City-wide Building Energy Efficiency Assessment Using EPC Data

The Energy Performance Certificate (EPC) requirements in Europe have provided rich data of energy efficiency status of individual buildings at scale, allowing appropriate assessments to be carried out without the need of conducting additional surveys. By 2012, the EPC data in England and Wales in the UK has reached a coverage of up to 45% of the entire building stock (DECC 2014), and the number of new certificates added every year is over 1 million. The work presented here seeks to understand the potential of using such dataset to deliver systematic analysis of energy efficiency of buildings at a city scale. This study utilises all EPC datasets available for the city of Southampton, UK, and developed an automatic geographic-referencing methodology so the EPC data can be integrated onto geographic information systems (GIS). Such methodology allows large quantity of EPC data to be analysed spatially, facilitating the assessment of energy performance of different regions in a city. The results show clearly areas in the city that have the lowest or highest level of performance in terms of buildings’ energy efficiency, and revealed the impact of certain building intervention measures (such insulation, double glazing) on the energy consumption within the considered buildings. The analyses show that factors such as the existence of high streets and new building developments have significant influence on the energy efficiency in the city where these are present. The geographic-referencing methodology developed in this study has the potential to be utilised in a wide range of subjects, bridging the current gap of data availability, allowing building related datasets to be incorporated with GIS analysis

Facilitating responsive interaction between occupants and building systems through dynamic post-occupancy evaluation

Post-occupancy evaluation (POE) is a process that can reveal the interrelations between key building performance factors and successfully integrate indoor environmental quality, thermal comfort, functionality, environmental strategy and occupants’ satisfaction. POE has become a prerequisite for several building certification systems and it is often presented as a method to improve the commissioning of buildings and as a user experience feedback mechanism. This paper is based on a POE undertaken through stages at the University of Southampton Mayflower Halls of Residence complex. The first stage included the evaluation of occupant satisfaction, indoor environment quality and energy use. Results from temperature and relative humidity monitoring and an online POE questionnaire were analysed in the context of energy use, thermal comfort and building controls’ functionality. The second part of this study monitored the air temperature in a sub-sample of 30 rooms where the residents participated in a thermal comfort survey with a “right-here-right-now” questionnaire and a portable instrument that monitored air temperature, relative humidity, globe temperature and air velocity in the rooms. This paper presents the results of the POE and discusses approaches for the improvement in the buildings’ energy performance and the environmental conditions in the living spaces of the students. Results suggest that current use of controls is not always effective, with implications for the buildings’ energy use. Large variability was found in occupants’ thermal perception and preferences, which points to a need for occupant-centric solutions. In this study, POE is approached as a dynamic process that could be used to facilitate the responsive interaction of occupants with building systems and deliver through their engagement high energy performance and comfort

Employment and the collateral channel of monetary policy

This paper uses a detailed firm-level dataset to show that monetary policy propagates via asset prices through corporate debt collateralised on real estate. Our research design exploits the fact that many small and medium sized firms use the homes of the firm’s directors as a key source of collateral, and directors’ homes are typically not in the same region as their firm. This spatial separation of firms and firms’ collateral allows us to separate the propagation of monetary policy via fluctuations in collateral values from that via demand channels. We find that younger and more levered firms who have collateral values that are particularly sensitive to monetary policy show the largest employment response to monetary policy. The collateral channel explains a sizeable share of the aggregate employment response

The Impact of an Electrical Mini-grid on the Development of a Rural Community in Kenya

Electrical mini-grids can provide electrification to rural communities far from the national network. However the benefits of such schemes are disputed. We observed changes in two matched trading-centres in Makueni County, Kenya, neither of which were initially electrified. During the study a solar photovoltaic mini-grid scheme (13.5 kWp) was constructed in one of the trading-centres. After electrification there were relative increases in the number of businesses and business income. Comparing the households in the areas around the trading centres, perceived wealth increased more around the electrified trading centre. Qualitative interviews indicated improvements in service provision by the local school and health centre. The cooperative set up to run the mini-grid was free to set its own kWh tariff and chose to reduce it to a level that covers operating costs and would recover 70% of the initial investment interest-free. However, the tariff finally agreed is higher than the national grid tariff, which would be difficult to achieve if the mini-grid was not owned by and run for the benefit of the local community. Overall, we found that the mini-grid had a positive effect over background development, recovered some of its cost and charged a higher tariff than the national rate

(Re-) Introducing the IMEJ: A home for the dissemination of research and development in marine renewable energy

Two years ago we launched the International Marine Energy Journal (IMEJ) in response to requests and encouragement from the marine renewable energy community to create a journal dedicated to our field of research. Four issues later and I can say that this has been a rewarding and challenging process

Dielectrophoresis and impedance studies of dielectric particles suspended in liquids

This thesis reports on a study of dielectrophoresis (the motion of dielectric particles due to polarization in a non-uniform electric field) and of the impedance characteristics of dielectric particles in various liquids. In order to determine the experimental approach suited to dielectrophoresis, a variety of techniques were investigated. These included Pohl's yield method, a particle velocity method, and a method involving the trapping of lone bubbles by balancing the dielectrophoretic force against buoyancy. The latter method was found to be the most amenable to dielectrophoresis. A ring-disc electrode system was initially used to establish a cusped electric field to produce the trapping effect. Conventionally, electrodes of the order of a few millimetres are used resulting in a high potential difference being required to trap the bubbles. By scaling down the electrodes it was possible to confine small particles in a position of stable equilibrium at potential differences of only a few volts. As only low voltages were required, variable frequency measurements in aqueous media were made and problems due to Joule heating and turbulence became negligible. The frequency response of lone microscopic divinyl benzene (DVB) particles and impedance characteristics of populations of these particles were determined in electrolyte solutions at various concentrations. The resultant excess polarization spectra of the lone particles was attributed to relaxation effects at the particle/liquid interface. These relaxation effects were also thought to be responsible for the dispersion in the impedance of the particle population.</p

Photovoltaic roofing: issues of design and integration into buildings

In the last decade, the development of photovoltaic roofing elements has been exceptional. These efforts were not limited to merely improving the integration methods with standard PV products but were also directed towards the production of appropriate elements that could replace roof tiles or shingles. This paper reviews some of the competing technologies for photovoltaic roofing and addresses the issues raised in the total integration of PV into roofing structures. The paper also discusses the general requirements of an idealised photovoltaic roofing system and some of the relevant variables that are required for the satisfaction of the end users. It has been shown that current strategies available for the true integration of PV elements as roof tiles or shingles utilising the sloped building fabric are limited. There are however, major on-going activities to research and develop roofing systems based on the footprint of a roof tile or shingle