The invention relates to a method of determining a desired power curve for a wind power plant for use in connection with the subsequent design and positioning of the wind power plant (307), where the wind power plant is to be coupled as energy source to a power network comprising a number of energy sources. The power curve is determined relative to the remaining energy sources of the power network to the effect that the power supply of the wind energy plant is maximised during periods (203) when the total power output (301) from the remaining energy sources of the power network is low. The invention further relates to a system of determining a desired power curve for a wind power plant. The invention also relates to a group of energy sources comprising a wind power plant and a number of remaining energy sources, where the power curve of the wind power plant is such that power supply is maximised in periods of time (203) when the total power output from the remaining sources of energy is low.