This chapter studies the control of an airborne wind energy system that is operated in pumping cycles and uses a rotating cylinder to provide aerodynamic lift with the Magnus effect. The proposed control strategy aims at stabilizing the output power production which can be used for off-grid applications, for example. In a first case study, the wind tunnel setup of a small scale system is investigated experimentally and by means of numerical simulation. The proposed controller works well to effectively manage the tether length. However, a comparison of the results demonstrates the penalizing effects of wind turbulence with a factor of three difference in power production. In a second case study, the control strategy is used for the numerical simulation of a medium scale prototype with a potential power rating of 50 kW. The results show that the control strategy is very effective to track the desired power production even in the presence of wind velocity fluctuations. In a third case study, the scalability of the system is evaluated by applying the control scheme to the numerical simulation of a MW scale platform. The results show that the system with a span equal to the diameter of a conventional wind turbine can generate an equivalent amount of power.