This study focuses on Small scale hydropower in Sweden. This means plants with a capacity of up to 10 MW. The study has a special focus on plants with a capacity up to 2 MW. The study has three aims. It strives to describe the small-scale hydroelectric industry in Sweden.

This master thesis has been performed at Vattenfall Power Consultant in Gothenburg and Trollhättan for Vattenfall Vattenkraft. In this report vacuum circuit breaker in small-scale hydropower stations with the rated power 4 MVA and below has been studied. Models of the stations are modeled and analyzed in PSCAD/EMTDC to study the high voltage transients that are created after current chopping with vacuum circuit breaker. Vacuum circuit breaker may chop the current before it reaches zero value, which means that high voltage transients can be created. The equipment of the stations can be destroyed by high voltage transients.The purpose of this thesis is to examine the use of vacuum circuit breaker in small-scale hydropower stations and the risk for high voltage transients from current chopping.According to the results there is a risk of high voltage transients after current chopping with small synchronous generators in stations with the operating voltages 0.4 kV and 3.6 kV.

Due to historically low prices for electricity in Sweden, many small-scale hydropowerplants were closed down. A small-scale power plant has more or less the samemaintenance costs as larger plants, but doesn?t generate as much income. Today?sincreasing price for electricity in combination with a desire for renewable energysources makes small-scale hydropower interesting again.

This master thesis covers the seasonal planning of a Small scale hydropower system. The system in this study is owned and operated by Mälarenergi Vattenkraft AB. The total system consists of 4 different main rivers with 24 hydropower stations and several dams. The total installed power in the system is 43.75 MW. Most of the hydropower stations are regarded as Small scale hydropower stations and thus entitled to green certificates.In this report the issue of planning is formulated as an optimization problem.

In Sweden there are 1894 small-scale hydropower plants in operation, which together generate 4.3 TWh of electricity per year according to Swedish hydropower compound (SVKF, 2011). This corresponds to the annual consumption of about 860,000 Swedish households (based on an annual consumption of 5000 kWh). In the mid-1950s there were around 4000 small-scale hydropower plants in operation in Sweden before cheap fossil fuels and uranium competed with them, in the current situation only 1,894 of these are in use. If slumbering small hydropower plants once again would be taken into use and some new ones are built, we would be able to extract about 7 TWh of renewable electricity from these annually in Sweden, representing about 1.4 million households.The thesis intends to calculate and construct a hydroelectric power plant at the existing dam in Olofsfors and give suggestions on how the power station should run during the time that fish migration is greatest in Leduån.The turbine and generator to the station in Leduån at Olofsfors is designed by the height of the fall and the water flow through the dam. The turbine selected for the station is a CK-1000RM turbine with a 4-pole 250 kW generator from Cargo & power turbine Sweden AB, which is expected to deliver 1.2 GWh per year.

Small hydropower plants have been an important source for electricity for many years. During the 70?s the general thought was that nuclear was the future. Around 2000 small waterpower plants were shut down. It wasn?t profitable to invest in.

When one experiences a place, it is a complex composition of both social and spatial factors.One of these spatial elements, is scale, which is influenced both by the room size and itsproportions. This paper aims to explore both large and small scale concepts and thus increasethe understanding of how scale directly and indirectly affects the experiences and uses ofurban space.First, is a theoretical discussion of scale in relation to aesthetics and the differencesbetween real scale and perceived scale. Next, is an analysis of spatial perception usingexamples from two existing sites. One, which is understood to have been planned in a largescale and one which is understood to have been planned in a small scale.When preparing this paper, the focus quickly became the importance of scale as itrelates to street spaces. The perception of a street usually takes place while in motion, whichforces it to be perceived in sections.

This master thesis is a study of the Swedish hydropower capacity to balance wind power. The Swedish government has decided that it should be possible to produce 30 TWh from wind power in the year 2020. The Swedish municipalities have to have plans for wind power plants with total yearly generation of 30 TWh. Wind power is an variable energy source that needs to be balanced by other energy sources. In Sweden the Swedish hydropower can be used for balancing a large scale introduction of wind power.

This master thesis is a study of the Swedish hydropower capacity to balance wind power. The Swedish government has decided that it should be possible to produce 30 TWh from wind power in the year 2020. The Swedish municipalities have to have plans for wind power plants with total yearly generation of 30 TWh. Wind power is an variable energy source that needs to be balanced by other energy sources. In Sweden the Swedish hydropower can be used for balancing a large scale introduction of wind power.

This report is focused on marketing opportunities for small-scale mango farmers in the Nyanza Province in Kenya. Kenya is a large horticultural producer in the world. Horticulture is an important income for a large share of the rural population in Kenya but profitability is low due to inefficiencies in marketing systems and poor infrastructure. The conditions for growing mango in the Nyanza Province are very beneficial and there are two harvesting seasons. Mango offers good income opportunities for small-scale farmers in the Nyanza Province.The aim of this study is to identify marketing conditions that will enable prospering business for small-scale mango farmers in the Nyanza Province, Kenya.

Milk yield levels in dairy cows are influenced by many factors such as nutrition, breed, health status, management and environment. This study was conducted among small scale farmers in Zambia, where the climate can be dry for up to six months per year and cause a lack of green pasture for livestock and on-farm produced feed. The purpose of this study was to identify management factors that can influence milk yield at small scale dairy farms in Zambia, and present advice that could improve productivity, without the need of expensive investments. The study included semi-structured questionnaires presented to the farmers (n=29) including questions about cattle management and milk production. Testing of somatic cell count (SCC) with DCC (DeLaval Cell Counter) from herd milk samples (n=56) and observation of housing and animal body condition on-farm was also made.

This master thesis was made to validate hydropower models of a turbine governor,Kaplan turbine and a Francis turbine in the power system simulator ARISTO atSvenska Kraftnät. The validation was made in three steps. The first step was to makesure the models was implement correctly in the simulator. The second was tocompare the simulation results from the Kaplan turbine model to data from a realhydropower plant. The comparison was made to see how the models could generatesimulation result that was similar to the reference power station.

Vattenfall AB is a large producer of electric energy where approximately half of the energy comes from hydropower. Vattenfall Hydropower has got almost a 100-year old history and the company has developed a lot since 1909. After that the number of power plants increased and the competition got more intense, there were higher demands on the reliability. One way to secure the reliability with a good satisfaction at the power plants is to implement a maintenance method named Reliability-Centred Maintenance. RCM is a result of the introduction of the complex aeroplane Boeing 747 in the 1960?s.

Assessing and measuring post-operative pain in all animals is a challenge, but doing it in small mammals, for example guinea pigs, presents an even larger difficulty. Validated pain scales developed for use in dogs in clinical practice are currently available, but no such scale has been widely accepted for use in guinea pigs in the veterinary setting. In this experimental study, six guinea pigs that had undergone surgery and anaesthesia were observed for behavioural changes that could be associated with pain. The six guinea pigs were also given pain scores with the use of Colorado State University Feline Acute Pain Scale (CSU-APSF), a scale which uses both behaviour when not handled, body tension and response to palpation to evaluate pain intensity. The six guinea pigs showed a number of different behaviours, for example rigid posture, fixed stare and ?wet dog response? (the body is vigourosly shaken), that could be associated with pain.

As a small and land scarce country, effective waste management is ofoutmost importance in Singapore. In this study the production of biogasthrough anaerobic digestion from the organic fraction of municipal solidwaste (OFMSW) was compared to incineration of the waste. At the momentalmost all of the OFMSW in Singapore is incinerated. Three differentscenarios were compared to the reference scenario (incineration): one with alarge scale biogas plant that can treat half of all OFMSW in Singapore, onewith a medium scale biogas plant about 15 times smaller than the large oneand one with a small scale biogas plant that can treat waste from e.g. ashopping center or a food center.By using life cycle assessment (LCA) the different scenarios were comparedin terms of global warming potential (GWP), acidification, eutrophication,energy use and land use.