Abstract: The sun’s free, zero-emissions energy produces no household air pollution, preserving the environment as people cook food and pasteurize drinking water. In recent years, much experience has been acquired with the solar cooking systems described. In present work a review has been made to study conducted researches in the field of solar cookers. Experimental, theoretical, numerical analyses are included to compare operation and efficiency of solar cookers. Also the article reviews and summarizes findings of conducted researches on factors influence solar cooker use rates.

Abstract: The intermittency is inherently affects the solar energy as the main hot water supplier in renewable systems. Therefore, the storage of the hot water is a vital part of a reliable energy supply system for buildings. Using a proper storage system makes it possible to fill the shortfall or emergency periods. This paper studies the daily thermal performance of a horizontal solar storage tank. It is assumed that the hot water load is similar to the Rand profile and the auxiliary heater is a biomass-fired boiler. The Rand profile assumes a daily hot water of consumption of 120 liters for a family of four. Furthermore, the tank is considered to be fully mixed because its height is relatively low. It means that the temperature in the solar zone of the tank is uniform. This assumption simplifies the analysis because the storage and the load temperature would be the same. The profiles for the storage water temperature, solar fraction and the useful energy gain was obtained and the effects of principal parameters are studied.

Abstract: Increasing of word demand load is caused a new Distributed Generation (DG) enter to power system. One of the most renewable energy is the Wind Energy Conversion System (WECS), which is connected to power system using power electronics interface or directly condition. In this paper an optimal Lead-Lag controller for wind energy conversion systems (WECS) has been developed. The optimization technique is applied to Lead-Lag optimal controller in order to control of the most important types of wind system with doubly Fed Induction Generator is presents. Nonlinear characteristics of wind variations as plant input, wind turbine structure and generator operational behavior demand for high quality optimal controller to ensure both stability and safe performance. Thus, Honey Bee Mating Optimization (HBMO) is used for optimal tuning of Lead-Lag coefficients in order to enhance closed loop system performance. In order to use this algorithm, at first, problem is written as an optimization problem which includes the objective function and constraints, and then to achieve the most desirable controller, HBMO algorithm is applied to solve the problem. In this study, the proposed controller first is applied to two pure mathematical plants, and then the closed loop WECS behavior is discussed in the presence of a major disturbance. Simulation results are done for various loads in time domain, and the results show the efficiency of the proposed controller in contrast to the previous controllers.

Abstract: The computational interface for hydropower plants was developed with Microsoft Visual Studio 2010 and tested using some available data from Jebba hydropower station to validate its functionality due to non availability of data for small hydropower plants which the interface is designed for. Hitherto several other methods have been used in hydropower computation, these methods range from manual computation with the use of pen and paper to the use of Microsoft Excel spreadsheet, some others utilize Visual Basic to commercial software. This interface was designed to compute flow duration values, plant capacity, power duration and the available energy. The program also have the project report feature, where user can view a concise report of the computation, save and print report sheets.

Abstract: Energy is basic need for growth of any country. The world energy demand is increasing so rapidly because of increases in industrialization and population that limited reservoirs will soon be depleted at the current rate of consumption. Both the energy needs and increased environmental consciousness have stimulated the researching of an alternative solution. So an attempted has been made to investigation of biodiesel production using transesterification reaction with solid or heterogeneous catalyst at laboratory scale and to compare the physical properties with the standard biodiesel properties. The selected process parameters are temperature ranged from 318 K to 333 K, molar ratio of methanol to oil from 4:1 to 8:1, mass ratio of catalyst to oil from 3% to 5% and rotation speed at optimum biodiesel yield was produced at 600 rpm.