Renewable energy sources are getting much more important to reduce the increasing threat coming from greenhouse gases. Hydropower is the most important source of renewable energy. However, development of a hydropower project is a challenging engineering process. Several computer programs have been developed to make initial estimations on hydropower schemes. A computer program named RETScreen Small Hydro Project Model has been developed with the objective to make complete pre-feasibility studies including costing and financial analysis. Two case studies, which have been under construction in Turkey, will be used to check the accuracy of software in Turkish practice. Then in light of the results, RETScreen software will be used to make a pre-feasibility report on an existing multipurpose dam in Turkey. Electricity can be generated at existing dams which requires minor civil works. Porsuk Dam which is a 36 year old dam used for domestic, industrial and irrigation water supply will be evaluated for energy generation by constructing a penstock, powerhouse and installing electromechanical equipment.

Francis type turbines are commonly used in hydropower generation. Main components of the turbine are spiral case, stay vanes, guide vanes, turbine runner and the draft tube. The dimensions of these parts are dependent mainly on the design discharge, head and the speed of the rotor of the generators. In this study, a methodology is developed for parametric optimization by incorporating Matlab codes developed and commercial Computational Fluid Dynamics (CFD) codes into the design process. The design process starts with the selection of initial dimensions from experience curves, iterates to improve the overall hydraulic efficiency and obtain the detailed description of the final geometry for manufacturing with complete visualization of the computed flow field. A Francis turbine designed by the procedure developed has been manufactured and installed for energy production.

In this thesis, a parametric methodology is investigated to design a Pump-Turbine system using Computational Fluid Dynamics ( CFD ). The parts of Pump-Turbine are created parametrically according to the experience curves and theoretical design methods. Then, these parts are modified to obtain 500 kW turbine working as a pump with 28.15 meters head. The final design of Pump-Turbine parts are obtained by adjusting parameters according to the results of the CFD simulations. The designed parts of the Pump-Turbine are spiral case, stay vanes, guide vanes, runner and draft tube. These parts are designed to obtain not only turbine mode properties but also pump mode properties.

Turkey is a developing country and its energy demand is increasing due to its growing population and industry. As a result, to fulfill this growing energy demand, Turkey is currently developing its unused hydropower potential, especially through small hydroelectric power plants (SHPPs). Estimation of annual electricity generation of a small hydropower plant strongly depends on streamflow data. In Turkey, there are a limited number of streamgaging stations so the estimation of streamflow at a potential SHPP location requires transferring streamflow time series from a reference streamgaging station to the ungaged basin. In order to determine daily streamflow time series for ungaged catchments, typically the nearest streamgaging station is chosen as the reference streamgaging station. However the distance between a reference streamgaging station and an ungaged catchment may not always be the most appropriate reference streamgaging station selection criterion. Archfield and Vogel (2010) proposed a new method called the Map Correlation Method (MCM) to select a reference streamgaging station to donate its observations to an ungaged catchment. MCM aims to identify the most correlated streamgaging station with the ungaged catchment. This new method is used at the Western Blacksea Basin in Turkey to select the best among possible reference streamgaging stations. The method proved to be promising / the most correlated streamgaging station for approximately one third of the study streamgaging stations are identified correctly by the MCM.

Run-of-river type hydroelectrical power plants are the facilities that use only the available flow on the river without storing it to generate electrical energy. These kind of facilities are composed of structural components such as diversion weir, conveyance line, forebay, penstock and power house. In this thesis, a computer program called &ldquo / MiniHEPP Hydraulic Design&rdquo / is developed in order to perform the hydraulic design of run-of-river type hydropower plants. This program which runs under the Windows operating system, was developed in C# programming language. MiniHEPP Hydraulic Design is capable of performing hydraulic design of structural components of diversion weir with sidewise intake and overflow spillway, canal, forebay, and penstock. In addition, it can determine the optimum design discharge and penstock diameter of this type of hydropower plants.

... Es ist sicher gut und nützlich, sich in diesem Zusammenhang einmal mit der Wassernutzung vergangener Jahrzehnte und Jahrhunderte zu beschäftigen, wie ich sie an Hand der Weißeritz dargestellt habe. Die vielfältige Nutzung des Wassers in der Vergangenheit nötigt uns Respekt ab, bereichert unser Wissen, verpflichtet uns aber gleichzeitig die Wasserressourcen sinnvoll einzusetzen sowie für eine Pflege des Flusses und seiner Ufer Sorge zu tragen. Das Thema - Staustufen, Mühlgräben ... - ist sehr vielgestaltig. Eine umfassende Darstellung war im Freitaler Stadtgebiet unter Einbeziehung der Talsperren, von Interesse. ... (aus der Einleitung)

<p>Mega projects are in most cases considered as the necessary evil of development. Before their benefits can be reaped, a lot of sacrifices and tough choices have to be made. The fear and uncertainties surrounding such projects range from the impacts on the local people, on the environment, the costs of investment, and to, if the project will deliver the promised benefits. Because of these fears and uncertainties, it is not unusual that most if not all such projects meet a lot of critics and resistance before their success or failures are witnessed. Today, it is more of a requirement than a belief (although without a guarantee) that stakeholders’ involvement and their active participation in all decision-making process concerning a project is the surest way of minimizing conflicts and ensuring justice. The Bujagali hydropower project being an example of such projects and without immunity to the problems faced by other mega project around the world has been a case study for this thesis. This study has therefore focused on institutional arrangements that governed the management and utilization of water resources in connection to hydropower development along the Nile River in Uganda, the procedures and stages of the negotiations for hydropower infrastructure development in Uganda, identified the major stakeholders that take part in such negotiations and looked in detail for what their issues and interests are. It has also examined the attitudes and opinions of stakeholders on the potential and benefits of hydropower against (solar, bio-fuel and geothermal) energy sources in the context of Uganda, taking into consideration the need for socio-economic development, preservation of culture and environmental protection. Finally, it has analyzed the conflicts/controversies that have arisen in the Bujagali hydropower project.</p>

Hydropower has been around for more than a century and is considered a mature technology, but with recent advancements in power electronics and simulation capability new exciting ways to increase efficiency and reliability is possible. At Uppsala University a brushless exciter has been constructed for the experimental test rig, SVANTE. Power electronics are mounted on the shaft for control of the generator's excitation current. In addition a wireless control and measurement system is needed to provide the desired switching patterns to the power electronics and to evaluate performance of the system. In this thesis a shaft mounted embedded system for control and measurement is constructed as well as magnetic field sensors with measurement range up to 700mT. The computational power comes from a National Instruments sbRIO-9606. The system has 14 individual totem pole power electronics driving channels, 48 analog input channels for current signals and it communicates wirelessly through a bluetooth connection. The system is tested and works satisfactory but has not been mounted on the rotating side of the generator due to delays in the manufacturing.

In 1990 Flödeskommittén released new guidelines which redefined the method used to determine design flows. The method, combined with more complete measurements of flow variations, has resulted in higher design flows which in turn call for increases in the discharge capacity of hydropower plants. This work is still in progress. Since many Swedish hydropower stations were constructed in the 1950's and 60's they require modernization. Today Statkraft owns and operates 55 hydropower stations in Sweden several of which have a discharge capacity below the design flow. For this reason, the dam safety of these hydropower stations is reduced. According to current guidelines the turbine flow is not added to the discharge capacity since the availability of the electrical grid is not guaranteed during extreme flows. When the electric grid is unavailable the generator has no load and cannot produce an electric torque. Without the electric torque the turbine accelerates which may result in equipment failure. This thesis considers the introduction of an alternative local load where the generator power can be dumped as heat, hence termed dump load. The dump load has the potential to increase the discharge capacity by adding the turbine flow. However, operation of the dump load requires the availability of the generator and turbine, making the discharge capacity dependent on the status of the plant. In turn, achieving a sufficient discharge capacity is of primary concern to dam operators since it determines dam safety. Consequently, this thesis evaluates the effects on dam safety when utilizing a local load to increase the discharge capacity. Three different designs were evaluated; a medium to high voltage electrode water boiler, electrodes submerged in the river and a low voltage electric water boiler. The evaluation shows that all three designs are feasible and can be used to increase the discharge capacity provided the generator and turbine have high availability. The complexity and number of components constituting the dump load should be minimized to reduce the risk of malfunctions and redundancy should be introduced for key components when feasible. The dump load power should be controlled using voltage regulation but further work is required to determine the specifics of this governor. The results also show that the cost of the dump load is a fraction of the cost of a new spillway. However, the topic is controversial and the dump load requires practical testing in order to evaluate operational reliability.

Denna rapport sammanställer vattenhydraulikens möjligheter samt fördelar och nackdelar vid konvertering av befintliga hydraulsystem, eller nya anpassade system inom vattenkraften. Dessutom ska en jämförelse mellan miljöpåverkan av olja jämfört med vatten som behandlats för att passa i olika hydraulsystem redovisas. En stor fråga är om vattenhydrauliken har samma hållbarhet som oljehydrauliken och ifall man får accelererad nötning ifall man konverterar ett befintligt system från oljehydraulik till vattenhydraulik. Vattenhydraulik i vattenkraft används redan till luckservon. För ledkransservo ställs högre krav på driftsäkerhet men vatten bör kunna användas där med. Pitchkontroll för kaplannav är under utveckling, det som saknas just nu är sviveln som sitter längst upp på turbinaxeln. Om man ska konvertera ett nav behöver man också byta ventilerna som sitter i navet för att få tillförlitlighet. För att kunna konvertera ett oljehydrauliksystem till vattenhydraulik behöver man byta vissa komponenter: ventiler, filter och pumpar då dessa behöver vara anpassade för att kunna få en anständig livslängd. Livslängden är garanterad till 8000-10000h för ett nyinstallerat vattenhydrauliksystem, detta är med avseende på pumpen som normalt sett är den detalj med kortast livslängd i systemet. Jämfört med oljehydraulik så är detta i stort sett samma livslängd, vilket har varit målet för leverantören Danfoss utveckling av vattenhydraulik. Ett vattenhydrauliksystem med rent vatten som hydraulmedium påverkar miljön minimalt om ett läckage sker, ett system med monopropylenglykol i vattnet ger väldigt liten påverkan då detta oftast är nedbrutet efter 24h i naturen enligt Dowcal som producerar glykolen. Monopropylenglykol är dessutom giftfri samt har inga påvisade fall av allergi, vilket gör arbetsmiljön och hanteringskostnader betydligt lägre än för hydraulolja. Olja behöver förhöjd temperatur i jord för en acceptabel nedbrytning, och även då tar det förhållandevis lång tid. Livslängden på glidbussningar förekommande i Älvkarleby luckcylindrar har utretts genom en laboration där friktion och nötning studerats med hydraulolja respektive monopropylenglykol med vatten (50/50). Kontakten var glidande rulle mot plan. Dessa tester visar att nötningen är desamma för kompositmaterial mot kromat stål, som testats i de båda medierna. Friktionsvärdet var lägre när man hade monopropylenglykol med vatten som smörjmedel. I fallet med brons mot kromat stål var resultatet detsamma, monopropylenglykol med vatten gav lägre friktionsvärde och återigen gavs samma slitage vid jämförelse av provbitarna som gått i hydraulolja respektive monopropylenglykol med vatten. Slutsatsen är att vattenhydraulik är ett bra alternativ till oljehydraulik, men ingående kunskap om hydraulikens systemkomponenter vid vätskekonvertering är nödvändig. Till exempel om materialen i systemet lämpar sig för konvertering eller behöver bytas ut. / This report puts together the possibilities of water hydraulics. It also compare pros and cons of new adapted systems or when converting existing oil hydraulic systems to water hydraulics. A small comparison of environmental effects from oil and water treated for use in hydraulic systems will be made. A large question concerning water hydraulics is if it has the same durability as oil hydraulics. Another is if you get accelerated wear when you convert an oil hydraulic system to water hydraulics. For hydropower, Water hydraulics is already used for sluice gates. For the operating ring you need very high reliability but water hydraulics should be suiting for this application as well. Pitchcontrol for kaplanrunners is under development, at the moment the swivel on top of the turbineshaft is missing. If you want to convert a kaplanrunner you will also need to change the valves in the hub to get a good reliability. To be able to convert an oil hydraulic system you need to change some components: valves, filters and pumps, these needs to be adapted for water to have a reasonable lifetime. The lifetime is guaranteed to be 8000-10000h for a recently installed water hydraulics system. This is regarding to the pump, which is the part of both water- and oil- hydraulics with the shortest lifetime. If you compare water- with oil- hydraulics they have about the same lifetime. That has always been the goal for the supplier Danfoss development of water hydraulics. A water hydraulic system with pure tap water as pressure media will not affect the environment at all. Systems with monopropylen glycol and water as media will have only a small environmental influence. Monopropylen glycol that has leaked out will be broken down in 24h if it is taken care of in a cleaning plant. In the nature it will take slightly longer according to dowcal who produces the glycol. Monopropylen glycol has no cases of allergy reported, which makes the working environment and handling better than for hydraulic oil. Oil needs elevated temperature and the presence of earth to be able to break down, and still it takes considerable time. The lifetime on sliding bushings existing in the hydraulic cylinders for Älvkarleby hydropowerstation sluice gates have been investigated by laboratory work. Friction and wear was compared with hydraulic oil or monopropylen glycol with water (50/50). The contact was a sliding wheel against a sheet. These tests shows that the wear is equal if you test a composite against chromed steel, with the two different hydraulic medias. The friction was however lower when you tested it with monopropylen glycol and water as lubricant. In the case bronze against steel the results were the same. Monopropylen glycol with water gave lower friction, though the wear was equal between the two medias. The conclusion is that water hydraulics is a good alternative to oil hydraulics, thorough knowledge of the hydraulic components is necessary though. For instance if the materials in the system is suitable for use in water hydraulics, or needs to be changed.