太阳电池非等宽主栅前电极栅线的优化设计

为提高太阳电池转换效率,降低生产成本,分析太阳电池功率损失机制,建立非等宽主栅太阳电池总体相对功率损失模型。通过求解该模型得到太阳电池最佳前电极栅线形状尺寸参数。采用PC1D软件进行仿真分析得到太阳电池的光电转换效率,该结果与理论值匹配度较高;当主栅线数为2～6时,非等宽主栅结构太阳电池相比于典型的等宽栅线结构太阳电池,光电转换效率分别提高了0.10%、0.09%、0.10%、0.09%和0.09%;主栅线总体积分别减少了0.72、0.68、0.64、0.58和0.47 mm³;细栅线总体积的增加量不超过0.07 mm³。表明非等主栅前电极栅线结构不仅提高了光电转换效率,也降低了银浆的使用量。     

Optimization of multi-layer front-contact grid patterns for solar cells

In a front-contact grid pattern for a solar cell there is a trade-off necessary between shadowing loss and excessive power loss due to voltage drop in the metalization itself. If the metalization is too little there may be excessive contact resistance to the underlying semiconductor and insufficient coverage to control losses in the thin front-surface layer of the solar cell. Optimization of grid pattern area and geometry is considered analytically to minimize total losses.Worthwhile performance advantages are shown to be possible, particularly in concentrator systems, if multi-layer grid patterns are used. The current carrying fingers should be approximately square in metal cross section and the main current feedout bars should not only be wider but also thicker than the primary collecting fingers. This is termed multi-level metalization.Effective use of multi-level grid metalization allows much greater concentration-to-loss ratio for a cell of large area and permits good performance from cells of high front-layer sheet resistance.     

Power generation of solar PV systems in Palestine

In Palestine, the electric power generated is not enough to meet the power demand of domestic and industrial sectors. In this article, a PV system of 220 kW peak was proposed as a renewable resource of power generation for grid connected applications in residential quarter in north Palestine. The proposed system was simulated using MATLAB solver, in which the input parameters for the solver were the meteorological data for the selected location and the size of PV panels. Results showed that it is possible for Palestine to use the solar energy to generate enough power for some villages or rural area. It is also possible to use such a system as a black start source of power during total shutdown time. Results also indicated that solar PV systems can be more economical than grid electricity.     

Status of amorphous silicon solar cell technologies in Japan

The present situation of a-Si solar cell technologies in Japan is reviewed and the future prospects toward the industrialization of a-Si solar cell modules for power generation are presented. The conversion efficiency, the stability, and the yield have reached a satisfied level to use a-Si solar cells for electric power generation. The last issue is a production cost, which will be overcome by developing the market and extracting the merits of a-Si solar cells instead of following the production process and applications of conventional solar cell modules.     

Optimization of cell to module conversion loss by reducing the resistive losses

Conventional silicon based photovoltaic industries, which convert silicon cells to modules attracted the attention of the researchers due to the cell to module conversion power losses. The conversion power losses are due to the various parameters such as shadow effect, inherent properties of the solar cells, properties of the materials used for fabricating the module etc. Among them, the inherent properties of the solar cells play a major role in module power. The electrical properties of the solar cell such as series resistance and fill factor drive the conversion power losses in the module. By increasing the number of contact points, the losses will be reduced. In this work it is found that by introducing an extra bus bar in metallization pattern leads to a great reduction in conversion losses. The fill factor gain is observed in three bus bar based modules compared to two bus bar based modules because of the contact points per cell increase which lead to low resistance losses. It is obvious that the power gain in three bus bar modules dominates shadowing loss due to an additional bus bar. A systematic approach on minimising the cell to module conversion loss by optimizing the front contact bus bar width has been studied. It is important that beyond the optimum value of bus bar numbers and its width the shadowing loss will dominate over the gain.     

Theory and applications for optimization of every part of a photovoltaic system

A general method is presented for quantitatively optimizing the design of every part and fabrication step of an entire photovoltaic system, based on the criterion of minimum cost/Watt for the system output power. It is shown that no element or process step can be optimized properly by considering only its own cost and performance. Moreover, a fractional performance loss at any fabrication step within the cell or array produces the same fractional increase in the cost/Watt of the entire array, but not of the full system. One general equation is found to be capable of optimizing all parts of a system, although the cell and array steps are basically different from the power-handling elements. Applications of this analysis are given to show (a) when should Si wafers be cut to increase their packing fraction; and (b) what are the optimum dimensions for solar cell metallizations. The optimum shadow fraction of the fine grid is shown to be independent of metal cost and resistivity as well as cell size. The optimum thicknesses of both the fine grid and the bus bar are substantially greater than the values in general use, and the total array cost has a major effect on these values. By analogy, this analysis is adaptable to other solar energy systems.     

Renewable power for China: Past,present, and future

This paper briefly examines the history, status, policy situation, development issues, and prospects for key renewable power technologies in China. The country has become a global leader in wind turbine and solar photovoltaic (PV) production, and leads the world in total power capacity from renewable energy. Policy frameworks have matured and evolved since the landmark 2005 Renewable Energy Law, updated in 2009. China’s 2020 renewable energy target is similar to that of the EU. However, China continues to face many challenges in technology development, grid-integration, and policy frameworks. These include training, research and development, wind turbine operating experience and performance, transmission constraints, grid interconnection time lags, resource assessments, power grid integration on large scales, and continued policy development and adjustment. Wind and solar PV targets for 2020 will likely be satisfied early, although domestic demand for solar PV remains weak and the pathways toward incorporating distributed and building-integrated solar PV are uncertain. Prospects for biomass power are limited by resource constraints. Other technologies such as concentrating solar thermal power, ocean energy, and electricity storage require greater attention.     

Renewable power for China: Past, present, and future

This paper briefly examines the history, status, policy situation, development issues, and prospects for key renewable power technologies in China. The country has become a global leader in wind turbine and solar photovoltaic (PV) production, and leads the world in total power capacity from renewable energy. Policy frameworks have matured and evolved since the landmark 2005 Renewable Energy Law, updated in 2009. China’s 2020 renewable energy target is similar to that of the EU. However, China continues to face many challenges in technology development, grid-integration, and policy frameworks. These include training, research and development, wind turbine operating experience and performance, transmission constraints, grid interconnection time lags, resource assessments, power grid integration on large scales, and continued policy development and adjustment. Wind and solar PV targets for 2020 will likely be satisfied early, although domestic demand for solar PV remains weak and the pathways toward incorporating distributed and building-integrated solar PV are uncertain. Prospects for biomass power are limited by resource constraints. Other technologies such as concentrating solar thermal power, ocean energy, and electricity storage require greater attention.     

Levelized and environmental costs of power-to-gas generation in Germany

The transformation to a greener energy system leads to new challenges, as wind and solar power are not always available. A solution for this challenge is the generation of synthetic natural gas (SNG) and hydrogen from (surplus) wind and solar power, so that the green gases can be stored in the natural gas grid long-term and be used for electricity generation when wind and solar power are not accessible. This solution is especially of interest if the storage infrastructure is already in place, as in Germany, since investment costs can be avoided. Because of that, the study investigates the levelized cost of SNG and hydrogen generation in Germany applying the cost estimation method by Rubin et al. For the investigation, different water electrolysis technologies (alkaline electrolysis, polymer exchange membrane, and solid oxide electrolyzer cell with a size of 1 and 100 MW) and energy scenarios (8,000 h grid, 2,000 h grid, wind, and solar) are contemplated. Besides that, the environmental costs of SNG and hydrogen generation in Germany are investigated due to the increasing importance of these costs for society and companies. The author concludes that the levelized costs of SNG and hydrogen are far too high compared to peer studies, as more cost factors have been considered after applying the method by Rubin et al. In terms of the environmental costs, the use of Germany's grid electricity is not recommended for SNG and hydrogen generation since the generation from wind and solar power is more environmentally friendly, whereby wind power is preferable over solar power.     

Technical and socio-economic assessment for a Si-based low-cost solar cells factory in West Africa

As the cost of silicon-based solar cells has been decreasing sharply in recent years, photovoltaic (PV) systems have dramatically increased their attractiveness in many countries and in mall power systems. This increase of attractiveness can be objectively described in terms of grid parity reached in many areas around the world and a substantial improvement for accessing to electricity without subsidies in places where the power supply is intermittent or, simply, is not offered. One of such places around the world where power supply is limited is West Africa. On the other hand, as the PV industry is maturing and the production capacity is increasing, it is expected that PV companies will place new factories close to markets in highly solar irradiated developing countries, where the demand will grow in the near future. In this work a technical and socio-economic assessment of silicon-based low-cost solar cells produced in a manufacturing factory located in West Africa is exposed. The cost of the solar cells, in terms of USD/W_p is obtained for different West African countries and compared to the production costs of a similar factory operating in China but exporting the cells to West Africa. A sensitive analysis of the final cost of the solar cells varying the cost of key input parameters (mainly labor, electricity, silicon contract price, investment and logistic costs) into a defined range is also exposed. The cost of the solar cells produced is integrated with other sensitive parameters for business competitiveness in a synthetic indicator which offers a ranking of the ten more favorable countries for the location of this PV factory.     

世界促进风电产业发展最新动向

近年来可再生能源发电发展迅速,其中风力发电表现尤为突出.在一些风电先行国家的推动下,风电机组大型化取得长足进展,单机容量从亚兆瓦级迅速提升到兆瓦级,研制中的10MW级风电机组即将问世.机组的大型化提高了风电的经济性和竞争力.风机设备利用率将由目前的25％左右提高至2015年的28％,同时投资成本将大幅下降,按照GWEC的高增长方案预测,投资成本将由2009年的1350欧元/kW降至2030年的1093欧元/kW.鉴于风力发电的间歇性和随机性,蓄电技术成为大量引入可再生能源的有效手段,美欧日等都投入专项经费支持蓄电技术的研究开发.IEA最近在报告中指出,与热电联产组合的方式可大幅扩大可再生能源的利用,其重点在于热供应.智能电网将成为解决风电大规模接入和输送问题的根本途径,它将使电力系统整体利用效率大大提高,有利于抑制发电厂的化石燃料消费.我国在智能电网方面已取得了一定成果,但仍面临许多问题.各国政府的可再生能源电力收购政策促进了风电产业的发展,其中德国的风电收购政策值得我国借鉴.     

基于水库大坝的水能与太阳能融合型并网发电系统研究与应用

针对中国大中型面南的水库电站大坝,向光性比较好,具备安装太阳能光伏发电系统的条件,并使得2种可再生能源融合并网发电模式具有一定的创新性.水库电站的发电系统是已建成的,增加太阳能光伏发电系统并建设融合型并网发电系统,不仅体现了投资成本低发电效益高等特点,同时具有节约国土资源、保护大坝和节能减排等社会效益.在设计和实践过程...     

Entirely renewable energy-based electricity supply system (small scale & large scale)

Our future energy needs will be supplied by a combination of many different sources, ranging from small wind turbine to provide power for a single house to central power stations that provide power in very large scale fed into the national grid. Computer control systems will integrate the performance of all these systems to make sure that as much power as possible comes from environmentally friendlier sources. As alternative sources become more widely available, small scale systems meeting local needs may start to replace current large scale central power stations. The author is investigating the feasibility of an entirely renewable energy - based electricity supply system. The developed system find so many applications as it can be used as small scale power system for Remote Area Power Supply, wind energy/battery or solar energy/battery, as well as large scale for interconnection with national grid.     

A new integrated single‐diode solar cell model for photovoltaic power prediction with experimental validation under real outdoor conditions

The output power prediction by a photovoltaic (PV) system is an important research area for which different techniques have been used. Solar cell modeling is one of the most used methods for power prediction, the accuracy of which strongly depends on the selection of cell parameters. In this study, a new integrated single‐diode solar cell model based on three, four, and five solar cell parameters is developed for the prediction of PV power generation. The experimental validation of the predicted results is done under outdoor climatic conditions for an Indian location. The predicted power by three models is found close to measured values within 4.29% to 4.76% accuracy range. The comparative power estimation analysis by these models shows that the three‐parameter model gives higher accuracy for low solar irradiance values <150 W/m², the four‐parameter model in the range of 150 to 500 W/m², and the five‐parameter model for >500 W/m². The present model is also compared with other models in literature and is found to be more accurate with less percentage error. The overall results also show that the power produced depends on temperature and solar radiation levels at a particular location. Thus, single solar cell model developed can be used with sufficient accuracy for power forecast of PV systems for any location worldwide. The follow‐up research areas are also identified.     

高空飞艇薄膜太阳电池内辐射量计算研究

修正了任一方向的平面内太阳辐射计算模型,使之适用于编程计算各种倾角和方位角平面上的太阳辐射。在曲面上进行网格划分,生成若干个小平面,推导出平面法向量与倾角和方位角之间的关系式,逐个计算每个小平面上太阳辐射量,叠加后近似代替整个曲面上的太阳辐射量。运用此方法计算了高空飞艇的薄膜太阳电池上辐射量,并与此薄膜太阳电池在水平投影面内辐射量计算结果进行比较。结果表明,用水平投影面内辐射量代替薄膜太阳电池内辐射量有很大的偏差。因此,在高空飞艇能源系统性能详细分析阶段需要使用曲面内太阳辐射量计算模型,为随后的光电转换与能源系统计算提供准确的太阳辐射数据。     

Photovoltaic grid-connection system as load-shaving tool in Riyadh,Saudi Arabia

A photovoltaic grid-connected (PVGC) system has been installed at the Solar Village in Riyadh. Because a PVGC system can use the utility grid as a store, the PVGC system does not need storage batteries.This will result in an initial cost reduction by about 40% as compared with an equivalent PV stand-alone system. The electric power is supplied from the PV generator or utility grid, or from both the PV generator and utility grid simultaneously. During the day time and if the load near the PVGC system is turned OFF, all the available power generated by the PV generator is supplied to the grid. The utility peak load during hot weather in the Riyadh region coincides with the maximum incident solar radiation, and hence the PVGC system produces the highest power, which can be used for load shaving and fossil-fuel conservation.     

大规模光伏接纳对电网安全稳定的影响及相关制约因素分析

我国西部地区太阳能资源丰富,开发条件便利。大规模光伏电力并网势必对电网运行特点、暂态及动态特性以及控制方式带来一定影响。文中详细阐述了大规模光伏电力接入对电网的影响,并以我国某实际电网为例,深入分析了光伏接入地点、运行方式安排、无功电压控制等关键因素对光伏接纳能力的制约作用。分析结论可为进一步提高电网安全稳定水平及光伏接纳能力,也可为电网的后续规划、运行控制提供参考依据和指导建议。     

Determination of the optimum hybrid renewable power generating systems for Kavakli campus of Kirklareli University,Turkey

This study is to search for possibilities of supplying the load demand of Kavakli campus of Kirklareli University with solar energy and the fuel cell power generating system (electrolyzer/hydrogen tank/fuel cell) by using the HOMER software due to the fact that hybrid power systems with renewables can significantly reduce emissions which are caused by utilization of non-renewable power sources. In this study, various hybrid systems will be examined and compared among themselves considering cost of energy (COE), renewable fraction, total net present cost (NPC) and hydrogen production. Additionally, this study will seek whether a fuel cell can be integrated into the hybrid systems. According to the study results, the grid connected systems appear cost-effective as expected. Although the grid-connected photovoltaic (PV) hybrid system has the lowest COE and NPC, the grid-connected PV/fuel cell hybrid system with COE, 0.294$/kWh has a slightly higher cost than the optimum one. It is strongly believed that this system may be chosen because it is a cleaner system and its emissions are fairly low.     

ANALYTICAL AND GRAPHICAL METHODS OR DETERMINATION OF SOLAR CELL PARAMETERS AND INVESTIGATIONS OF SHADOWING EFFECT

In actual solar cells, the main power loss is due to the effect of the internal series resistance and the shunt resistance of the solar cell. Two methods; mathematical and graphical, were used to determine these two resistances for an Iraqi monocrystalline solar cell (type AI-Mansour). The results show that both of the series resistance (0·09 Ω) and the shunt resistance (210 Ω) can usually be neglected in an array performance evaluation for systems which don't use concentration arrangements

In addition to the series and shunt resistances computations, the analysis of the mismatching among solar cells as well as the power dissipation by shadowed or faulty cells for different module configurations are discussed in detail in this paper. As a result it was found that the maximum number of cells that can be safely series, parallel connected are 50 and 6 cells respectively.     

Study on optimal configuration of the grid-connected wind–solar–battery hybrid power system

The capacity allocation of each energy unit in the grid-connected wind–solar–battery hybrid power system is a significant segment in system design. In this paper, taking power grid dispatching into account, the research priorities are as follows: (1) We establish the mathematic models of each energy unit in the hybrid power system. (2) Based on dispatching of the power grid, energy surplus rate, system energy volatility and total cost, we establish the evaluation system for the wind–solar–battery power system and use a number of different devices as the constraint condition. (3) Based on an improved Genetic algorithm, we put forward a multi-objective optimisation algorithm to solve the optimal configuration problem in the hybrid power system, so we can achieve the high efficiency and economy of the grid-connected hybrid power system. The simulation result shows that the grid-connected wind–solar–battery hybrid power system has a higher comprehensive performance; the method of optimal configuration in this paper is useful and reasonable.