Utilization analysis of small scale wind turbines at residential areas

The wind energy sector is developing day by day in Turkey as well as all over the world. The main reason for this improvement is the increase in electricity demand. At the same time, the need to obtain electricity from a renewable and clean energy source has also begun to gain importance (Because of the problems like running out of fossil fuel, increase at air pollution and the global warming). In the renewable energy sources after hydro power the most important source of electricity generation is wind energy in Turkey. A consequence of the geographical location, west winds are the biggest cause of wind energy potential in Turkey. Electricity is produced mainly by large-scale turbines from these winds. With the effect of developing technology, the usage of small scale systems as well as large scale systems has started to increase. However, development is very slow due to problems such as cost, system reliability and excessive payback period. In this study, firstly, wind energy situation in Turkey and in the world is examined with up to date data. General information related to technical and social issues of small scale turbines are given. The critical issues in the selection of the turbine have been analyzed. For some countries in the world, the energy policies of small scale wind energy systems and the studies on this subject have been analyzed. Countries studied as examples; Malaysia, Taiwan, New Zealand, China, United States and Iran. The United States and the China is chosen for analysis because they are the world leaders in the small-scale wind energy sector. On the other side, these countries can be a model for policy and other study for Turkey. The reason for examining of other countries, they are at he similar level about economically with Turkey. Later, have been mentioned about Turkey's policies, laws and regulations of small-scale wind energy in the area. Before the calculations, the methods were examined about the popularization of usage of small scale wind turbines. When selecting the turbines to be used in the calculations, has been made by the capacity to meet monthly electricity consumption of a minimum of one apartment in a building. Electricity consumption is defined as 250 kWh per month (a family of 4 people averaged) according to the Turkish Electricity Transmission Corporation's 2011 research. Capacity factor is agreed as % 25 (nearly maximum capacity factor) for small wind turbines and so the minimum turbine capacity was determined as 1 kW. The product ranges of the companies were examined and two different companies were identified. In the calculations, five turbines (two different brands and three different capacities as 1 kW, 2 kW and 2,5 kW) defined to the program. Beside three turbines (three different brands and two different capacities 1 kW and 2,5 kW) were used from the program's wind turbine library. Comparison of all wind turbines power curves and the separate curves of wind turbines have given at the appendix A. At first, for a sample calculation at small-scale wind turbines, a region was defined and wind datas were taken from meteorology office (hourly data for five years were taken from the meteorological office at the province of Bolu. Anemometer is at the ten meters high). Wind data were evaluated as using the Windographer. The height calculations are based on the average height of the buildings at selected area. The number of building floors is specified as 5 floors maximum (1 commercial, 4 settlement floors) in the reconstruction plans of the area where the measurement is received (because it is earthquake zone). When calculations made according to the architectural standards, the building height found as 19.7 meters. The roof height required by the roof standards established by the local government is 2.4 meters. The minimum height of the building was determined as 22.1 meters and the calculations were carried out at above these heights. Heights selected as 23 meters (for minimum tower height), 25 meters and 30 meters. In order to calculate for the wind turbines at selected heights, extrapolation were made according to the power law. Coefficient of power law taken as 0,14. Calculations have been made with the new wind velocities for each selected height. Each calculation screen added to the study and 30 meters calculation examine in detail. Avarage wind speed at 30 meters found as 1,69 m/s. The energy outputs from the turbines are low in the results of the first calculations and not enough to correspond of an apartment electricity need. Because of this, the calculations have been repeated to examine the change of location. In the new calculation, same conditions are preserved. A location from the Aegean Region known to be better in terms of wind speed was chosen. Second calculation's wind data was taken from Balıkesir province's Ayvalık district. Wind data is for one year and period of the data is ten minutes. Data taken from General Directorate of Electrical Power Resources Survey and Development Administration's (which new name is General Directorate of Renewable Energy) wind measurement station. For Ayvalık wind data, first calculation made at ten meters. And the extrapolation made at 23 meters, 25 meters and 30 meters as first calculation as power coefficient taken 0,14. Conclusions' of calculation examined and the results showed that five turbines had enough power output for an apartment's electricity consumption. Avarage wind speed is calculated as 6,19 m/s. Ayvalık's wind data has 30 meters wind measurement. For comparison of extrapolation at 30 meters calculations, evaluation repeated for measurement data. Avarage wind speed calculated as 6,23 m/s by program. And this value shows that the extrapolation has just % 0,6 diversion. Measurement graph summary sheet added on to extrapolation graph summary sheet for comparison. Energy output of turbines have been calculated for measurement data and examined for difference. And all of this steps shows that results from measurement calculation and from extrapolation calculation has not have a significant difference. Detailed turbine energy output calculations for Bolu and Ayvalık calculations have given at the appendix B. Bolu and Ayvalık results' comparison have been examined and the suggests about improving policies to increase the utilization of small wind turbine at the conclusion. Mentioned about regulations and the studies for popularization of small-scale wind turbines for Turkey.