Reflections on energy and housing


Jenny Love, UCL Energy Institute

I’m going to be leaving academia in a couple of months. Aside from my colleagues being able to finally get some peace and quiet and not having their chocolate supplies taxed on regular occasions, there are some other benefits to this. One is that it has made me reflect on what I have learned whilst doing a PhD in energy and housing. Here are four reflections that you may find interesting.

1. We still don’t really understand a lot of factors behind energy use in buildings.

Much of the blame for this can be attributed to a poor evidence base for physical performance of houses. For example, not enough studies have measured energy use and linked it to real measurements of heat loss from the building. Researchers like Virginia Gori, Sofie Pelsmakers and Sam Stamp are working on these actual measurements.

If we don’t understand how energy is used in the first place, this makes knowing the effects of things like retrofit quite difficult to predict. Researchers like Ian Hamilton are using the best data we currently have to assess the effect of energy efficiency measures.

2. Social scientists and physicists/engineers must go further than just collaboration

We have an unfortunate tradition in our field of a lack of respect between physical scientists and social scientists. What I mean by saying we must go further than collaboration is not just working together and bearing with each other – but setting an example of genuine appreciation of the other’s discipline – including stopping dissing each other’s disciplines behind our mutual backs. When I started my PhD I didn’t know much about social science, and therefore used to be quite rude about it. Now I have come to see that it’s the people who bring about the physics in buildings that I like to study. For example, I described here how when houses are retrofitted, the outcome is determined by the amount by which the occupants adjust the heating. Researchers have to understand what made the occupants adjust the heating, and then the effect that this has on energy use.

The best combination of social science and physics in one project I’ve seen is the work Lai Fong Chiu and Bob Lowe‘s Retrofit Insights team are doing, here. As it happens, the two lead authors of this study are married. Now, although this happened before they wrote the study, there’s nothing to say it couldn’t happen the other way round – you never know, multidisciplinary collaboration could lead to love. In my role as Dr. Love I’m happy to point you towards eligible physical or social scientists with whom you could start a multidisciplinary collaboration.

Another person to keep your eye on is Adam Cooper of UCL STEaPP, who is doing great work in starting to develop the theoretical framework within which social science and physics can fit together in order to study energy use.

3. ‘Behaviour Change’, like religion, is (mis)used as an excuse for all kinds of wrongs

What I mean by ‘Behaviour Change’ is trying to get occupants to reduce their energy use by changing their home heating behaviour. This is only beneficial if there is actual evidence that occupants are exhibiting wasteful behaviours in the first place. In my case study sample in social housing, many of them were heating far less than average and trying to get them to turn the heating down would not only be morally wrong but also bad for the house (leading to more mould, etc).

The second problem I have with ‘Behaviour Change’ is that it is sometimes used as a pretend solution in order to avoid the real issue – the fact that our housing stock is among the least thermally efficient in Europe. We need to get on with insulating it, instead of trying to make people colder by using less heating.

I’m certainly not against occupant engagement. Quite the opposite. What I would recommend it looks like is firstly listening to the occupants about how they do use the heating, and then, only if they are up for it, deliver tailored advice which will help them meet their heating needs using less energy. Also. we should be giving advice on wider aspects of maintaining a healthy home, like how to ventilate adequately.

4. Separate energy/climate change policy from warmth policy.

A crude description of the way retrofit policies worked during the time of my PhD is that energy companies ‘offset’ their CO2 emissions by funding retrofit of social housing. There is very little measurement of whether energy or CO2 has actually been saved, but if there were, it would be seen that some occupants do not save energy but have a warmer home instead – in fact, this is what the occupants need. However, this would be counted as essentially a failed policy, even though the occupants now have a better quality of life. Maybe that’s why no one measures the actual savings.

There are two agendas going on here  – allowing people to be warm in their homes, which is very important, and mitigating climate change by reducing energy use, which is also very important but is the opposite to making people warmer. The more you do of one, the less you do of the other: in my mind, the trade-off is like this:

trade off

I think our climate change and energy demand reduction policies should not target
social housing – there are plenty of other places to focus energy demand at. This sector
needs policies measured in terms how much more comfortable the previously-cold
occupants become.


So, there are some thoughts. I invite you to challenge or add to any of them in the
comment section below. As always, feel free to contact me on if you would like to have a more detailed discussion on anything raised above or have any questions about energy and climate change in general.

Becoming Dr. Love: part 3 (does behaviour matter?)

Jenny Love, UCL Energy Institute

Now, I realise that taken out of context the title of this post might be interpreted as, “Dr. Love will now answer your relationship questions”. Please don’t write to me with your relationship problems – I won’t be able to help unless they can be solved by building physics.

The title is actually referring to the implications of the previous post here, about the fact that when dwellings undergo energy efficient retrofit (e.g. insulation, double glazing), the outcome which arises is partly dependent on how the occupant reacts. I found some occupants who kept their home colder afterwards; I found others who for various reasons increased their use of heating and made their home much warmer. I couldn’t have predicted which occupants would do what.

This post is the ‘so what?’ question: does it really matter that occupants react to retrofit in different ways? What effect does this variation in behaviour have on their energy use?

I am going to explain the answer through the medium of cheese.


Now, that’s not entirely helpful in its current form: why this answer, and why the cheese?

  1. A model

When you’re trying to speculate on the value of something you can’t measure, you can use a computer model. For example, I wanted to know what the energy use of a household would be, at all different levels of insulation (a physical variable), and at all different levels of how much the occupants have the heating on (a behavioural variable). I couldn’t go and measure the same house with various different levels of insulation and various different types of behaviour, so I simulated it in a program called EnergyPlus.

  1. The results

After going to all the effort of learning EnergyPlus and working out how to assemble the results on a graph, all of which involved some near-all-nighters, a lot of tea and a significant quantity of Maltesers, I was rather disappointed to see that I had in fact produced….

…a large piece of cheese.

Let me explain. By the way, if you hate graphs, you can at this point skip to the summary.


The cheese shows energy use plotted against heat loss of the building, at different types of occupant heating behaviour. It is marked out by a blue line at the bottom and a red line at the top. The blue line is the relationship between energy use and the leakiness of the house for the situation where the occupants have the heating on as little as is realistic: one hour per day, only at 16 degrees C, only heating one room. If their house is leaky, they end up using more energy, but the relationship is not very steep.

The red line is the situation where the occupants have the heating on as much as possible: 24 hours a day, at 23 degrees C, all rooms of the house. You can see that the relationship is very steep: if the house is leaky, they use a lot more energy.

Since the blue and red lines mark out the extremes, everything within the cheese in between them represents possible energy use at possible types of heating behaviour. The green line in the middle, for example, represents people who have the heating on for 9 hours per day, in some rooms, to 20 degrees C: a sort of medium scenario.

Retrofit is moving from the right of the cheese, to the left. How far you go represents how ‘deep’ the retrofit is – how much more efficient the building is made.

Example 1. Shallow retrofit, no behaviour change

The type of houses I monitored started out where the pink dot is on the picture below. That is, they were very leaky and they weren’t using the heating very much. Let’s say that one of those houses then had the type of retrofit which really occurred on this estate (‘shallow’), and the occupant didn’t change their use of heating at all afterwards. The arrow represents how the house would move through the cheese. You can see that slightly less energy is used after retrofit.

cheese graph shallow no behaviour change

Example 2: shallow retrofit + behaviour change

This time, imagine the occupants do change their use of heating after retrofit. I saw people changing their behaviour in a variety of ways, so this can happen. In this picture it’s taken to the extreme – all possible changes in behaviour are shown.

cheese graph shallow behaviour change

There is a massive variation in energy use after retrofit resulting from this. Energy use could go down or up quite a lot. We might think it’s quite unlikely that after retrofit people use more energy than before, but I saw it happen in my small sample. Furthermore,  when new people move into the house their comfort standards might be a lot higher than the old occupants. I  saw this happen in my sample too, as some of the post-retrofit occupants had a baby and so had put the thermostat to 28 degrees C!

Example 3. Deep retrofit, behaviour change

cheese graph deep behaviour change

This time, imagine the houses start leaky and are made extremely efficient. The same variety of change in occupant heating behaviour – people going from the start point down to the blue line and up to the red line – as in the last graph, is plotted on. But this time, look at what happens to energy use. Whatever the occupants do – however they change their behaviour after retrofit – the resulting variation in energy use is very small. That is, in very efficient houses, whatever the occupants do with the heating doesn’t have much effect on energy use. That means it’s easier to predict the energy use after retrofit, and occupants can live in a warm house and still save energy, without us having to tell them what to do or trying to change their behaviour.


What I am arguing for, through the use of cheese, is that if we only have one chance to retrofit a building, we should do it deeply – put a lot of insulation on, treat all the places it loses heat – as opposed to ‘shallow’ retrofit – what the current policies are leading to in social housing. It is important that energy use decreases after retrofit whatever the behaviour of the occupants who live there through the retrofit, and whatever the behaviour of the the next ones who move in. I did see people increase their use of heating after retrofit, and I also saw new people who moved in and used heating more than the previous ones, and it is important that these actions still result in lower energy use than before.

I hope the cheese made sense to you. Any questions, feel free to ask – although  the invitation to ‘Ask Dr. Love’ applies strictly to energy and buildings…


1. There are many caveats to this work, and in applying the use of a ‘model’ to real buildings. I didn’t go into them here – this is a conceptual argument and not absolute truth.

2. For those who love graphs, you can find a more academic version of this argument here. Not for the faint-hearted.

3. I should say thanks to two very clever people: Tadj Oreszczyn and Andrew Smith (aka my supervisors), for helping me interpret the cheese graph and its five-dimensional counterpart which appears in my thesis.

Becoming Dr. Love: Part 2 (what occupants do)

Jenny Love, UCL Energy Institute

In my previous post here, I described the process of PhD data collection and some of the odd things which can happen when carrying it out. After publishing that post I went quiet for a bit to concentrate on the small matter of turning the data into a 90,000 word thesis. Having done that, and then recovering by alternating between sleep and eating nutella out of the jar, I am ready to face the world again. So in this post and the next one I’ll be describing some of my findings.


In this post I’ll talk about what light was shed on the complexities of occupant behaviour in the context of retrofit: how occupants change their heating behaviour afterwards, and why internal temperatures increase.  In the next post I’ll report some implications of this concerning whether our current retrofit strategy for social housing goes far enough.

What was I trying to find out?

There is a general concern that retrofit, here referring to insulation of dwellings, doesn’t save as much energy as it should for all the effort of wrapping a house up in a blanket. That’s because it is suspected that instead of what  is ‘supposed’ to happen (i.e. the occupants keep the heating at the same level after the retrofit and save energy), occupants will take this chance to heat to higher temperatures or for longer, and not save much energy after all. This is especially expected to happen in ‘fuel poor’ households: those who before retrofit struggle to heat their home to the temperature they would want, for whom insulation might mean they can be warmer.

As I described in more detail in the last post, instead of looking at just outcomes of retrofit  (i.e. these people saved X kWh of energy, or it was X degrees warmer in their house afterwards), I looked also at what actually happened in the homes: what did occupants think the retrofit was all about; how had they changed their use of heating since; were they using their home differently and was this requiring more or less energy? So the sort of things I was measuring were: their use of radiators, air temperature and humidity, and use of space;  I also interviewed the occupants before and after.

Variety in occupant reactions

When you wrap up a building in a big pink jumper (see photo below), it will lose heat less quickly afterwards, and so its average temperature will increase without the occupants doing anything.


But how occupants then react to this natural temperature increase is different in different households. I found three types of occupant reaction, ranging from occupants practically eliminating their use of heating to occupants using more hours of heating:

1. Temperature increase from the building, counteracted by occupants

Two of the case study households turned down the heating so much that the temperature went down after retrofit. However, they reported feeling warmer. How could both of these phenomena have come about? Here’s what I could gather from my data…

Both of these households had an income cut around the time of the retrofit and were really struggling for money. Also, before the retrofit they were both expecting the retrofit to lead to a warmer house with less heating needed. This could explain why they turned the heating down so much. But why did they feel warmer? I looked in the air temperature data: had the particular rooms they used got warmer at the times they used them? Or had the daily minimum temperature they experienced increased, say, when they got up in the morning? Neither of these had occurred. I had to conclude that there must be other comfort variables at work, like radiant temperature.

2. Temperature increase from the building, no change in occupant behaviour

These occupants carried on using the heating in pretty much the same way as before: they didn’t turn anything down, and they didn’t turn anything up. As was mentioned above and will be further explained below, this still leads to an increase in internal temperature.

3. Temperature Increase from the building, then occupants used more heating

Two different and interesting processes were seen in households who used the heating more after retrofit.

In one flat,  the occupant didn’t really bother with the central heating before the retrofit since the building was so leaky that it didn’t seem to make a difference. He heated the living room with a gas fire and stayed in there. After the retrofit he started using the central heating since it now actually did something.

In another case, even though the insulation made the house warmer, different rooms warmed up by different amounts. This had the effect of making the occupants’ bedroom feel cold, as it hadn’t warmed up as much as some other rooms. So they started heating the whole house all evening, so that their bedroom would be warm enough by the time they wanted to use it.

Turning heating up, down, the same…does that mean that anything can happen?

Yes. I will argue in my next post that with this type of ‘shallow’ retrofit (10 cm of insulation), it’s very difficult to predict the outcomes since you leave a lot of room for different outcomes to be possible, especially when new occupants move in. However we only started to see a glimpse of the range of possible outcomes. With the same people living there after retrofit as before, occupants probably aren’t going to massively increase their energy use after retrofit so we probably aren’t going to see those kind of outcomes.

Also, just because occupants reacted in a variety of ways, doesn’t mean that how they reacted totally determined the outcome. As we’ve seen, the building theoretically has a lot to do with it. We can try to quantify its influence in a few ways…

In most houses there was a temperature increase. What was it mostly caused by?

The answer is not the occupants but the building itself. How can I know this? By looking at when it occurred…

Firstly, most of the temperature increase compared to the previous year occurred when the heating was off. That is, the times when the heating was off, post-retrofit, were warmer than the times the heating was off pre-retrofit. I had a fancy equation to calculate how much of the temperature increase occurred during unheated hours, and it turned out to be 77-87% across the houses.

Within this, quite a bit of the temperature increase happened at night. It’s possible to see the houses cooling down slower at night, when the heating was off, whilst the occupants are fast asleep and therefore not thinking, ‘I know, I’ll increase the temperature in my dwelling’.

In some houses, the hours in which the heating was on got warmer after retrofit (accounting for 5%-23% of the temperature increase). This wasn’t due to people turning up the thermostats. It was either that the thermostat was at a sensible setting and the building was too leaky to get that warm before retrofit, or the thermostat was at a non-sensible setting like 30C (for whatever reason) and the heating system tried its hardest but still couldn’t reach it.

What to make of all this

The first point is that if the temperature increases in someone’s home after retrofit, it’s not necessarily their fault or their intention. To get the temperature not to increase, occupants would have to shorten their daily heating period by quite a few hours. Even when they increase their hours of heating, most of the temperature increase is still attributable to the building cooling down more slowly. So we can stop occupant-blaming.

not guilty

Secondly, there was quite a large range in terms of how occupants reacted, and whether they turned heating up or down, which makes it difficult to predict outcomes. However, this was a small range compared to what could have happened. I haven’t explained this statement yet, as I explore this further in the next post, where I talk about the effect of new tenants moving in over time –  and how the current way we do retrofit means we can’t guarantee energy savings afterwards.

That’s all for now – but feel free to get in touch with me if you would like any more detail on the sort of mechanisms I uncovered or if you have any questions:

Becoming Dr Love: Part 1 (what I did in my PhD)


Jenny Love, UCL Energy Institute

I have been blogging about energy-related topics for over a year now, and so far haven’t said anything about my own research. In this post and the next one (forthcoming), I’ll describe, hopefully in a fun way, how I went about doing research on making social housing energy efficient, and what I found out. This one, part 1, describes what I did and some of the adventures I had along the way.

The point was to go and find out why, when social housing is made energy efficient by putting insulation and double glazing in, not as much heating energy is saved as was predicted – instead, the house becomes warmer. Now, this could be because occupants find heating cheaper and decide to use more; it could be that they use their heating exactly the same after the insulation and the house keeps heat in better and so the temperature goes up; there are various other options.

Now, much as I love doing it, sitting in an office drinking tea and staring at graphs was not going to solve this one – I decided on a ‘mixed empirical methodology’ which involves going and finding out what is going on in the houses both physically and from the occupants’ point of view. On the physics side, I decided to measure (both before and after the insulation) temperatures, radiator activity (to find out how they used heating) and use of space (to find out if they were able to use more rooms in their house when the rooms got warmer). On the occupant side, I decided to interview people in their homes about their life there, the cold, the insulation, and other topics.

After gaining permission to do my research on a particular council estate, the first thing to do was recruit households. Now, other researchers use sophisticated-sounding ways to do this, such as ‘stratified random sampling’ and ‘systematic sampling’. Although it hadn’t been my intention, the method I ended up using to recruit people was: pity. Imagine: it’s snowing outside; you hear a knock at your door, and a girl and her friend are standing outside, teeth chattering. The girl is wearing oversized steel-capped boots she has obviously borrowed from a man, and a ridiculous yellow jacket like a lollipop lady. You have never heard of UCL Energy Institute and have no interest in what she is doing but since her lips are blue you bring her in and give her a cup of tea.

It was pretty much like that.

Some things stick with you when you go into random people’s houses. I now present an extract of probably one of the weirdest conversations I’ve ever had:

Occupant: “When we have the double glazing we’ll have to move Emily”

Jenny: “Emily?”

[Occupant points at very large model triceratops on the floor of the living room]

Jenny: “…Aah.” [for some reason the next thing that came into Jenny’ head was:]”For some reason I thought it was male.”

Occupant: “Oh, no. Listen to this: EMILY!”

Emily: “Raaaaah!”

Jenny: “Oh, it knows its name…”

Occupant: “Oh, yes. But it gets even better: put your hand in her mouth.”

Jenny: “I don’t know if I want to do that”.

[Jenny does it anyway]

Jenny: “Ooh, she’s teething me!”


So anyway, one month later I thought I had enough data from the houses, so went back to take the sensors out and interview the occupants. I arrived at the first house to be told that the children had taken the sensors down, and why had I put them up, they looked so much like toys. I apologised. I went to the next house and was told that the cat had taken the sensors down.

cat in 184 mary slessor

This very cat, yes, the one shown sitting here on my bag of sensors, out-intellectualised a PhD student by pointing out a flaw in her research design. I should invite it back to be my PhD examiner.

Aside from animal sabotage, some serious and quite sad things emerged in the interviews. One lady lived in the mouldiest house I had ever seen, and appeared to be trapped in a vicious cycle. She had COPD, which is a lung condition in which any cold caught goes to the chest and the sufferer ends up being rushed to hospital unable to breath. Her doctor had told her there was a simple way to stop this: turn the heating up to at least 18°C. But she couldn’t afford to do this. She was unable to work because of the condition, but that meant she was stuck in her house for longer, and couldn’t afford to have the heating on, so got more ill, so couldn’t work…etc…. I was wondering if the insulation would help break this cycle. I had never realised how important housing condition is in people’s lives. Staring at graphs or being in a lab would never have brought this kind of insight to my attention – you have to get out and chat to people in their own context.

After taking down all of the sensors which the children or cat hadn’t kindly done for me, I went back to UCL. It was a relief to finish wandering around in the snow, but equally it felt strange to go back to my plush office, knowing that the occupants were stuck in their freezing and sometimes mouldy houses. Anyway, it was time to analyse the interview data. I had thought I would cringe at hearing my own voice on tape, mostly due to my accent going strangely northern when I talk to people whom my subconscious decides are less posh than I am, but that was nothing compared to some of the questions I had accidentally asked:

“So, is there anything else you do in your bedroom to keep warm?”

[occupant changes the subject]

A year later, insulation and double glazing had been installed in the houses, and it was time to do my study again. Maybe because it wasn’t so stressful the second time round, I noticed a lot of things on the estate I hadn’t paid attention to the previous year: the prevalence of pubs, off-licenses and betting shops as opposed to healthier activities like anywhere to have a cup of tea, the lack of employment and purpose amongst the youth, and how recent welfare changes were affecting the people on the estate. I decided I did not want to just come in as the researcher and take from them, by gathering data, then leaving – I wanted to give them something back. I tried to show interest in their lives and always ask about them and their families – but I gradually realised that the main thing I had given them was a sense of value when I asked them to be part of the study. One occupant even reported that nobody normally wanted to know him, never mind study him. They felt they were giving something by being part of the study, and in that they felt valued. This had the side-effect of changing my opinion on how we should do social action in our communities – by involving people and doing things together with them, as this makes them feel more valued than just doing something for them of which they are the passive recipient.

I took extra care to make my sensors cat-proof and dinosaur-proof this time, but something I couldn’t avoid was that three sets of tenants had moved out since the last time I was there. I wanted to re-recruit the new people in those houses to be part of the study. This time I didn’t use pity, but cheerleading. As I was explaining the study to one potential recruit, another of my tenants, an elderly gentleman, came bounding up behind me, dancing around and exclaiming, “They’re good sensors!” The man whose front door I was stood in front of ushered me in quickly and shut the door.

In conclusion, having tried it I would recommend the method of collecting both physical data from sensors and gaining the occupant view from interviews. I would also recommend people who work in or want to work in policy to go and spend some time with the people that the policies affect. It was really special to do something together with the tenants for a while, and I learned a lot from them. In the next post you can read about what I actually found out!


What are the options for making privately rented housing energy efficient?

Jenny Love, UCL Energy Institute

leaky house

1. Introduction

Privately rented housing is universally acknowledged to be pretty cold, leaky and difficult to treat. There are 4 million privately-rented dwellings in England, and they are on average older and contain a higher proportion of the lowest bands of energy efficiency of the above types of housing. (you can see the facts in the English Housing Survey here).

Once I rented a flat in London where we sat, with the windows closed, watching the Christmas decorations in the kitchen blow off the wall. At least we never had to worry about letting in enough fresh air…

Why is the private rented sector lagging behind other types of housing in some areas of energy efficiency? It’s often due to a phenomenon known as the ‘Split Incentive Problem’, which is as follows: the tenants aren’t going to pay for energy efficiency measures, since they won’t be there long enough to reap the benefits of all they have spent. However, the landlord won’t pay for the measures either, as he/she doesn’t pay the energy bills so isn’t losing out from the property using a lot of energy to keep warm.

This article will go through some of the ways that have been and are being proposed to get around the Split Incentive Problem. See what you think could work in your situation, or not, as the case may be.

2. What’s being done about minimum standards?

In terms of the worst housing, there is good news (in a few years’ time, anyway – hold on to your Christmas jumper for now…):

– From 2016, landlords will not be able to “unreasonably” refuse requests from their  tenants to improve rented accommodation. I’m not sure what the definition of “reasonable” is and whether I could bring along my floored Christmas decorations to the negotiations, but it seems that such definitions are being worked out at the moment.

– From 2018, “the most inefficient properties, very likely those with an Energy
Performance Certificate (EPC) rating of F and G”, will become illegal to rent
(unless the landlord can show that all “reasonable” steps were
undertaken to improve a property but still no better than an F-rating was

I got the above from here, the group currently working on this on behalf of the government. It is welcome news that those housed in the worst conditions will not have to face extortionate bills any more, particularly those on low incomes, but on the other hand I also wanted to know what was being done to improve the rest of the stock – that which was not as dire but only mediocre in terms of energy efficiency.

3. What’s being done to bring houses up to better ratings than minimum?

– On the landlord side, they are able to claim £1500 of tax back under a scheme called the Landlords’ Energy Saving Allowance. To be honest, I’d never heard of this until researching it. Take-up by landlords has been rather low; I wonder if they haven’t heard about it either?

– On both the landlord and tenant side, a possibility to pursue is the Green Deal scheme. It’s worth spending a bit of time on this, to ponder its applicability as an option…

4. The Green Deal, as applied to private rented housing

Different readers will know different amounts about the government’s Green Deal scheme (you may have seen that my colleague and I wrote about it a year ago from a marketing perspective here). In a private rented context, the premise is that instead of either the landlord paying or the tenant paying for the energy efficiency works, the Split Incentive can be got around by no one paying. That is, no one pays up front. Tenants pay, as their bills will be reduced, so the cost of the works gets put onto their (electricity) bill, in a way that overall the tenants are paying the same or slightly less for their bills than they would have been had they not had the works at all.

Despite this being one of the topics we academics like to criticise over a cup of tea and a Penguin bar in the kitchen at work, and perhaps more seriously the fact that everyone left right and centre is criticising the way the Green Deal has been put into place, I wanted to hang on to it as a concept and think about how it would take shape in a private rented context. What follows is a thought experiment as to how the dialogue between a landlord and their tenants would go. It is telling that it is only a thought experiment – even though I am an Energy Freak I am still too scared to actually have the conversation with my landlord.

The first question is: who would approach the other: the landlord or the tenants? There are some fantastic energy-conscious and savvy landlords out there who want to install energy efficiency measures to make life better for their tenants and also to increase the value of their property, but in general I suspect it would be the tenants who had the most incentive to do a Green Deal since we’d be the ones living in the cold house.

What happens next in my imagination is that one or all of us in the house emails the landlord with a link to the Green Deal scheme, politely explaining that if we do it carefully, we can find a Green Deal Assessor who doesn’t charge to come and advise us what can be done to the house. My colleague Sofie has a great blog explaining what this bit of the process feels like for an owner-occupier here.

Probably, the next thing that happens is that the landlord says no. Nothing against landlords, but from scouting around on the internet as advised by this blog, it seems that currently the discourse between the government and landlords is not sufficient to convince the latter that it does not bring financial risk, such as being financially linked to one’s tenants if they default on payments, etc.

Then, in my mind, unfazed by this initial response, I email back and explain that everything will be fine. The landlord asks if I know any other tenants who have undergone this process.

At this point I look up some statistics, do a bit of maths, and calculate that there have been just over 700 Green Deal assessments on behalf of private rented landlords or tenants. To be honest, this is not bad at all – as I was commencing my thought experiment I imagined there may have been none.

What happens next? I don’t know, but what I do think is this: even though the Green Deal has been widely criticised, it is in theory a way to get round the Split Incentive Problem – and in fact, for the moment it is the Only Way, so in some ways we should do our best to make it work. I was encouraged that there had been assessments carried out in the private rented sector – meaning that the potentially awkward conversation between landlord and tenants has occurred to an extent that as agreement was made to let an assessor in (assuming that the properties were occupied when the GD assessment took place).

5. Conclusion

To sum up, it seems that currently, it is a choice between the Landlords’ Energy Saving Allowance or the Green Deal. One is unheard of and the other is problematic but should cover more expensive works than the former. The social dynamic of the landlord and tenants coming to a point where both agree that works will be carried out is currently difficult as the schemes are not mainstream to either party. In a few years, there will be relief for those in houses with very high heat loss, but for now, here’s what we did (all you need is a hairdryer, a local B&Q, and about £7…)

The next Brian Cox

two screenshots gif

Jenny Love, UCL Energy Institute

Featuring the work of Peter Warren, UCL Energy Institute

I’m very excited to feature my colleague Peter Warren’s recent work in this post. In a move to enable the general public to understand and engage with energy and sustainability issues, he has created the following two short films:

The View From Here

And Look Beyond

Since it’s quite unusual for an academic to use the medium of film to communicate his work, I asked Pete to explain more:

1) Why did you make these films?

I decided to make a series of short films about sustainability that could test the use of film as a medium to communicate energy and climate change research to the public, and to help stir individual thinking on the topic.  With no experience in making films, limited equipment, little time, and a £0 budget I managed to create these films.  I feel that researchers need to have a more engaging role with the public on such important issues, and to use more appealing methods of communicating their work, such as through TV, film and media.

2) What are the contrasting techniques you used in the two films?

The first film takes a more traditional approach to documentaries using factual information, though brings large and complex issues to the individual in their home by highlighting how they specifically contribute to some of the issues facing the UK over the next 5-10 years, and what they can do to not only ensure the lights stay on and their environmental impacts are reduced, but to benefit them financially.  Music that I composed was used to bring out the images on the screen and the script.

The second film is half the length of the first film in order to leave a quick and lasting message on people to highlight that it is everyone’s responsibility to adapt the way we live.  The film similarly focuses on the short term and is split into two parts – how we could live and how we do live.  However, the difference is deliberately subtle to convey the point that it is not necessarily about ‘changing’ the way we live but ‘adapting’ the way we live.  Hence, I focussed on everyday solutions that are to some degree already present in society that people may or may not have consciously thought about.  In the long term the message would be quite different – we do need to ‘change’ the way we live, but this is not the focus of the films.

3)      The second film is quite unusual; what are some of the things you are trying to evoke?

The first film uses the sciences to convey the message, whereas the second film attempts to use the arts.  In making the first film I became very interested in how the sciences and arts can combine to better provoke thought on the subject.  Thus, in using music, poetry and scenery footage in the second film, I tried to get across a similar message (though on a larger scale, not just energy consumption) but in a completely different way.  In short, using the arts to convey science.

4)      What is the plan for future films?

I would very much like to make a third and final film in the series that combines both approaches, though weights slightly more towards the approach of the second film.  I plan to make the film longer (~30 minutes) and hopefully with a budget of more than £0!  Whether or not it gets made also depends on the response to the first two films.  I have some ideas for what would be included in the film and how I could make it different and more exciting than the first two films, but I won’t give away any secrets now!


Personally, I think there is a real need for creative media in the communication of energy issues to a wide audience. I love the second film because of the emotional reaction it creates, and the sense of ownership of the problem and responsibility to bring about a solution it gives the viewer.

I think Peter’s job here is more difficult than that of, say, Brian Cox, as it’s one thing to display the beauty of the Universe (some would say the programmes are more about the  beauty of Brian Cox), but to stimulate actual action or behaviour change from the viewer is a further step.

You can find out more about Peter’s PhD project here:


Should we invest in Carbon Capture and Storage?

power station

Jenny Love, UCL Energy Institute

Based on a lecture by Prof Geoff Maitland, Imperial College, London

1. Context

In the energy field, a common saying is, “There’s no silver bullet”. That is, there does not exist a solution to the question of which single clean energy source we should use, since energy demand is too large for any of them to supply on its own and thus we need to combine a lot of technologies. However, when it comes to funding to get these technologies off the ground, there are a lot of possible energy sources and not enough money to fund them all. Therefore the limited money should be used to fund the most promising ones, and this requires a kind of competition between technologies to show that they are more viable than others, in contradiction to our acknowledgement that we need a combination of them.

Carbon capture and storage – the processes of recovering CO2 before it is released into the atmosphere and burying it underground –  entails high costs to bring it to commercial reality. In this context of limited funding, what is its potential, and should we invest in it over other technologies?

The following simple overview is mostly shaped by a recent lecture by Professor Geoff Maitland of Imperial College London, filtered of course through my own interpretation and limited understanding.

2. Some brief science

I won’t talk much about the science of carbon capture and storage (CCS) as it can be found elsewhere if you’re interested. Briefly:

There are three ways to do the ‘capture’ part of CCS (which, by the way, is the most expensive bit). You can capture the carbon before or after the burning of fuel (‘pre- or post- combustion’, or you can burn the fuel in a special way (‘oxyfuel’).

Once captured, the CO2 is transported usually via a pipeline, and injected deep into underground spaces as a supercritical fluid (not too quickly, otherwise the rock will crack). Once it’s there, we have to make sure it stays in – from my simplistic understanding, by a combination of not letting it escape while it’s a gas (‘capillary trapping’), getting it to dissolve in water (‘dissolution’) and longer-term getting it to solidify (‘mineralisation’).

3. How positive or negative are the benefits and disbenefits of CCS?

Maitland argues that after energy efficiency, CCS is the cheapest and greenest way to mitigate climate change. He does not by any means suggest that we don’t need other technologies too – for example he points out that even in theory only a third of our CO2 emissions can actually be captured and buried (10 gigatonnes out of our global annual release of 30 gigatonnes). This is because many CO2-releasing applications are not stationary large power stations, but e.g. moving vehicles and domestic boilers, which it would not be cost-effective to fit with CCS.

CCS advocates often describe themselves as realists, since their premise is that fossil fuels are here to stay, at least while we transition [slowly] to a low-carbon economy, and especially for developing countries. Therefore  CCS is absolutely essential if we are going to mitigate climate change.

Concerns have been raised about the effectiveness of CCS, especially in terms of the energy it takes to do which decreases the overall energy produced at the power station, the safety and guarantee of storing CO2 underground, and the time it will take to get enough plants working. A Greenpeace document, False Hope, lays out some of these concerns. Maitland’s argument is that while these are real concerns, their extent is not is great as purported in the Greenpeace report.

4. What is the current state of the technology?

According to Maitland, the technology is “in good shape and ready for widespread deployment”. Its constituent parts, such as capturing CO2, and pumping gas into underground reservoirs, have actually existed for decades due to their use by different industries.

There are various CCS pilot projects going on around the world at the moment, including:

– An interesting project in Masdar, United Arab Emirates, who are powering the capture process by concentrated solar power, here:

– A plant operating since 2004 in Algeria, here:

– A French plant operated by Total, here:

As for the UK,  CCS is part of the Department for Energy and Climate Change (DECC)’s heat strategy to 2050. For the moment, the government and the UK research councils are going to help fund the construction of up to 2 commercial projects. Those two look like they will be in Aberdeen and Yorkshire. The decision as to whether they will both go ahead will be made in early 2015.

5. So if the technology is ready, why isn’t it being done commercially?

It comes down to lack of two things: incentives and certainty. Lack of incentives is seen in that carbon is not taxed according to the environmental damage it does; lack of certainty in that the carbon price and future regulation about carbon storage have not been set out. Is is therefore too risky for companies to invest in CCS assuming that it will be economic in the future.

6. Conclusion

I’d like to conclude with the following statement from Maitland’s lecture: “The real cost of energy from fossil fuels is the generation costs PLUS the CO2 mitigation costs”.

In other words, at the moment we’re paying an artificially low price for energy, and any way in which we generate clean energy in the future will come with an increase in energy price. But, remembering the Stern report in 2006, it’s cheaper to pay more for clean energy now then clear up after the mess we make from global warming.

I think we need CCS; I agree with Maitland that we should develop it now but then phase it out if non-fossil-fuel energy can one day provide for energy demand. The main thing we need to get it going is a decent carbon tax, then industry will be falling over to buy CCS and no one will have to wait for government funding.

(More detailed information for keen people here)

A different view of climate change


What do you think of the infographic below? It was created by

Its raison d’etre:” Many of us hear the term climate change, but don’t really know how climate change is changing the environment and what it means to inhabitants of earth. This infographic will show how bad climate change has become and what it means for all of us.”

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Where does our recycling actually go?

Jenny Love, UCL Energy Institute

Let’s face it, we don’t know, do we? In my office, I shove most of my recycling in here (see below), occasionally wondering why it’s necessary to clean food containers, but on the whole glad someone else takes care of my waste:


The story about to be told is a mixed one. Although recycling capacity has dramatically improved over the last decade, I’ll try to demonstrate how the UK’s drive for quantity at the expense of quality has ended up with much of our waste going across the world for reprocessing. I’ll argue that one way to keep it in the UK is for us to put some effort into finding out what we can recycle and taking the advice of that sign in my office –  clean our items.

  1. The sorting process

From your recycling bin, the waste makes its way to a Materials Recovery Facility
(MRF) to be sorted. I live in Wandsworth, London. Our council has a nice and reasonably honest document on recycling:

There I learned that the council has a contract with a private company (like all councils, I guess) to take our waste to the local MRF in Kent.

There are some clever automated techniques used to sort materials. Some rely on size (e.g. broken glass falls through holes as everything else is bounced along a converyor belt), others on weight (a jet of air blows paper off the conveyor belt), some on shape and weight (horizontal shaking sends light flat materials to the top of a pile whilst small denser ones like cans and bottles go to the bottom), magnetism picks up steel, and clever use of electric currents detects non-magnetic metals including aluminium. Many materials then need further separation, including plastics, but it’s not yet done in the UK (see section 3). The final quality control is done by people.

If you’d like to visualise it, here’s a nice video of the sorting process used in south-west England:

However, there are two main factors which muck up this sorting process.  Firstly, incorrect items being put in the recycling. These have to be picked out, sometimes by hand, and put into landfill. If they’re not spotted, they compromise the quality of the reprocessed material.

The other factor is contaminant on a material – e.g. grease on paper, cheese on pizza boxes. This also compromises the quality of the reprocessed material. I had always assumed that materials like cardboard would be washed as part of the recycling process, but it turns out that we’re supposed to do that before we put it in the recycling. It also turns out that the cost of dealing with these contaminants is driving up the cost of reprocessing (the next step after the MRF) so much that we often can’t afford to do the reprocessing in the UK (more on this later). Resource Association chief executive Ray Georgeson said: “The drive for quantity has come in part at the expense of quality, and what might be seen as the delivery of cost savings at the collection end of recycling appears simply to be shifting costs into the manufacturing end of recycling.” That is, allowing us to shove everything in the ‘all waste except food’ bin with very minimal instruction is costing us down the line at the stage when sorted waste is to be made into new products. ( ).

2. What is reprocessed in the UK?

Here’s a nice visual where you can click on a material and see if it’s reprocessed in the UK or not:

We can recycle steel (in Wales), aluminium (Midlands),glass and paper (Cheshire), some types of plastic (various destinations), and paper (all the newsprint made in the UK is from recycled paper).

Something I want to know is: what about mixed-material packaging, like envelopes and
sandwich wrappers? I love buying a Sainsbury’s Meal Deal due to the (entirely false) feeling of beating the system when I only spend £3 as opposed to the sum of the constituent sandwich, crisps and drink. But the sandwich wrapper is lined with plastic and has a film on the front. Surely the label ‘Bag – paper: widely recycled” is untrue?


3. What is not reprocessed in the UK, and why?

Cartons are a relatively newly recyclable item. Therefore they have to go to a plant in Sweden, where the aluminium and plastic linings can be separated from the cardboard, the former being used for energy, the latter recycled.

The material with the most media attention is plastic. It is actually more profitable to send plastic to China for reprocessing than doing it in the UK. This is because China will pay a lot more for our waste than we can pay in the UK! Ways in which their costs are cut down include: plastic being sent on otherwise-empty ships which have come from China to the UK carrying all the stuff we bought from there, migrant workers being paid very low wages, and not always a lot of concern for the quality or contamination level of the plastic we sell to China.

The Guardian states that, “No detailed studies have been done of the environmental costs of shipping vast quantities of waste from Britain to China”

It claims that we only have plastic recycling now because China actually wants our rubbish. Plastic collection wouldn’t go ahead in the UK at all without this Chinese link. I don’t know exactly how true that is but it does seem that some UK reprocessing plants have gone out of business in recent years.

Is there anything to stop our waste going across the world? Not really. Perusing the DEFRA regulation yielded that although we’re not allowed to accept or export waste for disposal, we are allowed to accept or export waste for reprocessing. In fact, it is encouraged; the following is from DEFRA’s UK Plan for Shipment of Waste (2012):

“The Government has two main policy objectives relevant to shipments of waste for recovery:

–  to encourage international trade in waste for recovery where this is of environmental benefit in driving up levels of recovery at national, EU and global levels;

– to prevent damage to human health or the environment occurring as a result of this international trade.”

But my question is this: how do we know the ‘environmental benefit’ of this process if it is true that there are no good studies of the environmental damage from the transportation?

India rubbish picking

Here is some interesting further reading on the social, environmental and chemical factors involved in plastic recycling:

4. What can we as consumers do to help?

A point made over and over again, not just be me but  by experts such as Andrew Potter of MBA Polymers at the Oxford Climate Forum, is that a very important factor in recycling costs is what the consumer puts in the recycling bin, and in what state it is. So, not to labour the point, but

  1. Make sure you put correct items in the recycling.
  2. Clean the contamination off items.

Or, you could stick a sign up in your office like I’ve done here:

Energy Institute recycling bin modified

I don’t know, it might work in my office since in theory I can guilt trip us as we all work in energy. What more sensible things could you do in your office?

In general, I would like to see:

a)      More feedback to consumers in general on how to recycle, so that costs can be reduced by us recycling correctly. Seems like a no-brainer but it doesn’t happen.

b)       Consumers knowing what leaves the coutry, goes to China, etc. When asked, Sainsbury’s reported sending all its recycling there, Asda doesn’t know where its goes, and Tesco refused to comment (see previous Guardian article). I would like to see a study on the environmental impacts of this.

d)      All of us getting involved in some petitions to end irresponsible dumping of waste in Asia:

5. How do I find out what I can recycle?/Is it different in every area of the UK?

Different local councils have contracts with different private waste management companies which in turn have contracts with sorting and reprocessing plants. This is why if you move to a new city you might not be able to recycle some of the things you used to.

There’s a nice postcode finder here for what you can recycle where:;partner=default&partner=default&CFID=78015687&CFTOKEN=31015716

Below is a very interesting and at times counter-intuitive article on why some materials can and can’t be recycled: it talks about wrapping paper, mushroom punnets, biscuit tins and foil. I didn’t know most of it:

Finally, if you learned something from this article, why not paraphrase it yourself and spread the word?

Lessons on energy efficiency at Wickes

Paula Morgenstern, UCL Energy Institute

Coming back after Christmas, I discovered mould in my room. Big, ugly spots all around my window and in the outer corners of the room… Yuck! What a setback after a most relaxing break. But what – apart from voluminous lamenting – to do about it?

I settled on an excursion to Wickes, my trusted DIY store, to equip myself for the fight. I turned out not to be the only person declaring war on mould these days: one lonely can of anti-mould paint was awaiting me on the shelf, while Wickes on the whole seemed surprisingly busy. Meanwhile, mould didn’t seem to be the only problem people were facing in light of the current chilly temperatures: Wickes generous offer on convector heaters (Portable – Instant heat – Silent running – Only £16.99) was crossed out red, they had been sold out for days told me the friendly shop assistant. Fan heaters for even longer…

What does this wintery excursion to Wickes tell us about the energy efficiency of our houses? Nothing to encouraging I am afraid.

Landlords often blame tenants for mould growth on behalf of insufficient heating and poor ventilation, but in reality the fabric of a dwelling has an even bigger part to play. Mould needs two things to grow: an organic substance as nutrient (wall paint is often enough) and humidity.  In buildings, humidity can – from defect pipes to leaky roofs – have a myriad of causes. One is particularly important because it is present even in well-functioning buildings: condensation. During sleeping for example, people give off roughly one litre of water vapour a night. As long as the air is warm, this is no big problem but when it cools down its capability to hold the water vapour diminishes.  This typically happens at outer walls and close to windows. Because the air has a lower temperature there, the water vapour within condensates on the walls/windows. The resulting humidity is enough for mould to grow.

Yet, what does this say about energy efficiency? Well – mould is a serious problem in poorly insulated buildings because a lot of heat is lost through walls and windows. Consequently, the air at these surfaces will be colder than in the room and the event chain ‘vapour condensation – wall humidity – mould growth’ becomes effective. At the same time, poor insulation often means a choice between high heating costs and cold houses as warmth is not retained well inside the building. That is if this even is a choice because sometimes the installed heating systems are not even powerful enough to heat a property to comfortable temperatures. People in poorly insulated houses might have to fight both MOULD (by buying fungicidal wash and anti-mould paint?) and COLD (by buying surplus heaters?).

Not a great situation – neither for the afflicted residents nor for the environment because electric surplus heating is much more resource intensive than primary heating systems. To face the lack of insulation in British homes and to reduce carbon emissions at the same time, the government fully trusts in its Green Deal, a policy permitting loans for efficiency improvements repayable through the achieved energy savings (see here for official information). But a number of concerns have been voiced including whether the Green Deal will reach the people most in need of home improvements and whether upfront assessment fees might put them off. It has also repeatedly been pointed out that the public awareness of the scheme remains low.


My visit to Wickes seems to hint in a similar direction. It suggests both continued inefficiencies in the housing stock and the need for the improved communication of the government’s energy strategy seeking long term efficiency improvement. Meanwhile, nothing in Wickes points out cash incentives now available for home insulation or even the existence of the Green Deal itself. Clearly, without more consumer engagement efforts on behalf of the government electrical heaters will continue to yield Wickes a handsome profit during the next cold spell.