Case study of a large-scale solar and wind power hybrid system at Fakken Wind Farm, Troms

The objective of this thesis is to investigate the feasibility of a large scale hybrid system at Fakken, Troms. There is already an existing 54 MW wind farm at site. The wind farm has considerably higher power production during winter compared to summer, and the electricity grid is therefore not fully exploited during summer. Adding a solar panel utility to the site could be a solution to this issue. This thesis is centralized around simulating the hybrid system using \textit{HOMER Pro}. This tool requires a whole year of data to perform a simulation. Since only three months of observed radiation are available, will WRF simulated solar radiation data be used in the HOMER simulations. To evaluate the feasibility of such a system is an anti correlation analysis between the solar and wind resources at site conducted. A negative correlation would be optimal. The anti correlation analysis is performed on observed wind and solar radiation for February, March and April 2017. A similar analysis is conduced on simulated solar radiation data and measured wind data for a whole year as well. The analysis do not show any anti correlation on small to middle time scales. Only on a very large time scale is the anti correlation significantly high. The WRF model fails in producing a reliable solar radiation source partly because it overestimates the radiation levels and also because it has an offset in the daily profile of the radiation. Measures are taken for scaling the radiation to obtain more reliable results, but the offset is not corrected for. A 20 MW solar power system is simulated together with the pre-existing wind far, with a grid constraint of 54 MW. Sensitivity analysis are performed on several physical, technical and economic parameters that might affect the feasibility of the system. Under the most realistic conditions simulated, did the system not qualify as an economic feasible system. There is possible to extract large amounts of power from the system if the right measures are taken, but it was not enough for the system to become profitable

Polarization-Based Illumination Detection for Coherent Augmented Reality Scene Rendering in Dynamic Environments

A virtual object that is integrated into the real world in a perceptually coherent manner using the physical illumination information in the current environment is still under development. Several researchers investigated the problem producing a high-quality result; however, pre-computation and offline availability of resources were the essential assumption upon which the system relied. In this paper, we propose a novel and robust approach to identifying the incident light in the scene using the polarization properties of the light wave and using this information to produce a visually coherent augmented reality within a dynamic environment. This approach is part of a complete system which has three simultaneous components that run in real-time: (i) the detection of the incident light angle, (ii) the estimation of the reflected light, and (iii) the creation of the shading properties which are required to provide any virtual object with the detected lighting, reflected shadows, and adequate materials. Finally, the system performance is analyzed where our approach has reduced the overall computational cost

On the Meteoric Smoke Particle Detector SPID: Measurements and analysis from the G-chaser rocket campaign

The Smoke Particle Impact Detector (SPID), newly designed at the University of Tromsø, was launched from Andøya 09:13 UTC the 13. January 2019. SPID is designed to detect meteoric smoke particles (MSPs) in winter mesospheric conditions. The rocket had a velocity of 1600 ms-1 at ~55 km where the nosecone was separated. At ~ 60km, SPID detected a signal of 17nA on the middle plate. The dynamics of the particles entering the detector was investigated taking into account the drag of the neutral airflow as well as the electric field generated by the bias voltages of the detector. These conditions were applied to a model of the size and charge of mesospheric dust in the range of radii 0.5 to 8 nm. For this model of the meteoric dust we find that 97 percent of particles that the rocket encounters would reach the middle plate and that 30 percent of the particles would hit the middle plate directly at 60 km. Estimations of dust densities that could explain the measured current vary between 10^10 and 101^3 per m^-3. The density of positive ions is close to that of MSPs, and so it is also possible that the measured current, or a fraction of it, is caused by ions. A secondary goal of the campaign was to investigate the relation between MSPs and the winter radar echoes called Polar Mesospheric Winter Echoes(PMWE). For this, the background atmospheric conditions were monitored with the radar systems MAARSY (53.5 MHz) and EISCAT (224 MHz). The EISCAT measured incoherent scatter which showed weak precipitation above 85 km. MAARSY did not observe PMWE activity during the launch, but on the days prior and after launch. Because it is a prerequisite to observe PMWE that the electron density is sufficiently high, we cannot draw any conclusions on the link between PMWE and MSP from the presented observations. The spectral analysis of the measured current shows strong rotational effects at higher altitudes. The Power spectrum follows the Kolmogorov slope of k^-5/3 into the Bragg scale of MAARSY, suggesting turbulent conditions influence the current. Because the resolution of the SPID is close to the Bragg scales of MAARSY, no clear conclusion could be made for the Bragg scale turbulence conditions

Antireflection and self‐cleaning structures for solar cells using laser interference nanolithography

A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of Philosophy.This research comprehensively reviews the properties of regular micro and nano structures fabricated by laser interference lithography and reports on their applications in the antireflection and self‐cleaning surface. The research systematically investigates the laser interference lithography technology taking into account its advantages and abilities to realize various potential applications. Multiple‐beam interference lithography systems are constructed. Laser interference interaction with silicon wafer is analysed and the optical and hydrophobic properties are obtained via measurements. In order to fabricate the extremely low reflection and very large contact angle for solar cells, fabrication methods of antireflection and self‐cleaning are surveyed and their advantages and disadvantages compared. The research investigates the effect of heat transfer and the radiation of laser interference plasma on silicon wafer surfaces and proposes equations of heat flow and radiation effects of laser plasma of interfering patterns in a four‐beam laser interference distribution. Following the irradiation, the silicon wafer surface is covered with a periodic array of micrometer and nanometer‐sized structures, which have the shape of grating, cone and hole. The research also investigates the effect of different laser parameters on the optical and hydrophobic properties of the structured silicon wafer surface. The results of periodic hexagonally‐distributed hole structures fabricated by three‐beam laser interference reveals excellent design guidelines for obtaining an extremely low solar‐weighted reflection, (SWR, 1.86%) and relatively large contact angle (140°) which can provide a strong self‐cleaning capability on the solar cell surface. In addition, the research creates a novel dual structure with antireflection and superhydrophobic properties fabricated by three‐beam laser interference lithography. The fabrication method is three‐beam laser interference combined with focused laser processing interacting on the silicon wafer surface. This kind of structure has a very low SWR (3.6 %) and extremely large contact angle which is more than 150° in the wavelength range from 380 nm to 780 nm. The research shows that the laser interference lithography technology can be employed and further developed to fabricate micro and nano structures of strong antireflection and self‐cleaning functions for applications in solar cells

Experimental Validation of Optical Simulation for Complex Building Integrated Photovoltaic System.

Simulation of BIPV system performance is usually based on a Plane-Of-Array method, adopted from classical PV plant systems, to estimate power generation. This methods is very limited for simulating facades in complex urban environments, such as dense urban areas, as it uses simplified near-field shading to estimate system losses. Furthermore, this approach accounts only for PV electricity yield generation, while neglecting other architectural criteria like daylighting, especially important in case of semi transparent PV facade. For the purposes of complex BIPV facades, other methods, such as ray tracing, are more preferable. Therefore, this research aims to estimate capabilities and accuracy of RADIANCE ray tracing engine to calculate daylighting and irradiance on PV surface. Validation procedure has been carried out for complex BIPV façade module, composed of complex profiled glass tile and semi-transparent Dye-Sensitized Solar Cells. Results showed reasonably good agreement between simulation and experimental measurements, which proves that method is capable for being used for the general purposes of complex BIPV systems

An Investigation of Daylighting Performance in Sidelit Spaces

The positive influence of daylight on people’s work and well-being has been confirmed in many studies. However, excessive daylight causes discomfort glare, which decreases work productivity, impairs occupants’ vision, and may even cause headaches. Substantial studies explored glare by correlating physical lighting measurements and subjective evaluations. With the development of High Dynamic Range (HDR) image techniques, dynamic changes of daylighting distributions can be effectively captured. Consequently, more studies paired HDR image techniques with subject evaluations to explore glare. However, studies merely relying on field measurements are not only time-consuming and labor-intensive but may also disturb occupants. To address these problems, this dissertation proposed the method of integrating three research tools, HDR image techniques, simulations, and questionnaire surveys, to investigate daylight glare. Using sidelit spaces across five buildings as the example, this dissertation aimed to demonstrate the accuracy of simulation results and the correlations between subject occupant evaluations and physical lighting data derived from both field measurements and simulation results. This dissertation is comprised of three sections. The first section focused on field measurements. Over 200 HDR images across five buildings were taken and analyzed using select visual discomfort metrics. The results showed that daylight glare probability (DGP) outperformed the other visual discomfort metrics in terms of identifying intolerable and imperceptible glare. The second section utilized these HDR images to calibrate four of the five buildings’ Radiance models. The relative RMSE of simulated vertical eye illuminance under both the Perez all-weather sky model and the hybrid photo-radiometer sky model were 23.7% and 21.2%, respectively. The frequencies of accurate glare prediction under both sky models were 93.9% and 95.5%, respectively. The results indicated that Radiance models with precise geometries and material properties can accurately represent the real lighting environments. Finally, the third section paired questionnaire surveys with both the HDR image technique and simulations to investigate daylight qualities within an open-plan office. The study found that taller windows, proximity to windows, and facing towards windows caused severe glare. By removing workstation partitions and arranging seating orientations perpendicular to the windows, the renovated layout design increased occupant satisfaction with their daylighting environments and tolerance for daylight glare. The last section demonstrated the effectiveness of integrating the three tools in lighting studies and the importance of interior layout and furniture designs in terms of daylight glare reduction

The Future of Solar Energy in Marine Applications

The objective of this master's thesis is to investigate the current and future technical and economic feasibility of PV systems for marine applications. Two scenarios will be studied; a land-based PV power station to supply an in-land ferry in Norway and a PV system installed on a wind farm support vessel as a supplementary power source. The two scenarios are use cases that support the two research programmes ENERGIX and NEXUS, where Rolls-Royce Marine are participants. The simulation software PVsyst will be utilized in detail to perform computational simulations of different vessels, with focus on Key Performance Indicators, such as average produced energy per square meter given a certain operational area in the world. In addition, PVsyst will be used to perform an economic analysis. The results show that the land-based PV power station has an annual average energy production of 132 kWh/m2. It produces 2 046 MWh/year, which equals 110 % of MF Amperes annual consumption. The energy cost from the system will be 1.25 NOK/kWh. The PV system on the wind farm support vessel, Edda Passat, has an annual average energy production of 173 kWh/m2. This corresponds to a production of 87.9 MWh/year, which accounts for 2.86 % of Edda Passats annual consumption. The energy cost for this system will be 0.5 NOK/kWh. The land-based system and the system on Edda Passat is estimated to have an energy payback time of 2.5 and 2 years, respectively. In addition, the life-cycle analysis emissions could be reduced by 90-95 % by using power from solar PV instead of oil and gas. The future potential of solar PV is promising with an expected increase in efficiency of 26.4 % for monocrystalline Si-cells over the next 10 years, and a predicted total system cost reduction of 53 % by 2025. Based on this, the land-based system could produce 2 587 MWh/year with an energy cost of 0.59 NOK/kWh, and the system on Edda Passat could produce 111 MWh/year with an energy cost of 0.24 NOK/kWh by 2028. The future energy cost from the PV system on Edda Passat and the land-based system corresponds to 12 % and 30 % of present marine gas oil costs, respectively. Solar modules have a lifetime of at least 25 years and are classified for use in marine environments by the International Electrotechnical Commission. These numbers show that solar PV is an important part of power generation for future solutions in marine applications

Extraction and Integration of Physical Illumination in Dynamic Augmented Reality Environments

Indiana University-Purdue University Indianapolis (IUPUI)Although current augmented, virtual, and mixed reality (AR/VR/MR) systems are facing advanced and immersive experience in the entertainment industry with countless media forms. Theses systems suffer a lack of correct direct and indirect illumination modeling where the virtual objects render with the same lighting condition as the real environment. Some systems are using baked GI, pre-recorded textures, and light probes that are mostly accomplished offline to compensate for precomputed real-time global illumination (GI). Thus, illumination information can be extracted from the physical scene for interactively rendering the virtual objects into the real world which produces a more realistic final scene in real-time. This work approaches the problem of visual coherence in AR by proposing a system that detects the real-world lighting conditions in dynamic scenes, then uses the extracted illumination information to render the objects added to the scene. The system covers several major components to achieve a more realistic augmented reality outcome. First, the detection of the incident light (direct illumination) from the physical scene with the use of computer vision techniques based on the topological structural analysis of 2D images using a live-feed 360-degree camera instrumented on an AR device that captures the entire radiance map. Also, the physics-based light polarization eliminates or reduces false-positive lights such as white surfaces, reflections, or glare which negatively affect the light detection process. Second, the simulation of the reflected light (indirect illumination) that bounce between the real-world surfaces to be rendered into the virtual objects and reflect their existence in the virtual world. Third, defining the shading characteristic/properties of the virtual object to depict the correct lighting assets with a suitable shadow casting. Fourth, the geometric properties of real-scene including plane detection, 3D surface reconstruction, and simple meshing are incorporated with the virtual scene for more realistic depth interactions between the real and virtual objects. These components are developed methods which assumed to be working simultaneously in real-time for photo-realistic AR. The system is tested with several lighting conditions to evaluate the accuracy of the results based on the error incurred between the real/virtual objects casting shadow and interactions. For system efficiency, the rendering time is compared with previous works and research. Further evaluation of human perception is conducted through a user study. The overall performance of the system is investigated to reduce the cost to a minimum

Serious Games in Science Education. A Systematic Literature Review

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