Nevzat Onat

Recent Developments in Maximum Power Point Tracking Technologies for Photovoltaic Systems

In photovoltaic (PV) system applications, it is very important to design a system for operating of the solar cells (SCs) under best conditions and highest efficiency. Maximum power point (MPP) varies depending on the angle of sunlight on the surface of the panel and cell temperature. Hence, the operating point of the load is not always MPP of PV system. Therefore, in order to supply reliable energy to the load, PV systems are designed to include more than the required number of modules. The solution to this problem is that switching power converters are used, that is called maximum power point tracker (MPPT). In this study, the various aspects of these algorithms have been analyzed in detail. Classifications, definitions, and basic equations of the most widely used MPPT technologies are given. Moreover, a comparison was made in the conclusion.

Weibull distribution for determination of wind analysis and energy production

In recent years, decreasing reserves and environmental problems related with fossil fuels have increased the demand for clean and renewable energy sources, as with all over the world and also in Turkey. Wind energy is the one of the most rapidly growing among the renewable energy sources in terms of technological and utilization. Turkey is one of the rich countries in Europe in respect to wind energy potential. Productive and effective use of this potential is very important for Turkey that is depended on foreign countries especially in respect to fossil energy sources. Wind speed values are the most important data in calculation of electrical energy from wind turbines. In this study, latest developments and energy-power equations related to wind turbines are investigated. Using of the data obtained from the wind measurement station installed in Sakarya-Esentepe region, annual electrical energy production of an example wind plant is predicted.

Educational Software for Power System Analysis

This paper presents educational software that has an unconventional structure and friendly interface and can be used in computer-aided analysis of power systems. The software provides effective and fast solutions to in-line modeling of power systems, failure and power flow analyses. In addition, students using this software can demonstrate their own models and follow the solution steps in detail. The software also presents educational details and graphical mediums, similar to solutions provided by software developed for professional use. For this reason, it has a form that can be used in a workshop environment and distance learning activities.

Cost Calculation Algorithm for Photovoltaic Systems

The electric energy is directly correlated with vital elements for countries of today’s world. These elements can be divided into four sub-titles of production, national income, health and education. It is almost impossible for countries that lack of electric energy to ensure positive developments in such parameters. It is known that, even these days, at least 1.6-2 million people not to consume electricity in the world. Besides, in some countries, there exist great differences between the poor and the rich in obtaining energy (Belfkira et al., 2008). In that situation, the most benefit in the future of electricity generation sources, expected to be renewable energy sources especially solar and wind. It is also expected that the technical, economic, social and political barriers of widespread use of these resources will decline over time and these resources will own a very important share in the production of electricity at the end of this century. In this chapter, features of sustainable energy production and sustainability parameters of photovoltaic (PV) systems are summarized. This chapter focused on a life cycle cost analysis (LCCA) method that used in PV system design. In this point, apart from conventional cost analysis, calculable “external costs and benefits” are taken into account. In addition, effect of the capacity utilization (CU) on unit energy cost is explained particularly in stand-alone PV systems. Thus, detailed analysis of life cycle and unit energy costs -which the most disadvantaged parameter of PV within the parameters of sustainabilitywas, carried out. The topics discussed are supported with sample applications at the end of chapter.

Comparison of Turkey’s Geographical Regions in terms of Stand-Alone PV System Design and Cost Parameters

Stand-alone photovoltaic (SAPV) systems are widely used in rural areas where there is no national grid or as a precaution against power outages. In this study, technical and economic analysis of a SAPV system was carried out using meteorological data for 75 province centers in seven geographical regions of Turkey. Obtained results for each province center were separated by geographical area. The averages of the centers for each region are taken as output. A calculation algorithm based on MsExcel has been established for these operations. The analyses made with the developed algorithm are repeated for five different scenarios that they cover periods of time when a constant strong load is active for all seasons (winter, spring, summer, and autumn) and all year round. The developed algorithm calculates the life-cycle cost, the unit energy cost, the electrical capacity utilization rate, the amount of generated/excess energy per month, the initial investment/replacement, and operating and maintenance (O&M) costs of each element. As a result, geographical regions of Turkey are compared in terms of these outputs graphically. Further investigations may include the sale of excess energy generated, small-scale PV system cost factors parallel to the grid, and the effects of government incentives.