Smoothing effect of distributed wind farms and its impact on output fluctuation

In this study we examine 12 geographically distributed wind farms in Tohoku area in east Japan to improve our understanding of variable wind output in the point of output fluctuation. Wind power outputs are converted to frequency domain using FFT (Fast Fourier Transform). In frequency domain, we use Power Spectrum Analysis (PSA) to estimate correlation characteristics between wind farms in different frequency domains. Furthermore, we evaluate the degree of smoothing effect of solar power over a certain region and compare with wind power analysis to understand the difference between these two major forces of nature. Our examination of data shows clearly that the smoothing effect of distributed wind farms can contribute largely to its output fluctuation. We also discuss the expected impacts on power system stability, in the event of high level wind power penetration.