3 resultados para Area in square kilometer

em Dalarna University College Electronic Archive


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In this thesis the solar part of a large grid-connected photovoltaic system design has been done. The main purpose was to size and optimize the system and to present figures helping to evaluate the prospective project rationality, which can potentially be constructed on a contaminated area in Falun. The methodology consisted in PV market study and component selection, site analysis and defining suitable area for solar installation; and system configuration optimization based on PVsyst simulations and Levelized Cost of Energy calculations. The procedure was mainly divided on two parts, preliminary and detailed sizing. In the first part the objective was complex, which included the investigation of the most profitable component combination and system optimization due to tilt and row distance. It was done by simulating systems with different components and orientations, which were sized for the same 100kW inverter in order to make a fair comparison. For each simulated result a simplified LCOE calculation procedure was applied. The main results of this part show that with the price of 0.43 €/Wp thin-film modules were the most cost effective solution for the case with a great advantage over crystalline type in terms of financial attractiveness. From the results of the preliminary study it was possible to select the optimal system configuration, which was used in the detailed sizing as a starting point. In this part the PVsyst simulations were run, which included full scale system design considering near shadings created by factory buildings. Additionally, more complex procedure of LCOE calculation has been used here considered insurances, maintenance, time value of money and possible cost reduction due to the system size. Two system options were proposed in final results; both cover the same area of 66000 m2. The first one represents an ordinary South faced design with 1.1 MW nominal power, which was optimized for the highest performance. According to PVsyst simulations, this system should produce 1108 MWh/year with the initial investment of 835,000 € and 0.056 €/kWh LCOE. The second option has an alternative East-West orientation, which allows to cover 80% of occupied ground and consequently have 6.6 MW PV nominal power. The system produces 5388 MWh/year costs about 4500,000 € and delivers electricity with the same price of 0.056 €/kWh. Even though the EW solution has 20% lower specific energy production, it benefits mainly from lower relative costs for inverters, mounting and annual maintenance expenses. After analyzing the performance results, among the two alternatives none of the systems showed a clear superiority so there was no optimal system proposed. Both, South and East-West solutions have own advantages and disadvantages in terms of energy production profile, configuration, installation and maintenance. Furthermore, the uncertainty due to cost figures assumptions restricted the results veracity.

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Addressing building energy use is a pressing issue for building sector decision makers across Europe. In Sweden, some regions have adopted a target of reducing energy use in buildings by 50% until 2050. However, building codes currently do not support as ambitious objectives as these, and novel approaches to addressing energy use in buildings from a regional perspective are called for. The purpose of this licentiate thesis was to provide a deeper understanding of most relevant issues with regard to energy use in buildings from a broad perspective and to suggest pathways towards reaching the long-term savings objective. Current trends in building sector structure and energy use point to detached houses constructed before 1981 playing a key role in the energy transition, especially in the rural areas of Sweden. In the Swedish county of Dalarna, which was used as a study area in this thesis, these houses account for almost 70% of the residential heating demand. Building energy simulations of eight sample houses from county show that there is considerable techno-economic potential for energy savings in these houses, but not quite enough to reach the 50% savings objective. Two case studies from rural Sweden show that savings well beyond 50% are achievable, both when access to capital and use of high technology are granted and when they are not. However, on a broader scale both direct and indirect rebound effects will have to be expected, which calls for more refined approaches to energy savings. Furthermore, research has shown that the techno-economic potential is in fact never realised, not even in the most well-designed intervention programmes, due to the inherent complexity of human behaviour with respect to energy use. This is not taken account of in neither current nor previous Swedish energy use legislation. Therefore an approach that considers the technical prerequisites, economic aspects and the perspective of the many home owners, based on Community-Based Social Marketing methodology, is suggested as a way forward towards reaching the energy savings target.

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BACKGROUND: National quality registries (NQRs) purportedly facilitate quality improvement, while neither the extent nor the mechanisms of such a relationship are fully known. The aim of this case study is to describe the experiences of local stakeholders to determine those elements that facilitate and hinder clinical quality improvement in relation to participation in a well-known and established NQR on stroke in Sweden. METHODS: A strategic sample was drawn of 8 hospitals in 4 county councils, representing a variety of settings and outcomes according to the NQR's criteria. Semi-structured telephone interviews were conducted with 25 managers, physicians in charge of the Riks-Stroke, and registered nurses registering local data at the hospitals. Interviews, including aspects of barriers and facilitators within the NQR and the local context, were analysed with content analysis. RESULTS: An NQR can provide vital aspects for facilitating evidence-based practice, for example, local data drawn from national guidelines which can be used for comparisons over time within the organisation or with other hospitals. Major effort is required to ensure that data entries are accurate and valid, and thus the trustworthiness of local data output competes with resources needed for everyday clinical stroke care and quality improvement initiatives. Local stakeholders with knowledge of and interest in both the medical area (in this case stroke) and quality improvement can apply the NQR data to effectively initiate, carry out, and evaluate quality improvement, if supported by managers and co-workers, a common stroke care process and an operational management system that embraces and engages with the NQR data. CONCLUSION: While quality registries are assumed to support adherence to evidence-based guidelines around the world, this study proposes that a NQR can facilitate improvement of care but neither the registry itself nor the reporting of data initiates quality improvement. Rather, the local and general evidence provided by the NQR must be considered relevant and must be applied in the local context. Further, the quality improvement process needs to be facilitated by stakeholders collaborating within and outside the context, who know how to initiate, perform, and evaluate quality improvement, and who have the resources to do so.