This article presents a recent analysis of wind energy integration into the electricity systems of Germany and Austria. It raises the question of whether flexible demand can provide cheap balancing options to fulfil the growing need for balancing capacity. The main focus is on the interaction of wind power production and flexible demand to im-prove the total system efficiency. Detailed simulations of wind power production and power plant operation are used to quantify additional reserve power, which, next to grid extension, is the main issue concerning the integration of wind energy. An assessment of demand response potentials provided evidence that the costs of additional reserve power could be reduced and that demand response can be a valuable option for inte-grating wind power into electricity systems.