Evaluating the feasibility of wind energy utilization in Sistan and Baluchestan Province

Energy is one of the most important demands in the development of human societies. As world population continues to growth and the limited and non-renewable resources of fossil fuels begin to diminish, countries must take action to facilitate a greater use of renewable energy resources, such as geothermal and wind energy. Iran has a high wind energy potential, but except in a few specific regions such as Binalud and Manjil, the use and exploitation of such clean renewable source is still not addressed enough. Wind speed in Sistan and Baluchistan province especially in cities like Zabol is very high and sometimes it goes near 120 km/h. So this study aims to investigate the feasibility of wind harvesting in synoptic stations of Sistan and Baluchestan province. Moreover, the trend analysis of wind data is investigated in this paper.
This study is based on wind data in 8 synoptic stations, for a period 10 years (2005-2014). The analysis was based on 3 hours interval wind speed data measured in 10 m height above ground surface.
The most widely used model to describe the wind speed distribution is the Weibull two- parameter. These two parameters include k and c: the first is the shape parameter and the second is the scale parameter. There are several methods for calculating these parameter.In this paper, these two parameter were determined through the maximum likelihood (ML) technique.The Weibull distribution functionis expressed mathematically as: (1) where f(v) is the probability density function, k is the shape parameter, c is the scale parameter (m/s), and v is the wind speed (m/s).The probability of having a wind speed between two values of interest V1 and V2 is given by the equation
P(V_1 Monthly mean and standard deviation of wind speed data were calculated for the selected stations during 2005-2014. The results showed that the monthly variation (2 to 5 m/s) of mean wind speed for all years is similar as the highest and lowest mean wind speed was happened in winter and autumn, respectively.
The wind speed characteristics required to evaluate the feasibility of wind energy utilization were calculated for selected stations. The results showed that the maximum wind power density was seen for Zabol with amounts of 257.227 W/m2 and 512.713 W/m2 in 10 m and 50 m heights, respectively. The lowest wind power density was seen in Iranshahr with amounts of 40.196 W/m2 and 80.12 W/m2 in 10 m and 50 m heights, respectively. Comparing these data and data calculated for other stations with the standard classification criteria indicated that Zabol, Zahak and Konarak are the most suitable sites for wind turbines installation. Moreover, Zabol has the maximum probability of having the wind speed of 3 to 25 m/s, i.e. 0.71 and 0.82 for 10 m and 50 m heights, respectively. Therefore given a wind turbine installed in 50 m height, the probability of blowing wind with the speed of 3 to 25 m/s, is about 0.82 multiply by total hours of wind existence during a year (82*7566 hrs/year), i.e. 5822 hrs/year.
The results of trend analysis by Mann-Kandal test showed that there are either an increasing trend or decreasing trend in selected stations, however, increasing trends (e.g. Zabol, Iranshahr, Zahedan and Konarak) were more often. Wind speed in Zabol has shown a positive trend for all months (except September). However the trend was significant in 41.6 percent of times.In annual basis, wind speed in Zabol has positively increased at a significance level of 5%. Wind speed in Iranshahr showed a significant positive trend in both monthly (except April) and annual scale. Overall, annual wind speed showed a positive trend in half the stations considered and a negative trend in others.
According to findings achieved in this study, wind speed is lower in the last months of the year for all stations in Sistan and Baluchistan province. The highest variation of wind speed was seen for Zabol. Based on trend analysis, some significant positive trend of annual and monthly wind speed was seen in Iranshahr, Zabol, Zahedan, and Konarak in descending order. According to the results, the highest wind power density in 50 m height was seen for Zabol (513 W/m2) and Zahak (434 W/m2) and the lowest one was seen for Iranshahr (80 W/m2). Overall, based on wind speed existence and its annual continuity, three stations Zabol, Zahak and Konarak were realized to be appropriate for installing wind turbines.