The development of a computer model to optimize the performance of a 50kWp photovoltaic system

A computer model has been developed to optimize the performance of a 50kWp photovoltaic system which supplies electrical energy to a dairy farm at Fota Island in Cork Harbour. Optimization of the system involves maximising the efficiency and increasing the performance and reliability of each hardware unit. The model accepts horizontal insolation, ambient temperature, wind speed, wind direction and load demand as inputs. An optimization program uses the computer model to simulate the optimum operating conditions. From this analysis, criteria are established which are used to improve the photovoltaic system operation. This thesis describes the model concepts, the model implementation and the model verification procedures used during development. It also describes the techniques which are used during system optimization. The software, which is written in FORTRAN, is structured in modular units to provide logical and efficient programming. These modular units may also be used in the modelling and optimization of other photovoltaic systems.

Photonic integrated circuits for the generation of coherent optical signals

The demand for optical bandwidth continues to increase year on year and is being driven primarily by entertainment services and video streaming to the home. Current photonic systems are coping with this demand by increasing data rates through faster modulation techniques, spectrally efficient transmission systems and by increasing the number of modulated optical channels per fibre strand. Such photonic systems are large and power hungry due to the high number of discrete components required in their operation. Photonic integration offers excellent potential for combining otherwise discrete system components together on a single device to provide robust, power efficient and cost effective solutions. In particular, the design of optical modulators has been an area of immense interest in recent times. Not only has research been aimed at developing modulators with faster data rates, but there has also a push towards making modulators as compact as possible. Mach-Zehnder modulators (MZM) have proven to be highly successful in many optical communication applications. However, due to the relatively weak electro-optic effect on which they are based, they remain large with typical device lengths of 4 to 7 mm while requiring a travelling wave structure for high-speed operation. Nested MZMs have been extensively used in the generation of advanced modulation formats, where multi-symbol transmission can be used to increase data rates at a given modulation frequency. Such nested structures have high losses and require both complex fabrication and packaging. In recent times, it has been shown that Electro-absorption modulators (EAMs) can be used in a specific arrangement to generate Quadrature Phase Shift Keying (QPSK) modulation. EAM based QPSK modulators have increased potential for integration and can be made significantly more compact than MZM based modulators. Such modulator designs suffer from losses in excess of 40 dB, which limits their use in practical applications. The work in this thesis has focused on how these losses can be reduced by using photonic integration. In particular, the integration of multiple lasers with the modulator structure was considered as an excellent means of reducing fibre coupling losses while maximising the optical power on chip. A significant difficultly when using multiple integrated lasers in such an arrangement was to ensure coherence between the integrated lasers. The work investigated in this thesis demonstrates for the first time how optical injection locking between discrete lasers on a single photonic integrated circuit (PIC) can be used in the generation of coherent optical signals. This was done by first considering the monolithic integration of lasers and optical couplers to form an on chip optical power splitter, before then examining the behaviour of a mutually coupled system of integrated lasers. By operating the system in a highly asymmetric coupling regime, a stable phase locking region was found between the integrated lasers. It was then shown that in this stable phase locked region the optical outputs of each laser were coherent with each other and phase locked to a common master laser.

The use of fault detection and diagnostics to reduce air handling unit energy consumption

The contribution of buildings towards total worldwide energy consumption in developed countries is between 20% and 40%. Heating Ventilation and Air Conditioning (HVAC), and more specifically Air Handling Units (AHUs) energy consumption accounts on average for 40% of a typical medical device manufacturing or pharmaceutical facility’s energy consumption. Studies have indicated that 20 – 30% energy savings are achievable by recommissioning HVAC systems, and more specifically AHU operations, to rectify faulty operation. Automated Fault Detection and Diagnosis (AFDD) is a process concerned with potentially partially or fully automating the commissioning process through the detection of faults. An expert system is a knowledge-based system, which employs Artificial Intelligence (AI) methods to replicate the knowledge of a human subject matter expert, in a particular field, such as engineering, medicine, finance and marketing, to name a few. This thesis details the research and development work undertaken in the development and testing of a new AFDD expert system for AHUs which can be installed in minimal set up time on a large cross section of AHU types in a building management system vendor neutral manner. Both simulated and extensive field testing was undertaken against a widely available and industry known expert set of rules known as the Air Handling Unit Performance Assessment Rules (APAR) (and a later more developed version known as APAR_extended) in order to prove its effectiveness. Specifically, in tests against a dataset of 52 simulated faults, this new AFDD expert system identified all 52 derived issues whereas the APAR ruleset identified just 10. In tests using actual field data from 5 operating AHUs in 4 manufacturing facilities, the newly developed AFDD expert system for AHUs was shown to identify four individual fault case categories that the APAR method did not, as well as showing improvements made in the area of fault diagnosis.

Investigation of factors driving the costs of operating the 2020 Irish power system with large-scale wind generation

The main goal of this work is to determine the true cost incurred by the Republic of Ireland and Northern Ireland in order to meet their EU renewable electricity targets. The primary all-island of Ireland policy goal is that 40% of electricity will come from renewable sources in 2020. From this it is expected that wind generation on the Irish electricity system will be in the region of 32-37% of total generation. This leads to issues resulting from wind energy being a non-synchronous, unpredictable and variable source of energy use on a scale never seen before for a single synchronous system. If changes are not made to traditional operational practices, the efficient running of the electricity system will be directly affected by these issues in the coming years. Using models of the electricity system for the all-island grid of Ireland, the effects of high wind energy penetration expected to be present in 2020 are examined. These models were developed using a unit commitment, economic dispatch tool called PLEXOS which allows for a detailed representation of the electricity system to be achieved down to individual generator level. These models replicate the true running of the electricity system through use of day-ahead scheduling and semi-relaxed use of these schedules that reflects the Transmission System Operator's of real time decision making on dispatch. In addition, it carefully considers other non-wind priority dispatch generation technologies that have an effect on the overall system. In the models developed, three main issues associated with wind energy integration were selected to be examined in detail to determine the sensitivity of assumptions presented in other studies. These three issues include wind energy's non-synchronous nature, its variability and spatial correlation, and its unpredictability. This leads to an examination of the effects in three areas: the need for system operation constraints required for system security; different onshore to offshore ratios of installed wind energy; and the degrees of accuracy in wind energy forecasting. Each of these areas directly impact the way in which the electricity system is run as they address each of the three issues associated with wind energy stated above, respectively. It is shown that assumptions in these three areas have a large effect on the results in terms of total generation costs, wind curtailment and generator technology type dispatch. In particular accounting for these issues has resulted in wind curtailment being predicted in much larger quantities than had been previously reported. This would have a large effect on wind energy companies because it is already a very low profit margin industry. Results from this work have shown that the relaxation of system operation constraints is crucial to the economic running of the electricity system with large improvements shown in the reduction of wind curtailment and system generation costs. There are clear benefits in having a proportion of the wind installed offshore in Ireland which would help to reduce variability of wind energy generation on the system and therefore reduce wind curtailment. With envisaged future improvements in day-ahead wind forecasting from 8% to 4% mean absolute error, there are potential reductions in wind curtailment system costs and open cycle gas turbine usage. This work illustrates the consequences of assumptions in the areas of system operation constraints, onshore/offshore installed wind capacities and accuracy in wind forecasting to better inform the true costs associated with running Ireland's changing electricity system as it continues to decarbonise into the near future. This work also proposes to illustrate, through the use of Ireland as a case study, the effects that will become ever more prevalent in other synchronous systems as they pursue a path of increasing renewable energy generation.

Learning to Teach and its Implications for the Continuum of Teacher Education: A Nine Country Cross-national Study.

The purpose of this Report is to inform discussions, policy formulation, and strategic planning on teacher education in Ireland. The research gives priority to initial teacher education (ITE) and induction, their interface, and implications for the continuum of teacher education, including continuing professional development (CPD). The study involved a two-pronged approach: a narrative review of recent and relevant literature and a cross-national review of teacher education policies in nine countries, namely, Ireland, Northern Ireland, Scotland, England, Finland, USA, Poland, Singapore and New Zealand. Adopting a broad, balanced and comprehensive understanding of the role of the contemporary teacher, it provides a framework for developing quality teacher education in Ireland. The Report incorporates exemplars of good practice and notes their implementation challenges for the Irish context.  Chapter One provides a framework for conceptualising quality teacher education and the continuum. Key features that emerge from the literature are discussed: teachers¿ practice, quality teaching, the professional life-cycle, teacher learning and relationships. With more specific reference to the continuum, Chapter Two overviews initial teacher education, induction, learning outcomes and accreditation in the selected countries, including Ireland. Key features of policy in the various countries are summarised. Individual country profiles, incorporating descriptions of socio-political, teaching and teacher education contexts, are further detailed in Appendix A. Chapter Three analyses relevant literature on initial teacher education, induction, learning outcomes/professional standards and accreditation. Along with previous chapters it provides the basis for recommendations for teacher education that are presented in Chapter Four. Chapter Four draws together the findings emerging from the cross-national review in terms of the contemporary context of teacher education in Ireland and identifies key challenges and possible lines of policy development as well as recommendations for the Teaching Council and other teacher education stakeholders. Each generation has an opportunity to provide the vision and resources for renewing teacher education in light of ambitious social, economic and educational aspirations to meet perceived societal and education challenges (as occurred in the 1970s). Despite the publication of two key reviews of initial teacher education a number of years ago, there is considerable scope for further reform of teacher education. However, significant changes have occurred to teacher education course provision and content over the last 100 years. In this report, we have stressed the need for, and called for investment in, greater system and programme coherence, mentoring to support assisted practice, knowledge integration, critical reflective practice, inquiry and the development of vibrant partnerships between higher education institutions and schools as the basis for teacher education reform across the continuum. This Executive Summary presents the Report¿s context, key findings and recommendations emerging from the analysis.  

National food consumption surveys: micronutrient intakes and the role of fortified foods in the diets of Irish pre-school children and adults

This research investigated the micronutrient intakes of Irish pre-school children (1-4 years) and adults (18-64 years) and the role that fortified foods (FFs) play in the diets of these population groups. Dietary intake data were collected as part of the National Pre-school Nutrition Survey (NPNS) (2010-2011) and the National Adult Nutrition Survey (NANS) (2008-2010) using 4-day food and beverage records. Nutrient intakes were estimated using WISP©, which encompasses McCance and Widdowson’s The Composition of Foods and the Irish Food Composition Database. A FF is one in which one or more micronutrients are added. Key dietary sources of micronutrients in NPNS and NANS were “milk”, “meat & meat products”, “breakfast cereals”, “fruit & fruit juices” and “breads”. In general, intakes of most micronutrients were adequate with the exception of iron (1 year old children and adult women) and vitamin D (in all population groups). Small proportions of the pre-school population had intakes which exceeded the upper level (UL) (zinc: 11%, folic acid: 5%, retinol: 4%, copper: 2%). Less than 2% of adults had intakes of iron, copper, zinc and vitamin B6 which exceeded the UL. FFs were consumed by 97% of pre-school children and 82% of adults, representing 17% and 9% of mean daily energy intake respectively. Relative to energy intake, FFs contributed substantially greater proportions to intakes of key micronutrients, such as iron and vitamin D. FFs were effective in reducing the prevalence of inadequate micronutrient intakes in these population groups, particularly for iron in women and 1 year old children. FFs made a significant contribution to folate intake in women of childbearing age (72µg). FFs contributed greater proportions of carbohydrate and lower proportions of fat to the diets of consumers. Voluntary addition of nutrients to foods did not contribute appreciably to intakes exceeding the UL in these population groups.

Preserving patent policy space and securing access to medicines in developing countries: the role of states and pharmaceutical corporations

This thesis examines the tension between patent rights and the right to health and it recognizes patent rights on pharmaceutical products as one of the factors responsible for the problem of lack of access to affordable medicines in developing countries. The thesis contends that, in order to preserve their patent policy space and secure access to affordable medicines for their citizens, developing countries should incorporate a model of human rights into the design, implementation, interpretation, and enforcement of their national patent laws. The thesis provides a systematic analysis of court decisions from four key developing countries (Brazil, India, Kenya, and South Africa) and it assesses how the national courts in these countries resolve the tension between patent rights and the right to health. Essentially, this thesis demonstrates how a model of human rights can be incorporated into the adjudication of disputes involving patent rights in national courts. Focusing specifically on Brazil, the thesis equally demonstrates how policy makers and law makers at the national level can incorporate a model of human rights into the design or amendment of their national patent law. This thesis also contributes to the ongoing debate in the field of business and human rights with regard to the mechanisms that can be used to hold corporate actors accountable for their human rights responsibilities. This thesis recognizes that, while states bear the primary responsibility to respect, protect, and fulfil the right to health, corporate actors such as pharmaceutical companies also have a baseline responsibility to respect the right to health. This thesis therefore contends that pharmaceutical companies that own patent rights on pharmaceutical products can be held accountable for their right to health responsibilities at the national level through the incorporation of a model of civic participation into a country’s patent law system.