Stanford's global climate and energy project. She is faculty in the department of energy resources engineering. I know we have a few students from Sally's department here. And her research interests primarily are in the area of carbon capture, removal, storage and management. She has been involved with energy at, you know, since its inception or even the before that. So she is the person in this room with the most knowledge of energy at. We are celebrating 10th year of energy at running this year. And I'm so thrilled to welcome you all. So with that, Sally, it's over to you. All right. Okay. Anyway, so terrific to have you all with us. I'm so sorry we couldn't be together in person, but I hope this will be a terrific introduction to energy at Stanford. As, as Arpita said, I'm the co-director of the pre-court institute for energy. Actually, today is my very last day. And this will be the second to last official act as the co-director of the institute. But of course, I will be around and I really look forward to interacting with you over the coming years. And what I would like to do in the short time we have together is to introduce you to the Global Climate and Energy Challenge. Now, I'm sure that all of you are experts at this in many ways because obviously you chose to come to this workshop and also you're choosing to pursue your studies in this area. But I just thought it would be helpful to sort of get us on the same page. But before we jump into that topic, I just want to show you this beautiful aerial photograph of the Stanford campus. The normally we would be way across campus on this other side over here. We would be in the engineering quad. And I personally am in the Y2, Y2 building right now. And, and I hope that over the next year or next, obviously not the next couple months probably, but after that that we can get together and celebrate like we always do. Over 1,500 students have gone through the Energy and Stanford and Slack program. And our sincere hope is that through the EnRhoads project and other forms, other times for networking, that you use this to build friendships that will stick with you your entire time in Stanford. You know, once you get into your own particular program, you'll be have your department, so students in your department and so forth, and the students in your research groups. But this is a really great time to get to know people who are with a background entirely different than yours. But understanding that you all have the same common interest of energy. So, so with that brief background, I just want to sort of lay out really what I think is the defining issue for your generation. And it's this dual challenge that we need more energy. And we need about two times as much energy as we have today. And at the same time, we have to reduce greenhouse gas emissions. And at first this may seem like a tremendous contradiction because today about 85 percent of all the energy we use actually comes from fossil fuels, which of course when we combust them they emit carbon dioxide into the atmosphere. So our challenge is to figure out how do we provide all the additional energy that we need and reduce emissions at the same time. And just to put a little bit finer point on the energy we need. This is a map of electricity access and nearly one billion people or about one seventh of all the people on the planet don't have access to electricity today. Similarly they don't have access to transportation fuels. Things that are so essential to modern life and allow us to be productive and comfortable and engaged with each other. So this is what at least I spend all my time thinking about and then I hope that your passion for addressing this dual challenge will grow over your time at Stanford. So what I decided to do is to just sort of lay out so what I think of is big picture takeaways as we think about so we think about this dual challenge. And the first big picture take away is that we have a carbon budget that limits the acceptable emissions or the total amount of emissions that we can do before we are going to have too much warming. So this is a graph that IPCC developed and for me it's been one of the most instructive things for the way I think about the climate and energy challenge. So on the bottom axis we have the cumulative emissions for carbon dioxide since we began to measure them in earnestness and on the y-axis we've got the temperature change that is that is both that observed historically as well as the temperature change that we expect over time if we continue to add carbon dioxide to the atmosphere. So the simple way to read this is that if for example we want to limit warming to two degrees C that we're going to have a budget and that budget is indicated by this line here here's a 50-50 chance that we could keep warming below two degrees C and if we for example want to limit warming to with a 66 probability that will be below two degrees C we have a budget of about 3,400 billion tons of carbon dioxide and given that we've already emitted about 2,300 tons a billion tons of carbon dioxide that leaves a budget of 1,100 billion tons of CO2. Okay so for me this is useful because I'm you know an engineer and I like to have targets I like to know what I'm working for. Now of course if we wanted to limit warming to less than that say to one 1.5 degrees we would have even a much more stringent budget. Okay so we have a budget now we know our target at least if we want two degrees C is 1,100 billion tons of CO2 that we can emit before we're going to go over two degrees C. Okay so so how much time do we have to to do that? So today the emissions are about 40 million 40 billion 40 billion tons per year okay and that's between agriculture and fossil fuel fossil fuel use and if we were able to simply make sure that CO2 emissions didn't grow ever again in the future we would have 26 years before we were going to go through blow through our budget okay so so that says this is a very urgent issue we don't really have any time to waste. If however we could start decarbonizing at 1% a year then we'd have 30 years okay we're buying a little bit more time by beginning to decarbonize the global energy system. If we can go to 2% a year that gives us 37 years if we can go to 3% a year now we have 50 years half a century that starts making our job look a lot easier and if we can simply begin to reduce emissions at a pace of 4% a year we have over 100 years that we could that we could before we would have to get to carbon neutrality. So again I like numbers so for me my target is to think about what set of actions could we take that will get us on a pathway where we're reducing emissions at about 4% a year. Okay so that's the first thing this the second thing is that that our fossil fuel based energy system is largely responsible for climate change okay so we can't solve the climate and energy problem if we don't solve the energy problem. Okay so here's a picture of the world energy mix about a little over 20% from coal about 40% from oil about 35% from natural gas a little less than 10% for nuclear and here we see the renewables on the top of the stack. Okay so 82% from fossil fuels and of course we know the challenges is that when you combust fossil fuels you make carbon dioxide and water which leads to global warming. Okay so we've got to solve the energy problem we can't There are other important sources of greenhouse gas emissions agriculture is a big one but if we don't solve the energy problem we're not going to be able to solve the climate problem. So this is just some data that puts a little bit a finer point on this now these are the CO2 emissions okay total CO2 emissions are about 42 billion tons per year in the top the great line here these are emissions from from combusting fossil fuels and on the bottom here are CO2 emissions associated with land use change okay and land use change largely results from conversion of forest lands or grasslands to agricultural lands. So again emphasizing that we need to really go after emissions reductions from the electricity or the energy sector. Okay so the other thing is is there are many options to decarbonize the energy system and we need all of them. Some of these options are conservation you know ride a bike walk wear a sweater simply use less energy by by behavior or personal choice. Second thing we can do is efficiency improvements I think the best example is that I can buy a car that gets 25 miles to the gallon I can also buy a car that gets 50 miles to the gallon so it's technological improvements make us use energy more efficiently. We can also switch from coal to natural gas and you might be going why do we want to do that eventually we need to get to zero well you know certainly we do need to get to zero but there are many parts of the world that are dependent on coal and if they could switch to gas emissions could be reduced by about 50 for CO2 and in addition there are real benefits in terms of air quality. Third is we can switch to renewable generation or nuclear energy so these are basically energy sources that don't rely on fossil fuel at all and we'll talk more about renewable generation in particular and then finally for those areas where we can't eliminate the use of fossil fuels at least over the next you know several decades that we can actually capture the carbon dioxide and we can pump it back underground where it came from in the first place and the bottom line is that we need all of these. So one of the things that as you know over the past decade or so there's been so much enthusiasm for renewable generation in particular that we've kind of forgotten that energy efficiency is really the workhorse of reducing emissions. Basically by energy efficiency improvements we can reduce the amount of energy we need and every every bit of energy we don't use is that much closer to the solution and so these work and and they're needed and this is just an interesting graph so this is looking at the annual per capita energy use for different parts of the world so here you can see the average in the world is about 70 gigajoules per person and China increasing to nearly 100 gigajoules a person. Here's the United States okay really large per capita energy use here's the EU and here's India so you say well you know are people in the US living that much better than they are in the in the EU or is it simply that some societies like the United States in particular are particularly inefficient. So one way we can get some insight into this is to take a look at this graph which shows the energy per capita in gigajoules per person versus something called the human development index and the human development index is something the United Nations developed to try to characterize well-being and it involves health basically longevity it involves a level of education as well as the the wealth so it's not it's not purely a financial metric it actually measures other important societal indicators of well-being and one of the interesting things we can see is that if you look that the the human development index increases dramatically and quickly as you go from say 0.4 to 0.8 as you go from 0 to 100 gigajoules per capita but beyond this if you look at all these countries stretched out here what we can see is there's really very little benefit in terms of well-being for more intensive energy use. So from my perspective this creates the challenge is how can we as a global society try to evolve towards a point where we're in the range of a hundred gigajoules per person and actually this is the number when i said we are going to need twice as much energy that's predicated on the on the world moving to a place where everybody has access to about a hundred gigajoules per person so we have a lot of people who need a lot more energy but we have a lot of people who can reduce their energy use. Okay next a reason for enthusiasm and hope that renewable energy is abundant cheap and growing rapidly. So this is a chart that basically shows what is the size of these renewable generation resources compared to how much energy humans use okay. So if the number is one this says the energy resource would be exactly the same size as human energy consumption. So for example hydropower if we use all the hydropower in the world it would just about meet our demand okay that doesn't mean it would be cost-effective or economical or even environmentally sound to do that but that gives you a point of reference. So a couple of things to look at if we look at the solar and wind resource they are enormous the solar resource is about 6,000 times bigger than than humans use or would need wind about 70 or 80 say 80 times so very very big resources and the second one that's quite interesting is terrestrial biomass now clearly it's not very much bigger than than human energy consumption on the other hand it's been used for throughout human history and it's also something that we know how to use it we can use woody products we can also make things like ethanol so it's likely that the terrestrial biomass is also going to play an important role particularly for things like making fuels. Okay so what about costs I said that they're cheap and here's some data these are levelized cost of electricity and if we look at photovoltaics you can see that in about a decade ago they were actually really pretty expensive okay so the cost of for example coal generation or natural gas generation is here at about $50 per megawatt hour down around here and what we can see is the cost of solar energy has dramatically declined and it's it's about the same cost as as a traditional generation onshore wind, offshore wind, even battery storage rapidly decreasing towards parity and this is a new map that Bloomberg New Energy Finance has prepared which basically says what is the cheapest source of new bulk electricity generation for different countries if you look at the United States onshore wind if you look at places like like China utility scale solar and yeah so so you can see much of the world actual renewable generation is the cheapest form of electricity that's not true everywhere we can see that in places like Russia it's still natural gas and there are some parts of the world where where coal is cheaper but a decade ago this would have been inconceivable however just because renewable generation is inexpensive and renewable or abundant doesn't mean that we've solved all the problem that high penetration of renewable energy on electrical grids it creates challenges with operations and this is a very famous curve probably most of you have seen it we call it the duck curve in California so the idea of it looks like a duck this is the duck's head and this is the beak and this is the belly of the duck here and and the challenges are associated with you know we have to at every moment in time balance energy supply and demand and historically we did that because we could turn on and off generators and the operators of the grid understood the patterns of use very well and so they could do this extremely reliably but in the future we want to rely much more on solar we want to rely more on wind and it turns out those of course aren't predictable we can only have solar when the sun's shining and wind when the wind's blowing and and so there's a question of you know how do you build a system that's reliable but there are also challenges for example with certain parts of the day like when the sun goes down and it also turns out to be the time when there's peak energy demand okay so this is the here is the total energy demand and so you've got a major source of power generation going away demand is increasing so you rapidly have to do something and uh in California what we do now is we turn on our gas plants and turn on our imports but there are going to be limitations to how quickly and reliably we can we can do this so energy storage is certainly going to be important but but it remains a very significant challenge okay so what can we do about this well there are a variety of approaches for managing renewables integration we can add natural gas natural gas is very flexible for turning on and off we can make sure that our renewable generation are diversified so that we have lots of different sources we've got wind and solar and hydro and bio because the more you have the easier it is to manage this balance we can control when and where people use electricity to make the to to make both the demand for flexible as well as the generation flexible we can charge different amounts of for electricity when supplies are abundant to make it more expensive when they're scarce we can integrate the area over which we're bringing in renewables to the grid so just because the sun might not be shining in california maybe it is shining in arizona similar with wind so wide area integration of markets and of course energy storage is is an important technology so so here we can see this is lithium ion batteries again prices have really plunged dramatically and are expected to continue to drop but lithium ion batteries are largely used for short-term storage on the order of four hours and long-term electricity storage really remains an unresolved challenge i really think of this as the kind of the holy grail if we can get to long-term electricity storage where we have weeks of storage or even we can store energy over the course of a season that will really help us increase the generation from renewables and things like hydrogen are exciting options for being able to do that but some emissions are hard to eliminate with renewable energy here's an example of some things like shipping aviation long-distance road transport making iron and steel making cement and then what we call load following electricity getting to 100 renewable energy electricity generation is is really tough because you need to end up overbuilding the system which becomes very very costly so there'll be a certain amount of fossil generation at least in the short run that is likely to be necessary to get to to to keep the reliability so this is about nine billion tens a year or 25 percent of global emissions are hard to eliminate without a technology called carbon capture and storage so again this is one of the areas that i work on extensively the idea is here is that you capture carbon dioxide from a power plant you can compress it transport it and then pump it back underground into an oil reservoir gas reservoir or even put it just in a very salty water filled formation today there are over 19 projects operating capturing about 30 39 million tons of carbon dioxide a year it's been growing steadily at about a pace of 10 percent per year it's not nearly fast enough but but it is starting to make some headway so so the final sort of big picture takeaway is that we need a comprehensive deliberate and integrated plan if we're going to be successful in achieving emissions reductions at the needed rate of about four percent per year so the way i think about it is you know we need twice the current energy use if we can't be if we're all having 100 gigajoules per person if we could even conserve more if we could improve energy efficiency maybe we can get that down to say 1.6 times current energy use we need to think about things like switching from coal to gas switching to renewable energy electrifying vehicles huge potential for efficiency improvements and getting rid of tailpipe emissions and reducing greenhouse gas emissions carbon capture and storage nuclear and of course there are going to be new technologies that emerge and i hope many of you are going to be working on them because we uh this is a strong portfolio but we do need more but this isn't just about technology we need the enabling infrastructures of grid modernization and vehicle charging we need to have techno economic analysis to help make sure that we're making good energy choices as we go along this journey to decarbonize we need policy and finance support example being a revenue neutral carbon tax that will incentivize companies to begin that journey of decarbonization and of course at the end of the day it's really going to be behavior and public opinion that allow everybody to get on board and make the necessary changes to achieve these emissions reductions so we have a portfolio of solutions where everybody contributes and it's not just technology and in my last little few minutes i just want to say a little bit about stanford's central energy plant about eight years ago we began to dismantle our existing natural gas fired power generating station we decided to buy a lot of renewable generation and by 2022 we'll be at 100 percent renewable generation but we also did a really radical experiment and transformed the entire heating system to electricity and one year back on campus i hope you can go visit the central energy plant but it allows a much more efficient system and a total of 80 percent carbon emission reductions from the campus and also less water use and one of the fantastic things is that a number of students have been working very closely with the with the central energy operations and really i'd like you to think about stanford campus as a living lab where there are opportunities for you to do research and here's just a picture from aerial picture and one of the keys to what made the system work is massive energy storage so when we think about energy storage we think about battery storage but the reality is is we can also store heat and here are these you can see these here's the car so you can see just how enormous these are we have two cold storage tanks and one hot storage tank and this is what stores all the hot and cold water that runs in a loop around the campus and and provides all of our heating and cooling so that's what i wanted to say today but i do want to let you know about the classes i teach in the fall i teach energy 153 253 carbon capture and storage love to see you there we're also teaching a carbon dioxide removal research seminar and this is one unit class take a look if you're interested in the winter we have a hydrogen research seminar which is really interesting and then in the spring i teach a class called sustainable energy for nine billion so i hope to see you in class and thank you and i really look forward over the coming years to getting to know you and welcome to stanford thank you sally that was wonderful thank you for setting the stage for us and for highlighting the big takeaways that we should keep in mind as global citizens as we work on the energy problems somebody was asking about the central energy facility tours i know that their team is working on setting up some online tours and you know once the campus opens they will be doing in-person tours also so we will keep you guys posted when we learn more hi sally i had a question about the carbon budget you were talking about and i just wanted to understand the scale of what a one percent reduction would look like or you know one two three four like have we achieved something along the like a one percent reduction before or are we still at very much close to zero yeah great question actually carbon dioxide emissions have been going up a couple percent per year so so getting to you know even flat would be a big job getting to minus one percent is is an even bigger one so minus four percent is a big job but if you think about pursuing this portfolio of options all at once instead of doing it sequentially if we're more efficient if we're conserving at least i know in my own personal life i think i could easily reduce my emissions at that pace and i think that many other because if we just pay attention to it set our mind to it and you know put put our our action where our words are i think siddharth raised his hand siddharth go ahead and ask a question i'll request you to say your name and your department so that we know who you are perfect thank you so i'm said i'm going to say it i'm at the gsp and i'm in coming soon as well uh so i actually i'm on dual degrees to you know the kenney school at harvard and i spend the summer looking at energy efficiency investments in the u.s and there's a sort of cost effectiveness of that so i was wondering what you thought of energy efficiency on one hand versus just driving down the cost of renewables and generation on the other because one of the findings just from looking at the literature we didn't do any original research of ron was uh it's not tremendously cost effective to subsidize residential energy efficiency i totally agree with you i think from a personal level it's possible to reduce it but from our sort of government policy standpoint the sort of dollar cost per ton of co2 is in the hundreds of dollars um and there may be cheaper ways of getting to the same result if we you know decarbonize the electricity supply more quickly so i was just wondering where you think the balance of efforts should lie between those two things right you know it depends on the you know the type of efficient efficiency improvements you know some efficiency improvements actually uh you know payback so things like you know switching to led lighting can can actually pay you back um buying a car that's much more efficient as long as it's not a premium car you know that can actually make you money but but you're right there are many other things like structural things like putting into windows or putting in insulation where you know it is quite expensive so from my perspective you know none of this is going to come free that you know we're going to have to pay you know just like when we decided that we we're not going to throw trash out you know the window and you know have a pile up on the streets you know we pay for that just like we you know wastewater we don't let that run freely into rivers we we you know send it to sewage treatment plants so you know this is not going to come for free but if you look at say equivalent of hundred dollars per ton of co2 that's in the United States is an example that's corresponding to like two two and a half percent of GDP is is comparable to a hundred dollars per ton so you know yes it's a lot of money looked at one way but another way it really isn't doesn't look like that much particularly when you consider the benefits of of stabilizing the climate so that we don't have to deal with massive sea level rise you know continued extreme weather and so forth. Great thank you it's Mayank Goethe from the GSV I'm an incoming Sloan fellow and my question is on carbon capture and I just wanted to tell you I'm not an expert in that domain but just doing some research are there different types of carbon capture and some which are more permanent and some which are more temporary their methodology of sinking carbon that we need to be careful about when we when we look at them. Yeah so yes there are so if for example you convert carbon dioxide to a mineral then that's going to be permanent if you pump co2 back underground into an oil reservoir or or a saline formation that too you know is essentially permanent if on the other hand you grow a forest and then a forest fire comes along that's not going to be permanent if you change your agricultural practices to to increase the soil carbon and you might build up soil carbon but if a the farm changes hand and somebody comes and tills up that soil again all that carbon could be released so so the biosphere solutions tend to be less permanent than the geologic ones is the way I think about it and just in terms of the technology the technological carbon capture that we're now seeing including direct air capture how should we think about that in the same way should we be more skeptical about certain methods and more support for others yeah so direct air capture as is envisioned there are like three major companies you know it's an engineered solution and it's basically very similar to a carbon capture that would be used on a concentrated point source there are solvents that capture the carbon dioxide and the way I think about direct air capture is compared to for example capture on a point source typically on point sources concentrations are say between five and a hundred percent co2 whereas in air you know it's a tiny fraction of what I would point point point oh four percent for example so in one case we've already done part of the work for us to concentrate the co2 so it requires much less energy than if we try to capture carbon dioxide directly from air so to me that's the that's the big difference I don't think that you know other than cost and efficiency I don't think there's a big difference between them they both sort of achieve the same result you know one takes carbon out of the air the one another one avoids it going in the air in the first place and then both of them take that carbon died well if it's carbon capture and storage both of them would for example put the carbon back underground is the dominant technology today