  The construction of exact linearized solutions to the Einstein equations
within the Bondi-Sachs formalism is extended to the case of linearization about
de Sitter spacetime. The gravitational wave field measured by distant observers
is constructed, leading to a determination of the energy measured by such
observers. It is found that gravitational wave energy conservation does not
normally apply to inertial observers, but that it can be formulated for a class
of accelerated observers, i.e. with worldlines that are timelike but not
geodesic.
