Blades are the most important components of wind turbines in order to convert wind energy to mechanical energy. This study investigates the aerodynamic performance of Horizontal Axis Wind Turbines (HAWTs) with forward and backward swept blades. The effect of the blade sweep direction, the location of the sweep start up and the tip offset on the aerodynamic performance are investigated using a model HAWT with a 0.9 m rotor as the baseline configuration. Changes in power and thrust coefficients with swept blades are investigated for the design tip speed ratio of the baseline wind turbine at a wind speed of 10 m/s. The wind turbine with the forward swept blade that has sweep start up at rss/R=0.15 and tip offset of d/D=0.2 has been found to give a remarkable boost to the power output with an increase of about 2.9% over the baseline turbine. The backward swept blade with rss/R=0.75 and d/D=0.2 has shown the highest reduction in thrust coefficient, namely 5.4%, at the design tip speed ratio. In conclusion, it is found that the forward swept blades have the ability of increasing the performance while the backward swept blades tend to decrease the thrust coefficient.

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Hydroelectric plants play an important role in electricity production in Turkey as well as all over the\ud world. However, the increase in the irregularity of flow regimes and the decrease in water ranges of the\ud rivers due to global warming in recent years have revealed that supporter systems are necessary. One\ud alternative solution that could be applied is an integrated system with both hydropower and wind energy.\ud In this study, a system consisting of a hydroelectric power plant (HEPP) and/or wind power plant(s)\ud (WPP) is designed to resolve the energy demand for the Konya water treatment plant, and the results\ud were analyzed. The wind power calculator program and local wind energy measurement data were used\ud to design the WPP. In addition, the water flow rate due to the mean of the elevation difference between\ud the bend of the dam and plant was used to design the HEPP. The electrical energy consumption of the\ud Konya water treatment plant was considered in the design of the WPP and HEPP. The energy production\ud of the WPP and HEPP, the energy demand of the water treatment plant, the monthly and yearly\ud affordability of the energy production were calculated. Additionally, an economic analysis was performed,\ud where the basic payback period was calculated. All the data used in this study are based on longterm\ud measurement

Abstract. The use of wind power has become an important and growing part of the electrical energy supply in many countries all over the world. Wind turbines are the main components of wind power stations and every single development on these turbines affects the market. Latest developments in wind turbine technologies caused to decrease in costs, thus, besides high-wind-speed regions, low-wind-speed regions are taken into account as a feasible option to generate electricity. The present work investigates the feasibility of a wind power station located in a low rated wind speed region of Turkey providing a general approach for selection of the suitable wind turbine. Economic analysis was performed by calculating the key financial figures such as net present value (NPV), basic payback period (BPP) and the internal rate of return (IRR) for five various options and hourly mean, monthly and seasonal power productions are simulated for the most feasible option using the wind speed measurements in the region. Results show that it is possible to obtain a reasonable capacity factor in low rated wind speed regions with wind turbines that have larger rotors. Although the average wind speed is low in the examined region, a wind power station is still found to be feasible. According to the simulation results, maximum power is produced during the evening hours on a daily basis and during the summer months on a seasonal basis, ensuring power flow usually when maximum power consumption levels are reached. All the data used in this study are based on long-term measurements.

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