Lightning lectures: Powering the future
Thank. You thank, you very much. Thank. You very much good afternoon welcome. I'm. Coming. From the Center for sustainable, chemical, technologies, at the University of Bath where we do a lot of research on renewable, energy trying. To answer questions, such as how can we power the future how can we decarbonize. Our energy mix and. It's great to see so many of you here interested in the topic because it is a very important, topic, some. Say it's the most, significant. Challenge that we have faced ever, okay, I, can't, promise to give you the answer to this question okay but, what I thought I will do is. To from. A few objective, scientific basis lay. Out the challenges, and show you some of the options that we have how, we might avoid. A scenario, like this and move towards a future more, like that okay. So. As. Background may be I don't think I need to show anyone these these, numbers really in particular I'm sure you've heard this before if, you just look at the energy mix this is UK data don't mind the actual units. Or numbers in here just look at the composition of what makes up all. The energy where do we get the energy from at the moment that. We use in various applications, and that, we will see yes, we are increasing, the amount of fire energy and renewables, I mean. This ends at 2015, and there has been a bit of development. In the area since until. Now but. Still today, it's. Around 85 percent of fossil. Resources. And, it's coral coal oil and, gas okay, now, we've all committed we have all committed the government has now committed to. Reduce co2 emissions to basically and at zero by 2050, which is only about 30 years away and so, that basically means we'll have to bring. This down as close to zero as possible, and. The question is how, do we do this how can we tackle this now. If you want to think about how, you can decarbonize. Energy or get away from all these fossil fuels you have to look at where all that energy is going where. Do we spend, the energy where do we use it and so, I started, to give you an idea here so this is an, overview graphic, it's so-called a sector breakdown again. Don't mind the actual values, or the numbers in here and just look at the percentages, and the relative contributions. This. Is data from the International Energy Agency by the way but this is a fair. Estimate for developed, and country's, so. You can see that the biggest chunk of energy that we consume goes in so-called centralized. Large-scale, power generation. Okay, this, is the electricity, that comes conveniently, out of the sockets in our houses that we use to. Power all sorts of devices both. Domestic, and centralized. Source street lighting and so on and is also largely used for. Producing food okay. Then. In the in the purple bits here you see everything, that can be classified as transportation now, you hear a lot of, talk about greening. Up the car fleets and moving away from combustion, engines if. You look at it you know cars, which is called a light road they, only make up about just, over 10% of the overall energy that we use so. It's important, that we do, something about the combustion engines in cars which, are polluting and contribute, to co2 emissions but, that's that's not all there is okay, because they're significant, heavy transportation. That, has just about as much impact and there, are also other industries, or other sectors. That consume lots of energy and especially. This ones here all the ones shown in red are, rarely talked about in public debates okay, so. This is all the industry, chemical, industry that, happens in the background that supplies us with all the goods that we apparently cannot live without okay, so, it's cement manufacturing, steel aluminum, polymers. All these things that, our modern world is made of it. All needs to come from somewhere we need energy to make it and that in itself, consumes. About, as much energy as transportation certainly, more than the cars alone okay and domestic.
Use You can see this up here in the yellow bits it's, actually a relatively small proportion okay. So that's heating in your house and in, cooking and so on so. I'm not saying you shouldn't use LEDs okay you shouldn't have you meat-free Mondays and, you shouldn't carpool, and use bicycles, whenever you can instead of cars but. The key message from, this what I want you to take away is that that, alone won't be enough okay. So. Most of the power is used, in large central, facilities, such a central power generation industry, and, heavy, transportation. And we. Have to do something. Fundamental. We have to change fundamentally how these, large-scale energy, sectors. Are powered, if we, want to avoid a collapse, of the ecosystem, of the earth, okay. Now. You, might remember that thermodynamics. Tell us that energy can't be created or. It cannot, neither be destroyed we can only transform, it into from, one form into another okay we can move it around and change its its, shape and appearance so. We, have two household, with, what we've got on this planet okay now. This is a graphic again that, in relative terms or the bubble sizes are relative to the percentages. And you. Can, contrast so you can see what, we have on one hand here on the right hand side the, finite resource, of fossil. And nuclear fuels. Okay, total reserves and, if you compare these two the annual world consumption which is shown here in the middle and you, can see we could if we wanted to live for another 50 perhaps hundred years of these. Finite resource because there's, quite a lot of them now, we don't want to do that because we've already created, too much damage by using them excessively over the 200 years the. Good news is that here on the left side all the renewable forms of energy is. Wave. Energy geothermal, hydro. Wind, energy and that. Big plot here is solar, energy there. Is lots of it this is every, year okay, it. Said it's estimated that in one hour enough solar energy strikes, the surface of the earth to power the entire planet for a year so. Thermodynamically. Speaking, the good news is that we, have lots, of energy we have lots of renewable energy so, certainly, we have enough solar, energy okay so, these are on the table these are viable options we won't, be limited by the availability of these the. Problem is that these energies, come in very different forms, to what we are used to from, the fossil fuels one. Of the problems is that they're very dispersed, and. They're very diffuse okay, so, these free maps show the distribution of wind energy around, the globe tidal. Energy and. Solar energy around the globe and you. Can see there are areas that benefit a lot from solar energy like Australia most. Of the NHANES and there are areas which, have a lot of wind energy so, the north of Russia, for instance in here the South America. And. Tidal energy again, there are spots on the planet they have lots of those but. These come very dilute okay, so, it's not like finding, a coal mine or an oil well and then essentially pumping money out of the ground even, in areas where you have lots of them you, still need to harvest them and concentrate. Them, and the, other problem with them is that even, if you have access. To these and you can manage to harvest them, they. Don't they're not available as. Fossil. Fuels are the Sun shines when the Sun shines the wind blows when the wind blows and the tide comes when it comes, and. We can't just, you. Know make energy appear, when, we want it okay, so although as an overall sum of energy there is enough solar, wind.
And Tide energy but. The temporal distribution does, not match any. Of the demand profiles, of the domestic sector of, transportation, or of, the industrial sector okay, so, there's lots of it but we somehow need to level, it out and transform it into forms, that we can use on demand. So. That basically means we have to harvest. A lot. Of that energy and, transform. It into something else okay and there's something else is sometimes. Called fuels or energy carriers as different words of it they all mean the same thing and. They entail taking, the electricity, that, we get from so I should hold this up higher that. We get from solar farms or wind parks and transform. It into something else now electricity is convenient, to use. And to transport but, it doesn't store very well now, there's lots of talks about battery technology, these days okay, batteries, can store directly, electric. Energies voltages, that we get from these, energy sources but. The problem is that batteries. Are. Not very, efficient, when it comes to storing, a lot of energy in a small amount of space or volumes so here I've shown you. The energy densities, of a range of different energy. Carriers so here our combustion fuels that we use focuses diesel, and gasoline liquefied. Natural gas ethanol, methanol and some biomass on here down. Here we have hydrogen, which is often discussed. As a future, fuel. Or energy, carrier and then, down here we've got batteries so this is not the old let's of uric acid battery, these are state-of-the-art lithium-ion, batteries, so. They. Are great because they can directly store electricity, from, renewables, and they. Will certainly play, a very important, role in certain sectors for mobile applications, you know phones laptops small, devices perhaps, even cars we'll see but. There won't be enough to, cover and, satisfy. All the different energy sectors, I mean, many people found it very hard to believe including myself that, we would ever develop, a battery technology, that would be energy dense enough to fly an aeroplane on or to power a cement factory with okay so we need something else and just to illustrate this difference in energy density. Here. I've got. Four, like a hydrogen balloon so the energy contained in this volume if this was pure hydrogen would. Be equivalent to a battery that is 300, times heavier, than this so this would be one gram of hydrogen this, would have be a free hundred gram lithium-ion, battery, and. If this is the same amount of energy, was. Transformed, into diesel it will be just five, milliliters about three grams okay, so, three, different forms of energy in very different weights. And volumes, but. That's not even everything so that's complicated enough, but on top of the volume and the weight there comes the question of you. Know how expensive is it to store this, hydrogen how. Expensive or efficient is it to store this electricity and, how expensive is it to store, and transfer these fields okay, so hydrogen is great for certain applications, batteries. Are great for certain applications, but liquid fuels will be needed and I think this aspect is often overlooked in these public debates that scent, tend, to focus on either batteries or hydrogen, okay. Now. The problem why. Our society, or industry, is so based on these liquid fuels is not only because they're so conveniently, energy rich but. Also because historically we used to directly. Get them from fossil fuels fossil resources so we can burn, them directly to get power we can transform them into or refine them into diesel petrol and we can make chemicals from them but. Going forward we shouldn't. Dig these out of the ground anymore and burn them simply. For energy we must reverse part of this process, take. This renewable power that we get from these options, and turn. It into something, like this okay, so we need to reverse this. Flow of energy and, you can collect renewable, energy and transform, it into some. More, dense form that we can use in our, society. And the. Key bit for doing this. Hydrogenated. Way now is. A quite, old technology, called, electrolysis, okay, electrolysis is simply a means of, converting. Electrical, power a voltage or current flow. And putting, that into an aqueous solution and applying, a minimum voltage of 1.3 volts and it would split, the water into its constituents, so it would split it into hydrogen and oxygen now, the oxygen in this case it's. The byproduct it's, the one that you don't need so if that can be vented or used for other things but. All the energy that, comes from these renewable sources will, be contained, in the hydrogen that you make okay, so.
That, Hydrogen you could use for certain sectors it's great for certain parts of the industry, it might even power certain applications, but, you can do lots of other things with it now. If we, want to make this sort, of the backbone of our energy society, or energy conversion. Then, this process needs to be as efficient. And as robust as possible ok electrolyzers. Have been around for a long time but. Efficiency, has never been a primary concern okay but, if we want to use it to. Turn elect renewable. Electricity into. A chemical fuel and then satis, for all the different sectors from there we need very good electric, Atta lists for doing this water splitting and this is the only short. Plug for our own research that we developed together, with some other people electro. Catalysts, that you could put on the surface of the electrodes that increase, the efficiency, of the water splitting so you have less losses, going from here over, the electrolysis into hydrogen and other, fuels from there now. To give you a flavour or. At, least a range of some options that we can make. Molecules that can synthesize if we have access to this renewable hydrogen, look. At these free reactions here so this is the only bit of real chemistry that I'm showing you today and so you can relax you, can take that hydrogen can, react it with co2 from, the atmosphere or, from any other point source that you have it and, you can synthesize methanol, from it methanol, already is a decent fuel it's, not as as, energy density so if you want something ideally, you can react it further and create, oxy methylene ethers and oxy methylene Eva's are chemically pure compounds, synthetically. Manufactured. Then. Are, basically. Diesel, they have the same energy content as Caesar they burn very cleanly and they can be used in combustion engines with little to no modification. Now. If you don't like diesel for whatever reason, you can do related. Chemistry you can take co2 and hydrogen do. What is called a reverse water gas shift reaction. And create. Carbon monoxide, which you can react further with hydrogen and what is called official tropes reaction and you can make hydrocarbons, hydrocarbons. Gasoline. Or kerosene okay. And that you can use directly for aeroplanes and for other mobile applications. Other. People are even investigating, using nitrogen based fuels. For energy carriers, and this, is essentially the harbor Bosch process it's reacting nitrogen, with hydrogen to make ammonia which is another very energy, dense liquid, fuel which, you can use to power fuel cells or even combustion, engines and the.
Point About all of these is that this is chemistry which we've done for decades on large scale okay. So. The, reactions, the catalysts, the reactors for all of these are available we know exactly how to do this chemistry we know exactly how these compounds behave and store so, this is readily, available technology. Which, in principle we could power a tirely. With renewable energy via, water splitting making. Clean hydrogen, and if you do it this way although, they look like you know the bad guys that got us into trouble in the first place because. They're only carrying, the hydrogen that comes from the renewables, when. They're burned again there, is no net co2, released into the atmosphere, okay, now. Which of these will make the race and would be the answer I can't tell you there, will be an, expert workshop at the Royal Society in about two weeks so look at some of these options but, I'm convinced that some of this will feature in the future energy mix okay. So, with this thank you for your attention and I think we've got time for questions, right. Yes. Do. You want a microphone. Yeah. Oh. Yes. Yeah. Well. To some extent, so I'm not so well I'm looking back to the slide so yes when it when I saw a renewable energy I mean energy, that is constantly, coming in from the Sun onto the planet so overall. As a universe the energy is constant, but on the planet we have a net influx from the Sun so yes. And there is a fault if we take away some, of the solar energy or the wind energy that, we've got that we disturb the ecosystem, in other ways, but. If you think about the contribution I mean if you just take solar energy for as an example there, is so much excess solar energy that is not directly used in the ecosystem, you. Know we only need a percent, or less of that to. Power our planet so the effect of whatever it. Might affect things will be negligible and I. Mean it looks like if, you keep the distribution in mind that, we will use a mix of different renewable. Energy forms in different parts of the planet anyway it, will have to be managed it will have a nonzero, effect, but. I'm convinced. That it will be less than the effect of burning fossil fuels and unlocking co2, into the atmosphere continuously. That's. The best I can say about that at this point okay. Yeah. Okay. Yeah. And, then. Yeah. Now. This is why this question is a little bit complex so all this looks very feasible but. In every step and every conversion, so, in harvesting, solar. Energy or wind energy you have a certain efficiency, you don't capture a hundred percent all, the photons or all the wind energy so, there's a certain loss associated, here there's. A certain loss associated, with the electrolysis, making. The hydrogen and then, every, other step down, the way has, a certain energy loss associated, with it so the, final, say we're making oxy, methylene ethers and sustainable, or renewable diesel, it. Will not be a hundred percent renewable, energy it will only contain I don't know 30 percent or something so, this is what we have to do we have to do a techno-economic analysis.
Of All of these value, chains and see, which one is most promising, which one conserves. Most of the energy that we're putting in. Again. Sorry I can't give you a precise answer on this but. You. Have to lay out the facts and do the calculations, it's not that difficult because we have done almost. Each, of these steps in different contexts already so you know it's it's quite scalable but we just have to sit down and neutrally look at the facts and and do that and this is what the workshop will be about in two weeks. Yeah. So. The. Intermittency, that I showed in the diffusivity, that applies primarily to, solar wind, and wave so. Geothermal, for instance is much more stable but. There's also a lot less of it okay. So that's it, will factor into the mix but it won't nearly be as important, as these three okay. Nuclear, is another one I personally, don't view nuclear as renewable, or green or sustainable energy, because. You're consuming, a finite resource and you're, creating a waste and. You. Know from a purely scientific point of view it might be okay to use it as a translation, or step in between from fossil to fully renewable. But. It's not a very popular topic. Okay. Hmm. Well. Okay. I mean it might be okay but you. Know in the and it's soft as well but you, know in the long term I'd say we'll have to use. Some of those I mean it could be an intermediate. Solution. Yeah. Say. Oh mechanically, yeah. Yeah. Yes. Yeah. Switzerland. Has done this for instance so whenever you have big. Dams for instance you can simply. Run them in the reverse and you store energy which you have surplus your own you know on a sunny day to, pump water back up and then in the night you just, let it flow down again and you're copied. Again. There are technical omec studies on these and they are viable in certain spots but, not universally. Viable as something. Like a. Chemical. Fuel and. Again this is only, for the sector of central power generation which is admittedly one, of the largest one but, for transportation, for instance that that wouldn't do it, how. Much it will feature in the future energy mix I can't, say. You. Know if you have a dam you would do it locally but, if you don't I don't think you would build one for it. One. More yes okay well, one more question. So. This complicates, the whole picture further so I think with, a move towards multi renewable, energy will also see a decentralization. Of some of these sectors now. That can't happen immediately. We can't say suddenly, okay everyone you go and make your own power here's, a solar panel here's a wind turbine that won't work, but there will be a larger degree of individual, small scale power generation and, I. Don't see why not why people wouldn't have you know a winter one in the back of the yard if if there is enough wind just as people have solar panels on the houses already so. Yeah that will that will happen to some degree. Okay. I'm, still. Available for further questions and discussions outside probably after. This okay thank you.
2020-07-23 07:02
