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Abstract Building Energy Management is identified as a key part of the move towards localised energy generation and control. The significant discrepancy between building energy use as designed and during actual operation shows a need to evaluate the relationship between building occupants and energy requirements. The need to better account for the influence of occupants on building energy use has been established through post-occupancy studies, highlighting the characteristics needed for more successful building control systems. This paper provides an overview of current building control systems technology and discusses existing academic research into more advanced occupant-centric controls. The potential for application of various methods is compared. It is found that study into occupant-centred control systems covers a wide array of approaches, ranging from simple presence-based switching of lighting systems to full model predictive control. Studies suggest an optimum point balancing the complexity of a system against its potential for saving energy. Highlights • Occupant-centred Building Energy Management technologies and systems were reviewed. • Occupant measurement technologies varied in accuracy across different building types. • Wider occupancy data increasingly feasible with smart devices and wireless sensors. • Studies suggest an optimum, balancing system complexity against potential for saving energy. • A major challenge is robustness to uncertainty around unexpected occupant behaviours. [ABSTRACT FROM AUTHOR]

In the UK, finances and resources are invested into the application of new technologies, construction materials and control systems for homes, with the aim of improving energy efficiency. One such example is the experimental BASF house, built to study the thermal performance to achieve a comfortable home that uses energy efficiently. The house includes low to zero carbon (LZC) technologies that are promoted to reach a higher level within the UK Code for Sustainable Homes (CSH). For this study a mixed-methods sequential explanatory design (Creswell JW. Research Design. Qualitative, Quantitative, and Mixed Methods Approaches, 3rd edn. Sage Publication, 2009; Nataliya VI, Creswell JW, Stick SL. Using mixedmethods sequential explanatory design: from theory to practice. Field Methods 2006;18:3) that has been developed in the field of social and behavioural sciences has been applied, consisting of two distinctive phases: quantitative and qualitative. The rationale behind is for the quantitative data and its analysis is used to understand system performances while the qualitative data explain the numerical results in-depth, through the subjects in study, the occupants' perceptions. This article presents conclusions from an investigation into the use and performance of a biomass boiler and passive design features, derived from a live-in experience in a well-insulated and airtight CSH Level 4 home over two consecutive winter periods (2008-9 and 2009-10), which is part of on-going research project. The study also discusses a number of issues regarding the effective efficiency and appropriateness of the systems, which were selected based on a desire to comply with regulations for a better rated home rather than on their user friendliness and comfort for the occupants of a sustainable home; jeopardizing people's safety in times. [ABSTRACT FROM AUTHOR]

A hydrogen community energy storage (H-CES) system including a PEM electrolyser, metal hydride tank and PEMFC unit was designed, built and tested for a low carbon community. The H-CES performs end user applications including PV energy time-shift and demand load shifting. The system proved to have good flexibility and capability for mid-term and long term energy storage, with a round trip efficiency of 52%. Mid-term energy storage was demonstrated when the H-CES performed demand load shifting and hydrogen was stored for use one day later. Additionally, when PV energy time-shift was added to demand load shifting the operational hours of the electrolyser increased by 116%. Some improvements for future H-CES systems are also discussed in this study, the consideration of the optimum electronic equipment for the technology and rating being considered a key factor to maximize the discharge rating, round trip efficiency and reliability. [ABSTRACT FROM AUTHOR]

The energy expended for conditioning buildings around the world is worryingly large and increasing every year. Currently, almost half of houses around the world use some type of energy-expensive conventional air-conditioning system. These systems are high emitters of gases such as carbon dioxide and so high contributors to climate change. Consequently, alternatives must be considered. Earth-air heat exchangers (EAHEs) and phase-change materials (PCMs) may be options; they have, however, limitations. This paper proposes a novel hybrid space-conditioning system combining EAHEs with PCMs, which uses surfaces as sources of heating or cooling to provide better temperature distribution across a space and comfort enhancement with low energy use. The idea is to use an EAHE to provide cool air to discharge the PCM, consequently helping to overcome most of the limitations of both strategies. Two of a series of experiments undertaken to test the proposed system are reported in this article. The EAHE + PCM system compared with a reference room could decrease temperature swings by up to 47%. The system was proved to work although further work is required to make it commercially viable. [ABSTRACT FROM AUTHOR]

A novel method has been designed to obtain the optimum community energy storage (CES) systems for end user applications. The method evaluates the optimum performance (including the round trip efficiency and annual discharge), levelised cost (LCOES), the internal rate of return and the levelised value of suitable energy storage technologies. A complimentary methodology was developed including three reference years (2012, 2020 and zero carbon year) to show the evolution of the business case during the low carbon transition. The method follows a community approach and the optimum CES system was calculated as a function of the size of the community. In this work, this method was put in practice with lead-acid (PbA) and lithium-ion battery (Li-ion) technologies when performing PV energy time-shift using real demand data from a single home to a 100-home community. The community approach reduced the LCOES down to 0.30 £/kW h and 0.11 £/kW h in 2020 and the zero carbon year respectively. These values meant a cost reduction by 37% and 66% regarding a single home. Results demonstrated that PbA batteries needs from 1.5 to 2.5 times more capacity than Li-ion chemistry to reduce the LCOES, the worst case scenario being for the smallest communities, because the more spiky demand profile required proportionately larger PbA battery capacities. [ABSTRACT FROM AUTHOR]

Abstract: To meet the UK's decarbonization targets the introduction of novel integrated renewable energy generation, storage and demand management systems is required. In this paper the current role of fuel cells in the British domestic sector is discussed using simulation results of a solid oxide fuel cell (SOFC) system in a typical British single dwelling. 17% of carbon dioxide emissions are saved and 69% of the electricity generated by the SOFC system is exported to the grid for this single dwelling according to simulation results. Additionally, the same SOFC system is integrated with photovoltaic technology in a 7 home zero carbon community. The community approach adds a significant benefit given it increases the amount of electricity generated by the SOFC system which is used onsite by 128%, being the price of imported electricity 3 times higher than the export tariff. Then, a combination of short-term and long-term energy storage strategies is suggested by means of a lithium-ion battery and polymer electrolyte membrane (PEM) electrolyser which increased the self-consumption by 118%. According to simulation results, a 6 kW PEM electrolyser with an annual efficiency of 66% only generates 19% of the hydrogen which is consumed by the SOFC system which was used to meet the peak demand using PV generation. [Copyright &y& Elsevier]

Highlights: [•] Compared three occupancy measurement technologies for domestic energy efficiency. [•] Overall occupancy, room occupancy, number of occupants and location were assessed. [•] Passive infra-red: only good at occupancy detection, but prone to negative false. [•] CO2: highly depends on air circulation, thus only detects overall occupancy reliably. [•] Device-free localisation shows clear potential and requires more research. [ABSTRACT FROM AUTHOR]

Since its opening, the BASF prototype house at the Creative Energy Homes project has attracted significant attention due to the two main aspects of the design brief: energy efficiency and affordability. The house was built using modern methods of construction and incorporates a number of passive and active measures to achieve comfort. An evaluation of the home's thermal performance and potential climate resilience is presented in this article. An analysis of a summer period showed that, when occupied, the house presented a small degree of overheating with temperatures exceeding benchmarks. Subsequently, the house was dynamically simulated in future warmer climates where the issue was exacerbated even with mitigation strategies in place. The paradox lies in the fact that the rising risk of overheating may be a result in the effort to reduce energy demand for heating and this case study shows that this issue needs to be considered in order to avoid a rise in the use of air-conditioning in British homes. [ABSTRACT FROM AUTHOR]

As electricity networks are being transformed in order to enhance their flexibility and ability to adapt to low-carbon energy sources, there is more emphasis on demand-side management. The electricity demand can be modelled based on the bottom-up approach. The UK Time Use Survey 2000 data are used to create a model for electricity demand. By introducing a new filter when processing the Time Use data, the effect of seasonal variation on active occupancy and electricity demand has been investigated and presented here in this work. [ABSTRACT FROM PUBLISHER]

The main purpose of this paper is to present a robust methodology for quantifying the correlation between domestic energy consumption and occupant behaviour patterns, in response to various technological interventions, by using a test house whose performance and occupants are fully monitored and recorded. The E.ON Research House is one of the seven ‘Creative Energy Homes’ which are experimental eco houses, designed and constructed to various degrees of innovation and flexibility on the University of Nottingham campus. The E.ON House is a replica of a typical 1930s three-bed semi-detached property, which is representative of many of the existing houses in the UK. The objective of this study is to determine the most efficient way to refurbish it, within 3 years to reach a ‘zero-carbon’ standard. The house is occupied by a family (father, mother and a daughter) and is fully monitored in order to get real-time occupancy data for energy use, environmental conditions and occupant location. The post-occupancy evaluation study includes environmental monitoring (using a network of temperature, humidity and indoor air quality sensors), electricity (using whole house, circuit and appliance meters), energy associated with space and water heating. The occupancy patterns and space use are analysed using a real-time location system (supplied by UBISENSE) with ultra-wideband radio-frequency technology to track patterns of space usage in the house for time and location. The objective of post-occupancy study is to evaluate the relationships between occupancy and energy usage, as well to diagnose the performance and energy efficiency. [ABSTRACT FROM AUTHOR]

This paper presents the study of a thermoelectric cooler (TEC) designed for small-scale space conditioning applications in buildings. A theoretical study was undertaken to find the optimum operating conditions, which were then applied in the laboratory testing work. A TEC unit was assembled and tested under laboratory conditions. Eight pieces of UltraTEC were shown to generate up to 220 W of cooling with a COP of 0.46 under the input current of 4.8 A for each module. Thermo-economical analysis was carried out and results showed that a system with PV panel can compete with an equivalent system without a PV panel when PV costs fall down to or lower than £1.25 per Watt. For the cases without a PV panel, the system with a high level of TEC power input delivered a better performance in terms of the average cooling energy price than that system with a low level of TEC power input after critical interest rate (currently 4%). Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents the study of the novel thermoelectric heat pipe heat pumping system. Bent heat pipes with sintered powder wicks were utilized in a configuration which used centrifugal forces, due to rotation, to enhance heat transfer. The revolving heat pipes worked both as a fan and as a heat exchanger; however, extra fan blades were required to improve the fan performance. Fan performance tests were carried out, followed by the thermal performance, within which eight pieces of thermoelectric devices were applied to provide the heat pumping. The results showed that the system could provide airflows of up to 168.7 m3/h with the revolving speed of 600 RPM, and maximum static pressure was up to 37 Pa. The system could supply the heating of up to 257.1 W with the coefficient of performance of up to 1.96. Comparisons were made between the revolving and stationary systems, and the results showed that the former increased the thermal performance by up to 10% in heating and up to 20% in cooling. [ABSTRACT FROM PUBLISHER]

Domestic hot water (DHW) in the UK accounts for ∼7.5% of all energy use. For manufacturers of heating and hot water appliances to be in a position to respond to patterns of demand a full understanding of the effect of user-defined DHW profiles, different DHW systems and heating technologies are essential. This paper presents the prediction of the temperature characteristics of drawn DHW using artificial neural networks (NNs). We demonstrate whether, based on one NN model, different hot water system temperature loads can be accurately predicted. Two NN models were constructed and examined on a total of three systems. Both models trained on their associated systems produced errors of <11%; however, both NN models, when presented with unseen systems, produced large single errors. NN model 2 gave the lowest error when compared with NN model 1. [ABSTRACT FROM AUTHOR]

Vehicle-to-grid (V2G) has been identified as a key technology to help reduce carbon emissions from the transport and energy sectors. However, the benefits of this technology are best achieved when multiple variables are considered in the process of charging and discharging an electric vehicle. These variables include vehicle behaviour, building energy demand, renewable energy generation, and grid carbon intensity. It is expected that the transition to electric mobility will add pressure to the energy grid. Using the batteries of electric vehicles as energy storage to send energy back to the grid during high-demand, carbon-intensive periods will help to reduce the impact of introducing electric vehicles and minimise carbon emissions of the system. In this paper, the authors present a method and propose a V2G control scheme integrating one year of historical vehicle and energy datasets, aiming towards carbon emissions reduction through increased local consumption of renewable energy, offset of vehicle charging demand to low carbon intensity periods, and offset of local building demand from peak and carbon-intensive periods through storage in the vehicle battery. The study included assessment of strategic location and the number of chargers to support a fleet of five vehicles to make the transition to electric mobility and integrate vehicle-to-grid without impacting current service provision. The authors found that the proposed V2G scheme helped to reduce the average carbon intensity per kilowatt (gCO2/kWh) in simulation scenarios, despite the increased energy demand from electric vehicles charging. For instance, in one of the tested scenarios V2G reduced the average carbon intensity per kilowatt from 223.8 gCO2/kWh with unmanaged charging to 218.9 gCO2/kWh using V2G. [ABSTRACT FROM AUTHOR]

Global warming, pollution, and increasing energy demand have compelled electrification of the transport sector. Electric vehicles are not only an attractive and cleaner mode of transport, but they also possess the capacity to offer flexible storage alternative based on bidirectional vehicle-to-grid schemes. Vehicle-to-grid or V2G technology permits electric vehicles' batteries to store energy and discharge it back to the power grid during peak-load periods. However, the feasibility and economic viability of V2G is still a matter of concern and needs investigation. In this paper, the authors delved into the feasibility of V2G technology by analysing the real time-charging data of a V2G demonstration project named EV-elocity, located at the University of Nottingham campus in the UK. The authors analysed the charging data and trip-status data of two charging sites and put forward some insights regarding the feasibility of V2G and the behavioural traits of the vehicles. This paper will enlighten the research community regarding the feasibility and benefits of V2G in a real-world environment by analysing the charging/discharging and vehicle behaviour and reporting the opportunities and benefits of vehicle-to-grid technology. [ABSTRACT FROM AUTHOR]

The UK building stock, being amongst the oldest in the developed world, is also one of the least energy efficient and accounts for approximately 45% of UK carbon emission. Energy use from housing alone was responsible for 13% of total UK carbon dioxide and greenhouse gas emissions in 2015. Therefore, achieving the national target of an 80% reduction in carbon emissions by 2050 against 1990 baseline conditions is highly dependent on the reduction of energy consumption in dwellings. The complexity of the problem of retro-fitting energy saving measures in the extensive and diverse aging housing stock is further compounded due to the number of ‘hard to treat’ properties that comprise over 40% of homes in the UK. In this article, the authors present an evaluation of the theoretical and experimental performances of a novel prototype external wall insulation system, developed to improve energy efficiency in ‘hard to treat’ housing. The system was designed to be primarily used to retrofit social housing, which comprises up to 18% of the current UK housing stock. A thorough testing regime was undertaken to test the suitability and effectiveness of the new product in the most common social housing construction typologies. This included: an investigation of the theoretical thermal performance of the prototype product through steady state modelling, a laboratory based prototype test, an analysis of empirical data collected from a cross section of social housing properties in Nottinghamshire, UK used to inform whole house dynamic modelling, and the development of dynamic simulations to assess the energy and carbon reduction impacts of the new product. The theoretical modelling suggested that the integration of the system resulted in thermal performance improvements for all construction types with space heating demand reduced by up to 42%. The results of the whole house dynamic modelling assessment also suggested that the addition of the system resulted in a reduction of heating energy demand of up to 49%. The prototyping testing shown that the system is easy to install requirement minimum building skills. The findings suggest that the new product not only meets the performance of existing external wall insulation systems, but also provides unique selling points with respect to easy installation and non-reliance on weather conditions. The project finished with a pilot study when one house was retrofitted using the novel product. [ABSTRACT FROM AUTHOR]

Evidence suggests that many UK dwellings are subjected to overheating or will be at some point in the future. Dwellings built using modern methods of construction may have a higher overheating risk due to the low levels of thermal mass associated with most of these methods. The Nottingham HOUSE, a prefabricated timber modular building designed to zero-carbon and Passivhaus standards, was examined in terms of overheating occurrence. The ability of a high-density fibreboard and phase change materials to provide additional levels of thermal mass was examined with the results suggesting that these can help regulate internal temperatures with the benefit of being easy to integrate. [ABSTRACT FROM AUTHOR]

Growing support to decarbonise energy systems together with increasing retail energy prices are converting self-generation into a more attractive energy supply option. At the consumption level, solar PV is the most widespread generation technology due to declining capital costs, modularity and easy maintenance. The intrinsic dependence of solar energy generation on weather patterns and conditions affects the performance, final supply to the local demand load (i.e. local self-consumption) and final revenue. Energy storage is an available technological option to increase the value of local PV generation by increasing the self-consumption of PV-generated electricity. Therefore, understanding the performance, cost, value and optimum energy storage technology for managing PV generation is a key aspect for current and new customers with rooftop PV installations. In this study, energy storage for single homes is optimised by quantifying the performance, levelised cost, levelised value and profitability of hot water tanks (supplying domestic hot water), lead-acid batteries and lithium-ion batteries (supplying electricity). Although the assumed storage medium cost for Li-ion batteries (350 £/kWh) was 2.5 times higher than that of PbA batteries (140 £/kWh), Li-ion technology's greater round trip efficiency and cycling capability resulted in lower levelised cost (0.37 £/kWh) and higher levelised value (0.15 £/kWh) than PbA technology. The best economic case was for hot water tanks with a size ranging between 100 l and 200 l which were able to achieve internal rate of return values higher than the assumed discount factor (4%), especially when the property already had a hot water tank and domestic hot water was previously met by using retail electricity. [ABSTRACT FROM AUTHOR]

In this study, the effect of environmental conditions on plant operation was investigated for hydrogen refuelling stations with an external storage facility. Hydrogen storage pressure with respect to tank surface temperatures have been measured and used to create empirical equations for each tank showing the effect of surface temperature on the tank pressure. A physical model of the hydrogen storage tanks has been created in DesignBuilder (EnergyPlus) to simulate the surface temperature of tanks throughout the course of a year with respect to location, site orientation, tank size and surface colour, shading and operating pressure. Finally, the effect that environmental conditions may have on a plant operation is assessed through the prediction of pressure dependent events, namely the frequency of alarms and pressure relief occurrences and hours of plant downtime over the course of a year. The modelling results indicate that location, tank size, surface colour and sunshade can have substantial impacts on the plant operation, whereas the influence of site orientation is less significant. Frequency of pressure dependant events increase as the tank size decreases due to more significant heat gain observed with higher surface-to-volume ratios. Simulation results also prove that the provision of a sunshade or white paint colour could avoid/minimise the interference of ambient conditions in plant operation in cold and mild climates. However, they are not sufficient enough to mitigate against solar gain effect in warmer climates. Although reducing the maximum operating pressure would also help reduce the number of solar gain pressure events, it would also result in increased cushion level and hence reduced plant performance. The optimum design and operating strategy should be chosen for each individual station considering the daily and annual temperature profiles of the location. [ABSTRACT FROM AUTHOR]

• An energy system integrates heating grid, EV smart charging, peak shaving, solar PV. • The demand ratio of DHW to SH defines the supply temperature of the heating network. • The electric peak demand can be reduced from over five time increase to 33%increase. • A model identifies the required degree of housing thermal efficiency improvement. • A modelling tool indicates energy system requirements and hourly electricity demand. Electrification in energy supply–demand plays a critical role in domestic heating and road transport, delivering an electrified community to reduce carbon emissions. This solution, however, places a significant power demand increase on the distribution networks. To ensure the security of electricity supply, an efficient energy system and energy demand reduction are essential. In this paper, a multi-vector community energy system, applying an electrified heating network, electric vehicle smart charging, community-scale peak shaving and photovoltaic (PV) generation, is demonstrated in three models to manage an electrified community. Firstly, a heating network model, comprising a central ground source heat pump, low-temperature district heating system, electric heaters and thermal storage, is established to measure the optimum distribution temperature. Next, an electrified community model illustrates hourly electricity demands and performances of a community energy system, which is then used to identify the required degree of housing thermal efficiency improvement (i.e., heating demand reduction). The third model evaluates decentralised PV/storage units to maintain the power demand below a targeted power. Modelling results show that the demand ratio of domestic hot water to space heating determines the distribution temperature, which indicates the temperature is increasing with growing housing thermal efficiency. Moreover, the electrification of a community could increase the peak power demand on the highest demand day by over five times, converting heating demands into electricity directly. This significant peak demand can be possibly reduced to only a 33% increase by employing a community energy system. The model of PV/storage units is validated through a 12-week assessment. Ultimately, a modelling tool is developed by assembling the mentioned models, providing four pathways to attain electrification. Users can adjust specific parameters and database to align with the local conditions. The results indicate the requirements of building a community energy system and electricity demands in the highest consumption period. [ABSTRACT FROM AUTHOR]

This report is intended to review existing photocatalytic reactors as used in research and commercial applications. The guiding principles of effective reactor design are discussed, stressing the challenges faced by design teams. An account of specific reactor designs is given, highlighting innovative work and novel concepts. A concerted effort has been made to draw information from a wide variety of international sources, including scientific literature and web based sources. [ABSTRACT FROM AUTHOR]

Summary A numerical parametric study is presented of a domestic thermal storage heat exchanger to explore the effect of highly localized positive temperature coefficient cylindrical heating elements in a phase change material (PCM) with conductive enhancement by open‐pore metal foam. By using 90 L of commercially available Rubitherm RT70HC wax, 5.7 kWh of thermal energy is captured by the unit. The discharge is via a central convective air channel. The constant low‐temperature heating elements are inherently safe for combustible PCM. The heat distribution by Fourier's law and the creeping flow is investigated using the local thermal equilibrium assumption between the PCM and metal foam. Heating element position, diameter, and temperature are varied to optimize charge time and exit air temperature. Two heating elements of 1 cm diameter and constant temperature of 90°C produce a suitable performance for overnight store charging of 7.23 hours. Discharge via the air channel provides an average temperature of the output air over 30°C. The results indicated that the PCM inside metal foam almost follows Fourier's law. The creeping flow of molten PCM inside the pores of the porous medium (free convection heat effect) has an inconsiderable influence on heat transfer in the domain. [ABSTRACT FROM AUTHOR]

Summary: The effect of various arrangements of airflow channel in a proposed storage heater based on copper foam soaked in a phase change material (PCM) is investigated. Different configurations of the air channel using a serpentine channel, as well as numbers of the air channels, are examined in a representative three‐dimensional computer‐based model (Ansys Fluent). Evaluation is performed by PCM discharging rate and output air temperature of the unit. The goal is to improve both uniformity and value of air temperature. Changing the airflow arrangement using serpentine configuration to increase heat exchange surface area reduces solidification time and increases output maximum air temperature as well as pressure drop; conversely, exit air achieves lower temperature uniformity. In the case of the shortest solidification time using one air‐channel with the length of 51 cm, the solidification time reduces to almost 6 hours, compared with 13.6 hours for the straight channel with 37 cm length, with the average output temperature of 56°C compared to 41°C for the straight channel; however, the achieved temperature difference from the initial to the end of solidification time is 13.7°C compared to 4.5°C for the straight tube. [ABSTRACT FROM AUTHOR]

As an important indicator of construction quality and envelope integrity of buildings, airtightness is responsible for a considerable amount of energy losses associated with infiltration. It is crucial to understand building airtightness during construction and retrofitting to achieve a suitable envelope airtightness which is essential for obtaining a desirable building energy efficiency, durability and indoor environment. As a convenient means of measurement, the current steady pressurisation method has long been accepted as a standard testing method for measuring building airtightness. It offers an intuitive and robust approach for measuring building airtightness and performing building diagnostics. However, it also has some shortcomings that are mainly related to its high pressure measurement, requirement for skilful operation, long test duration and change to the building envelope. Efforts have been made by manufacturers and researchers to further improve its accuracy and practicality with much progress achieved. Work has also been done to develop alternative methods that can overcome some of the issues. This paper provides a practical review on the incumbent methodology and efforts that have been made over the past decades in research and development of other methods to achieve a similar purpose. It compares them in relation to aspects that are considered important in achieving an accurate, quick and practical measurement of building airtightness and the finding shows other methods such as acoustic and unsteady technique have their own advantages over the steady pressurisation method but also add some of their own restrictions, which therefore makes them suited for different applications. • This manuscript provides a review on the steady pressurisation. • The alternatives to the steady pressurisation method are reviewed and summarised. • Reviewed methods are compared with each other from perspectives that are considered important for a practical measurement. • Unsteady technique and acoustic method offer advantages but also add some of their own weakness. [ABSTRACT FROM AUTHOR]

• An empirical data set contained indoor and outdoor microclimate data for year 2019 is presented. • The heat-index and wet-bulb temperatures were checked using present and future climate scenarios. • Using IESVE, the dynamic simulation results are validated using empirical data set. The integration of vernacular strategies in Myanmar housing seems to have remained remarkably resilient and is still the norm even in modern dwellings. However, no regard is given to the possible impact of climate change. Using one-year monitored indoor and outdoor thermal environment data, typical and a morphed weather data representing future climate change scenarios, the authors investigated whether modern dwellings in Myanmar can provide thermal comfort in the present and future, and measured how vulnerable to overheating risks they are. Building envelope materials based on typical construction found locally and window shading were varied in the simulations, in order to understand their role in the resultant building performance. The analysis showed that the number of hours above 30 °C in 2019 doubled when compared to a typical weather year. This study contributes valuable insights into how the combined effect of air temperature and humidity will affect building thermal performance in future climate scenarios. Temperature readings reaching the 'danger' heat index threshold were 14.06% of the time in 2019 and only 5.49% in the typical weather year. This indicated that modern dwellings in Myanmar are facing two challenges: high vulnerability to extreme heatwave events, and inadequate response to increased mean air temperatures. [ABSTRACT FROM AUTHOR]

Since occupant behaviour impacts the energy performance of buildings, its study is relevant in order to bridge the performance gap. While the factors influencing occupant behaviour have been established, most studies have focused on those factors that motivate the action, such as environmental and temporal conditions. Contextual factors including spatial and occupant characteristics, which act as action moderators, remain a subject to explore. In this way, this article aims to identify patterns in the occupants' actions in office environments, based on spatial and human factors. A field study, including 514 occupants in 85 office spaces, was carried out in 11 buildings in Concepción, Chile. The results indicate that spatial layout is significantly related to the operation of windows, blinds, and thermostats, but not personal devices. Gender did not influence whether an occupant was active or not and age range was only significant regarding blinds. In shared spaces, there were fewer active occupants and whose acts depend on the perception of opportunity that they have, which is associated with element control distance and occupant age. The findings suggest that the probability that actions occur varies based on spatial and human factors, particularly because these factors affect occupant perception of opportunity. [ABSTRACT FROM AUTHOR]

This paper evaluates the discharging mechanism in a PCM (phase change material) to air heat exchanger for the purpose of space heating using a composite of copper foam and PCM. The composite system is modelled with both 2-D and 3-D computational fluid dynamics approach for different inlet air temperatures to consider the effect of room temperature using the thermal non-equilibrium model for the porous medium compared with the thermal equilibrium one. The results show the significant advantages of composite heat exchanger compared with a PCM only case. For the inlet air temperature of 22 °C, the composite unit is solidified in 43% shorter time with 73% higher heat retrieval rate compared with that for the PCM only. After 10 h, the temperature variation between the inlet and outlet of the air channels for latent heat storage heat exchanger system with the composite system is 41 °C and 34 °C for the inlet air temperatures of 0 °C and 22 °C, respectively, while it is 33 °C and 29 °C for the system with PCM only. This study show the possible usage of PCMs in the energy storage heaters by introducing metal foams which is not possible using PCM only alternatives. Image 1 • Composite metal foam/PCM-air thermal stores can be used as domestic room heaters. • High porosity (95%) metal foam provides faster (>40%) phase change. • PCM with metal foam provides uniform output air temperature to room. • 2D and 3D simulations nearly match due to adiabatic walls and size. • 3D is superior due to non-equilibrium modelling, not available in 2D. [ABSTRACT FROM AUTHOR]

Given the increasing penetration of renewable energy technologies as distributed generation embedded in the consumption centres, there is growing interest in energy storage systems located very close to consumers. These systems allow to increase the amount of renewable energy generation consumed locally, they provide opportunities for demand-side management and help to decarbonise the electricity, heating and transport sectors. In this paper, the authors present an interdisciplinary review of community energy storage (CES) with a focus on its potential role and challenges as a key element within the wider energy system. The discussion includes: the whole spectrum of applications and technologies with a strong emphasis on end user applications; techno-economic, environmental and social assessments of CES; and an outlook on CES from the customer, utility company and policy-maker perspectives. Currently, in general only traditional thermal storage with water tanks is economically viable. However, CES is expected to offer new opportunities for the energy transition since the community scale introduces several advantages for electrochemical technologies such as batteries. Technical and economic benefits over energy storage in single dwellings are driven by enhanced performance due to less spiky community demand profile and economies of scale respectively. In addition, CES brings new opportunities for citizen participation within communities and helps to increase awareness of energy consumption and environmental impacts. [ABSTRACT FROM AUTHOR]

While the management of PV generation is the prime application of residential batteries, they can deliver additional services in order to help systems to become cost-competitive. They can level-out the demand and potentially reduce the cost and emissions of the energy system by reducing demand peaks. In this study, community energy storage (CES) is optimised to perform both PV energy time-shift and demand load shifting (using retail tariffs with varying prices blocks) simultaneously. The optimisation method obtains the techno-economic benefits of CES systems as a function of the size of the community ranging from a single home to a 100-home community in two different scenarios for the United Kingdom: the year 2020 and a hypothetical zero emissions target. It is demonstrated that the levelised cost and levelised value of CES systems reach intermediate values to those achieved when both applications are performed independently. For the optimal performance of a battery system being charged from both local PV plants and the grid, our results suggest that the battery should be sized suitable to ensure it can fully discharge during the peak period. [ABSTRACT FROM AUTHOR]

Community energy storage (CES) is becoming an attractive technological option to facilitate the use of distributed renewable energy generation, manage demand loads and decarbonise the residential sector. There is strong interest in understanding the techno-economic benefits of using CES systems, which energy storage technology is more suitable and the optimum CES size. In this study, the performance including equivalent full cycles and round trip efficiency of lead-acid (PbA) and lithium-ion (Li-ion) batteries performing demand load shifting are quantified as a function of the size of the community using simulation-based optimisation. Two different retail tariffs are compared: a time-of-use tariff (Economy 7) and a real-time-pricing tariff including four periods based on the electricity prices on the wholesale market. Additionally, the economic benefits are quantified when projected to two different years: 2020 and a hypothetical zero carbon year. The findings indicate that the optimum PbA capacity was approximately twice the optimum Li-ion capacity in the case of the real-time-pricing tariff and around 1.6 times for Economy 7 for any community size except a single home. The levelised cost followed a negative logarithmic trend while the internal rate of return followed a positive logarithmic trend as a function of the size of the community. PbA technology reduced the levelised cost down to 0.14 £/kW h when projected to the year 2020 for the retail tariff Economy 7. CES systems were sized according to the demand load and this approximated the performance of PbA and Li-ion batteries, the capital cost per unit energy storage (kW h) of the latter assumed to be the double. [ABSTRACT FROM AUTHOR]

In this paper, the findings from a field study of the thermal performance of a low-energy dwelling are presented and discussed. The study aimed at evaluating the precision and accuracy of the QUB/e method in the field under UK climatic conditions. A series of in situ measurements were carried out in a low-energy detached house located in the University Park campus, University of Nottingham to determine both the whole building Heat Transfer Coefficient (HTC) and the thermal transmittances (U-values) of the external walls and the glazings. The values determined with well-established quasi-static measurement methods (coheating test, ISO 9869-1 average method) were used as reference (benchmark) values to assess the accuracy of the QUB/e method. In total 18 consecutive QUB/e tests were conducted. The QUB/e method was able to provide precise and accurate estimates of the whole building HTC: 94% of the results (i.e. 17 out of 18) were found to be within ± 15% from the mean and 78% of the HTC estimates (i.e., 14 out of 18) obtained with a QUB/e test could not be considered statistically different from the HTC determined with the coheating test (benchmark). It should be noted that the reported confidence intervals associated with the HTC estimates obtained with the QUB/e tests were slightly larger than the one reported for the coheating test (i.e., 11.6% in average and 6.1%, respectively). The Mean Bias Error (MBE) and the Root Mean Square Error (RMSE) associated with the HTC estimates obtained with the QUB/e tests were approximately 11%. The QUB/e method was also able to provide precise and accurate estimates of the thermal transmittances of the external walls and the glazings. We observed that all but seven (i.e., 119 out of 126 or 94%) U-values estimates of the external walls obtained with a QUB/e test could not be considered statistically different from the U-values determined with the ISO 9869-1 average method (benchmark). With regard to the glazings, this was observed for all U-values estimates (i.e., 162 out of 162 or 100%). It should be noted that the reported confidence intervals associated with the U-value estimates obtained with both test methods were close (i.e., approximately 10% in average) for all elements except for the ICF wall. [ABSTRACT FROM AUTHOR]

[Display omitted] Due to the success of the energy-efficient Passivhaus building envelope and its principles in regulating indoor thermal comfort in European climates, the potential implementation of it in other climates has been subjected to much attention in recent years. In this work, we adopted the hypothesis that slightly higher U-values of walls and floors than Passivhaus suggestion could be sufficient to achieve Passivhaus targets in the tropical context if the synergistic effects between shading and building envelope design were considered in a naturally ventilated condition. Firstly, thermal comfort thresholds were reviewed to establish the boundaries in the tropical context, choosing Myanmar as a case study. Secondly, Passivhaus steady-state calculation for shading design was compared with other dynamic simulation programs to inform the next step. The impacts of other parameters, which were excluded in Passihvuas's PHPP calculation, were then investigated. Finally, thirty shading scenarios for ten different building envelopes were analysed in free-running modes using typical and future weather scenarios. The results showed that the hypothesis was true and 3.6% of annual overheating hours were reduced by coupling Passivhaus building envelope, thermal mass and shading devices, and also overall extremes of temperature were reduced by more than 2.4 K on the hottest day. [ABSTRACT FROM AUTHOR]

Vehicle-to-grid services make use of the aggregated capacity available from a fleet of vehicles to participate in energy markets, help integrate renewable energy in the grid and balance energy use. In this paper, the critical components of such a service are described in the context of a commercial service that is currently under development. Key among these components is the prediction of available capacity at a future time. In this paper, we extend a previous work that used a deep learning recurrent neural network for this task to include online machine learning, which enables the network to continually refine its predictions based on observed behaviour. The coronavirus pandemic that was declared in 2020 resulted in closures of the university and substantial changes to the behaviour of the university fleet. In this work, the impact of this change in vehicles usage was used to test the predictions of a network initially trained using vehicle trip data from 2019 with and without online machine learning. It is shown that prediction error is significantly reduced using online machine learning, and it is concluded that a similar capability will be of critical importance for a commercial service such as the one described in this paper. [ABSTRACT FROM AUTHOR]

A photocatalytic side-emitting optical fibre mop fan prototype was designed, constructed and tested. The performance was compared with a previously tested polymer fibre mop fan. It was found that the system has better efficiency than the polymer fibre mop fan due to a more reasonable UV lamp arrangement and even UV-light transmittance. It was also found that the final room pollutant concentration depends on the pollutant generating rate by using the photocatalyst mop fan air cleaning system. The system is more compact than the polymer fibre mop fan. [ABSTRACT FROM AUTHOR]

Vehicle-to-grid (V2G) services utilise a population of electric vehicle batteries to provide the aggregated capacity required to participate in power and energy markets. Such participation relies on the prediction of available capacity to support the reliable delivery of agreed reserves at a future time. In this work real historical trip data from a fleet of vehicles belonging to the University of Nottingham was used and a simulation developed to show how battery state-of-charge and available capacity would vary if these trips were taken in electric vehicles that were charged at simulated charging station locations. A time series forecasting neural network was developed to predict aggregated available capacity for the next 24-h period given input data from the previous 24 h and its increased predictive capability over a regression model trained using automated machine learning was demonstrated. The simulations were then extended to include delivery of reserves to satisfy the needs of simulated market events and the ability of the model to successfully adapt its predictions to such events was demonstrated. The authors conclude that this ability is of critical importance to the viability and success of future V2G services by supporting trading and vehicle utilisation decisions for multiple market events. • CNN-LSTM neural network accurately predicts available capacity from a vehicle fleet. • Deviations in typical patterns of available capacity are predicted over a short horizon. • Model predicts the impact of exporting energy as part of a simulated V2G service. • Prediction accuracy reduces as prediction horizon increases. • Multivariate input improves accuracy for longer-term prediction horizons. [ABSTRACT FROM AUTHOR]

In this paper the findings from a long-term field study of the thermal performance of a circa 1950s dwelling are presented and discussed. The study aimed at evaluating the robustness of the QUB method in the field under UK climatic conditions. A series of 147 QUB tests were performed during the whole heating period (September 2016 – March 2017) in a detached house located in the University Park campus, University of Nottingham considering two distinct conditions: as-built and with increased airtightness. The QUB method was able to provide consistent and robust estimates of the Heat Transfer Coefficient (HTC) of the whole dwelling with approximately 80% of the results within ± 10% from the mean and more than 95% of the results within ± 15%. The need to treat heat losses occurring through the ground when assessing the thermal performance of buildings through experimental diagnostics methods was highlighted, especially in uninsulated concrete slab floors. The method devised to isolate the ground floor heat losses from the whole building losses resulted in reduced dispersion of the adjusted Heat Transfer Coefficient with a coefficient of variation of 5% and 98% of results within ± 10% from the mean. [ABSTRACT FROM AUTHOR]

Vehicle-to-grid services draw power or curtail demand from electric vehicles when they are connected to a compatible charging station. In this paper, we investigated automated machine learning for predicting when vehicles are likely to make such a connection. Using historical data collected from a vehicle tracking service, we assessed the technique's ability to learn and predict when a fleet of 48 vehicles was parked close to charging stations and compared this with two moving average techniques. We found the ability of all three approaches to predict when individual vehicles could potentially connect to charging stations to be comparable, resulting in the same set of 30 vehicles identified as good candidates to participate in a vehicle-to-grid service. We concluded that this was due to the relatively small feature set and that machine learning techniques were likely to outperform averaging techniques for more complex feature sets. We also explored the ability of the approaches to predict total vehicle availability and found that automated machine learning achieved the best performance with an accuracy of 91.4%. Such technology would be of value to vehicle-to-grid aggregation services. [ABSTRACT FROM AUTHOR]

This study numerically investigates the performance of the melting process for a PCM based heat storage system under the effect of different variables in a vertical container with a copper metal foam. Different cases were studied and compared including the effects of variable porosities and pore densities, non-equilibrium porous medium model, a multiple-segment metal foam case and different heater locations in the system on the liquid fraction and temperature as presented by contour plots and diagrams. The results show high performance for the copper foam-PCM unit compared with on its own PCM, for reducing the melting time by almost 85%. By changing the location of constant temperature heater from the bottom to the side and top surface, the melting time decreases by 70.5% and 4.7%, respectively. By using a multiple-segment porous system, the melting time reduces by 3.5% compared with the case of uniform porosity. Furthermore, the more accurate non-equilibrium numerical model shows a 7.4% difference in the melting time compared with the equilibrium model. This study optimises the design to improve practical application performance and to reduce waste energy. • Studying numerically the performance of the melting process for a PCM. • Porous-PCM composite reduces the melting time by 85% compared with on its own PCM. • The location of the heater has a great influence on the melting time. • Multiple-segment porous system shows better performance than the uniform porosity. • Non-equilibrium numerical model is more accurate than the equilibrium model. [ABSTRACT FROM AUTHOR]

• Design of a composite PCM to air heat exchanger for space heating. • Performance analysis of the system for 16 h discharging and 8 h changing. • A uniform output temperature of 46.9 °C for 17.4 h with 0.01 kg/s air mass flow rate. • 56% less solidification time using a composite PCM compared with PCM-only. • Compare the results of 2-D and 3-D modelling of the composite PCM to air heater. The objective of this numerical study is to develop a latent heat storage (LHS) air heater in both charging and discharging processes to find the geometrical and operating conditions for dwelling space heating. The aim of the storage heater is to provide a uniform output temperature according to the required heating load of a typical room in the required heating hours. The phase change material (PCM) is embedded in a copper porous structure to enhance the rate of heat transfer and overcome the low thermal conductivity of PCMs. The geometrical parameters is first obtained from analysing the discharging process including the height, air channel and PCM shell widths and air mass flow rate according to the discharging time as well as the output temperature of the air. Then, the charging mechanism is assessed to find the required area for the employed rectangular heating element. The results show the significant advantages of composite metal foam/PCM-air heat exchanger in comparison with the PCM-only unit on both the discharging time (56.5% reduction) and the uniformity of output temperature. The system with the height of 30 cm, PCM and air channel thickness of 15 cm and 2 cm, respectively, and a depth of 1 m, is capable to provide the desired output temperature of 47 °C for almost 17.4 h with the air mass flow rate of 0.01 kg/s. The charging analyses shows that the dimensions of the required rectangular heating element with constant temperature of 100 °C is 15 × 60 cm located at both sides of the unit. [ABSTRACT FROM AUTHOR]