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[en] The difficulty of exploiting energy without damaging the environment is a highly discussed topic. The lack of energy (electricity) is actually an issue of nature preservation and it is also an obstacle. One solution to these problems is renewable energy, which affects the environment less. However, these energies are sometimes infeasible due to its high costs, by the potential energy generated that in most cases is not sufficient enough to enable them economically. However, there are some of them that have an acceptable power generation, as is in the case of hydrokinetic energy. There are many ways of taking advantage of this type of energy, some of them costly, some very complex and others still in development and/or unprecedented as is the case with 'Hidropolio', presented in this article. This article describes the equipment and its operating principle and also presents the results obtained in laboratory tests at the National Center of References of SHPs - CERPCH (Centro Nacional de Referencias em Pequenas Centrais Hidreletricas- CERPCH) at the Federal University of Itajuba - UNIFEI, whose results proved quite promising, mainly for use in sections of shallow river and low speeds.
[en] Energy is essential for sustenance of life in the biosphere. This article covers biomass gasification and highlights the need of bioenergy for electricity generation covering its potential in India and power scenario in the world. Finite energy resources will get consumed in the near future. And bioenergy is essentially renewable or carbon neutral. For electricity generation, the biomass is required to be upgraded in terms of more easily handled fuels, namely gases, liquids, and charcoal using various technologies such as pyrolysis, gasification, carbonization, digestion, fermentation, etc. Biomass gasification is the renewable energy options of future energy and has potential in electricity generation from biomass. (author)
[en] In restructured and de-regulated power systems, generating companies (Gencos) are responsible for supplying electricity for both energy and reserve markets, which usually operate simultaneously. In this condition, the question is how much and for what price must each Genco generate for each market to maximize its profit, so this paper intends to answer to this question. In this paper, first, the combined energy and reserve markets are considered, and the Nash equilibrium points are determined. Then, the bidding strategies for each Genco at these points will be presented. The bids for the energy and 10 min spinning reserve (TMSR) markets are separated in the second stage, and again, the bidding strategies for each Genco for the two separated markets will be demonstrated. Comparison of the results shows that the separated bidding strategies, while being simplified with the algebraic optimization model and reducing the time consumed, give the same results as the combined ones. The Western System Coordinating Council (WSCC) nine bus test system is employed to illustrate and verify the results of the proposed method. (author)
[en] Clean and renewable energy technologies using ocean energy give us non-polluting alternatives to fossil-fueled power plants as a countermeasure against the global warming and growing demand for electrical energy. Among the ocean energy resources, wave power takes a growing interest because of its enormous amount of potential energy in the world. Therefore, various types of wave power system to capture the energy of ocean waves have been developed. However, suitable turbine type is not normalized yet because of relatively low efficiency of the turbine systems. The purpose of this study is to investigate the performance of a newly developed direct drive hydro turbine (DDT), which will be built in a caisson for wave power plant. Experiment and CFD analysis are conducted to clarify the turbine performance and internal flow characteristics. The results show that the DDT obtains fairly good turbine efficiency in both cases of with wave and no wave conditions. As the turbine performance is influenced considerably by the wave condition, designed point of the turbine should be determined according to the wave condition at an expected installation site. Most of the output power generates at the runner passage of the Stage 2.
[en] We developed an electrostatic micro power generator for low-frequency energy harvesting applications. This micro power generator consists of a new vibration structure and a new electret structure (stripe masked electret). The advantage of this micro power generator is the high power generation structure of both the controlled gap between electrodes and long-range movement at low frequency. This generator shows 40 µW of power output at very low frequency vibration (2 Hz, 0.4 G)
[en] Power which is scaled using "2"5"2Cf source conversion method, is an important benchmark experimental date in CFBR-Ⅱ reactor. The principle of the experiment of scale was introduced, and the power of measurement results was discussed. The factors which mainly affect the results of measurement are energy 'corresponding gently' and 'point source' assumed correct, and they were fully considered in the experiment. Through the power scale experiment, different indications at corresponding typical power level were obtained. The synthetic standard uncertainty of using the "2"52"Cf source conversion method to scale power is 7%. (authors)
[en] The biogas sector has never before aroused so much attention as it does today. Elected officers and investors' interest has been fired by the gradual introduction of regulatory restrictions on the treatment of organic waste and the renewable energy commitments recently made by the European Union Member States. The biogas sector is gradually deserting its core activities of waste cleanup and treatment and getting involved in energy production, with so much enthusiasm that in some countries its scope of action has extended to using energy crops. Across the European Union, the sector's progress is as clear as daylight, as in 2009, primary energy growth leapt by a further 4.3 per cent. (author)
[en] The changing structure of the electric power industry is bringing wheeling costing into a new focus. In a competitive market environment, deregulation of the electricity industry and transmission open access make it even more important to fairly allocate the cost of transmission service. Consequently, the power tracing which determines the contributions of individual generators to individual line flows and individual loads becomes more and more important. The proposed method can deal with the problem of reactive power decomposition without any restrictions, even convection lines are considered. Moreover, the proposed method provides possible allocation of line loss to individual generators or loads. An equivalent nominal-T line model replacing the nominal-p model for reactive power decomposition is presented as well. The Graph technique and Proportional Sharing principle are employed for determination of power-tracing sequence and power decomposition. Active power contribution of generators to lines and loads as well as reactive power contribution of generators and lines to loads are calculated. To demonstrate the effectiveness of the proposed method, an IEEE 30-bus system is applied. (author)
[en] The Bacterial Flagellar Motor is a rotary molecular machine that rotates the helical filaments which propel swimming bacteria. Extensive experimental and theoretical studies exist on the structure, assembly, energy input, power generation and switching mechanism of the motor. In our previous paper, we explained the general physics underneath the observed torque-speed curves with a simple two-state Fokker-Planck model. Here we further analyze this model. In this paper we show (1) the model predicts that the two components of the ion motive force can affect the motor dynamics differently, in agreement with the latest experiment by Lo et al.; (2) with explicit consideration of the stator spring, the model also explains the lack of dependence of the zero-load speed on stator number in the proton motor, recently observed by Yuan and Berg; (3) the model reproduces the stepping behavior of the motor even with the existence of the stator springs and predicts the dwelling time distribution. Predicted stepping behavior of motors with two stators is discussed, and we suggest future experimental verification.