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• Overheating regulations and calculation methods in 26 European countries were compared. • Most of the existing calculation methods are outdated and do not fit climate-proof buildings. • France requires a mixed-mode operation of naturally ventilated households. • The UK developed a heatwave-based calculation approach. • Comfort-based, multi-zonal, and time-integrated calculation approaches are needed. With the ongoing significance of overheating calculations in the residential building sector, building codes such as the European Energy Performance of Building Directive (EPBD) are essential for harmonizing the indicators and performance thresholds. This paper investigates Europe's overheating calculation methods, indicators, and thresholds and evaluates their ability to address climate change and heat events. e study aims to identify the suitability of existing overheating calculation methods and propose recommendations for the EPBD. The study results provide a cross-sectional overview of twenty-six European countries. The most influential overheating calculation criteria are listed the best approaches are ranked. The paper provides a thorough comparative assessment and recommendations to align current calculations with climate-sensitive metrics. The results suggest a framework and key performance indicators that are comfort-based, multi-zonal, and time-integrated to calculate overheating and modify the EU's next building energy efficiency regulations. The results can help policymakers and building professionals to develop the next overheating calculation framework and approach for the future development of climate-proof and resilient residential buildings. [ABSTRACT FROM AUTHOR]

Abstract: Papermaking is known as an energy-intensive, but not always efficient industry. This is at least partly due to the fact that the majority of papermaking technologies and procedures were established at a time when energy was both cheap and plentiful. A considerable fraction of the energy required for papermaking is consumed in removing water by the use of steam in the paper machine’s drying section. It is also known that even a small reduction in steam use can result in a significant reduction in production costs and environmental effects. To date, a great deal of research has been undertaken, aimed at improving the performance of the drying section by making more efficient use of dryer steam. This paper investigates a new approach to reducing thermal energy use in paper making by seeking to enhance the amount of water removed in sections of the machine prior to the drying section. The proposed method is focused on sequential modelling of the effect of vacuums used in the forming section on the thermal energy consumption in the drying section. The primary models explain how different vacuum pressures can affect the flow of water from the sheet in the forming section whilst the secondary models describe the effect of increased drainage on the steam requirements in the dryer. Operational data from a UK paper mill are used to illustrate the proposed method. The models developed can have subsequent application to optimising the use of thermal energy in paper making. [Copyright &y& Elsevier]

There has been general recognition within the construction industry that there is a discrepancy between the amount of energy that buildings actually use and what designers considered that they should use. This phenomenon is termed “The Performance Gap” and is normally associated with new buildings. However, existing and older buildings contribute a greater amount of operational carbon. In response to the Performance Gap, CIBSE have developed the TM54 process which is aimed at improving energy estimates at design stage. This paper considers how the TM54 process can also be used to develop energy management procedures for existing buildings. The paper describes an exercise carried out for a university workshop building in which design energy use has been compared with the actual building energy use and standard benchmarks. Moreover, a sensitivity assessment has been carried out using different scenarios based on operation hours of building/equipment, boiler efficiency and impact of climate change. The analysis of these results showed high uncertainty in estimates of energy consumption. If carbon challenges are to be met then improved energy management techniques will require a more systematic approach so that facilities managers can identify energy streams and pinpoint problems, particularly where they have assumed responsibility for existing buildings which often have a legacy of poorly metered fuel consumption. [ABSTRACT FROM AUTHOR]

• EV presents a technical challenge to the grid and an opportunity to introduce sustainable and novel solutions. • A sustainable energy strategy is proposed to exploit the synergy between EV batteries and heat pumps. • Electrification of transport and heat in buildings can reduce typical householder carbon footprint by up to 87%. The demand for electricity has been increasing worldwide and it is predicted that this trend will be particularly reinforced in developing countries by the gradual electrification of the transport sector and heat generation in buildings. The energy supply infrastructure required to meet the additional electricity demand should be carefully managed in light of the climate change carbon emission targets and commitments. A large proportion of the new electricity loads will be met from renewable sources. Therefore, means of power storage become vital to smooth out the intermittent nature of these energy supplies. The introduction of Electric Vehicles (EVs) could provide a viable and dynamic power storage solution through the concept of Vehicle-to-everything (V2X). This involves the storage of renewable energy (RE) in EV batteries during the charging cycle and restitution to the grid (V2G) or homes (V2H) when needed. In this context, this paper presents a methodology involving several strategies to stabilise the grid system and examines the impact of various types of EVs and heat pumps (HPs) for supplying heat in buildings. The results of this research approach show that the synergy of using V2H could reduce the carbon footprint of a typical domestic building in the United Kingdom (UK) by up to 87% and potentially recover up to 21.9 kWh/day of surplus renewable energy. [ABSTRACT FROM AUTHOR]

• Households change their heating patterns when they switch to a heat pump. • Typically, a setback temperature 2–5 °C lower than the desired thermostat setting. • We calculate the increase in heat demand with varied parameters. • The increase in heat demand is determined by heat loss and thermal mass. • This would be a useful metric for 'heat pump readiness'. Heating with air source heat pumps is an important step in the transition to Net Zero Carbon for many households. When predicting the resulting energy consumption it is frequently assumed that heating demand is unchanged from before the switch from gas heating. However, heating patterns usually change, with a net increase in heating demand to achieve the same level of thermal comfort. This paper discusses the change in pattern and uses modelling to determine the resulting increase in energy demand. It shows that the increase can be predicted with information about dwelling heat loss and thermal mass as well as weather and the pre and post switch heating pattern. The increase can be 20% or more for homes with high heat loss. It proposes that the metric for heating demand increase would be a useful measure of heat pump readiness, and that the parameters required to assess this should be provided on energy performance certificates. [ABSTRACT FROM AUTHOR]

Abstract Ice cream is consumed daily worldwide and yet its environmental impacts are scarcely known. This paper presents a first comprehensive life cycle assessment of market-leading vanilla and chocolate ice creams, considering both regular and premium products. The results suggest that their impacts are broadly similar across the 18 impact categories considered. For the majority of the impacts, chocolate regular ice cream is a slightly better option than the other varieties. Overall, the regular versions of the product have lower environmental impacts than the premium. Raw materials contribute most to the majority of impacts (>70%). The exception is ozone depletion, which is mainly due to refrigerated storage at the retailer (95%). The impacts are highly sensitive to the duration of storage and the type of refrigerant. Furthermore, the global warming potential of chocolate ice cream is very sensitive to land use change associated with cocoa beans cultivation, increasing the impact by 60%. Considering annual consumption of ice cream in the UK, the total primary energy demand contributes to 3.8% of energy consumption in the whole food sector while greenhouse emissions contribute 1.8%. Future improvements in the supply chain should focus on milk and cocoa production, reduced storage time and types of refrigerant used. Product reformulation to reduce the amount of milk (fat) and sugar should also be considered, in line with the emerging health-driven market trends. In addition to industry and policy makers, the findings of this study will be of interest to consumers, enabling them to make better choices with respect to environmental impacts of most popular ice creams. [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]

In this paper, a systematic review of academic literature and policy papers since 2008 is undertaken with an aim of identifying the prevalent energy systems models and tools in the UK. A list of all referenced models is presented and the literature is analysed with regards sectoral coverage and technological inclusion, as well as mathematical structure of models. The paper compares available models using an appropriate classification schema, the introduction of which is aimed at making the model landscape more accessible and perspicuous, thereby enhancing the diversity of models within use. The distinct classification presented in this paper comprises three sections, which specify the model purpose and structure, technological detail and mathematical approach. The schema is not designed to be comprehensive, but rather to be a broad classification with pertinent level of information required to differentiate between models. As an example, the UK model landscape is considered and 22 models are classified in three tables, as per the proposed schema. [ABSTRACT FROM AUTHOR]

Airtightness testing is widely undertaken to assess the as-built performance of dwellings, in support of achieving energy and ventilation strategies. Mandatory schemes operate in some countries, such as the UK, to ensure that dwellings are built in accordance with their design air permeability. However, testing is only useful if the results give a true picture of the airtightness of the building. Previous literature has investigated factors which could influence airtightness test results but has not questioned data quality, despite the pressure on builders to achieve design targets. This paper presents air permeability results from the largest UK dataset, comprising 144,024 dwellings tested under the Air Tightness Testing and Measurement Association (ATTMA) scheme. The data show an unexpected distribution of test results with narrow peaks just within test targets. Such results were not expected theoretically but do reflect findings in other fields where performance-based targets are in place. Such a close match between design and tested airtightness may be achieved by remedial works taking place during the test rather than afterwards. Recommendations are made with respect to quality assurance systems, design guidance and on-site sealing practices to increase the likelihood of long-term airtight buildings being constructed first time. [ABSTRACT FROM AUTHOR]

This paper investigates factors associated with variation in daily total (electricity and gas) energy consumption in domestic buildings using linked pre-COVID-19 smart meter, weather, building thermal characteristics, and socio-technical survey data covering appliance ownership, demographics, behaviours, and attitudes for two nested sub-samples of 1418 and 682 British households selected from the Smart Energy Research Laboratory (SERL) Observatory panel. Linear mixed effects modelling resulted in adjusted R2 between 63% and 80% depending on sample size and combinations of contextual data used. Increased daily energy consumption was significantly associated (p -value < 0.05, VIF < 5) with: households living in buildings with more rooms and bedrooms, that are older, more detached, have air-conditioning, and experience colder (more heating degree days) or less sunny weather; households with more adult occupants, more children, older adult occupants, higher heating temperature setpoints, and that do not try to save energy. The results demonstrate the value of smart meter data linked with contextual data for improving understanding of energy demand in British housing. Accredited UK researchers are invited to apply to access the data, which has recently been updated to include over 13,000 households from across Great Britain. This paper provides guidance on appropriate methods to use when analysing the data. [ABSTRACT FROM AUTHOR]

The ability to accurately model and predict timing and duration of activities for different individuals is essential for successful and widespread Demand Side Response (DSR) policies, especially in the residential sector. Understanding what people do during the day and what factors influence their activity participation decisions is important for planning an effective DSR strategy to harness the end-user flexibility. The recent Covid-19 pandemic has shown how much activities can be shifted to a virtual mode in the presence of mobility restrictions. Further, participation in activities via digital devices (virtual activity participation) has spread across society. Such virtual activities, including teleworking, online shopping, and virtual social interactions, are observed to explicitly impact travel behaviour and activity scheduling. And yet, activity-based models of mobility and energy demand do not accommodate the trade-offs between activity types, location and virtual activity participation. This paper presents a model of activity participation that captures the relationship between the three dimensions of: activity type (such as work, study, shopping), activity location (in-home, out-of-home), and activity modality (in-person, virtual). A Multiple-Discrete Continuous Extreme Value (MDCEV) model structure is applied, and the empirical analysis is undertaken using the 2015 United Kingdom Time Use Survey (UKTUS). The model results provide insights for better understanding of the trade-offs made by individuals as they participate in and allocate time across a set of activity type-location-modality alternatives, and the heterogeneity in these trade-offs. Further, holdout sample validation and policy scenario analysis exercises are presented to demonstrate the reliability and suitability of the model for policy implications. The empirical results presented in our paper suggest that this framework embedded in an activity and agent-based simulator of energy demand will enable us to test a variety of scenarios related to end-user flexibility and activity behaviour change, including consideration of virtual activity participation trends. [ABSTRACT FROM AUTHOR]

Energy and environmental sustainability in urban rail transport have attracted substantial attention in the last decade. In the UK, about 29% of the current train fleets are run solely on diesel fuel, and the UK Government has pledged to remove all diesel-only trains by 2040. One option to achieve this ambitious goal is replacing diesel trains with hybrid trains. However, little has been done to evaluate the operational performance of replacing diesel trains with hybrid trains on the same track. This paper develops a novel Hybrid Train Simulator which can analyse the driving performance and energy flow among multiple energy sources (diesel, hydrogen and battery). Several practical case studies are presented based on typical mainline railways in the UK. Operation performance using diesel trains and hybrid trains is compared. This paper also proposes automatic smart switching control between multiple power sources according to the altitude of the route for hybrid trains. The case studies indicate that hybrid trains increase the journey time due to their low power capacity but improve energy efficiency significantly. Besides, implementing auto-switching on hybrid trains can reduce energy consumption by 6% compared with benchmark hybrid trains. [ABSTRACT FROM AUTHOR]

Recent research into the determinants of household energy consumption has aimed to incorporate findings from economics, sociology and psychology in order to obtain a more comprehensive understanding of the factors determining energy demand. The current paper contributes to this nascent stream of literature by studying the relationship between risk attitudes, trust propensity and energy consumption at the household level. Drawing on the British Household Panel Survey, a well-known data set in the context of energy studies, I show that trust is negatively correlated with household energy demand, while higher risk tolerance leads to increases in residential energy use. Potential explanations for these findings are investigated, suggesting that risk preferences may be related with overall appliance stock and the size of the rebound effect. [ABSTRACT FROM AUTHOR]

This paper quantifies the impacts of policy objectives on the composition of an optimum new passenger vehicle fleet. The objectives are to reduce individually absolute energy use and associated emissions of CO 2 , NO x and PM 2.5 . This work combines a top down, diversity-led approach to fleet composition with bottom-up models of 23 powertrain variants across nine vehicle segments. Changing the annual distance travelled only led to the smallest change in fleet composition because driving less mitigated the need to shift to smaller vehicles or more efficient powertrains. Instead, managing activity led to a ‘re-petrolisation’ of the fleet which yielded the largest reductions in emissions of NO x and PM 2.5 . The hybrid approach of changing annual distance travelled and increasing willingness to accept longer payback times incorporates management of vehicle activity with consumers’ demand for novel vehicle powertrains. Combining these changes in behaviour, without feebates, allowed the hybrid approach to return the largest reductions in energy use and CO 2 emissions. Introducing feebates makes low-emitting vehicles more affordable and represents a supply side push for novel powertrains. The largest reductions in energy use and associated emissions occurred without any consumer behaviour change, but required large fees (£79–99 per g CO 2 /km) on high-emitting vehicles and were achieved using the most specialised fleets. However, such fleets may not present consumers with sufficient choice to be attractive. The fleet with best diversity by vehicle size and powertrain type was achieved with both the external incentive of the feebate and consumers modifying their activity. This work has a number of potential audiences: governments and policy makers may use the framework to understand how to accommodate the growth in vehicle use with pledged reductions in emissions; and original equipment manufacturers may take advantage of the bottom-up, vehicle powertrain inputs to understand the role their technology can play in a fleet under the influence of consumer behaviour change, external incentives and policy objectives. [ABSTRACT FROM AUTHOR]

Abstract: Thermal energy loss in the process industry is a significant issue due to the high temperatures and multiple heat intensive processes involved. High-grade thermal energy is typically recovered within processes. However, lower grade heat is often rejected to the environment. The benefits of capturing and utilising low grade thermal energy are highly dependent on the qualities and properties of the heat in the waste streams. The temperature of the low grade heat stream is the most important parameter, as the effective use of the residual heat or the efficiency of energy recovery from the low grade heat sources will mainly depend on the temperature difference between the source and a suitable sink, e.g. another process or space heating/cooling. In general, the temperatures of these waste heat sources are too low to produce electricity and direct heat use will depend on whether potential user can be found. This paper presents past and current drivers for heat recovery studies. High and low grade heat sources are defined according to the viability of recovery within the processes. Firstly, high grade heat capture within the processes is reviewed. Then, the focus is on the potential for low grade heat capture outside of the original plant. The paper addresses the potential for low grade heat recovery with regard to new incentives and technological advances. Finally, different aspects which influence the decision making for low grade heat recovery in the process industry are discussed. It is concluded that organisational, financial and economic barriers might be overcome and benefits from a holistic vision could be gained with stronger governmental policy and regulation incentives. [Copyright &y& Elsevier]

• Implementation of a model predictive control scheme for HVAC systems is presented. • The hardware/software solution is generalisable to most building management systems. • Cloud solutions can offer low-cost, scalable control in commercial buildings. • Economic MPC reduced energy usage by 1.7% compared to baseline control. • Building thermal performance strongly affects viability of MPC schemes. Many businesses are looking for ways to improve the energy and carbon usage of their buildings, particularly through enhanced data collection and control schemes. In this context, this paper presents a case study of a food-retail building in the UK, detailing the design, installation and cost of a generalisable model predictive control (MPC) framework for its Heating, Ventilation and Air Conditioning (HVAC) system. The hardware/software solution to collect relevant data, as well as the formulation of the MPC scheme, is presented. By utilising cloud-based microservices, this approach can be applied to all modern building management systems with little upfront capital, and an ongoing monthly cost as low as $6.39/month. The MPC scheme calculates the optimal temperature setpoint required for each Air-Handling Unit (AHU) to minimise its overall cost or carbon usage, while ensuring thermal comfort of occupants. Its performance is then compared to the existing legacy controller using a simulation of the building's thermal behaviour. When simulated across two months the MPC approach performed better and achieved the same thermal comfort for a lower overall cost. The economic optimisation resulted in an energy saving of 650 kWh, with an associated cost savings of $240 (an improvement of 1.7% compared to the baseline), while the carbon optimisation gave negligible CO 2 savings due to the inability of the building to shift heating to low-carbon periods. Findings from this study indicate the potential for improving building performance via MPC strategies, however the level of impact will depend on specific building attributes. [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]

The fishing industry is heavily reliant on the use of fossil fuel and emits large quantities of greenhouse gases and other atmospheric pollutants. Methods used to calculate fishing vessel emissions inventories have traditionally utilised estimates of fuel efficiency per unit of catch. These methods have weaknesses because they do not easily allow temporal and geographical allocation of emissions. A large proportion of fishing and other small commercial vessels are also omitted from global shipping emissions inventories such as the International Maritime Organisation's Greenhouse Gas Studies. This paper demonstrates an activity-based methodology for the production of temporally- and spatially-resolved emissions inventories using data produced by Automatic Identification Systems (AIS). The methodology addresses the issue of how to use AIS data for fleets where not all vessels use AIS technology and how to assign engine load when vessels are towing trawling or dredging gear. The results of this are compared to a fuel-based methodology using publicly available European Commission fisheries data on fuel efficiency and annual catch. The results show relatively good agreement between the two methodologies, with an estimate of 295.7 kilotons of fuel used and 914.4 kilotons of carbon dioxide emitted between May 2012 and May 2013 using the activity-based methodology. Different methods of calculating speed using AIS data are also compared. The results indicate that using the speed data contained directly in the AIS data is preferable to calculating speed from the distance and time interval between consecutive AIS data points. [ABSTRACT FROM AUTHOR]

The change in climate has led to an interest in how this will affect the energy consumption in buildings. Most of the work in the literature relates to offices and homes. However, this paper investigates a supermarket in northern England by means of a multiple regression analysis based on gas and electricity data for 2012. The equations obtained in this analysis use the humidity ratio derived from the dry-bulb temperature and the relative humidity in conjunction with the actual dry-bulb temperature. These equations are used to estimate the consumption for the base year period (1961-1990) and for the predicted climate period 2030-2059. The findings indicate that electricity use will increase by 2.1% whereas gas consumption will drop by about 13% for the central future estimate. The research further suggests that the year 2012 is comparable in temperature to the future climate, but the relative humidity is lower. Further research should include adaptation/mitigation measures and an evaluation of their usefulness. [ABSTRACT FROM AUTHOR]

• Severe PV ramping at high penetration could cause voltage instability in presence of Induction motor loads. • Replacement of Induction motor by Variable Speed Drive (VSD) loads enhances voltage stability of distribution network. • Enhanced stability with VSD is studied theoretically with Q-V analysis and with time simulations. • Minimum IM replacement by VSD is determined for realistic distribution network at various PV penetration levels. The Photovoltaic (PV) sources have become the most popular renewable energy resources as it is modular and are deployed quickly. However, the distributed PVs are highly volatile and can have high ramping characteristics where the ramping can go up to 90% of its capacity in about 20 s due to events such as the passing of fast-moving clouds. This kind of PV ramps with high magnitudes can lead to voltage instability in distribution networks that are usually dominated by Induction motor (IM) loads. This paper explains the mechanism of such an instability analytically using Q-V analysis with distribution feeder and IM load characteristics. Highlighting the gradual replacement of IM loads by Variable Speed Drive (VSD) loads due to energy efficiency policies, the paper demonstrates the enhanced voltage stability under VSD loads by both time simulation and analytical approach. Furthermore, the analysis is extended to a realistic distribution network namely, United Kingdom General Distribution System (UKGDS) and extensive case studies are conducted to analyze the voltage stability during PV ramping events at various load compositions of IMs and VSDs. Moreover, the minimum VSD penetration level required to avert the voltage instability at various PV penetration levels have also been determined. [ABSTRACT FROM AUTHOR]

• New building development projects underperform often. • Underperformance leads to increased energy consumption and CO 2 emissions in building operation. • The paper links building project development and building operational performance. • Two simulation methods are combined in a multi methodology framework in the paper. • The paper explores the implications of project partner collaboration for operational building performance in the case of a recent building project. The "performance gap" in the United Kingdom construction industry is a persistent problem as new building development projects underperform more often than not. The "performance gap" is partially attributed to the number of stages involved in building project development and the coordination difficulties of partners with different incentives. The project outcome is important for energy consumption, carbon emissions and occupant well-being. Thus, it is important to study the project management process in terms of the standard time, cost and quality parameters, but also in terms of project partner incentives and coordination, and the subsequent energy performance and resultant indoor environmental conditions. A system dynamics model of project management processes is developed to explore the implications of partner coordination for building quality. The system dynamics model is coupled to a building performance simulation model to explore building energy consumption and Indoor Environmental Quality, and apply this on a recent building project case study. Results show that greater project partner alignment can reduce annual energy consumption up to 12% and CO 2 emissions up to 37%, with greater emphasis in the design stage of the project subject to resource availability. The trade-offs involved on value appropriation are considered and discussion of results points to possible ways for improvement. [ABSTRACT FROM AUTHOR]

• A switchable photovoltaic window based on thermotropic hydrogel is developed. • Selected hydrogel can reversibly switch between highly transmissive and scattering states. • The window performance is evaluated by indoor and outdoor experiments. • This window can passively control daylighting and heat gain during hot sunny days. • This window offers better electrical performance than conventional PV glazing. Daylighting control technologies have become an essential part of sustainable building design to reduce overheating, glare and energy consumption in buildings. In this paper, a smart glazing system where a Building Integrated Photovoltaic (BIPV) glazing is coupled with an optically switchable thermotropic hydrogel layer is proposed to improve the daylighting control and electricity generation performance of traditional BIPV glazings. Thermotropic (TT) hydrogels made of various weight percentage combinations of hydroxypropyl cellulose (HPC) polymer, gellan gum and sodium chloride (NaCl) salt were synthesised and first evaluated by visible-near-infrared spectroscopy. Subsequently, small-scale prototypes of the proposed BIPV thermotropic (BIPV-TT) laminated glazing based on these TT hydrogels were fabricated and characterised experimentally under controlled laboratory conditions. The TT hydrogel, which was synthesised of 6 wt% HPC, 0.5 wt% gellan gum and 4.5 wt% NaCl, was selected for further experimental characterisations in a dynamic outdoor environment, due to its appropriate transition temperature of 30.7 °C for use in mild climates with a wide modulation range of solar transmittance from 85.8% (in the transparent state) to 9.6% (in the light-scattering state). The outdoor tests were conducted in Nottingham, the UK, on typical summer days with sunny and partial cloudy conditions. The results showed that using the prototype BIPV-TT laminated glazing can reduce up to 80% of the solar radiation transmitted into the outdoor test cell, while providing up to 12% higher electrical power outputs, compared to its counterpart system with no thermotropic hydrogel applied. [ABSTRACT FROM AUTHOR]

This paper considers how energy-related external costs change through time. It focuses on one of the key periods in the history of energy. After a period of declining coal prices and soaring consumption which fuelled the Second Industrial Revolution, the nineteenth century British economy was externalising the social costs of energy production and consumption on a massive scale. Rising from 25% in the 1820s, an estimated 60%–70% of the average social costs of coal were externalised in the 1880s, imposing damages close to 20% of GDP. The eventual decline in air pollution concentration (around 1900) occurred fifty years later than was broadly socially optimal. This experience highlights the evolution of the demand for and supply of environmental quality in the context of economic growth, and the nature of related market and government failures, implying the necessity for adaptation rather than encouraging mitigation. This experience may offer lessons for climate analysis and policy-making. [Copyright &y& Elsevier]

Abstract: This paper introduces the concept of the Adaptive Comfort Degree-Day, a temperature difference/time composite metric, as a means of comparing energy savings from Adaptive Comfort Model standards by quantifying the extent to which the temperature limits of the thermal comfort zone of the Predicted Mean Vote Model can be broadened. The Adaptive Comfort Degree-Day has been applied to a series of climates projected for different locations (Edinburgh, Manchester and London) under different emissions scenarios in the United Kingdom for the 2020s, 2030s, 2050s and 2080s. The rate at which energy savings can be achieved by the European adaptive standard EN15251 (Category II) was compared with the ASHRAE 55 adaptive standard (80% acceptability) during the cooling season. Results indicate that the wider applicability of the European standard means that it can realise levels of energy savings which its counterpart ASHRAE adaptive standard would not achieve for decades. [Copyright &y& Elsevier]

Abstract: As the debate on policy responses to climate change gathers pace, there has been an increasing focus on tools to model national scale energy use and emission characteristics of UK dwellings. This paper reviews some existing models and highlights limitations of their common underlying methodologies. We argue that a radically different, integrated, approach is required to tackle these challenges and ensure that the modelling remain robust and able to meet future demands. We suggest that Agent Based Modelling (ABM) is a suitable candidate modelling paradigm to achieve an integrated modelling framework. We also present DECarb-ABM (an ABM based implementation of an existing model, DECarb) with many of the desired properties of such an integrated framework. The new model is validated against both the existing model and historical data. [Copyright &y& Elsevier]

Abstract: Green roofs are a passive cooling technique that stop incoming solar radiation from reaching the building structure below. Many studies have been conducted over the past 10 years to consider the potential building energy benefits of green roofs and shown that they can offer benefits in winter heating reduction as well as summer cooling. This paper reviews the current literature and highlights the situations in which the greatest building energy savings can be made. Older buildings with poor existing insulation are deemed to benefit most from a green roof as current building regulations require such high levels of insulation that green roofs are seen to hardly affect annual building energy consumption. As over half of the existing UK building stock was built before any roof insulation was required, it is older buildings that will benefit most from green roofs. The case for retrofitting existing buildings is therefore reviewed and it is found there is strong potential for green roof retrofit in the UK. [ABSTRACT FROM AUTHOR]

This paper presents a societal level exergy analysis approach developed to analyse transitions in the way that energy is supplied and contributes to economic growth in the UK, the US, Austria and Japan, throughout the last century. We assess changes in exergy and useful work consumption, energy efficiency and related GDP intensity measures of each economy. The novel data provided elucidate certain characteristics of divergence and commonality in the energy transitions studied. The results indicate that in each country the processes of industrialization, urbanisation and electrification are characterised by a marked increase in exergy and useful work supplies and per capita intensities. There is a common and continuous decrease in the exergy intensity of GDP. Moreover for each country studied the trend of increasing useful work intensity of GDP reversed in the early 1970s coincident with the first oil crisis. [Copyright &y& Elsevier]

Abstract: Possible solutions for zero energy building design in UK are discussed in this paper. Simulation software (EnergyPlus and TRNSYS 16) are employed in this study, where EnergyPlus simulations are applied to enable facade design studies considering building materials, window sizes and orientations and TRNSYS is used for the investigation of the feasibility of zero energy houses with renewable electricity, solar hot water system and energy efficient heating systems under Cardiff weather conditions. Various design methods are compared and optimal design strategies for typical homes and energy systems are provided. [Copyright &y& Elsevier]

This paper quantifies fossil resource inequalities amongst income quintiles in the UK between 1968 and 2000. It calculates a resource-based Gini coefficient using an input–output based resource allocation model. The results show that the Gini coefficient for total fossil resource consumption grew by 24% over the time period. By comparison the Gini coefficient for overall household expenditure rose by only 13%. The increase in resource inequality was prompted by the rising demand by high income quintiles for goods and services such as: “fuel and light” (heating and lighting the home), “car use” (private transportation), “recreation”, “travel” and “other services”. The analysis shows further that the Gini coefficient for “direct” fossil resources (“fuel and light” and “car use”) was lower and rose less steeply than the Gini coefficient for fossil resources embodied in other goods and services (indirect fossil resource requirements). Investigation into the drivers behind direct and indirect resource inequalities suggests a number of policy conclusions. Firstly, it is clear that policy initiatives to reduce fossil resource requirements (and the associated climate change impacts) must pay careful attention to distributional differences. Additionally, increased attention needs to be paid to the inequalities associated with indirect fossil resources consumption as well as the more visible direct resource inequalities. [Copyright &y& Elsevier]

This paper presents figures for the small power equipment loads encountered by the Welsh School of Architecture in UK offices while undertaking a programme of research and monitoring into the energy efficiency of air-conditioning systems in use. The findings are based on surveys undertaken in 30 air-conditioned offices between April 2000 and October 2002. Peak small power equipment loads were calculated using the CIBSE nameplate-ratio method. The results show that the small power loads averaged 17.5 W/m2 with a range between 6 and 34 W/m2 of treated floor area. When normalised for occupancy the calculated peak small power equipment loads averaged 158 W per person, with a range between 124 and 229 W per person. Current industry guidance could lead to the overestimation of small power equipment loads by as much as 650%, ultimately resulting in increased capital and running costs of air-conditioning plant and reduced thermal comfort. A more accurate method of estimating peak small power equipment loads in UK office buildings is suggested based on occupant density. [Copyright &y& Elsevier]

• Domestic energy mapping can rapidly and accurately target appropriate dwellings. • Dwelling-level data collection by local community improved input for energy model. • Multiple routes of targeting using high energy use, fuel poverty and typologies. • Projected 89–94% mean energy reduction using whole house retrofit package. • Funding programmes need to be customised for different household segments. A long-standing challenge for area-based mass retrofits has been the ability to rapidly and accurately target appropriate dwellings for energy improvements. This paper demonstrates the application of a data-driven localised Geographical Information System (GIS)-based domestic energy mapping approach to create house-by-house baseline energy models and predict the potential for whole house energy retrofits in a case study of 431 dwellings in Oxford (UK). Top - down spatial datasets on energy, housing, socioeconomics and fuel poverty are combined with bottom-up energy modelling underpinned by actual dwelling details gathered through questionnaire surveys by the local community group. Multiple routes to identify suitable dwellings were tested such as grouping dwellings with high energy use, those with high levels of fuel poverty and by common dwelling characteristics. About 300 dwellings were found to be suitable for a whole house retrofit package, equating to 89–94% mean energy reduction over baseline. While the most common dwelling typology, 1930s semi-detached had high retrofit need, it fell in an area with low annual household income. The second most common dwelling typology, 1930s terrace, was dominant in areas with median level of household income. Funding programmes will need to be customised for different household segments to increase the take-up of energy retrofits. [ABSTRACT FROM AUTHOR]

• Tank size and temperature set point of 1.2 m3 and 75 °C are optimal system design. • Should charge storage at 3am and 2pm for morning and afternoon demands, respectively. • The best load shifting positively affects the grid. • Achieve running costs and CO 2 savings with the best load shifting, compared to oil boilers. Cascade air-to-water heat pumps may have good potential for retrofitting UK domestic buildings because they can directly replace existing fossil-fuel boilers without the requirement of considerable modifications to heat distribution systems. A widespread uptake of these heat pumps, however, would pose challenges to the grid. Furthermore, wind power generation has increased in the UK to achieve the target of decreasing CO 2 emissions by 2050, but there are high levels of wind curtailment due to the mismatch between electricity supply and demand. In this paper, a load shifting study for cascade heat pumps coupled with thermal energy storage addressing these issues is presented. The main objective is to find the best tariff-based schedule load shifting for cascade heat pumps, which can help to avoid peak demand periods while obtaining enhanced system energy efficiency with minimised running costs and reduced wind energy curtailment. How the retrofit performance of the cascade heat pumps with load shifting is further investigated. TRNSYS was used to simulate the system performance validated against experimental results. Northern Ireland (UK) was selected as the evaluated scenario. Simulation results showed that the tank temperature set point of 75 °C and the storage size of 1.2 m 3 could wholly shift the cascade heat pumps' operation to off-peak periods. The best times to start the cascade heat pumps to charge the storage were at 3 am and 2 pm for the morning and afternoon heating demands, respectively. Compared to oil boilers, the cascade heat pumps with load shifting could obtain lower running costs (16–34%) and carbon emissions (20–37%). [ABSTRACT FROM AUTHOR]

Most European countries have committed to ambitious emissions reduction goals. Energy generation in particular is responsible for more than 30% of global emissions, where significant focus has been placed on renewable energy generation, including biomass. On the one hand, there are countries, like the UK, where the biomass stock is insufficient to meet the demand; on the other hand, there are countries, like Brazil, where the stock significantly exceeds the demand. To promote a natural symbiosis, it is necessary to take on the challenge of transporting biomass through long distances in an environmentally and economically efficient manner. This paper aims to assess the efficiency of alternative pathways of international biomass supply-chains. The alternatives involve different biomass origin regions, transportation modes, export ports and processing technologies, including torrefaction. Data Envelopment Analysis (DEA) has been used for the first time to assess the efficiency of the alternative biomass supply chain pathways in a Latin American context, considering multiple-criteria relating to economic and environmental performance simultaneously, such as the biomass delivered cost, the environmental impact and the fossil energy consumption. Additionally, a sensitivity analysis was performed to analyse the robustness of the results under uncertainty in parameter values. The DEA approach presented can assist the process of planning biomass sourcing and improve decision-making under multiple decision criteria. The results can support medium- and long-term strategic decisions for decision- and policy-makers. • Efficiency assessment of biomass supply chain pathways between Brazil and the UK. • 56 alternative pathways considered with different supply chain structure. • Data Envelopment Analysis used for multi-criteria efficiency assessment. • Results can support decision and policy making. • Trade-offs between different criteria identified. [ABSTRACT FROM AUTHOR]