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In the face of a changing climate, a growing number of construction firms are adopting carbon reduction targets on individual projects and across their portfolios. In the wake of the Paris Agreement, some firms are seeking a means of aligning their targets with sectoral, national and international mitigation commitments. There are numerous ways by which such an alignment can be achieved, each requiring different assumptions. Using data from the UK construction industry, this paper reviews current company commitments and progress in carbon mitigation; analyses the unique challenges in aligning construction targets, and presents a series of possible sectoral decarbonisation trajectories. The results highlight the disparity between current company targets and the range of possible trajectories. It is clear that a cross-industry dialogue is urgently required to establish an appropriate response that delivers both a widely-accepted target trajectory and a plan for its delivery. This paper is intended to stimulate and support this necessary debate by illustrating the impact of different methodological assumptions and highlighting the critical features of an appropriate response. [ABSTRACT FROM AUTHOR]

In light of the global energy and climate crises, integration of low-carbon technologies into energy systems is being considered to mitigate the high energy costs and carbon footprint. The wide range of available capacities, efficiencies, and investment costs of these technologies and their different possible operating schedules can unlock several pathways towards decarbonisation. This paper presents an optimisation framework for a public healthcare facility to determine the optimal operation schedule of the site's energy system. A detailed techno-economic analysis of low-carbon power generation, conversion, and energy storage technologies that can be incorporated into the system based on real historical data was carried out for different scenarios. The results reveal that a heat pump with a capacity of 1800 kW can replace gas boilers on-site to meet the heat demand while recovering the investment in 5 years and providing an operating and carbon cost saving of 22.47% compared to the base case. The analysis shows that a more electrified mode of operation is favoured during high gas prices, thus making electrical energy storage more attractive than thermal energy storage. While handling real data, the optimisation algorithm was sensitised to discriminate conventional energy supplies from clean energy sources by considering their carbon impact so that it minimises energy bills in a smart and eco-friendly way. The optimisation algorithm and the subsequent techno-economic analysis provide a comprehensive framework to decision-makers for facilitating energy investment decisions. The framework can be used based on the short and long term goals of the energy system, visualising the evolution of financial benefits over equipment lifetime, and understanding the environmental impacts of integrating renewable energy. • Heat pumps are the most favourable decarbonisation technology for the hospital. • The moderate variations in energy demand limit the scope of energy storage. • Fuel price surcharge favours EES over TES and reduces payback period of retrofits. • PVT's savings scale linearly with roof space until 3 times the available capacity. • Monetising the carbon footprint shortens the DPP of clean retrofit technologies. [ABSTRACT FROM AUTHOR]

Highlights • Energy consumption in higher education institutions (HEIs) modelled. • For the first time, panel data used, with cross-sectional and time-series variations. • Over time and across HEIs, energy use increases as income and size increase. • Economies of scale as HEIs grow, but energy use still rising with sector growth. • Research universities more energy intensive. Abstract Among the various sustainability goals of higher education institutions (HEIs), reducing energy use and carbon emissions are particularly important. However, not much is known about energy demand from the higher education sector – especially since there is a lack of robust models of energy demand in this sector. This paper, the first to utilize a panel dataset and advanced panel econometric techniques in order to model energy use in higher education, investigates variations in energy use between HEIs (cross-sectional analysis), and also changes in energy use over time (temporal analysis), using the UK as a case study. We argue that panel dataset and methods are more useful for understanding growth (and reduction) in energy use within the HE sector than the methods used within previous cross-sectional studies. Results show that, over time and also across the sector, energy consumption in the HEIs increases with increases in income and floor space, but at a slower rate. As HEIs grow overall (in terms of income, floor space, student and staff number) over time, they become more 'energy efficient' (using less energy per unit of area, population or income), indicating economies of scale in the temporal dimension. Results also show that after controlling for income and size, research intensive HEIs consume more energy. We also find a small but statistically significant effect of energy prices on energy consumption, as might be expected. Simulation using the model parameters for an example scenario suggests that energy consumption will continue to increase unless there is a significant change in the policies driving income growth and spatial expansion in the HE sector in the UK. [ABSTRACT FROM AUTHOR]

Abstract In the UK, housing has been identified as a major sector for contributing to the 80% reduction in carbon emissions over the 1990 baseline by 2050, required by the Climate Change Act 2008. However, pre-1919 housing stock is the least energy efficient and consequently poses challenges to meeting this target. Using a mixed methods approach, the current study demonstrates that, in actuality, there is a significant potential for reducing emissions among this sub-sector of housing, and that the major barriers to energy efficiency retrofits concern a lack of funding, the payback period for the investment, disruption to home life and finding a trustworthy and skilled installer. Moreover, this study finds that homeowners are motivated primarily by the desire to improve home comfort and aesthetics along with a reduction in energy bills rather than in reducing carbon emissions. The paper concludes with recommendations for improving the viability of retrofitting pre-1919 homes through enhanced financial resources, policy support and the promotion of social and economic benefits. [ABSTRACT FROM AUTHOR]

The four Higher Education Funding Councils in the United Kingdom want all universities to reduce CO 2 emissions by 34% by 2020 compared to a 2005 base. Universities that have installed Combined Heat and Power (CHP) technology are making good moves towards achieving their CO 2 reduction target. For a CHP project to be successful, a detailed technical, economic and environmental assessment is required. Generally, this assessment is carried out using a computer-based model. Currently, available CHP models have limitations in terms of flexibility, accuracy, reliability and complexity and their use could result in an undersized or oversized CHP scheme that could lead to a complete failure of the project. Therefore, there is an urgent need for a robust and user-friendly model, which integrates multiple features that are missing in the currently available models. This paper presents the development of a spreadsheet based CHP sizing model for a single or multiple university buildings. The major strengths of the model are its simplicity, flexibility of data entry, selection of multiple electrical and thermal demands, an in-built real database for a range of CHP sizes, multiple control strategies, multiple investment routes and their life cycle cash flow analysis, and the potential for detailed sensitivity analysis of payback period using the Monto Carlo Simulation technique. The model, which we call the London South Bank University (LSBU) CHP model, has been tested with three other CHP models for different control modes for the same building and the comparisons are discussed. [ABSTRACT FROM AUTHOR]

Relatively little energy research has attended to justice considerations. The limited energy justice inquiry that exists focuses on justice in relation to impacts of energy production, consumption, and policies that either exacerbate or seek to mitigate distributive and procedural concerns. Programmes aimed at facilitating the so-called ‘energy transition’ have strong implications for energy justice. For example, efforts to reduce energy consumption and/or carbon emissions, policies to increase energy security, and programmes to increase energy access and affordability all address distributive concerns. Nevertheless, the costs associated with meeting such goals and running such programmes also have justice implications and should be viewed alongside the other aforementioned normative issues as an aspect of energy justice. Here, we examine public perceptions of who should fund programmes designed to ease the transition to a more sustainable and equitable energy system, finding most responsibility assigned to energy companies, and beliefs about procedural justice meaningfully shaping thoughts on who should pay. Our UK-based mixed methods inquiry reveals that whilst our respondents (survey) and participants (focus groups) accept some personal costs directed towards governmental programmes that could reduce energy injustices, acceptance is dependent on several factors, including perceived importance of distributive justice and whether the energy system exhibits procedural justice. The influence of normative factors on cost acceptance has implications for feasibility of polices to promote energy justice. We conducted a survey (N = 3,150), followed by five focus groups (N = 6–9 each) throughout Great Britain with survey respondents to explore further their answers and explain some of our quantitative findings. We conclude this paper with tangible policy recommendations for government, such as the amount (cost) and types of environmental and social levies that are viable, based on their public acceptance, and suggestions for other approaches to funding energy transitions, so as not to exceed the limits of public acceptance. [ABSTRACT FROM AUTHOR]

Electric heat pumps (HPs), hybrid heating technology and district heating networks (DHN) are the main low-carbon heating technologies that can deliver the ambitious carbon reduction target in the UK. The optimal design of the heating system on a national scale to maximize the economic benefits regarding both investment cost and operation cost while satisfying the carbon target remains an open question. This paper aims to compare the economic advantages as well as the associated impacts on the electricity system under the full deployments of ASHP (air source HP), hybrid HP-Bs (ASHP and gas boilers) and DHNs. To do so, a novel whole-system approach is applied with the explicit consideration of the coordinated operation between heat and electricity system. The optimized strategy for heat sector decarbonisation is also demonstrated, providing an outline of the optimal deployment for different heating technologies in terms of their penetrations and deployed areas. The UK case study suggests the significant economic advantage of the hybrid HP-B over the other two heating technologies, while DHN may play an important role in urban areas under the optimized heat decarbonisation strategy. The results also clearly demonstrate the changes on the electricity side driven by the different decarbonisation strategies in the heating system. [ABSTRACT FROM AUTHOR]

The UK housing stock is responsible for some 27% of national energy demand and associated carbon dioxide emissions. 80% of this energy demand is due to heating (60%) and domestic hot water (20%), the former reflecting the poor average thermal integrity of the envelope of the homes comprising this stock. To support the formulation of policies and strategies to decarbonise the UK housing stock, a large number of increasingly sophisticated Housing Stock Energy Models (HSEMs) have been developed throughout the past 25 years. After describing the sources of data and the spatio-temporal granularity with which these data are available to represent this stock, as well as the physical and social phenomena that are modelled and the range of strategies employed to do so, this paper evaluates the 29 HSEMs that have been developed and deployed in the UK. In this we consider the models’ predictive accuracy, predictive sensitivity to design parameters, versatility, computational efficiency, the reproducibility of predictions and software usability as well as the models’ transparency (how open they are) and modularity. We also discuss their comprehensiveness. From this evaluation, we conclude that current HSEMs are lacking in transparency and modularity, they are limited in their scope and employ simplistic models that limit their utility; in particular, relating to the modelling of heat flow and in the modelling of household behaviours relating to investment decisions and energy using practices. There is a need for an open-source and modular dynamic housing stock energy modelling platform that addresses current limitations, can be readily updated as new (e.g. housing survey) calibration data is released and be readily extended by the modelling community at large: improving upon the utilisation of scarce developmental resources. This would represent a considerable step forward in the formulation of housing stock decarbonisation policy that is informed by sound evidence. [ABSTRACT FROM AUTHOR]

Industrial processes such as Portland cement manufacture produce a large proportion of anthropogenic carbon dioxide and significantly reducing their emissions could be difficult or expensive without carbon capture and storage. This paper explores the idea of synchronising shutdowns for carbon capture and storage installation with major shutdowns required to refurbish major process units at industrial sites. It develops a detailed bottom-up model for the first time and applies it to the United Kingdom's cement industry. This research demonstrates that several policy and technology risks are not identified by the top-down models and it highlights the importance of reducing shut-down times for capture plant construction. Failure to do so could increase installation costs by around 10 per cent. This type of approach, which is complementary to top-down modelling, and the lessons learned from it can be applied to other capital- and energy-intensive industries such as primary steel production. It provides important information about what actions should be prioritised to ensure that carbon capture and storage can be applied without extra unnecessary shutdowns which would increase the overall cost of carbon dioxide mitigation and could delay action, increasing cumulative emissions as well. [ABSTRACT FROM AUTHOR]

This paper uses a socio-technical building performance evaluation (BPE) approach to assess the pre- and post- actual performance of two discrete deep low energy retrofits in the UK – a Victorian solid-wall house and modern 1990s cavity-wall house. A ‘low-energy first, then low-carbon’ approach was adopted in both cases, to achieve an 80% reduction in annual CO 2 emissions. Pre-retrofit, both houses had lower measured annual gas consumption as compared to predictions made by energy models, although the electricity consumption in the modern house was higher than modelled, due to occupancy pattern and occupant behaviour. Post-retrofit, it was found that the Victorian house achieved nearly 75% CO 2 reduction, while the modern house achieved only 57% CO 2 reduction over the baseline emissions. Key reasons were higher than expected air permeability rates, installation issues with micro-renewable systems, lack of proper commissioning, usability of controls, occupant preferences and behaviour. Despite the gap between expected and actual carbon emissions, occupant comfort and satisfaction was significantly improved across both retrofits. This evidence-based understanding of the process and outcomes of deep low carbon retrofits is vital not only for learning and innovation, but also for scaling-up deep retrofit programmes for meeting national and international carbon targets. [ABSTRACT FROM AUTHOR]

There is currently a lack of data recording the carbon and emissions inventory at household level. This paper presents a multi-disciplinary, bottom-up approach for estimation and analysis of the carbon emissions, and the organic carbon (OC) stored in gardens, using a sample of 575 households across a UK city. The annual emission of carbon dioxide emissions from energy used in the homes was measured, personal transport emissions were assessed through a household survey and OC stores estimated from soil sampling and vegetation surveys. The results showed that overall carbon patterns were skewed with highest emitting third of the households being responsible for more than 50% of the emissions and around 50% of garden OC storage. There was diversity in the relative contribution that gas, electricity and personal transport made to each household’s total and different patterns were observed for high, medium and low emitting households. Targeting households with high carbon emissions from one source would not reliably identify them as high emitters overall. While carbon emissions could not be offset by growing trees in gardens, there were considerable amounts of stored OC in gardens which ought to be protected. Exploratory analysis of the multiple drivers of emissions was conducted using a combination of primary and secondary data. These findings will be relevant in devising effective policy instruments for combatting city scale green-house gas emissions from domestic end-use energy demand. [ABSTRACT FROM AUTHOR]

A techno-economic analysis is undertaken to assess hybrid PV/solar-thermal (PVT) systems for distributed electricity and hot-water provision in a typical house in London, UK. In earlier work (Herrando et al., 2014), a system model based on a PVT collector with water as the cooling medium (PVT/w) was used to estimate average year-long system performance. The results showed that for low solar irradiance levels and low ambient temperatures, such as those associated with the UK climate, a higher coverage of total household energy demands and higher CO 2 emission savings can be achieved by the complete coverage of the solar collector with PV and a relatively low collector cooling flow-rate. Such a PVT/w system demonstrated an annual electricity generation of 2.3 MW h, or a 51% coverage of the household’s electrical demand (compared to an equivalent PV-only value of 49%), plus a significant annual water heating potential of to 1.0 MW h, or a 36% coverage of the hot-water demand. In addition, this system allowed for a reduction in CO 2 emissions amounting to 16.0 tonnes over a life-time of 20 years due to the reduction in electrical power drawn from the grid and gas taken from the mains for water heating, and a 14-tonne corresponding displacement of primary fossil-fuel consumption. Both the emissions and fossil-fuel consumption reductions are significantly larger (by 36% and 18%, respectively) than those achieved by an equivalent PV-only system with the same peak rating/installed capacity. The present paper proceeds further, by considering the economic aspects of PVT technology, based on which invaluable policy-related conclusions can be drawn concerning the incentives that would need to be in place to accelerate the widespread uptake of such systems. It is found that, with an electricity-only Feed-In Tariff (FIT) support rate at 43.3 p/kW h over 20 years, the system cost estimates of optimised PVT/w systems have an 11.2-year discounted payback period (PV-only: 6.8 years). The role and impact of heat-based incentives is also studied. The implementation of a domestic Renewable Heat Incentive (RHI) at a rate of 8.5 p/kW h in quarterly payments leads to a payback reduction of about 1 year. If this incentive is given as a one-off voucher at the beginning of the system’s lifetime, the payback is reduced by about 2 years. With a RHI rate of 20 p/kW h (about half of the FIT rate) PVT technology would have approximately the same payback as PV. It is concluded that, if primary energy (currently dominated by fossil fuels) and CO 2 emission minimisation are important goals of national energy policy, PVT systems offer a significantly improved proposition over equivalent PV-only systems, but at an elevated cost. This is in need of careful reflection when developing relevant policy and considering technology incentivation. Currently, although heat outweighs electricity consumption by a factor of about 4 (by energy unit) in the UK domestic sector, the support landscape has strongly favoured electrical microgeneration, being inclined in favour of PV technology, which has been experiencing a well-documented exponential growth over recent decades. [ABSTRACT FROM AUTHOR]

Abstract: The UK consumes almost 5% of world's wine production, drinking 12.9 million hectolitres annually or 21 l per capita per year. Australian wines are most popular with the UK consumer, accounting for around 17% of total take-home purchases. This paper focuses on Australian red wine and presents the life cycle environmental impacts of its consumption in the UK. The results indicate that a 0.75 l bottle of wine requires, for example, 21 MJ of primary energy, 363 l of water and generates 1.25 kg of CO2 eq. For the annual consumption of Australian red wine, this translates to around 3.5 PJ of energy, 600 million hectolitres of water and 210,000 t CO2 eq. Viticulture and wine distribution are the main hot spots contributing over 70% to the environmental impacts considered. Shipping in bulk rather than bottled wine would reduce the global warming potential (GWP) by 13%, equivalent to 27,000 t CO2 eq. annually. For every 10% increase in recycled glass content in bottles, the GWP would be reduced by 2% or 3600 t CO2 eq./yr; the savings in other environmental impacts are smaller (0.7–1.5%). A 10% decrease in bottle weight would reduce the impacts by 3–7%; for the GWP, the saving would be 4% or 7000 t CO2 eq./yr. If only 10% of the wine was packaged in cartons instead of glass bottles, the GWP savings would be 5% or 10,600 t CO2 eq./yr; the other impacts would also be reduced by 2–7%. These measures could together save at least 48,000 t CO2 eq./yr, almost a quarter of the current emissions from the UK consumption of Australian red wine. [Copyright &y& Elsevier]

Abstract: Tourism holds a significant share in the global carbon footprint. Transportation to the destination is recognized as the primary contributor, although its contribution can be less dominant in the context of short-haul travel. Previous studies do not provide a critical comparative analysis of how changes in travel behaviour, notably modal shift, affect the total carbon impacts from short-haul holidays; nor do they explore the relative contribution of the specific elements of the holiday product or account for global variations when measuring those contributions. This paper presents a carbon impact assessment case study of short-haul tourism to Southern France by British tourists. It applies an advanced, Life Cycle Assessment-based, method of evaluation, the hybrid DEFRA-LCA (Ecoinvent) approach, which is capable of appraising both the direct and the embodied ‘indirect’ greenhouse gas emissions. The principal finding supports the traditional view that transportation generates the largest carbon footprint and that the most significant carbon savings can be achieved by switching from air and car-based travel to train and coach. However, the study also indicates that if tourists stay at the destination longer, and travel to the destination by train or coach, the destination-based elements of the holiday can make a large carbon contribution and even outweigh the share of the transit element. The Life Cycle Assessment also shows that the ‘indirect’ greenhouse gas emissions from tourism in Southern France are significant, thus emphasizing the importance of their incorporation into future carbon impact appraisals. [Copyright &y& Elsevier]

• Emissions performance of road surface transport in UK is investigated up to 2050. • User behaviour of hybrid electric car owners will have a significant impact. • UK transport sector might fail to meet the 4th, 5th, 6th and 7th carbon budget targets. • The authorities might have to start discussing a hybrid car ban in the near future. The United Kingdom aims for an 80% reduction of carbon dioxide emissions by 2050 compared to the levels in 1990. If the transport sector will be able to achieve its share is questionable. This paper aims to analyse how the pace of Battery Electric Vehicles transition and driving behaviour of Plugged in Hybrid Electric Vehicles users can impact the Green House Gas emissions reduction performance of the UK transport sector in meeting the carbon targets by 2050. A reference model for different types of vehicle classes is developed to determine the emissions contributed. The growth of each vehicle class, improvements in efficiency of Electric Vehicles and low carbon fuel targets are projected until the year 2050. Scenario-based models are then developed to analyse how varying the pace of Battery Electric Vehicle transition and hybrid car user driving behaviour would impact the emissions reduction performance. The results of the paper show that the current pace of Battery Electric Vehicle adoption is insufficient for the UK transport sector to achieve the 4th to 7th carbon budgets, due to the slow reduction in Internal Combustion Engine Vehicles. For the 8th and final carbon budgets, emissions may still exceed the carbon budget despite transiting to Electric Vehicles if hybrid car users continue to drive on gasoline modes. The proposed model will serve as a useful reference to assess if the current UK transport strategies and policies suffice and if more actions are necessary to meet the 2050 carbon target. [ABSTRACT FROM AUTHOR]

Energy policy is too often not designed for energy consumers in a low-cost and consumer-friendly manner. This paper proposes a novel Stackelberg game and Blockchain-based framework that enables consumer-centric decarbonization by automating iterative negotiations between policy makers and consumers or generators to reduce carbon emissions. This iterative negotiation is modeled as a Stackelberg game-theoretic problem, and securely facilitated by Blockchain technologies. The policy maker formulates carbon prices and monetary compensation rates to dynamically incentivize the carbon reduction, whereas consumers and generators schedule their power profiles to minimize bills and maximize profits of generation, respectively. The negotiating agreement is yielded by reaching a Stackelberg equilibrium. The exchanged information and controlling functions are realized by using smart contracts of Blockchain technologies. Case studies of GB power systems show that the proposed framework can incentivize 9% more bill savings for consumers and 45.13% more energy generation from renewable energy sources. As a consumer-centric decarbonization framework, it can at least reduce carbon emissions by 40%. [Display omitted] • A novel consumer-centric and negotiation-based framework to decarbonize power systems. • A Blockchain based platform to integrate the exchanged information and controlling functions of the power system scheduling into data structures, nodes, and smart contracts of Blockchain networks. • How Blockchain based platform can prevent cyber attacks is discussed. • Case studies demonstrate the effectiveness of the proposed framework in the context of Great Britain power systems. [ABSTRACT FROM AUTHOR]

Abstract: In order to reduce carbon emissions and alleviate fuel poverty, the UK Government has outlined proposals for a “Green Deal” to help provide financing for the installation of cost-effective retrofit measures to the existing UK housing stock. However, the Green Deal proposals have the potential to generate financial risk, due to a possible overestimation of the energy savings arising from retrofit measures. This paper proposes a framework for handling the uncertainties associated with the prediction of these energy savings, as well as demonstrating how decisions can be made in the face of the uncertainties involved in the retrofit analysis of a housing stock. The proposed framework is applied to a case study set of dwellings and it is seen that a limited range of measures will be cost-effective under the Green Deal proposals for these dwellings; as a result, subsidies will be required if higher impact measures are to be considered viable. Finally, however, it is also seen that the monetary value of additional societal benefits, such as reduced carbon emissions and improved thermal comfort, is likely to more than outweigh the cost of any subsidies. [Copyright &y& Elsevier]

Abstract: Does the association between household characteristics and household CO2 emissions differ for areas such as home energy, transport and indirect emissions? This question is policy relevant because distributional implications of mitigation policies may vary depending on the area of emissions that is targeted if specific types of households are likely to have higher emissions in some areas than in others. So far, this issue has not been examined in depth in the literature on household CO2 emissions. Using a representative UK expenditure survey, this paper compares how household characteristics like income, household size, education, gender, worklessness and rural or urban location differ in their association with all three areas as well as total emissions. We find that these associations vary considerably across emission domains. In particular, whilst all types of emissions rise with income, low income, workless and elderly households are more likely to have high emissions from home energy than from other domains, suggesting that they may be less affected by carbon taxes on transport or total emissions. This demonstrates that fairness implications related to mitigation policies need to be examined for separate emission domains. [Copyright &y& Elsevier]

Abstract: This paper outlines the development and application of a domestic heat pump model for space heating and cooling energy. The model is intended to bridge the gap between the single coefficient of performance parameter currently used in the UK procedures for the assessment of the energy efficiency of dwellings and the dynamic simulation models frequently developed for the academic estimation of heat pump energy use. It is responsive to variations in source and sink temperatures whilst being simple enough to be embedded in a spreadsheet model. The model was developed by: building a regression model, using heat pump performance test results, relating heat pump coefficient of performance to the differential between source and sink temperatures – “lift”; deriving estimating rules for monthly supply temperature estimates for commonly-used heat pump sources and for demand temperatures for normal wet central heating sinks to give a monthly estimate for the source/sink differential; embedding the regression model in the UK standard model for domestic energy estimation, with additional routines to estimate energy consumption for additional heat and for space cooling. The model developed was validated by comparison with the existing BREDEM model. Compared with the standard BREDEM estimates, the resulting model showed correct response to changes in ambient temperatures, allowing correct estimating of consumption for additional heat under conditions of climate change. It showed variation of heat pump coefficient of performance across the year, allowing better estimation of winter peak load. [Copyright &y& Elsevier]

Abstract: Historic dwellings in the UK make up to 20% of all homes. In the Georgian city of Bath this rises to 30%. These buildings are amongst the most poorly performing part of the English housing stock in energy use terms, with the lowest SAP rating and highest average annual CO2 emissions. The legal aim to reduce CO2 emissions of 80% by 2050 will involve all existing dwellings, including historic buildings. The degree to which proposals to retrofit the UK housing stock can reduce emissions depends on how much energy they currently use, what it is used for and how much CO2 they emit. This paper establishes a benchmark of energy use and CO2 emissions for historic dwellings in Bath. This permits comparison of their energy performance against other parts of the housing stock and will facilitate evaluation of potential retrofit adaptations. [Copyright &y& Elsevier]

Abstract: This work reviews the advantages and disadvantages of using mineral wastes for CCS and their potential in CO2 abatement, highlighting the potential applications and scenarios. This study indicates that a variety of inorganic waste materials such as pulverised fuel ash, municipal solid waste ash, cement kiln dust, biomass and paper sludge ash and sewage sludge ash are available feedstocks for Carbon Capture and Storage by Mineralisation (CCSM) in the UK. The high variability of both the waste amounts and chemical composition represent a major obstacle to the deployment of these materials in CCSM. Currently, mineral waste resources for mineral carbonation have the theoretical potential to capture about 1Mt/year CO2 in the UK, considering only the materials not recycled that are currently sent to landfill. Moreover, inorganic waste as a CCSM resource is in many ways more complex than the use of natural minerals due to uncertainty on future availability and high chemical variability and might be viable only in niche applications. For example, the use of inorganic wastes (concrete waste and steel slag) and buffer solutions in spray trickle bed systems (able to sequester 50% of the CO2 entering the system) was estimated to have costs competitive with geological storage. [Copyright &y& Elsevier]

Abstract: This paper examines the efficiency (in terms of energy use and carbon emissions) with which 5 different types of domestic water heating systems employed in the UK are able to produce hot water for sanitary use. A method of normalisation is employed allowing results from case studies with different systems and usage levels to be compared. Water heating appliances studied include gas boilers, a micro CHP, heat pumps, an immersion heater, and a solar thermal system. It is found that instantaneous production of hot water is much more efficient than delivery via tank storage for gas-fuelled systems. For electrical systems, an immersion heater is found to perform better in some circumstances than heat pumps and also has advantages when combined with a solar thermal system leading to the proposal that this combination offers the most potential as a low carbon method for domestic hot water provision in the long term. Opportunities are identified to improve the performance of all systems with storage through better control of heat inputs. Inconsistencies in, and problems of compliance with, established standards for mitigation of Legionella in hot water systems are also identified. [Copyright &y& Elsevier]

Abstract: In the context of ambitious commitments to reduce CO2 emissions in industrialised countries, the domestic sector will play a crucial role as one of the biggest sources of end-use emissions. In the past, several studies have aimed to analyse the costs and the technical feasibility of CO2 emissions reduction in the domestic stock. This paper addresses the issue of abatement costs and potentials in the housing stock from a systems perspective in order to capture interactions and interdependencies with the wider energy system. Marginal abatement cost (MAC) curves for the UK residential sector are derived based on the energy systems model UK MARKAL in combination with decomposition analysis. The results indicate that it is cost-effective to implement conservation measures, as well as increase the share of district heat and biomass for space and water heating. The decarbonisation of electricity and heat dominates the lower part of the residential sector MAC curve up to £50/t CO2. The MAC curve is found to be robust to fossil fuel prices, while more expensive electricity and limited availability of biomass significantly reduce the abatement potential. The results underline the need to assess emissions reduction from a systems perspective to capture system-wide interactions. [Copyright &y& Elsevier]

Abstract: The UK government’s economy-wide 60% carbon dioxide reduction target by 2050 requires a paradigm shift in the whole energy system. Numerous analytical studies have concluded that the power sector is a critical contributor to a low carbon energy system, and electricity generation has dominated the policy discussion on UK decarbonisation scenarios. However, range of technical, social and market challenges, combined with alternate market investment strategies mean that large scale deployment of key classes of low carbon electricity technologies is fraught with uncertainty. The UK MARKAL energy systems model has been used to investigate these long-term uncertainties in key electricity generation options. A range of power sector specific parametric sensitivities have been performed under a ‘what-if’ framework to provide a systematic exploration of least-cost energy system configurations under a broad, integrated set of input assumptions. In this paper results of six sensitivities, via restricted investments in key low carbon technologies to reflect their technical and political uncertainties, and an alternate investment strategies from perceived risk and other barriers, have been presented. [Copyright &y& Elsevier]

This paper presents a socio-economically disaggregated framework for attributing CO2 emissions to people's high level functional needs. Based around a quasi-multi-regional input–output (QMRIO) model, the study, in theory, takes into account all CO2 emissions that arise from energy used in production of goods and services to satisfy UK household demand, whether the emissions occur in the UK or abroad. Results show that CO2 emissions attributable to households were 15% above 1990 levels in 2004, and that although absolute decoupling occurred between household expenditure and CO2 during the UK's switch from coal to gas in the early 1990s, since then only slight relative decoupling is evident. The proportion of CO2 that arises outside UK borders in support of UK consumption is rising, and reducing these emissions is particularly problematic in a global trading system. Investigation into the carbon footprint of different segments of the UK population shows wide variation: the segment with the highest carbon footprint emits 64% more CO2 than the segment with the lowest. Results show that recreation and leisure are responsible for over one quarter of CO2 emissions in a typical UK household in 2004. We conclude that expanding lifestyle aspirations are significant factors in driving household CO2 emissions, but the study also emphasizes that attention must be paid to the infrastructures and institutions that result in considerable amounts of CO2 being locked up in basic household activities through which people meet their everyday needs for subsistence, protection, and communication with family and friends. The findings highlight the sheer scale of the challenge facing UK policy-makers, and suggest that policies should be targeted towards segments of society responsible for the highest carbon footprints. [Copyright &y& Elsevier]

This paper introduces the method of decomposition analysis, and briefly discusses how it has been used in relation to patterns of energy consumption. It then uses decomposition analysis to discuss two radically different scenarios of UK energy use through to 2050, both of which result in a 60% reduction in emissions of carbon dioxide. The ratios of the decomposition analysis are discussed in relation to the social and economic drivers of energy use, and the kinds of changes in these drivers which would be necessary to bring the ratios about. In this way decomposition analysis is shown to be a useful technique both to generate quantitative scenarios of this kind, and to cast light on the socio-economic conditions which they imply. [Copyright &y& Elsevier]