Back to: In the home agenda
Kaela: So, our next speaker today is going to be Professor Nick Eyre from University of Oxford, and I'll leave him to tell you what he's gonna talk about.
Nick Eyre: Thanks. Thanks, Kaela. And good afternoon ladies and gentlemen. Yes, so I work in the University of Oxford and I also work in a centre that's called the Centre for Research into Energy Demand Solutions. And as the name implies, I with my colleagues therefore spend quite a lot of time thinking about how we use energy in lots of different ways and particularly how we can use less energy whilst making our lives better. I think putting those two together is important. There's various freight terms that get used, energy conservation, energy efficiency, saving energy, energy demand reduction. They all sort of basically mean roughly the same thing. It's about how to get more value out of the energy that we use, how to make our lives better whilst using less energy. And historically this has been really important. It's been one of the main ways, probably it's, in fact it's been the most important way that we've reduced carbon emissions today, is through through energy efficiency. I'm gonna focus on homes because that's what we're talking about. And this is the only graph I'm going to show you. So this graph shows how much energy we've used in all our homes put together in the UK in each year from 1970 through to 2018. It's a bit pf a wiggly line and that's because in any one year it really depends how cold the winter is, how much energy we use, as you might expect. But what you say about the general trend is it goes up until about 2004, 2005 and then it and then it starts to go down on. You would sort of expect it to go up historically, because we've had more homes, we've got warmer homes, we've got more energy using equipment in our homes, huge changes in that way since the 1970's for those of you can remember that far back. So many people think it's a bit of a surprise that it's now going down and the reason for that is that we are using energy better through some of the techniques that I'm going to talk about in the next few minutes. We are we are doing better. We are reducing our energy demand, and that's driven to some extent by individual action, but actually much more by the action of government which around about that time started taking how to reduce energy demand seriously. So that's a really important point.#
I'm going to talk about just four basic ways in which we can reduce energy demand in our homes. So the first is insulation. Houses lose heat through the roof, the walls, the floor, the doors, the windows. And in all those cases we can insulate them better. So all insulation means is slowing down the rate of heat loss through something. And if we reduce the rate of, that heat is lost from a house, then we reduce the rate we have to put heat in, so we don't need as much heat from the heating system. That means it's cheaper to run the heating system and it means the carbon emissions are lower.#
As Jenny said, for new houses, this should be relatively easy, so I'm going to focus on on older homes. Now each home is different. We've actually done reasonably well in UK homes in rolling out loft insulation, and double glazing, most homes have now got that. An early priority I think, must be to do those more of those measures to make sure that every home has got those. And that would reduce our energy bills by about 5 to 10%. But the largest savings are going to be more difficult, and that's principally because they are more disruptive and more expensive. We're talking about things like ripping up floors to put insulation under the floor. We're talking about putting a thick insulation on the outsides of solid walls, things that are really quite disruptive and quite difficult. And so that does raise some skills, which I think you might want to think about. How do we how do we get a building industry that can do these measures at the scale that's needed? How do we provide the right incentives for householders to want to do this? Because it's quite disruptive and who pays for those, who pays for those measures? All of those I think are going to be the really difficult questions that Jenny mentioned.#
The second way we can reduce energy use in our homes is by increasing heating system efficiency. Now the next speakers are going to talk quite a lot about heating systems, so I'm not going to say a lot about this. But it is important to think about the efficiency of the heating system, how much energy is needed in the heating system to keep a home warm. Again we've got a cup half full a cup half empty issue. We've done very well in rolling out condensing boilers, which are an efficient sort of gas boiler. Most homes have a gas boiler, now they're mainly condensing, and they're a lot more efficient than old fashioned boilers used to be. And if you remember that graph I showed you, one of the main reasons that energy use has started to come down is that our gas boilers are a lot better than they used to be. But as this slide shows we probably need to change to an even more efficient system. I think most people think that heat pumps will play a big role in the future. And the point of a heat pump is that unlike a boiler, which where you burn fuel to produce heat, a heat pump you use some fuel to pump heat from outside the house to inside the house, so you get more heat into the building than the energy that you use in the heat pump. Now, again, we're talking about quite disruptive, quite quite big changes, and I know that the next speakers are going to talk to about that. But in many ways it raises the same sorts of challenges that I talked about for building insulation. How do we get the industry to make such a huge change? How do we make it attractive for householders to do this and who's going to pay for it? The same sorts of issues apply.#
So my third area that I want to talk about is reducing temperatures in homes. This is where it maybe gets a bit more controversial. But the facts are that for every one degree centigrade we reduce the temperature in our homes, we save about 10% of the fuel bill. And therefore about 10% of the carbon emissions from heating as well. So there are real cost and environmental benefits in doing this. Now it's it's not without problems. Far too many people in this country still live in homes that are too cold and where they are, where these are families with young children or those people who are sick or disabled or elderly people, there are really health risks if we make those homes colder, so we shouldn't be thinking about making all our homes colder. But for those of us fortunate enough to be healthy adults living in warm homes then actually we can live in cooler conditions. And I think it's fair to think, how can we do that? There's two broad ways we can do that. The first is using controls, so controls are already extensively used. Timers, thermostats, radiator valves, those sorts of things, most of you will will be familiar with. What they essentially allow us to do is not overheat buildings or parts of buildings, or to switch the heating off when there's nobody there. Which is of course a very wasteful thing to be doing. I think we're beginning to see these sort of devices come come onto the market. Some of you may have them in your home. Smart thermostats. I think again they will help us deliver that sort of smarter approach to having the right heat in the right place at the right time. So controls can do quite a bit for us. I think we also need to think about clothing and that may sound a bit surprising. I couldn't resist this photograph, sorry. So clothing is a sort of insulation, it insulates the people, or the dogs in this case, rather than the building. And so we all know if we put on extra clothing we can live comfortably at colder temperatures. And modern clothing, things like fleeces, are much easier to wear, they're much less bulky than old fashioned warm clothing. So it does seem to me possible that we could do this. I think it would need to be fashionable to be taken up. And I'm not the fashion expert, so I'm not going to talk about how to make fleeces fashionable indoors. But it's something you might want to think about because, you know, why do we live all in short sleeves when we could wear warmer things. And if in the broader context, you're going to be asked and I think you are, about thinking about how you travel, what your diet should be, then what you wear inside, I think, seems a sensible thing to put on that list. So that's the third area reducing temperatures in homes. Now all those three areas insulation, improved heating systems, reducing temperatures in homes, they are all about heating. And as Jenny showed you, water heating and space heating are most of what we what we use energy on.#
So I've got one slide to go. But the rest of our energy is used in lights and appliances, roughly equally split between cooking, lighting, refrigeration, washing and electronic appliances. Again there's a pretty good story to tell in some areas here, that the light emitting diode bulb of that type is 10 times more efficient than a tungsten light bulb. In other words it only uses one tenth of the electricity to produce the same amount of lighting. The similar good stories to tell. We use much less energy in fridges and in freezers than we used to do. You'll have seen this energy label on many of those products in shops that helps us buy the right product, but it also helps government regulate those products. So you can't buy inefficient fridges anymore. It's illegal for people to sell them to you. There are areas where demand has been growing. Not surprisingly in electronics, and we will always need to keep an eye on these areas where products are growing rapidly. So I'm just going to end with a few conclusions. Some of this is easy and some of it's difficult. So you know, not buying the wrong wrong product that's relatively easy, insulating our homes, changing heating systems, that's going to be much more difficult. That means that some of this we can do each of us independently, but actually a lot of it is going to need government and business to work on this with householders to make these big changes happen. So I think it's a needs to be a shared enterprise, but it has to happen. We're not going to get to net zero without most of these changes. Thanks.
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