Advanced Materials Research Vols. 860-863

Abstract: This paper shows photovoltaic (PV) power generation systems in Nagaoka University of Technology. On the basis of acquired data, installation angle of PV module and effect of sunlight reflection in winter are examined. Consequently, it is cleared that there is the optimum angle for each season, and the reflection against snow is very effective for the PV power generation. The angle usually depends on the latitude of location, but taking account of this effect, suitable installation angle changes. It implies that the optimum angle of all year round has flexibility. Actually, we can get about the same electric power when the angle is between 30 and 60 degrees.

Abstract: The comprehensive MPPT algorithm, which is combined with three approaches including the constant voltage tracking method (CVT), the perturbation and observation method (P&O), and the incremental node-voltage conductance method (INC), aims to study how to improve the solar energy utilization of the solar battery energy-saving control system of field monitoring equipment. To obtain the parameters needed for numerical simulation, solar power meter is used to measure light intensity curve within 30 seconds in spring. Then we establish the photovoltaic array simulation model and get the power tracking curve. Comparing with the curves based on the comprehensive MPPT algorithm with the mainstream MPPT algorithms, its proven that the time consumption of tracking MPP is shorter and that the efficiency of photovoltaic power generation is higher.

Abstract: As the proportion of photovoltaic power increasing, the impact on the power system is evident. An accurate mathematical model for PV power generation system is necessary. This paper demonstrates the detailed mathematic models for PV power generation system consisted of PV cell, converters, flow model are summarized. This work might provide a generic PV power system models for the research of characteristics of PV generation system and its grid-connected operation.

Abstract: Hydrogen is the most potential clean energy in the twenty-first century and can be obtained by the electrolysis of water. As a secondary energy, its production would be restricted by large amount of energy consumption and low efficiency. It is advantageous if an electrolyser can be simply and efficiently coupled to a renewable source of electrical energy. In this paper, it investigated the optimal way to maximize the transference of energy from a photovoltaic (PV) array directly coupled to a polymer electrolyte membrane (PEM) electrolyser in a photovoltaic-electrolyte hydrogen generation system (PV hydrogen system). The pivotal strategy is to find the series parallel combination of the PV cells and electrolyser stacks, which produces the highest energy transfer efficiency. The optimal configuration is a PV array consisted of three parallel connected PV cells directly coupled to a PEM electrolyser consisted of twelve series-connected electrolyser stacks with a day energy transfer efficiency of 99.52%. Comparisons between direct coupling systems and traditional ones have been presented. The result shows that direct coupling technology is feasible to improve the energy transfer efficiency in a PV hydrogen system.

Abstract: This paper presented a biogas-solar hybrid system and investigated the feasibility of using biogas to increase the enthalpy of parabolic trough collectors steam so as to increase the cycle efficiency and power production. High temperature anaerobic digestion (AD) was adopted to produce biogas by using corn straw, manure and sewage. Biogas fraction and energy-to-electricity efficiency were used to evaluate the biogas contribution to the electricity generation and the energy utilization efficiency based on off-design performance analysis respectively. A comprehensive levelized electricity cost (LEC) and life cycle assessment (LCA) for the hybrid system power production were performed. The simulation calculation results show that biogas utilization plays an important role in the decrease in systemic LEC and greenhouse gas emissions. Improvement is achieved in both of generation cost and greenhouse emissions for biogas-solar hybrid plant compared to solar-only plant.

Abstract: This paper describes the design of a linear Fresnel concentrating lens for a medium concentration type solar concentrator and reports the results of a sensitivity analysis.

Abstract: s: In this Article, the author took the solar energy project of Wenhai Village, Lijiang as an example, comprehensively analyzed the impacts of the solar energy project on the sustainable livelihood of the community from the analytical perspective of sustainable livelihood framework by participatory development and evaluation of indicators. The evaluation results indicated that the solar energy project had significantly positive impacts on the community. The project had relatively greater effects in increasing the social assets, financial assets and human assets of the community. While conducting case analysis, the author also explored the approaches and operation processes for sustainable livelihood framework in community development projects. Research Background

Abstract: Due to today's energy shortage and low efficiency of the photovoltaic conversion, the solar charging technology becomes more and more important. In this paper, the design of a solar powered battery charger with both pulse charging method and maximum power point tracking method is proposed. While the photovoltaic panels output power is small, the pulse charging method is used to prevent lead-acids sulfation reaction. The maximum power point tracking method is used while the photovoltaic panels output power is large to increase the charging efficiency. In the end, an application result is given out to demonstrate the effectiveness of the solar charger.

Abstract: In solar applications, collectors are usually installed with a tilt angel to obtain the maximum amount of radiation. In this paper, the anisotropic model -Hay model was used to calculate the daily total radiation on the tilt face and theoretical analysis was used to get the optimum tilt angel of southern collector face in winter months. Then the diffused radiation on horizontal face was obtained by using the isolation between daily total radiation and daily diffused radiation. Computer program was written to calculate the month radiation under different tilt angel and the maximum angel corresponding to the maximum month radiation was found. At last, the two results were compared and analyzed.