  The energy of gravitational waves is a fundamental problem in gravity theory.
The existing descriptions for the energy of gravitational waves, such as the
well-known Isaacson energy-momentum tensor, suffer from several defects. Due to
the equivalence principle, the gravitational energy-momentum can only be
defined quasilocally, being associated with a closed spacelike 2-surface
bounding a region. We propose a new approach to derive the energy of
gravitational waves $directly$ from the quasilocal gravitational energy. Such
an approach is natural and consistent with the quasilocality of gravitational
energy-momentum.
