Field and laboratory measurements characterize the performance of vertical axis hydrokinetic turbines operating in uniform and non-uniform inflow conditions for river applications. High sampling frequency velocity measurements, taken at 200 Hz upstream of a stopped and operating 25-kW H-type vertical axis hydrokinetic turbine in the Winnipeg River, show the existence of large eddies with an order of magnitude of the turbine’s diameter. Scaling laws allow modeling river conditions in the laboratory for more detailed investigations. A small-scale, 30 cm diameter, squirrel-cage vertical turbine designed, manufactured and equipped with a torque and position sensors is investigated for the detail behavior of the turbine subjected to different inflow conditions in a laboratory setting to study the effect of flow and fluid structures. The adjustable design of the laboratory turbine enables operations with different solidities, 0.33 and 0.67, and preset pitch angles, 0°, ±2.5°, ±5° and ±10°. Tests are first performed with uniform inflow condition to measure the sensitivity of the turbine to solidity, preset pitch angle, free-surface, and Reynolds number to obtain the optimum operating conditions. During the free-surface testing a novel dimensionless coefficient, clearance coefficient, is introduced that relates the change in turbine efficiency with change in the free-surface height. High-speed imaging at 500 fps of semi-submerged blades visualizes the vortex-shedding pattern behind the blades and air entrainment. High-speed imaging results of large eddy pattern behind the vertical turbine are consistent with theory and measurements. Subsequently, cylinders of different diameters create non-uniform inflow conditions in the water tunnel by placing them at different longitudinal and lateral locations upstream of the model turbine. Thus, the effects of non-uniform inflow generated under controlled settings shows the impact of eddies and wake on the turbine performance. High sampling frequency measurements of torque and position at 683 Hz enables investigating the impact of flow variations on turbine performance in the frequency domain. These results are also useful for fatigue analysis. Finally, entrained air bubbles in the flow—in river and laboratory settings—affect turbulence quantities, as measured using an acoustic Doppler velocimeter, and successfully addressed by implementing a new hybrid filter developed for this application.

The cost of grid based electrical and diesel sea water pumping to salt fields is one of the major cost components out of the total production cost in Puttalam Salt Limited, situated in northern part of Sri Lanka. In order to explore ways and means to improve the energy efficiency and alternative resources to meet the energy requirement a feasibility study was conducted using power system simulation software, (HOMER) and also detailed technical, environmental and financial tools.    This research study is conducted to evaluate the performances and applicability and propose the most suitable sustainable renewable energy source and methodology for water pumping to salt fields instead of currently utilized grid based and fossil fueled energy supply.   Preliminary results obtained by simulation software shows that direct wind mill pumping and solar PV water pumping was found to be unfeasible due to its limited pumping capacity and high investment cost. More over solar PV does not seems much feasible due to its high cost of energy (0.234 US $/kWh) compared to wind powered rivals in this type of applications.   Based on comparisons of the analysis it is seen that the wind/ grid combined configuration of 04 units of AOC15/50 model (50kW manufactured by AOC Renewable Energy - Canada) wind turbine units with 150kw inverter seems to be a logical supplement for water pumping energy requirement than using grid based electricity which costs 0.201 US $/ kWh. The solution in this research affords an attractive 60% annual average renewable fraction as well as an approximate 215.8 tCO2(eq) of annual Carbon Footprint saving. Also it assures a moderate Discounted Payback Period of 6 years and 5months with a 15% of Internal Rate of Return.

Field and laboratory measurements characterize the performance of vertical axis hydrokinetic turbines operating in uniform and non-uniform inflow conditions for river applications. High sampling frequency velocity measurements, taken at 200 Hz upstream of a stopped and operating 25-kW H-type vertical axis hydrokinetic turbine in the Winnipeg River, show the existence of large eddies with an order of magnitude of the turbine’s diameter. Scaling laws allow modeling river conditions in the laboratory for more detailed investigations. A small-scale, 30 cm diameter, squirrel-cage vertical turbine designed, manufactured and equipped with a torque and position sensors is investigated for the detail behavior of the turbine subjected to different inflow conditions in a laboratory setting to study the effect of flow and fluid structures. The adjustable design of the laboratory turbine enables operations with different solidities, 0.33 and 0.67, and preset pitch angles, 0°, ±2.5°, ±5° and ±10°. Tests are first performed with uniform inflow condition to measure the sensitivity of the turbine to solidity, preset pitch angle, free-surface, and Reynolds number to obtain the optimum operating conditions. During the free-surface testing a novel dimensionless coefficient, clearance coefficient, is introduced that relates the change in turbine efficiency with change in the free-surface height. High-speed imaging at 500 fps of semi-submerged blades visualizes the vortex-shedding pattern behind the blades and air entrainment. High-speed imaging results of large eddy pattern behind the vertical turbine are consistent with theory and measurements. Subsequently, cylinders of different diameters create non-uniform inflow conditions in the water tunnel by placing them at different longitudinal and lateral locations upstream of the model turbine. Thus, the effects of non-uniform inflow generated under controlled settings shows the impact of eddies and wake on the turbine performance. High sampling frequency measurements of torque and position at 683 Hz enables investigating the impact of flow variations on turbine performance in the frequency domain. These results are also useful for fatigue analysis. Finally, entrained air bubbles in the flow—in river and laboratory settings—affect turbulence quantities, as measured using an acoustic Doppler velocimeter, and successfully addressed by implementing a new hybrid filter developed for this application.

This thesis is a documented energy audit and long term study of energy and water reduction in a ghee factory. Global production of ghee exceeds 4 million tonnes annually. The factory in this study refines dairy products by non-traditional centrifugal separation and produces 99.9% pure, canned, crystallised Anhydrous Milk Fat (Ghee). Ghee is traditionally made by batch processing methods. The traditional method is less efficient, than centrifugal separation. An in depth systematic investigation was conducted of each item of major equipment including; ammonia refrigeration, a steam boiler, canning equipment, pumps, heat exchangers and compressed air were all fine-tuned. Continuous monitoring of electrical usage showed that not every initiative worked, others had pay back periods of less than a year. In 1994-95 energy consumption was 6,582GJ and in 2003-04 it was 5,552GJ down 16% for a similar output. A significant reduction in water usage was achieved by reducing the airflow in the refrigeration evaporative condensers to match the refrigeration load. Water usage has fallen 68% from18ML in 1994-95 to 5.78ML in 2003-04. The methods reported in this thesis could be applied to other industries, which have similar equipment, and other ghee manufacturers.

The proposed Sustainable Energy Model is based on rice husk and the development of briquettes made from agricultural waste, which will increase efficiency in the domestic sector, and potentially replace conventional polluting fuels such as firewood. Large volumes of rice husks from millers are found scattered in rural agricultural areas of the San Martin region of Peru, where people are exposed daily to the emissions of polluting gases produced by burning these wastes, causing respiratory and lung diseases. Despite present circumstances, this waste has a great energetic potential that is not yet used by society, representing an opportunity to encourage socioenvironmental development and generate added value to the husk. Based on a compaction and drying process, briquettes were obtained with 4,040 kcal / kg of heat power and 80.39% combustion efficiency, allowing the little use of biofuel compared to firewood, and consequently, the utilization of this biofuel would reduce levels of deforestation. In contrast to similar projects, the sustainability of an energetic model of briquette production will be achieved when economic, environmental and social aspects are met, developing clean technologies and an efficient supply chain, from the supply of the husk to the commercialization of briquettes

Low levels of energy access in sub-Saharan Africa and the acknowledgement of anthropogenic climate change have made sustainable energy products such as solar lanterns and efficient cookstoves a popular subject of international development programmes. At the same time, market-based approaches for distributing such ‘humanitarian goods’ have become increasingly prevalent. Based on ethnographic material from inside two development intermediaries, Global Village Energy Partnership (GVEP) International’s ‘Developing Energy Enterprises Project’ (DEEP) in Kenya and Uganda and SolarAid’s social enterprise ‘SunnyMoney’ in Malawi, this thesis argues that: 1) the complexity of applied market devices enhances inequalities between market actors; 2) the engendering of economic subjectivities within distribution chains can increase value-sharing; 3) there is space for both for-profit and non-profit ‘development’ intermediaries in marketisation processes, and; 4) further focus should be put on the promotion of domestic manufacturing. Stabilised market maps are used to present the activities of each organisation before turning to three frames of analysis that consider the problematisation, qualification and valuation of the energy products, the recruitment and training of supply chain ‘entrepreneurs’ and the specific market roles of development intermediaries, including provision of ‘brokerage’ services and as integral market actors. Bringing a theoretical vocabulary from economic sociology and science and technology studies into the arena of international development, the thesis reveals the extensive socio-technical configurations that constitute markets and create power asymmetries between actors. Without neglecting the vulnerabilities of the ‘bottom of the pyramid’ (BOP) as a ‘target group,’ it enhances our understanding of the shifts away from charity dependent beneficiaries’ towards ‘entrepreneurs,’ ‘customers’ and investment opportunities within sub-Saharan Africa.

This research considers the motivating factors behind energy use in the residential sector, which in 2011 accounted for more than 26% of overall energy use in the UK. The study took a mixed method approach and considered case studies in both the UK and Australia, two countries with very different energy regimes. UK case studies were analysed using predictive energy modelling, quantitative assessment of actual energy use and thermal comfort, and qualitative interview and focus group assessment of individual motivation around energy use. The Australian case studies were assessed qualitatively and their attitudes compared to the UK core group. Additional perspectives were gained through interviews with UK landlords, a large environmental group, a senior politician, and two senior policymakers from a large energy company. The investigation assesses the implied importance of the key strands developed from previous research in instigating changes in behaviour amongst occupants. These include psychological, social, financial, educational and regulatory factors. In particular, it looks at the ineffectiveness of the Green Deal on energy behaviour in the residential sector. The research offers a reasoned explanation as to why it is important to record predictive, actual, and intended behaviour with regard to energy use. The study concludes that a variety of incentives are necessary to encourage behaviour change, and that the complexity of occupant behaviour makes it difficult to develop a single policy to encourage more sustainable energy use. There is sometimes a disconnect between intention and behaviour. However, there seems to be a certain commonality among the occupants, in that their behaviour around energy is often other than predicted by conventional economics and more likely to incorporate predictions from behavioural economics. This is recognised by the case study participants in both the UK and Australia, and they largely agree on the beneficial role of government in regulating them and "nudging" them in the right direction with regard to influencing their motivations around energy use. Financial incentives are also a key driver in motivating residents to use energy more sustainably, but they need to be carefully aligned to suit a wide range of individuals. Another issue that became clear in the research is that policy focusing purely on energy efficiency can be ineffective, if the policy goal is to mitigate the effects of climate change. The rebound effect is likely to result in a lower demand for residential energy transferring to increased demand for energy elsewhere in the economy. The study recommends that policy should focus on sustainable energy use, using financial and other mechanisms to discourage the use of fossil fuels.

Wind energy is identified a promising energy resource in Sri Lanka. Therefore, it is important to use proper technologies for efficient energy capturing in order to minimize cost of energy. Small scale wind turbines are usually installed in constricted places (particularly in urban areas) where wind flow is turbulent and difficult to predict. Savonious type vertical axis wind turbines are important due to several reasons such as good response to turbulent winds, high initial torque, low cost, low noise, less maintenance.In this study, a modified flat plate type Savonius wind rotor was proposed to cost effectively harness wind energy in constricted places. Generally, vertical axis wind turbines (VAWT) are less efficient than horizontal axis wind turbines, one reason behind this issue is wind force difference between the 2 sides of the axis is small and due to this reason torque is small and power generation capacity is less.A prototype of the proposed VAWT was fabricated and the performance was determined by acquiring experimental data. Artificial wind blow which was generated by a huge fan was used to measure rotational speed and torque characteristics at varying wind speeds. Data were collected with 1-second sampling time and a data acquisition system was developed under this study. In the proposed design one side of the turbine blades are facing the wind direction in order to capture maximum force while other side is edging the blades to have minimum opposite torque. With this concept it is expected to maximize the torque of the axis and generate more power. A sort of a passive pitch mechanism is therefore utilized in order to save energy and simplify the system. Turbine blades are simple flat plates and it eliminates usage of complex aero foils. Due to the simplicity of this design it would be possible to use this turbine for domestic electricity generation at affordable costs.Nowadays, net metering systems are being promoted in Sri Lanka and it would be beneficial to introduce low cost VAWT which operates at low winds as well as turbulent wind conditions. Based on typical household hourly load profile, viability of proposed vertical axis wind turbine was evaluated by considering rural and urban wind regimes in Sri Lanka. The costs of wind energy at two selected locations were determined in the context of net metering.

Recent literature has shown a close correlation between economic prosperity and the intensity of energy use in a country. In this study, an investigation to determine the extent of evolution of the concept of sustainability in the energy industry to realise the aim of Kenya Vision 2030 development blueprint is presented. In this study, journals, government reports, statutes and policies dating back to the end of the eighteenth century were reviewed to establish the research gap. Interviewing of key stakeholders in the energy industry a survey of rural, peri-urban and urban households on energy use and supply in the country and a geographical information system were methods used for data analysis. The study findings revealed that; the current energy policies are a legacy of colonial policies which benefit the urban and commercial centres along the railway line; the current policies are skewed to promoting electricity and petroleum sectors in energy industry and; biomass is the main source of fuel for rural and peri-urban households and, increased household energy demand has a negative impact on environment. In light of these findings, the practice of energy use and policies have to evolve significantly so that the aim of the Vision 2030 has to be realised. Therefore, this study is an innovative, analytical and methodological approach to sustainable energy use and policy assessment for developing countries. The study also makes contribution to the body of knowledge in the field of sustainable energy use and policies for developing countries by literature publication.

Temos aktualumas. Šiuo metu klimato kaitos problemos užima vis didesnę reikšmę ES bei pasaulinėje aplinkosaugos ir energetikos politikoje. Vis akivaizdžiau pasireiškianti klimato kaitos problema, kelia didelį susirūpinimą visame pasaulyje, o jos sprendimui būtinos visuotinės pastangos. Žengiant link tobulesnių technologijų, gamybos plėtros, ekonomikos vystymosi yra susiduriama su vis sudėtingesnėmis problemomis, kurios daro didelį neigiamą poveikį aplinkai ir kelia grėsmę žmonių sveikatai. Energijos gamyba ir jos naudojimas turi ypač didelę įtaką aplinkos kokybei: vietinių energijos išteklių naudojimas ir išeikvojimas, atliekos, miškų iškirtimas, vandens ir oro tarša, rūgštūs krituliai, dirvožemio suardymas, klimato atšilimas – visa tai energijos naudojimo ir jos plėtros padarinių pavyzdžiai. Energetika yra labai svarbi šiuolaikinei ekonomikai, nes energijos tiekimo sutrikimai galėtų visiškai sutrikdyti žmonijos gyvenimą. Tačiau nuo jos priklauso ne tik gamyba, infrastruktūros funkcionavimas, bet ir aplinkos kokybė, nuo kurios priklauso ir mūsų sveikata. Problemos ištyrimo lygis. Nors teršalų išmetimas į aplinką Baltijos šalyse yra sumažėjęs, tačiau taršos problema yra vis dar aktuali ir su ja yra kovojama. Daugelyje pasaulio šalių atsinaujinančiųjų energijos išteklių naudojimas energijos gamyboje duoda puikius rezultatus, kovojant su šia problema. Baltijos šalyse taip pat pastebimi teigiami pokyčiai, tačiau šiose šalyse šių išteklių skatinimo priemonės nėra pakankamai... [toliau žr. visą tekstą] / Today global warming is a worldwide problem that requires global solutions and the main cause of this problem is inefficient usage and making of energy. Sustainable energy means solving all social, economical and environmental problems in ways that support human development over the long term. Current energy system deals with many aspects of unsustainability and energy efficiency and intensity, increasing the share of renewable energy in the energy balance, researches and development of new technologies, energy pricing, reducing Carbon Dioxide emissions, cleaner fuels, subsidization and internalization of externalities and market opening are the main targets of sustainable energy development. Even though all three Baltic States have implemented similar policies and measures helping to reduce GHG emissions but the results are different. And this is mainly because of differences between those three countries: in size, primary energy mix, and in final energy consumption. The object of this work is support mechanisms for climate change mitigation. The main aim is to evaluate the preferences of the potential energy consumers by choosing instruments for the promotion of green energy and by choosing the way energy power is being produced. Research lasted 30 days, from the 3 of April till the 2nd of May. 330 people were questioned in supermarkets: “Mega”, “Savas” and “Akropolis”. There are slightly more respondents who would rather use atomic energy than energy produced by using... [to full text]