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This paper mainly focuses on the design of solar concentric parabolic cooker with proper arrangement of phase change material (PCM) heat storage system. The receiver is a hollow concentric cylinder with inner and outer radii being 0.09 m and 0.1 m, respectively. The thickness or the gap between the two layers of the receiver is 0.01 m and is filled with heat transfer oil. The outer layer of the receiver is surrounded by the vertical cylindrical PCM tubes of diameter 0.025 m. The three modes of heat transfer, radiation, convection, and conduction, are explained and analyzed by heat transfer network. The schematic view of the receiver is shown with the help of sketchup software. The performance parameters, heat loss factor, optical efficiency factor, cooking power of the solar cooker, were calculated with and without PCM in the receiver. 7.74 W m-2 and 2.46 W m-2 are the heat loss factors, and 0.098 and 0.22 are the optical efficiency factors of the solar cooker without and with PCM presented in the receiver. The optical efficiency factor of the solar cooker with PCM receiver is two times more than that receiver without PCM. The cooking power of the solar cooker with PCM receiver is 125.3 W which is 65.6 W more than that of the cooking power without PCM receiver. From these results, it can be concluded that the design of PCM solar cooking system can expand the applicability of solar cookers as a compatible cooking solution for cooking applications instead of using fossil fuel based cooking systems. [ABSTRACT FROM AUTHOR]

Hydrogen and Compressed Natural Gas are great alternatives to the pure fossil fuels. Many researches confirm the advantages of using hydrogen and natural gas blended together for the internal combustion engine in both areas of improving performances and reducing emission levels. In a short to medium range terms, the air pollution throughout the globe could be significantly reduced by using HCNG in the internal combustion engine and in many other applications with the substitution of using HCNG as a main source of fuel or as a secondary source of fuel such as the dual fuel operation system in the diesel vehicle. This paper investigates the emission characteristics of using HCNG as a secondary source of fuels on a EURO 4 diesel vehicle with four cylinders of 2494 cc displacement D4D commonrail direct injection diesel engine comparing to the original diesel operation with diesel and HCNG blended dual fuel operation. The experiments were conducted with minimum pilot diesel injection into the engine and maximum additional HCNG into the engine with using H2 electrolyzer for hydrogen supplies. In this experiment, the pilot diesel and HCNG blended were operated with special designed closed loop stepping motor diesel to CNG dual fuel system and hydrogen electrolyzer for the internal combustion engine. The results indicated that the average CO emission decreased by 12.97%, HC emission decreased by 15.84%, NOx emission decreased by 1.16% and PM emission decreased by 9.14% with the diesel HCNG dual fuel mode comparing to the pure diesel operation from low RPM (800) to highest RPM (4000). [ABSTRACT FROM AUTHOR]

Abstract: Most of the literatures related to university–industry (U–I) and technology transfer assume that the collaboration particularly the U–I joint research is beneficial to both university and industry which as a result underpins the sustainable development of economics and living standards of developed and developing countries. The U–I joint research for photovoltaic technology transfer in a developing country like Thailand should have been increased considering the fact that (i) the government implemented various strategies to support the renewable energy research and market development, (ii) the university aimed to be “research-based university and (iii) the Thai photovoltaic industry struggle for competitiveness and survival in the global market. However, evidence revealed that the university and industry conducted little number of U–I joint projects. In this paper, we investigate the factors influencing the effective U–I joint research for photovoltaic technology transfer (UIJRPTT). In an attempt to better understand the influence of the factors, the path model with factors related to characteristics and perspectives of the university and the industry as well as joint research mechanism and their linkages to higher growth and improved economic and quality performance of the U–I joint research is developed and validated. The developed model empirically explains interaction between the factors and the outcome factors and can assist the government, the university and the industry to devise target strategies to improve the growth and performance of UIJRPTT. [ABSTRACT FROM AUTHOR]

This paper presents a fuzzy logic based algorithm developed to bring smart functionality to an ordinary PV-battery system in order to maintain the grid voltage stability of the 22 kV distribution system in Thailand. This research focuses on minimizing grid voltage fluctuations by converting a typical PV system into a smart PV-battery system (SPVs-BSS). A SPVs-BSS will be able to control the electrical power from a PV system to maintain the grid voltage in case of unexpected events or emergencies. Grid support functions such as a variable reactive power control and active power control will be discussed, leading to strategies for charging and discharging the battery system in response to the status of grid voltage. Fuzzy Logic was used to develop this control algorithm, which is named the Voltage Stability Fuzzy Logic Algorithm (VSFL Algorithm). The methodology of this research consists of three parts. First, testing the grid inverter operated on grid support functions. Second, the VSFL algorithm was developed to manage both the grid inverter and the battery system. Third, a SPVs-BSS equipped with the VSFL algorithm was simulated by using DIgsilent PowerFactory software. Results showed that the SPVs-BSS equipped with the VSFL Algorithm successfully maintained grid voltage in target range. [ABSTRACT FROM AUTHOR]

Energy from the sun is harnessed through a photovoltaic (PV) array in form of DC. This available DC voltage is converted into AC for industrial or domestic use as per the requirement. In some topologies the extracted DC voltage is stepped up to a higher level of DC using a boost or a buck-boost converter and then this stepped up DC voltage is converted into AC by the use of an inverter. However this process is pretty costly because of the larger number of components employed. An efficient alternative to this two-stage approach is the Single-Stage Inverter (SSI). SSI does the boosting of DC and inversion of the DC to AC using only a single circuit and hence the name Single-Stage Boost Inverter. SSBI give us the advantage of reduced and robust circuitry along with reliability and efficiency. This paper presents a review of the various (however not all) SSI topologies in PV systems. [ABSTRACT FROM AUTHOR]

Renewable energy sector is undergoing rapid expansion as the global focus is shifting towards cleaner, reliable and sustainable resources. As the new installation of these resources are well underway, there is tremendous potential for exploring these to more advanced control algorithms. Model predictive control is gaining immense popularity because of its flexible controllability, its ability to be used in any of application irrespective of its field as well as the availability of fast processors. This paper presents a systematic review on Photo-voltaic (PV) and wind energy systems controlled by Model predictive control approach. The work presented here will help the researchers to further explore the flexibility of this controller for design, analysis and implementation in renewable energy systems. [ABSTRACT FROM AUTHOR]

Soft Computing (SC) methods are emerged as an alternative approach to conventional techniques for Grid connected Photovoltaic (PV) system because of their ability to solve the complex non-linearity problems. Soft Computing (SC) techniques are developed to handle the adverse environmental conditions such as sudden change in temperature and irradiation which are not addressed by conventional methods. The main focus of this paper is to summarize the application of various SC techniques which apply to different stages of a grid connected PV system such as panel reconfiguration, Maximum Power Point Tracking (MPPT) technique in the converter, Harmonic elimination in inverter and islanding detections. Furthermore, the comparison is made on the performance of SC methods based on several conditions, namely convergence, algorithm complexity, real time implementation, System dependency, Periodic tuning and Oscillations around the operating point. It is envisioned that the information provided in this paper is intended to serve as a valuable reference for future research in grid connected PV system. [ABSTRACT FROM AUTHOR]

Multiphase interleaved boost DC–DC converters are typically used as a fuel cell power conditioner due to their low input ripple current. This paper presents analysis and design of a 2-phase interleaved boost DC–DC converter controlled by a single chip DSP to enhance reliability and flexibility. The PI regulator for the output voltage control was tuned by the extended symmetrical optimum method to optimally operate in the fuel cell ohmic region with a guaranteed phase margin of 45° for the entire fuel cell voltage range. The set point weighting technique was used for soft starting, which was effective. The effects of switching and sampling time delays were analysed and compensated. Experimental results of the 1-kW, 120-V prototype converter connected with a PEM fuel cell stack closely agreed with simulation results in MATLAB/Simulink. The DSP-based fuel cell converter has the potential for further development as a compact fuel cell generator or fuel cell electric vehicle with embedded online diagnosis and fault-tolerant operation. [ABSTRACT FROM AUTHOR]

With ever-increasing demands for energy and gradual climate changes, development and advancements of renewable energy have become a major priority of every country. The applications of renewable energy increase many folds when coupled with wireless power transfer (WPT) technology. About a century ago the advents of Tesla provided us with the principles of WPT. Since then a lot of research has been done in this field. Many efforts have been put to transmit power of renewable energy wirelessly. In this paper, the basic principles and various methods of WPT are reviewed and also discuss the recent developments in wireless transmission of renewable energy. An update for application and limitations of WPT has been presented. The possible systems produced with the coupling of WPT are also presented. [ABSTRACT FROM AUTHOR]

Heat batteries show outstanding charging and discharging thermal energy capability with the latent heat of fusion (H m) for solar thermal application. In this work, novel magnesium nitrate hexahydrate (MNH) based heat batteries are fabricated and tested for 1000 sequential thermal cycles. The MNH heat batteries demonstrate a high level of operational stability with the least corrosive rate. Real-time performance of the heat batteries was studied by incorporating them in the parabolic solar thermal cooking module. The developed MNH heat batteries based solar cooking module illustrates excellent heat retention capacity over 6 h after the sunshine. Temperature profiles under no load and full load conditions reveal the moderation and enhancement in the solar thermal cooking module's operational efficiencies. The solar cooking module's efficiency with the heat batteries reaches a maximum of 22.8% and 42.5%, under no load and full load conditions, respectively. Real-time cooking capacity with different edible materials under both outdoor and indoor environments proves the effective performance. Further, it is estimated that MNH heat batteries can be in full performance for a minimum of 2 years with maintenance-free and emission-free operations. [ABSTRACT FROM AUTHOR]