With limited indigenous conventional energy resources, Mauritius imports over 80% of its energy supply from foreign countries, mostly from the Middle East. Developing independent renewable energy resources is thus of priority concern for the Mauritian government. A tropical island surrounded by the Indian Ocean, Mauritius has enormous potential to develop various renewable energies, such as solar energy, biomass energy, wind power, geothermal energy, hydropower, etc. However, owing to the importance of conventional fossil energy in generating remarkably cheap electricity, renewable energy has not yet fully developed in Mauritius, resulting from a lack of market competition. So, in order to reduce the external dependency of fuel, and also to cut down the expenses involved in the imported fuels, the Mauritius Government introduced attractive policies and invited investors of the homeland and abroad to invest in renewable energy technologies. Consequently, numerous promotional and subsidy programs have recently been proclaimed by the Mauritian government, focused on the development of various renewable energies. Thus, the Government of Mauritius has a long-term vision of transforming Mauritius into a sustainable Island. One important element towards the achievement of this vision is to increase the country’s renewable energy usage and thereby reducing dependence on fossil fuels. Democratisation of energy production is determined to be the way forward. A step in this direction is to transfer citizens the ability and motivation to produce electricity via small-scale distributed generation (SSDG), i.e. wind, photovoltaic, Hydropower. As a stepping stone the Government and the Central Electricity Board, with the help of the UNDP, established a grid code in May 2009 which encompasses tariffs and incentive schemes that have in many countries proved essential in order to achieve any substantial development in renewable electricity production based on SSDG.   In line with the government’s vision on renewable energy, the University of Mauritius is working as a partner with DIREKT team to promote renewable energy infrastructure locally. The DIREKT (Small Developing Island Renewable Energy Knowledge and Technology Transfer Network) is a teamwork scheme that involves the participation and collaboration of various universities from Germany, Fiji, Mauritius, Barbados and Trinidad & Tobago.  The aim of the DIREKT project is to reinforce the science and technology competency in the domain of renewable energy through technology transfer, information exchange and networking, targeting ACP (Africa, Caribbean, Pacific) Small Island developing states. This study was therefore initiated to investigate the main renewable energy technologies that stakeholders, institutions as well as businesses and organizations would like to invest in Mauritius based in the attracting incentive schemes provided by the Government.   From the study it was found that the majority of the Organizations, Institutions, Businesses and stakeholders are ready to accept and invest in the solar photovoltaic technology. Moreover, the economic evaluation for the implementation of the photovoltaic technology revealed that within a period of 4.3 years (payback period), the total capital invested can be recovered and after that, the capital generated from the excess electricity produced will contribute to the profit of the organization, Business or Institution.

My project attempts to nuance the bodies of knowledge produced in relation to processes of natural resource extraction in Norrbotten, Sweden. Operating between fact and fiction, I have presented the project as a speculative video narrative. The protagonist is the Lule River, where the implications of its domestication and agency is explored.  This territory can be understood as a wilderness, a cultural landscape, the Sami homelands and a place of extraction. Prior to Vattenfall’s acquisition of Porjus, the estate belonged to Erik Abraham Olofsson Rim (1844-1920). Olofsson Rim was Forest Sami with background in Sjokksjokk sami village. Speculative fiction is a powerful tool to contemplate societal issues and grapple with complex realities. The result lies in the audience’s reading of the project, where the goal is to spark discussion and reflection. In the aesthetics of the proposed post-fossil world, I have ventured into the playfully surreal. The playful in terms of unexpected elements and color palette. The surreal is expressed through composition, scale and juxtaposition. Dealing with such huge infrastructure objects, which are surreal and abstract in themselves, I have attempted to make the line between the real and the unreal fluid, to evoke the audience’s reflection of the possibilities at hand.

This study provides a long-term understanding of the impact of climate varia-bility and land use on seasonal water balance conditions for sustainable agricul-ture development, hydropower generation and ecosystem stability in the Lower Rufiji Basin. The severity of soil drought, extreme flooding and salinity intru-sion in the lower Rufiji floodplains are currently increasing smallholder poverty and enhance the sensitivity on the natural wetlands for shifting farming and livestock pastures. The CoupModel and SWAT hydrological model were ap-plied to assess and compare the impact of climate variability on the water bal-ance. The monthly river discharge was used for calibrating and validating the runoff at the Stiegler's Gorge. The simulated results for water balance compo-nents at Stiegler's Gorge showed 55% of accumulated precipitation is lost through evapotranspiration and 42 % is river runoffs for downstream agricul-ture and ecosystem services. The evaluation of the models simulation perfor-mance and posterior distribution of parameter behavioral value indicates the (GLUE) calibration method in the CoupModel agreed satisfactory with the Bayesian calibration (BC). The minimal variance in the Bayesian Calibration posterior parameter distribution was observed in the parameter for regulating water uptake from (CritThresholDry) and soil moisture availability for soil evaporation(PsiRs_ip). The SWAT simulation showed that south of the central floodplains has high risk of soil drought. The overall assessment implies that drought and river runoff dynamics in the LRB is affected by upstream land use activities. The strategies for building smallholder resilience towards climate change and land use impact requires collective and coordinated water manage-ment actions powered by individual, institutional, financial and technological adaptation.

To make sure that a dam is safe it is important to have good knowledge about the energy dissipation in the spillway. Physical hydraulic model tests are reliable when investigating how the water flow behaves on its way through the spillway. The problem with physical model testing is that it is both expensive and time consuming, therefore computational fluid dynamics, CFD, is a more feasible option. This projects focuses on a spillway located in Sweden that Vattenfall R&D built a physical model of to simulate the water discharge and evaluate the energy dissipation in order to rebuild the actual spillway. The main purpose of this project is to evaluate if the physical hydraulic test results can be reproduced by using CFD, and obtain detailed results about the flow that could not be obtained by physical testing. There are several steps that need to be completed to create a CFD-model. The first step is to create a geometry, then the geometry needs to be meshed. After the meshing the boundary conditions need to be set and the different models, multiphase model and the viscous model, need to be defined. Next step is to set the operating conditions and decide which solution method that will be used. Then the simulation can be run and the results can get extracted. In this project two CFD simulations were performed. The first simulation was to be compared with the physical hydraulic model test results and the second CFD simulation was of the rebuilt spillway. The results proved that the physical model test results could be recreated by using CFD. It also gave a better understanding of how the energy dissipation was in the spillway and indicates that the reconstruction of the actual spillway was successful since the new spillway both had a higher water discharge capacity and better energy dissipation.

This diploma thesis deals with a study of a small hydropower plant in Osík on the Desná river. Part of the work is the calculation of the produced energy and the estimation of the return on investment.

Es kann davon ausgegangen werden, dass sich die Erdbevölkerung bis Ende dieses Jahrhunderts verdoppeln wird. Der Energiebedarf wird sehr wahrscheinlich um mehr als das Doppelte steigen, da der Bevölkerungszuwachs ausschließlich in Entwicklungsländern stattfindet, wo bekanntlich ein erheblicher Bedarf an Energie besteht. Die Prognosen gehen daher von einer Zunahme der Energie aus, die unseren heutigen Verbrauch um das 2- bis 3- Fache übersteigt. Vor dem Hintergrund, dass die Energieoptionen – Rohöl, Erdgas, Uran – in diesem Jahrhundert nahezu aufgebraucht sein werden, gewinnen zunehmend die erneuerbaren Energien an Bedeutung. Die Wasserkraft ist dabei weltweit die bedeutendste regenerative Energiequelle. Die Planungen sehen vor, dass sich die Wasserkraftnutzung bis zum Jahr 2050 verdoppeln wird. / It can be expected that the world population will double by the end of this century. The energy demand will very probably increase even more significantly, as the population is increasing exclusively in the developing countries, where an extreme energy demand is already known to exist. Three to four times the present energy demand is predicted. When it is considered that crude oil, natural gas and uranium resources will be practically exhausted during the coming century, renewable energies become more and more important. Hydropower is worldwide the leading renewable energy source. It is planned to double the use of hydropower by the year 2050.

No description available.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23480号 / 工博第4892号 / 新制||工||1764(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 立川 康人, 准教授 市川 温, 教授 堀 智晴 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Cavitation has been known for a long time to cause damages in spillways athydropower plants, aerators are therefore often implemented to prevent this.The majority of the hydropower plants in Sweden are installed in the northernpart of the country. In this environment, construction details like vents areexposed to rain, snow, leaves, and other difficult nature conditions for a majorpart of the year. It is therefore of interest to see what will happen if the ventsare sealed.Similar experiments have earlier been investigated at Vattenfall AB, oneof the largest energy companies in Sweden. The investigation consists ofcase studies with multiple variables, closed and open vents, low and highwater levels. The calculations are done with help from computational fluiddynamics and the goal is to see how parameters such as pressure, spreading,and horizontal length change when the aerator is sealed compared to open.The calculations were also carried out in a way so tests in the future can bedone by Vattenfall to validate the results from the computational simulations.The geometry of the hydropower plant is taken from a plant in Skellefteälvenin northern Sweden.

Climate change drives policymakers to reduce emissions and enhance the integration of variable renewable energy sources (VRES) into the power system. Wind power is considered among the most beneficial VRES as it can generate cost-effectively carbon-free electricity but comes with inherent intermittency. Hydropower is a proposed solution among the research community to handle VRES output volatility and ensure balanced energy output to the electricity grid. This thesis addresses the problem by investigating the integration of intermittent wind power into a hydropower system cost-effectively. The research question "How does the integration of wind power affect the hydro operations and the cost of purchased electricity?" is answered within the Design Science Research framework by optimizing a subset of the Røldal-Suldal hydropower system in Norway's NO2 region. The cost-minimization model utilizes historical data from 2018 on water inflows, hourly electricity prices, hourly wind production, and hourly energy consumption for a smelter within the NO2 zone. To reduce the 8,760-time steps and computational concerns, the kmeans clustering algorithm is implemented to obtain four representative weeks. A multiperiod linear programming model is structured to assess the joint operation of wind and hydropower while ensuring a minimum energy production to satisfy the system's power demands. A benchmark scenario with no wind capacity is formed to serve as the basis for comparisons. Ten scenarios with 100-MW incremental steps of wind capacity are implemented. The minimized cost for the benchmark scenario is €104,981,312.34, with electricity purchases covering more than 75% of the energy demand and hydropower satisfying the remaining 25%. Adding 100 MW of wind capacity reduces costs by more than €2,000,000, restricting the purchased energy’s share by 1.49%, which is the equivalent increased share of wind power during each incremental step. A wind capacity of 1,000 MW leads to a 21.24% cost reduction. Hydropower production remains unaffected by the wind integration based on terminal values of reservoir level or turbined water volume. However, the distribution of hydropower production throughout the year changes after installing wind capacity enabling hydropower to utilize stored water optimally to minimize the costs of purchasing energy. A sensitivity analysis to assess the uncertainties tied with the model coefficients shows that increasing initial reservoir levels and adding 1,000 MW of wind capacity is the most influential factor in the optimization model.