This work proposes a novel technique for the localization of low-velocity impacts in composites without a-priori knowledge of the mechanical properties nor the speed of propagating waves, thus overcoming current limitations of existing impact localization methods. The proposed algorithm is based on the estimation of the power of acoustic emissions generated by impacts on a composite plate instrumented with embedded piezo-transducers. The signal power values calculated at sparse sensor locations are interpolated over the sample by using radial basis function networks. The impact coordinates on the specimen surface are estimated by a center-of-gravity method based on the interpolated power values. Experimental tests were performed by using both an instrumented impact hammer and a drop tower. The results obtained showed the validity of the presented approach, which was able to identify the impact locations with high level of accuracy.