Development and Comparison of Methods Based on Grey and Fractal Models for Predicting Natural Gas Prices

Today there is consensus regarding the importance of predicting the price of energy carriers for economic development, including natural gas as a preferred energy source on environmental grounds. In this paper we analyze the nonlinear behavior of natural gas prices over time by use of the Grey Method (GM), Developed Grey Method (DGM), Fractal Discrete Grey Method (FDGM) and a compound Method II (IFS-AF).  Our results indicate the effectiveness of these methods in predicting gas prices. In addition, due to the fractal structure of natural gas prices in the period under review, the results show that the prediction error of the compound method is always less than 2 percentage points.  We note that due to the flexibility of the method, a combination of Grey and Fractal methods produce excellent results.