Sustainable Energy – Without the Hot Air

"Gates takes a very big interest in this whole area. He’s a big fan of Václav as well as MacKay. The fact that Gates continuously refers to Smil as the main thinker in this area is one of the reasons why the world doesn’t believe that transition can happen quickly, because Gates thinks Smil is right and thinks that it will take a long time. In Gates’s words, it will take a miracle to change things. What the late David MacKay did was give us a rigorous understanding of the way that we use and generate energy. The book is aimed at a British audience but he wanted it to have international relevance and it sold very well abroad. There is a great deal about the basic physics of renewable energy in the book but the majority of the numbers in the book are about British energy consumption and production patterns. Get the weekly Five Books newsletter Why this is such a successful book is that it marries both anecdote about how we use energy and a lot of physics to say what the constraints are on us with how that energy is generated, and the mathematics that govern how much we can extract or not extract per unit of time or unit of area. It’s the book that people like me always see when we’re giving talks to groups of people in cold community centres halfway up the country. In the front row there are reliably a few hard-headed engineers with this book sitting on their laps. Their copies of MacKay’s book often have bookmarks showing at the top and have many annotations throughout the text. They quietly wait to challenge anything stupid you say. Although ten years old now, it is extraordinarily influential and it appeals very much to the trained mind because it uses readily comprehensible science to prove its points. I think that is indeed what he wanted us to take away from this. He hoped we would say ‘Crikey, this is going to be very difficult indeed. We really do need to invest in nuclear energy. We don’t have any choice’ . But I think that a lot of his assumptions about renewables now look very conservative. Renewables such as wind and solar are far, far more effective sources of energy than he indicated a decade ago. He definitely didn’t project that. He also didn’t project that mainstream commercial solar panels would become as efficient at collecting sunlight as they are today. He told us what the absolute maximum efficiency could be because that’s set by physics, but what he wasn’t able to do was to predict the way in which solar power would come down in price worldwide. He also didn’t want us to put large amounts of solar panels in fields. In a sense, he was an unashamed romantic and wanted the English countryside to stay as it was and thought it would be better to have fifty nuclear power stations dotted around the country rather than perhaps 10 to 15 percent of the country given over to renewable generation of one form or another. I think he was probably wrong but I understand his reluctance to change the landscape. Were he working today, I think MacKay would recognise that nuclear power now looks very expensive compared to renewables plus storage. The other thing that he doesn’t deal with in any way in the book is demand management. That is to say, the whole of the electricity system in the UK and most other parts of the world was set up simply to provide the availability of capacity to produce as much electricity as could ever be needed at the peak half hour, which in this country is on something like a December Thursday at about 5 o’clock in the early evening. We now know that it’s actually rather easy to get people to change their electricity consumption patterns, either by price or by digitalised assets of one form of another. David didn’t talk about that here. He was trying to build a world in which there was availability whenever we wanted it, at a consistent price with no risk of intermittency and no worries about not being able to produce electricity whenever we want it. So, there is also very little in here about storage. There’s a bit about batteries and storage. But it was over ten years ago when he wrote, so that is understandable; he didn’t envisage the huge growth of electric cars and the falling price of batteries that has resulted from that."

"Well, this is a very interesting book by a very interesting person. David Mackay was a professor of physics at Cambridge, but also the chief scientific advisor at the Department of Energy and Climate Change, so he was very influential. Before he had that appointment he wrote this book, which really tries to put things in context. He does very simple, back-of-the-envelope sums, as to how much energy could we get from bio-fuels, how much energy could we get from wind power, how much land would it take? He looks at all these scenarios that you hear talked about, and his conclusion is that they can make a significant contribution but it is basically not going to solve the problem. We are probably going to need additional things like carbon capture and nuclear energy to help fill the gap."

"The best thing about David’s book is that it simplifies all the issues. So many people in the energy market make it really complicated, so that no one can really understand it. What David did was to take it down to some simple numbers across the board in terms of how much energy people use in their homes, how much energy people use in their cars, what we use as a society, and what that is going to look like in the next five, 10 or 20 years. If we want to provide power from alternative sources, where can that come from? What are the resources at the moment in the UK and what are the possibilities? This is a fantastic piece of work to start people thinking about this in a wider debate, rather than just amongst scientists and energy specialists. He broadened it out to lots of people who might find this kind of information difficult to collate themselves. He came up with six or seven possible outcomes of what you could do. He now works at the Department of Energy and Climate Change, and they have created a pathway so you can create your own model of the future based on the work that he did in the book. We’ve done that at Good Energy, looking at what you would need to do and what technologies you would need to introduce to make the UK 100% [renewable] by 2050. It involves changes to UK energy at every stage of the process, from grid management to investment, and from research and development to transport. The answer will be increased electrification of all our networks, in turn pushing electricity demand to at least double current levels. Meeting that increased demand from renewable sources will be more than a goal, it’ll be a necessity."