Energy Efficiency through Thermal Energy Storage : Possibilities for the Swedish Building Stock

The need for heating and cooling in buildings constitutes a considerable part of the total energy use in a country and reducing this need is of outmost importance in order to reach national and international goals for reducing energy use and emissions. One important way of reaching these goals is to increase the proportion of renewable energy used for heating and cooling of buildings. Perhaps the largest obstacle with this is the often occurring mismatch between the availability of renewable energy and the need for heating or cooling, hindering this energy to be used directly. This is one of the problems that can be solved by using thermal energy storage (TES) in order to save the heat or cold from when it is available to when it is needed. This thesis is focusing on the combination of TES techniques and buildings to achieve increased energy efficiency for heating and cooling. Various techniques used for TES as well as the combination of TES in buildings have been investigated and summarized through an extensive literature review. A survey of the Swedish building stock was also performed in order to define building types common in Sweden. Within the scope of this thesis, the survey resulted in the selection of three building types, two single family houses and one office building, out of which the two residential buildings were used in a simulation case study of passive TES with increased thermal mass (both sensible and latent). The second case study presented in the thesis is an evaluation of an existing seasonal borehole storage of solar heat for a residential community. In this case, real measurement data was used in the evaluation and in comparisons with earlier evaluations. The literature reviews showed that using TES opens up potential for reduced energy demand and reduced peak heating and cooling loads as well as possibilities for an increased share of renewable energy to cover the energy demand. By using passive storage through increased thermal mass of a building it is also possible to reduce variations in the indoor temperature and especially reduce excess temperatures during warm periods, which could result in avoiding active cooling in a building that would otherwise need it. The analysis of the combination of TES and building types confirmed that TES has a significant potential for increased energy efficiency in buildings but also highlighted the fact that there is still much research required before some of the technologies can become commercially available. In the simulation case study it was concluded that only a small reduction in heating demand is possible with increased thermal mass, but that the time with indoor temperatures above 24 °C can be reduced by up to 20%. The case study of the borehole storage system showed that although the storage system worked as planned, heat losses in the rest of the system as well as some problems with the system operation resulted in a lower solar fraction than projected. The work presented within this thesis has shown that TES is already used successfully for many building applications (e.g. domestic hot water stores and water tanks for storing solar heat) but that there still is much potential in further use of TES. There are, however, barriers such as a need for more research for some storage technologies as well as storage materials, especially phase change material storage and thermochemical storage.

Thermal energy storage in Swedish single family houses : a case study

In a Nordic climate, space heating (SH) and domestic hot water (DHW) used in buildings constitute a considerable part of the total energy use in the country. For 2010, energy used for SH and DHW amounted to almost 90 TWh in Sweden which corresponds to 60 % of the energy used in the residential and service sector, or almost 24 % of the total final energy use for the country. Storing heat and cold with the use of thermal energy storage (TES) can be one way of increasing the energy efficiency of a building by opening up possibilities for alternative sources of heat or cold through a reduced mismatch between supply and demand. Thermal energy storage without the use of specific control systems are said to be passive and different applications using passive TES have been shown to increase energy efficiency and/or reduce power peaks of systems supplying the heating and cooling needs of buildings, as well as having an effect on the indoor climate. Results are however not consistent between studies and focus tend to be on the reduction of cooling energy or cooling power peaks. In this paper, passive TES introduced through an increased thermal mass in the building envelope to two single family houses with different insulation standard is investigated with building energy simulations. A Nordic climate is used and the focus of this study is both on the reduction of space heating demand and space heating power, as well as on reduction of excess temperatures in residential single family houses without active cooling systems. Care is taken to keep the building envelope characteristics other than the thermal mass equal for all cases so that any observations made can be derived to the change in thermal mass. Results show that increasing the sensible thermal mass in a single family house can reduce the heating demand only slightly (1-4 %) and reduce excess temperatures (temperatures above 24 degrees C) by up to 20 %. Adding a layer of PCM (phase change materials) to the light building construction can give similar reduction in heating demand and excess temperatures, however the phase change temperature is important for the results.

Electrical Evaluation of a Low Concentrating PVT Collector Based on Performance Ratio

Photovoltaic Thermal/Hybrid collectors are an emerging technology that combines PV and solar thermal collectors by producing heat and electricity simultaneously. In this paper, the electrical performance evaluation of a low concentrating PVT collector was done through two testing parts: power comparison and performance ratio testing. For the performance ratio testing, it is required to identify and measure the factors affecting the performance ratio on a low concentrating PVT collector. Factors such as PV cell configuration, collector acceptance angle, flow rate, tracking the sun, temperature dependence and diffuse to irradiance ratio. Solarus low concentrating PVT collector V12 was tested at Dalarna University in Sweden using the electrical equipment at the solar laboratory. The PV testing has showed differences between the two receivers. Back2 was producing 1.8 energy output more than Back1 throughout the day. Front1 and Front2 were almost the same output performance. Performance tests showed that the cell configuration for Receiver2 with cells grouping (6- 32-32-6) has proved to have a better performance ratio when to it comes to minimizing the shading effect leading to more output power throughout the day because of lowering the mismatch losses. Different factors were measured and presented in this thesis in chapter 5. With the current design, it has been obtained a peak power at STC of 107W per receiver. The solar cells have an electrical efficiency of approximately 19% while the maximum measured electrical efficiency for the collector was approximately 18 % per active cell area, in addition to a temperature coefficient of -0.53%/ ˚C. Finally a recommendation was done to help Solarus AB to know how much the electrical performance is affected during variable ambient condition and be able to use the results for analyzing and introducing new modification if needed.

Physical disability and sexual esteem

The current study investigated the impact of physical disability on sexual feelings, sexual experiences, and sexual esteem. Thirty-five respondents (18 males and 17 females), with physical disabilities between 19 to 60 years (SD = 10, mean = 38) participated in focus groups where they discussed how their physical disability impacted on their sexuality. They also responded to a series of questions that were designed to examine disability-specific issues in sexual esteem using a four-point Likert-type scale. The data demonstrated that the participants struggled with many social and sexual barriers that were associated with having a physical impairment. This appeared to lead to increased feelings of negativity in many participants, including a belief that they were less sexually desirable than an able-bodied person and that having a disability seriously limited their sexual expression. The implications of these findings for practitioners and suggestions for future research are discussed.

University and employer expectations of new dietetic graduates

Objectives:  The first objective of this study was to identify the knowledge, skills and attributes (KSAs) that employers seek in newly graduated dietitians. The second objective was to compare the KSAs that employers seek in newly graduated dietitians to the Deakin University Graduate Attributes and to the Dieticians Association of Australia (DAA) Competencies in order to determine if there is a mismatch.

Methods:   Views were gathered from a combination of group and individual in-depth, semistructured interviews with 19 employers from a range of employment settings and sorted into an existing framework using the DAA Competencies and the Deakin University Graduate Attributes. Data from taped interviews were transcribed and sorted into a table of generic skills and a KSAs matrix.

Results: Employers sought graduates who had practical knowledge of dietetics and the workplace, Key skills sought included communication, interpersonal, work management and information technology skills. Key attributes sought were the ability to be a team player, to demonstrate some insight into one's own limitations, to demonstrate an appropriate level of initiative, and to be flexible and adaptable. There was a large overlap between the KSAs identified by employers as being important and those that have been identified by the DAA and Deakin University. However, there were some areas of mismatch. The University and employers valued information technological skills, whereas the DAA did not state these as a competency. The University and the industry employers were concerned about the global perspective, but the DAA and the clinical employers were not.

Conclusions: The results of this study show a large overlap between the KSAs valued by the profession, the University and the employers.

Fabrication of novel metal alloy foams for biomedical applications

Degeneration of the weight bearing bones of the ageing population often requires the inception of metallic biomaterials. Research in this area is receiving increased attention globally. However, most of today's artificial bone materials are dense and suffer from problems of adverse reaction, biomechanical mismatch and lack of appropriate space for the regeneration of new bone tissues. In the present study, novel ZrTi alloy foams with a porous structure and mechanical properties that are very close to those of bone were fabricated. These ZrTi alloy foams are biocompatible, and display a porous structure permitting the ingrowth of new bone tissues.

Linking environmental uncertainty to non-financial performance measures and performance : a research note

Several previous research studies have reported mixed results concerning the direct association between non-financial performance measures and  performance. The presence of environmental uncertainty on this relationship has not been established. This paper makes a contribution to this area by proposing that it is in conditions of environmental uncertainty that non-financial measures are most useful in improving organizational performance. It analyses empirical data from a sample of New Zealand manufacturing organizations to test the hypothesis that non-financial measures of performance would lead to improved organizational performance under conditions of increased environmental uncertainty. Multiple regression analysis of the data suggests that performance should be a declining function of the size of the ‘mismatch’ between an organization's environment and use of the different combinations of non-financial performance measures. Further, the paper concludes that prior mixed results may be attributed to the omission of environmental uncertainty.

Assessing the case for mandatory folate fortification : policy-making in the face of scientific uncertainties

This paper presents the view that policymakers face scientific uncertainties in assessing the case for mandatory folate fortification as a policy response to epidemiological evidence of the relationship between folate and neural tube defects. Moreover, the resolution of these uncertainties is confounded by the under-resourced state of nutrition information systems in Australia and New Zealand. The uncertainties relate to potential risks and benefits associated with the intervention for the target group and the population in general. These risks and benefits reflect the mismatch between evidence and policy that arises when addressing a presumed genetic abnormality in at-risk individuals with an intervention that is population-wide in its scope. There is an urgent need to conduct ongoing national nutrition surveys and monitor and evaluate policy interventions to strengthen the capacity of nutrition information systems to inform decision-making for this current, and future, public health nutrition policy.

(Re)examining identities: working with diversity in the pre-service teaching experience

Australia, like the United States (US) and the United Kingdom (UK), continues to experience a mismatch between the cultural backgrounds and socio-economic class of teachers and those of the students they work with. This article reports on a study that explored how a group of Australian teacher-education students understand their own ethnic and socio-economic class identities and how they work with students of ethnic and class backgrounds different from their own. Analysis of data from interviews and focus groups with the student-teachers is presented to highlight how they make sense of difference and how they take up the challenges of teaching for diversity. The paper raises issues and concerns regarding how diversity and difference might be addressed in teacher education.

Style wars: revolution in the suburbs?

Is there a revolution occurring in the Australian suburb? From a brief examination of demographic, economic, political and aesthetic changes, it appears that the suburbs of the new century are very different from those of the last. With the demise of key underpinnings of the older suburban form—the sexual division of labour, particular family forms, localised communities and bucolic private gardens—has gone an end to official support of the expansive suburb and a major shift in their politics, planning, economies and relationship to the CBD and other centres. With falling household sizes has gone a seemingly contradictory trend toward larger houses on smaller blocks of land. In the context of these many changes along with urban containment and consolidation, this paper argues that there is a convergence occurring between the design of inner, middle and outer suburban dwellings. The negativity long heaped upon the suburban bungalow by the custodians of taste is being revisited. The style wars are easing, as suburban homes increasingly resemble those appearing in densified cities across the nation.

Automated Negotiation Between Publishers And Consumers Of Grid Notifications

Notification Services mediate between information publishers and consumers that wish to subscribe to periodic updates. In many cases, however, there is a mismatch between the dissemination of these updates and the delivery preferences of the consumer, often in terms of frequency of delivery, quality, etc. In this paper, we present an automated negotiation engine that identifies mutually acceptable terms; we study its performance, and discuss its application to a Grid Notification Service. We also demonstrate how the negotiation engine enables users to control the Quality of Service levels they require.

Automated Negotiation for Grid Notification Services

Notification Services mediate between information publishers and consumers that wish to subscribe to periodic updates. In many cases, however, there is a mismatch between the dissemination of these updates and the delivery preferences of the consumer, often in terms of frequency of delivery, quality, etc. In this paper, we present an automated negotiation engine that identifies mutually acceptable terms; we study its performance, and discuss its application to a Grid Notification Service. We also demonstrate how the negotiation engine enables users to control the Quality of Service levels they require.

Mature workers, training and using TLM frameworks

Mature workers have been at the centre of policies aimed at encouraging higher workforce participation, longer working life and enhanced savings for retirement. Low mature age workforce participation rates reflect labour market withdrawal in the face of multiple barriers to participation for many. Their apparent voluntary joblessness conceals the fact that mature workers endure longer periods of unemployment, discrimination, redundancy and other barriers to employment (hence the drift to 'early retirement'). The policy dilemma is not just about addressing discrimination barriers, access to appropriate retraining or skills enhancement for mature workers, but what this tells us about lifelong learning as a means of managing and mitigating risk. The mismatch between work opportunities/skills shortages and the low education and skills base of many mature workers, means it is simplistic to think that working longer might be a short term way to address skills shortages; without an enormous investment in the current ageing cohort. Drawing on Transitional Labour Market (TLM) theory and European reform agendas, this article argues that the link between investment in lifelong education/ skills training and stronger labour market participation needs attention; not just for current cohorts of excluded or underemployed mature workers but to position strategically for future generations.

Assessing adult adjustment to relationship separation : the Psychological Adjustment to Separation Test (PAST)

Relationship separation is associated with substantial adult adjustment problems. The Psychological Adjustment to Separation Test (PAST) was developed as a self-report measure of 3 key dimensions of separation adjustment problems: lonely negativity, ex-partner attachment and coparenting conflict. Two independent samples (n = 219 and n = 169, respectively) of recently separated adults, 60% of whom had children, completed the PAST and other measures of general adjustment. Exploratory and confirmatory factor analyses demonstrated a replicable 3-factor structure, with each factor showing satisfactory test–retest and internal reliability and good convergent and discriminant validity. The PAST meets initial criteria for a potentially useful new measure of adult separation adjustment.

The challenge of reconciling working time demands and life transitions : a policy proposal

Labour markets, like all market institutions, exhibit structural and dynamic characteristics. Both the structural and dynamic characteristics of labour markets inevitably change and evolve over time in response to a host of exogenous and endogenous factors. In the case of the Australian labour market, structural changes are reflected in significant shifts in the industry and occupational composition of employment, the decline of full-time work and the concomitant rise in part-time and atypical forms of employment, demographic changes in the labour force, as well as changes in social and individual preferences. Dynamic shifts can be found in cyclical pattern of employment and wages growth, the growth in labour mobility, and transitions between various labour market states.
The starting point for this paper is that these structural and dynamic changes have given rise to an increase in the likelihood that individuals will experience a transition between various labour market states, and a greater diversity in the range of transitions they may experience over their working life. This acceleration in the rate of transition generates ‘transition costs’ for both employers and employees, as well the likelihood of mismatch between employer and employee working time preferences. As a consequence, existing labour market policy regimes, based on the traditional model of labour market participation over the life course may not provide adequate protection for most workers today.
Gunther Schmid (1998) and others have proposed institutional reforms which promote ‘transitional labour markets’. Transitional labour market institutions are those that allow individuals (and firms) to successfully adjust to critical events. While transitional labour market institutions may consist of traditional ‘active labour market policy’ mechanisms, Schmid and others have proposed a range of innovative policy responses which allow individuals (and firms) to adjust the intensity of their abour market participation over the life cycle. In this paper we use the general approach of advocated by the transitional labour market concept to do three things. First, we investigate the processes by which the nature of labour market transitions has changed over time. Second, we review the range of policy options available to government to smooth labour market dysfunctions associated with labour market transitions, with the objective of ensuring labour markets operate more efficiently and more equitably. Third, we focus on one possible way in which an existing labour market institution, Long Service Leave (LSL), could be reformed to make way for a more comprehensive transitional labour market institution in the form of a ‘working time bank’.