<p>Receivers for use in solar energy collector systems and solar-powered electrical energy generating plants are provided. The receivers (400) comprise a solar radiation absorbing core (414) that converts absorbed solar radiation to thermal energy. The core (414) comprises a refractory material to allow the receivers to operate continuously at high temperatures reached by absorbing concentrated solar radiation. The thermal energy so generated in the core may be stored in the receiver for a transitory period, or for a more extended period. Receivers (400) may comprise one or more fluid channels (415) in and/or around the core for conveying a working fluid to facilitate extraction of stored thermal energy from the core.</p>