Driven by the fact that the global oil market has become extremely volatile and the EU dependence on oil continues to grow, this paper argues that with more emphasis on renewable energy and by using domestically produced alternative energy sources instead of importing foreign oil the EU Member States would drastically improve their energy security and energy independence. The study investigates both past and present trends in the EU energy sources supply and consumption patterns. Additionally, the paper considers possibilities of the renewable and alternative energy both at the current stage and future development of this sector in the EU. The research findings confirm the initial hypothesis as to whether the share of alternative and renewable energy will be sufficiently large to contribute to solving a problem of the EU energy security and independency. The role of the renewables in national energy security strategies of three EU Member States is studied and government supporting policies that enhance renewable sources development are analyzed.

Title: Legislation of renewable energy sources and their use Abstract The presented thesis deals with issues of legal regulation of renewable energy sources with target on legal regulation of system of support in the Czech Republic. The thesis contains the overview of documents and instruments from international enviroment. As a result of the Czech Republic membership in the European Union the thesis presents instruments of union legislation which due to integration of EU member states legislation and due to marking out obligatory goals aims to opened unified and liberal energy market. The thesis describes historical development of this phenomenon from partial legislation to complex and sophisticated legislation and artificially formed systems of support including and puts them into context with social economic aspects of pursued period of time. Due to comparative method the thesis brings not only comparation of legislation in the course of time in Czech and European background but also evaluate them and try to estimate progress and find possible solution. One of the thesis targets is to provide the comprehensive view on legislation of renewable energy sources from businessmen points of view and put this relationship into context with institute of environment protection.

Thesis title: Legal regulation of the use of alternative energy resources The goal of the paper is to analyze the legal regulation of the use of alternative energy sources and to provide a summary and logical overview of this matter that is closely related to environment and climate protection. The greenhouse effect is frequent topic of current debates regarding the climate changes that lead the international communities to decision on limitation of greenhouse gases emissions by using among others renewable energy sources. The reason for my research is a long-term interest in renewable energy sources. The thesis is composed of seven chapters, each of them dealing with different aspects of promotion of the use of alternative energy sources. Chapter One is introductory and provides the overview of the research topic. Chapter Two explains the term alternative energy sources and its relation to renewable energy sources. Chapter Three is divided into two subchapters dealing with international and European aspects of the climate protection and related law. History of the Czech legal regulation of promotion of renewable energy sources is provided in Chapter Four and the main issues are outlined. Chapter Five deals with current Czech legal regulation on promotion of renewable energy sources and provides...

This thesis is focused on the legislation on the renewable energy sources, especially on the mechanisms of promotion granted to the producers of the electricity and heat from the renewable sources of energy. The thesis describes the contemporary regulation in the Czech republic and compares it to the relevant German regulation.

Wind energy has been growing rapidly during recent years. This paper aims to estimate the impact of wind power generation on the Swedish wholesale electricity price, using monthly time series data over the periods 2000-2016. The error-correction model is used to measure the price effect by including other factors that influence the electricity supply and demand. Thefindings suggest that the impact of changes in wind power production on the wholesale priceof electricity is negative in the short-term. When the wind power production increases by 1%, the wholesale electricity price decreases with 0.08%. Furthermore, the magnitude of the coefficient increases to 0.10% in the long-term.

Around 770 million people lack access to improved drinking water sources (WHO 2013), urgently necessitating implementation of contaminant removal by e.g. desalination systems on a large scale. To improve water quality and enable use of brackish water sources for human consumption in remote arid areas, a directly coupled wind – electrodialysis system (Wind-ED) was developed. Modularity, sustainability and above all suitability for the practical use in off-grid locations were the main motivations and design objectives. The direct coupling of wind energy with membranes reduces the system costs as well as technical drawbacks associated with using intermediate energy storage systems. During this research, systematic experiments were performed using the Wind-ED system in order to determine desalination performance and clean water production, specific energy consumption (SEC) and current efficiency (ηc) under relevant conditions, such as varying: i) wind speed, ii) wind turbulence intensity, iii) oscillation periods, iv) varying NaCl concentrations and v) flow rates. Moreover, the competitive removal of four commonly available inorganic contaminants in brackish groundwater sources, nitrate (NO3-), fluoride (F-), sulphate (SO42-) and chloride (Cl-), were investigated. Firstly, to establish a systematic understanding of how and to what extent energy fluctuations influence the transport of the salt (i.e. NaCl) ions across the membranes, experiments were conducted using pulsed electric field assisted electrodialysis (pulsed-ED) over a wide range of frequencies (0.001 – 10 Hz) and duty cycles (20 – 80). The results showed that pulsation applied in the sub-limiting regime resulted in reduced water production, explained by the delays caused by the off-periods during the pulsed desalination process. At higher current densities, pulsation led to considerable improvements in current (e.g. up to 95%, for a feed solution of 500 mg/L and a pulse regime of 1 Hz at 50 V peak voltage) and significant reduction in water dissociation, explained by a reduction of concentration polarisation. Importantly, the pulsation had no significant effect on energy consumption or current efficiency suggesting that ED could be suitable for direct coupling to fluctuating energy sources such as wind energy. ED was consequently coupled to a wind turbine system and a series of desalination tests were performed over a wide range of wind speeds (2-10 m/s), turbulence intensities (TI of 0-0.6) and oscillation periods (0-180 s). Results showed that water production and SEC increased with wind speed. However, both the water production and SEC stopped increasing as the power output from the turbine levelled off at wind speeds above the rated value (vrated: 7.9 – 8.4 m/s). The impact of wind speed fluctuations on the system performance were insignificant up to a TI of 0.4. The desalination performance declined under high turbulence intensity fluctuations (TIs ≥ 0.5) and long periods of oscillation (> 40 s), as the wind-ED system periodically cycled off in response to operation below the cut-in wind speed of the wind turbine (vcut-in: ~ 2 m/s). The off-cycling of the system caused significant delays in the desalination process, and thus resulted in reduced water production. Further reduction in the water production resulted as the wind-ED system operated under intermittent wind speed conditions with off-wind periods longer than 10 s. It was concluded that the main challenge in direct coupling of ED to a wind resource was not the magnitude of the fluctuations but the impact of the power cycling off during long periods of oscillation and lengthy periods of no wind. Interestingly, the SEC of the process remained relatively unaffected by the fluctuations and intermittencies in the wind resource. The effect of energy fluctuations on the competitive transport of F-, Cl-, NO3- and SO42- from artificial brackish water (TDS ~4350 mg/L) was investigated using different sets of real wind data. The ion removal, independent of the wind regime tested, followed the order: NO3- ≥ Cl- > F- > SO42-. The competitive removal of the ions was linked to differences in physicochemical properties (i.e. hydration energy, ionic mobility and valence). The specific selectivity (e.g. preferential transport of NO3- over SO42- ions) was found to increase with concentration polarisation being either minimised (by lowering the mean wind speed) or disrupted (by fluctuations in the wind resource). The results from flow rate and feed concentration experiments, showed that power production of the wind turbine depended on not only the available wind energy but also the resistance of the load (i.e. the ED stack). Thus, increasing the feed concentration and the flow rate resulted in reduced resistance in the ED stack (Rstack), which inversely influenced the current induction counter torque force applied on the shaft of the wind turbine and caused the rotor to spin at a lower angular velocity. This led to increased sensitivity of the wind-ED system to wind speed fluctuations (e.g. system cycled off due to extreme fluctuations and intermittencies with low TDS feed concentration of 2400 mg/L) and hence a reduction of desalination performance. Impact of flow rate on the SEC was found to be negligible; this was attributed to the automatic voltage to current adjustments done by the wind turbine, in order to minimise the impacts of Rstack on the power production by the turbine at a given wind speed. Increased flow rate and resulting shrinkage of the boundary layer’s thickness, caused the concentration profiles at the solution-membrane interface to become steeper. This favoured the transport of ions with the highest diffusion coefficients in the mixture (i.e. Cl- and NO3-). Decreased flow rate favoured the transport of ions with larger valence numbers and higher electric mobility inside the electrolyte (i.e. SO42-); as the former property governed the faster migration of SO42- ions through the thick boundary layer and the latter property assisted with the improved affinity of the ion-exchange membrane to SO42- ions compared to the monovalent anions in the mixture. Increasing the feed concentration of Cl- from 500 to 2,550 mg/L led to reduced transport numbers for the other anions in the mixture and significantly reducing their removal rate. The results obtained from both the pulsed-ED and wind-ED experiments showed that, despite direct coupling to the fluctuating energy source the SEC of the process remained relatively unaffected by the energy fluctuations. Although the desalination process might require more time to be completed when operating under extreme wind speed fluctuations and intermittencies, the quality of the drinking water produced was always within the WHO standards. In conclusion, the findings from this research prove the wind-ED system to be an energetically robust and a reliable off-grid desalination technique suitable for the treatment of brackish groundwater in water stressed remote regions.

A photovoltaic thermal solar collector (PVT) produces both heat and electricity from a single panel. PVT collectors produce more energy, for a given area, than conventional electricity and heat producing panels, which means they are a promising technology for applications with limited space, such as building integration. This work has been broken down into 3 subprojects focusing on the development of PVT technology. In the first subproject an experimental testing facility was constructed to characterise the performance of PVT collectors. The collectors under investigation were assembled by combining bespoke thermal absorbers and PV laminates. Of the two designs tested, the serpentine design had the highest combined efficiency of 61% with an 8% electrical fraction. The header riser design had a combined efficiency of 59% with an electrical fraction of 8%. This was in agreement with other results published in literature and highlights the potential for manufacturers of bespoke thermal absorbers and PV devices to combine their products into a single PVT device that could achieve improved efficiency over a given roof area. In the second project a numerical approach using computational fluid dynamics was developed to simulate the performance of a solar thermal collector. Thermal efficiency curves were simulated and the heat removal factor and heat loss coefficient differed from the experimental measurements by a maximum of 12.1% and 2.9% respectively. The discrepancies in the findings is attributed to uncertainty in the degree of thermal contact between the absorber and the piping. Despite not perfectly matching the experimental results, the CFD approach also served as a useful tool to carry out performance comparisons of different collector designs and flow conditions. The effect of 5 different flow configurations for a header collector was investigated. It was found that the most efficient design had uniform flow through the pipe work which was in agreement with other studies. The temperature induced voltage mismatch, that occurs in the PV cells of PVT collector was also investigated. It was concluded that the temperature variation was not limiting and the way in which PV cells are wired together on the surface of a PVT collector did not influence the combined electrical power output.

Ocean Thermal Energy Conversion (OTEC) is a renewable energy technology that has to overcome several key challenges before achieving its ultimate goal of producing baseload power on a commercial scale. The economic challenge of deploying an OTEC plant remains the biggest barrier to implementation. Although small OTEC demonstration plants and recent advances in subsystem technologies have proven OTEC’s technical merits, the process still lacks the crucial operational data required to justify investments in large commercial OTEC plants on the order of 50-100 megawatts of net electrical power (MWe-net). A pre-commercial pilot plant on the order of 5-10 MWe-net is required for an OTEC market to evolve. In addition to the economic challenge,OTEC plants have potential for adverse environmental impacts from redistribution of nutrients and residual chemicals in the discharge plume. Although long-term operational records are not available for commercial sizeOTEC plants, synergistic operational data can be leveraged from the desalination industry to improve the potential for OTEC commercialization. Large capacity desalination plants primarily use membranes or thermal evaporator tubes to transform enormous amounts of seawater into freshwater. Thermal desalination plants in particular possess many of the same technical, economic, and environmental traits as a commercial scale OTEC plant. Substantial long-term economic data and environmental impact results are now widely available since commercial desalination began in the 1950s. Analysis of this data indicates that the evolution of the desalination industry could be akin to the potential future advancement of OTEC. Furthermore, certain scenarios exist where a combined OTEC-desalination plant provides a new opportunity for commercial plants. This paper seeks to utilize operational data from the desalination industry as a progressive approach towards OTEC commercialization.

M. Tech. (Engineering: Electrical, Department Electronic Engineering, Faculty of Engineering and Technology), Vaal University of Technology, / “If we think oil is a problem now, just wait 20 years. It’ll be a nightmare.” — Jeremy Rifkin, Foundation of Economic Trends, Washington, D.C., August 2003. This statement harmonises with the reality that human civilisation faces today. As a result, humankind has been forced to look for alternatives to fossil fuels. Among possible solutions, fuel cell (FC) technology has received a lot of attention because of its potential to generate clean energy. Fuel cells have the advantage that they can be used in remote telecommunication sites with no grid connectivity as the majority of telecommunication equipment operates from a DC voltage supply. Power plants based on phosphoric acid fuel cell (PAFC) have been installed worldwide supplying urban areas, shopping centres and medical facilities with electricity, heat and hot water. Although these are facts regarding large scale power plants for on-site use, portable units have been explored as well. Like any other fuel cell, the PAFC output power is highly unregulated leading to a drastic drop in the output voltage with changing load value. Therefore, various DC–DC converter topologies with a wide range of input voltages can be used to regulate the fuel cell voltage to a required DC load. An interleaved synchronous buck converter intended for efficiently stepping down the energy generated by a PAFC was designed and developed. The design is based on the National Semiconductor LM5119 IC. A LM5119 evaluation board was redesigned to meet the requirements for the application. The measurements were performed and it was found that the converter achieved the expectations. The results showed that the converter efficiently stepped down a wide range of input voltages (22 to 46 V) to a regulated 13.8 V while achieving a 93 percent efficiency. The conclusions reached and recommendations for future research are presented. / Telkom Centre of Excellence, TFMC, M-Tech, THRIP.

M.Ing. / The necessity for deployment of Concentrated Solar Power (CSP) technology in the South African energy sector is examined in this dissertation. A background is given on the different technologies that exist in the solar power sector with specific reference to Concentrated Solar Thermal Power (CSTP). The economic, social and environmental benefits that this technology embodies in the near-, medium-, and long-term is discussed in detail. It highlights the local market potential for the establishment and large-scale roll out of CSP technology in a South African context and the economic value-chain that could subsequently be created...