An overview of domestic energy consumption in the UK: past,present and future

Global contribution from domestic sector towards energy use is quite remarkable, accounting for 20–40% of total primary energy consumption in developed countries. Current predictions indicate that the domestic energy consumption will steadily increase as a consequence of notable growth in world population, everlasting technological developments, growing demand for building services and rising comfort levels. In this respect, an accurate understanding and interpretation of energy consumption data in domestic sector is of vital importance for further amendments in energy policies at the global scale. Within the scope of this paper, an overview of the trends and some key drivers that have affected domestic energy consumption in the UK from 1970 to present is presented. Energy consumption by fuel type and end use, average domestic gas and electricity use in recent years, energy consumption per household and per person are illustrated in a comparable way.     

Whole life costing of domestic energy demand reduction technologies: householder perspectives

A recent, major UK research project investigated technical and social aspects of reducing the CO₂ emissions of UK domestic housing by 50% by the year 2030. As 80% of the UK housing stock that will be present in 2030 has already been built, this study aimed to research the whole life costs of three sets of energy demand reduction technologies for existing housing, over a 25‐year period, suitable to deliver significant CO₂ emissions reduction up to 50%. Demand side technological interventions in the form of fabric upgrades and ventilation systems are identified. Whole life cycle analysis of interventions carried out on two housing variants prominent in the domestic stock under different energy price scenarios is carried out using discounted cash flow and compared with the do‐nothing option. The results show that, despite reducing annual energy bills, there is no clear financial case even over a 25‐year horizon for householders to invest in the proposed interventions that contribute to CO₂ emission reduction targets. When discussed with respect to household income and consumption preferences, the results reveal the need for new policy approaches to overcome the financial and non‐financial hurdles for a mass uptake of energy efficient technologies.     

Trends in home computing and energy demand

Household energy demand due to domestic computer usage has changed beyond recognition over the past thirty years. Computers are now used in most homes, almost every day and laptop ownership has overtaken traditional desktop computers. Mobile devices give access to services that in the past required desktops, and they are usually more energy efficient. Today's computers usually rely on wireless routers that are often run all day. The effect of these changes on electricity use in the home has been profound. At least 60% more electricity was used for UK home computing in 2012 than in 1990. The implications of recent changes in information technology use are assessed for domestic electricity use and carbon emissions, using data from the Household Electricity Survey (HES) – the most detailed survey of electricity consumption in UK homes. On average, routers use twice as much energy per day as the laptops they serve. Laptops also draw power at a different time of day compared with desktop computers – which has implications for generation. Policy and practical recommendations are made for reducing energy use for information technology, including the estimated energy savings that could be achieved if UK routers met the US Energy Star standard for energy efficiency.     

Suburbanisation of important aquifers in England and Wales: estimating its current extent

The UK rate of conversion of rural into suburban land cover will increase as the UK population is projected to rise to 70 million by 2056, household size continues to decline and previously developed land becomes scarcer and less attractive. The resultant change in landuse will significantly impact underlying groundwater resources. Geographical information system (GIS) analysis is used to estimate the current extent of suburbanised land cover overlying locally and nationally important aquifers in England and Wales. The effect on groundwater catchments will be marked in southern, central and eastern England, where high groundwater dependence and intense pressure for new housing will inevitably lead to a rise in suburban land cover on periurban catchments that are currently rural land. Water resource planning implications would be better understood with more catchment-scale research. Meanwhile, areas of aquifer most likely to urbanise by 2050 and public supplies most vulnerable to the consequent changes need identifying.     

Sun,surf and sustainable housing—cohousing,the Californian experience

Increasing environmental problems associated with the domestic sector and the decline of local social capital and resident participation in their locality has led the UK government to seek more sustainable housing models. Cohousing could provide one option. However, cohousing has been relatively unsuccessful in the UK so far. The author sets out to prove that cohousing is a more sustainable housing model (using international examples) and that it in fact achieves many of the sustainability objectives of the new urbanist movement. An international comparison of the experience of cohousing in the UK and California and the factors influencing success and failure of cohousing in both locations are then explored. Drawing on the Californian experience the author then tries to provide some indication of how the development of cohousing could be encouraged in the UK in the future.     

Energy use in non-domestic buildings: the UK government's new evidence base

Policy for reducing carbon emissions from non-domestic buildings in the UK relies at present on survey and modelling work carried out in the 1990s. The UK government's Department of Energy and Climate Change (DECC) is engaged in a programme of new research to update this evidence base. The work has two main components. The first is a database – the National Energy Efficiency Data framework (NEED) – in which floor area and activity data for non-domestic premises are being linked to electricity and gas consumption at the individual property level. The second is a research project of sample surveys designed to elicit information about buildings and energy use, but also opportunities for abatement and the behavioural and organizational factors affecting efficiency improvements. A pilot survey of the food and mixed retail sector has been carried out in advance of further surveys of the entire range of building types. The research programme is described along with some of the methodological problems it raises.     

A method for fully automatic operation of domestic heating

Complex, inconvenient and badly arranged push buttons and menus on domestic heating controls often cause users to enter unsuitable settings that result in impaired comfort and poor operating efficiency. This paper proposes a novel approach to the human interface of home heating systems that greatly simplifies the input required from the user. Time settings are derived automatically from electricity consumption and hot water use, also a temperature set point is provided that adapts to user activity levels and external temperature. Practical results from a prototype control system incorporating these methods are reported, showing useful energy savings. It is argued that this increased automation of control allows the benefits of low carbon technologies such as micro-combined heat and power, and solar hot water heating, to be fully exploited.     

Fit for the task: the future of the small scale domestic repair and maintenance industry in the UK

The poor condition of much of the UK's older housing stock is an important policy issue. Some disrepair arises because owners cannot afford work, because they are not aware of the need for it or because they do not know how to go about organizing it. However, the poor reputation of that sector of the building industry dealing with small scale domestic repair and maintenance is also a deterrent. If anything, the problems of this sector have worsened during the recession as the supply of unskilled ‘cowboy’ operators has increased. This paper reviews the factors leading to underinvestment and poor quality work in the privately owned housing stock and examines the extent to which the shortcomings of the building industry contribute to this phenomenon. It describes the results of a survey of firms operating in the domestic repair and maintenance sector of the UK building industry, the majority of which were very small. The survey examined the size and composition of firms, their organization and working practices, the types of work they carried out, how they went about obtaining business, the extent to which their work-force was trained and the problems they faced in competing with one another and with the cowboy sector. On the basis of the survey conclusions and discussions with a wide range of organisations representing the industry, consumers, local authorities and government, a series of options for reform are discussed with the aim of stimulating debate on the future of this sector of the construction industry. It is argued that the problems of the UK industry cannot be solved by tighter controls on builders alone, but by a range of measures designed to provide more support and training to reputable builders, measures to exert greater controls over building techniques and safety provision to reduce unfair competition and programmes to educate the consumer to demand better standards and to be willing to pay for them. Ultimately only compulsory measures may succeed in improving standards, but much could be achieved by voluntary licensing or registration schemes backed up by incentives to use qualifying firms such as guarantees. This is more likely to work if backed up for an initial period by government or local authority funding. In the long run, however, the improvements to building quality could save public money.     

热岛强度对办公楼空调采暖能耗的影响

城市热岛效应带来的城市温升影响着建筑物的空调和采暖能耗。利用Dest—C软件对武汉某办公楼全年冷热工况进行了模拟分析,并且得出：虽然热岛强度和空调能耗或采暖能耗影响呈线性关系,但是热岛强度对全年能耗的影响关系是呈抛物线趋势上升的。由此可以看出,办公楼全年能耗随着热岛强度的增加而以更大幅度的趋势增加。     

The impact of climate change uncertainties on the performance of energy efficiency measures applied to dwellings

European Union and UK energy policy recognise the potential contribution the domestic sector can make in reducing energy consumption. In the UK, improvements to existing dwellings are likely to play a critical role in realising such potential.There is growing evidence that the global climate is changing. In the UK, projected climate changes could have a considerable impact on the thermal performance of the built environment and on measures implemented to improve such performance.Building simulations designed to investigate the potential impact of climate change uncertainties on the performance of insulation measures, applied retrospectively to an existing residential dwelling, suggest their effect could be considerable. Thermally, double glazing is the best option because although it is more sensitive than the others to climate change, it still delivers the highest savings in heating energy demand for the lowest induced cooling load. Loft insulation is the worst option in thermal terms.     

Electricity consumers under the state and the private sector: comparing the price performance of the French and UK electricity industries 1990–2000

Particularly because a preoccupation with process has tended to dominate the debate about electricity privatisation and liberalisation, this paper focuses on price outcomes by comparing the relative price performance of the French and UK electricity industries between 1990 and 2000. The main conclusion is that in 1990 the state-owned French electricity industry was performing better for most consumers than the state-owned UK industry, and a decade later it was still doing so with respect to the privately-owned UK industry. While this conclusion could be qualified by saying that, heavily prompted or assisted by the Regulator, the UK privately-owned industry has shown itself capable of achieving faster reductions in prices to close the gap between itself and the French, this achievement has been concentrated in the industrial market and even there the very significant gains were mainly restricted to the very largest consumers. In the context of the European Union the UK is shown to have performed relatively poorly for the smallest domestic consumers and, while both countries did much better in the rankings of industrial prices, they were still a long way behind the top performers.     

A comparison of the UK Standard Assessment Procedure and detailed simulation of solar energy systems for dwellings

The drive to reduce worldwide carbon emissions that are directly associated with dwellings and to achieve a zero carbon home dictates that renewable energy technologies will have an increasingly large role in the built environment. The Standard Assessment Procedure (SAP), formulated by the Building Research Establishment (BRE), is the UK Government's approved methodology for assessing the energy ratings of dwellings. This article presents an evaluation of the advantage given to SAP ratings by the domestic installation of typical photovoltaic (PV) and solar domestic hot-water (SDHW) systems in the UK. Comparable PV and SDHW systems will also be simulated with more detailed modelling packages. Results suggest that calculation variances can exist between the SAP methodology and detailed simulation methods, especially for higher performance systems that deviate from the default efficiency parameters.     

Simulation of Legionella concentration in domestic hot water: comparison of pipe and boiler models

The energy needed for the production of domestic hot water (DHW) represents an important share in the total energy demand of well-insulated and airtight buildings. DHW is produced, stored and distributed above 60°C to kill Legionella pneumophila. This elevated temperature is not necessary for DHW applications and has a negative effect on the efficiency of hot water production units.

In this paper, system component models are developed/updated with L. pneumophila growth equations. For that purpose, different existing Modelica pipe and boiler models are investigated to select useful models that could be extended with equations for simulation of bacterial growth. In future research, HVAC designers will be able to investigate the contamination risk for L. pneumophila in the design phase of a hot water system, by implementing the customized pipe and boiler model in a hot water system model. Additionally it will be possible, with simulations, to optimize temperature regimes and estimate the energy saving potential without increasing contamination risk.     

Financial viability of school retrofit projects for clients and ESCOs

The energy performance contracting market is potentially substantial but very little work has been undertaken to understand the characteristics of successful projects. This study uses a probabilistic analysis of four hypothetical projects in the UK schools sector under the 2014 policy regime, combined with qualitative interviews with practitioners, to explore the conditions for a viable project. It finds that the proposed approach has the potential to allow more detailed exploration of project structures and scope for creating greater understanding of likely returns and the factors affecting them. Evidence is found that the use of deterministic risk screening techniques such as simple payback results in viable opportunities being overlooked. The risk profiles for clients and contractors (energy service companies – ESCOs) are not symmetrical and they will each find different projects more attractive. The results suggest that greater consideration needs to be given to the precise risk allocation between client and contractor to ensure that likely returns are properly understood. This study demonstrates a method for exploring project characteristics that can be used to understand their impacts on the financial returns for clients and contractors.     

Priority water research questions as determined by UK practitioners and policy makers

Several recent studies have emphasised the need for a more integrated process in which researchers, policy makers and practitioners interact to identify research priorities. This paper discusses such a process with respect to the UK water sector, detailing how questions were developed through inter-disciplinary collaboration using online questionnaires and a stakeholder workshop. The paper details the 94 key questions arising, and provides commentary on their scale and scope. Prioritisation voting divided the nine research themes into three categories: (1) extreme events (primarily flooding), valuing freshwater services, and water supply, treatment and distribution [each > 150/1109 votes]; (2) freshwater pollution and integrated catchment management [100-150 votes] and; (3) freshwater biodiversity, water industry governance, understanding and managing demand and communicating water research [50-100 votes]. The biggest demand was for research to improve understanding of intervention impacts in the water environment, while a need for improved understanding of basic processes was also clearly expressed, particularly with respect to impacts of pollution and aquatic ecosystems. Questions that addressed aspects of appraisal, particularly incorporation of ecological service values into decision making, were also strongly represented. The findings revealed that sustainability has entered the lexicon of the UK water sector, but much remains to be done to embed the concept operationally, with key sustainability issues such as resilience and interaction with related key sectors, such as energy and agriculture, relatively poorly addressed. However, the exercise also revealed that a necessary condition for sustainable development, effective communication between scientists, practitioners and policy makers, already appears to be relatively well established in the UK water sector.     

The impact of energy externalities on the cost effectiveness of energy efficiency measures applied to dwellings

European Union and UK energy policy recognise the potential contribution the domestic housing sector can make in reducing energy consumption. In the UK, improvements to existing dwellings are likely to play a critical role in realising such potential. The need to consider both the value and uncertainty of external environmental and social costs in developing effective policy is also made explicit.This analysis investigates the impact of such values and uncertainties on the relative performance of a range of insulation measures applied retrospectively to an existing residential dwelling.Results from a case study suggest that large variations in capital cost, energy saving potential and the value of externalities have a significant impact on the relative cost effectiveness of these measures. However, in general, current investment decision-making based on normal market energy prices and today's climate is likely to deliver solutions that remain effective under significant levels of uncertainty.     

The Residential Housing Market in Iceland: Analysing the Effects of Mortgage Market Restructuring

In June 2004 the government-backed Housing Financing Fund eased its loan regulations in an attempt to consolidate its position in the domestic credit market. This led to a strong response from the domestic commercial banks that actively entered the mortgage market for the first time. These changes led to a substantial decline in long-term real mortgage rates, increased the access to credit, and allowed homeowners for the first time to withdraw equity from their homes without actual transactions. This paper sets up a simple model of housing demand and supply to analyse these effects. The results suggest that the structural changes led to a substantial rise in housing demand, with house prices rising by 25 per cent one year after the shock. This triggered a similar rise in housing investment approximately two years after the shock. The model predicts that the effects on house prices gradually die out as house prices return to the level that is consistent with normal profit margins in the construction sector. However, the housing stock remains approximately 5 per cent larger than in the baseline scenario.     

Understanding the early stages of the innovation diffusion process: awareness,influence and communication networks

The themes of awareness and influence within the innovation diffusion process are addressed. The innovation diffusion process is typically represented as stages, yet awareness and influence are somewhat under-represented in the literature. Awareness and influence are situated within the contextual setting of individual actors but also within the broader institutional forces. Understanding how actors become aware of an innovation and then how their opinion is influenced is important for creating a more innovation-active UK construction sector. Social network analysis is proposed as one technique for mapping how awareness and influence occur and what they look like as a network. Empirical data are gathered using two modes of enquiry. This is done through a pilot study consisting of chartered professionals and then through a case study organization as it attempted to diffuse an innovation. The analysis demonstrates significant variations across actors’ awareness and influence networks. It is argued that social network analysis can complement other research methods in order to present a richer picture of how actors become aware of innovations and where they draw their influences regarding adopting innovations. In summarizing the findings, a framework for understanding awareness and influence associated with innovation within the UK construction sector is presented. Finally, with the UK construction sector continually being encouraged to be innovative, understanding and managing an actor’s awareness and influence network will be beneficial. The overarching conclusion thus describes the need not only to build research capacity in this area but also to push the boundaries related to the research methods employed.     

Understanding the impact of cultural and religious water use

This paper investigates the effect that cultural and religious backgrounds have on water consumption patterns among ethnic minorities in UK cities. District meter area data were combined with ethnicity and religion data from the 2001 UK census to highlight particular areas of interest. The research identifies startling differences in water use patterns, which are clearly linked directly with religious and cultural practices. The overall conclusion is that it would be extremely unwise to exclude these social parameters in any further research into understanding domestic water demand. The research has application in the wider context of research or practice outside the western world, where the factors identified in this research may characterise the vast majority of water supply systems.     

Policy implications for the performance gap of low-carbon building technologies

ABSTRACT

It is widely recognized that the actual impact of low-carbon technologies is often lower than predicted by models alone, a phenomenon which has been coined the ‘performance gap’. Despite this awareness, in many instances estimates of both energy savings and renewable energy generation in domestic buildings continue to rely on engineering models and building energy simulations rather than approaches that are based on measured parameters. Much of the existing literature on the performance gap focuses on energy efficiency and is concerned with the quantification of the scale of the performance gap. This paper adds to this body of evidence by drawing retrospectively on a range of grey literature evaluations of low-carbon technologies (including energy-efficiency measures, renewable heat and renewable electricity) in the UK household sector. The focus is on not only the quantification of the performance gap but also the qualitative factors often overlooked, such as installation issues or installer/user behaviour. Recommended policy changes include the development of evaluation standards, the experimentation with pay-for-performance programmes, ensuring that installation standards for low-carbon technologies are being enforced, and taking reasonable steps to ensuring that end users can use any new technology effectively.