Joint optimization of the number, type and layout of wind turbines for a new offshore wind farm

Abstract

Prominent problems, including the high investment cost and limited generation revenue of offshore wind farms, are of concern. To tackle these problems, a bi-level model is proposed, whose upper level represents the offshore wind farm optimization for the target of maximizing the profit, and the lower level represents the day-ahead market clearing with the participation of an offshore wind farm. In the upper level, the number, type, and coordinates of wind turbines are simultaneously optimized on the premise of the determined sea area. The layout of an offshore wind farm in irregular sea areas can be obtained by constructing specific penalty functions. In the lower level, under different wind conditions and load, the day-ahead market with the goal of maximizing social welfare is cleared, and the cleared wind power and local marginal prices of an offshore wind farm are provided for the upper level model. Finally, the optimal number, type, and coordinates of wind turbines are obtained by solving the two-layer model. In a rectangular planned sea area, the bi-level optimization model is successfully applied. The test results show that when 27 wind turbines with a rated capacity of 6.45 MW are placed in the planned sea area, the annual investment profit reaches the maximum value of 22.6 × 106 euros. When the optimized layout of an offshore wind farm is used, the power deviation of 67% wind turbines caused by the wake effect can be controlled within 7%, which verifies that the optimized layout plays a role in reducing the wake effect.