Future generation of interferometric gravitational wave detectors is hoped to provide accurate measurements of the final stages of binary in-spirals. The sources probed by such experiments are of extragalactic origin
and the observed chirp mass distribution carries information about their redshifts. Moreover the luminosity distance is directly observable is such experiments. This creates the possibility to establish a new kind of cosmo-
logical tests, supplementary to more standard ones. The paper discusses the utility of gravity wave experiments for testing the dark energy in the Universe, which is one of the most important issues in modern cosmology.