Abstract: A light element with a translucent surface includes an energy converter, wherein the translucent surface is so formed as to direct only that portion of the radiation onto the energy converter that impinges on the translucent surface. The energy converter may be a solar cell, a fluid line or a light guide. The light element is particularly suited for illuminating interior spaces with diffuse light.

Abstract: A photovoltaic device for converting radiation energy into electric power, includes a front side exposed to radiation from a radiation source, a backside; and a cooling unit having a liquid medium, e.g. water, arranged between the front side and the radiation source. The liquid medium is surrounded by an envelope, and forms with the envelope a selective filter allowing passage of radiation useful for the photovoltaic effect and converting the longer wave radiation into hear which is immediately dissipated to substantially prevent heating of the photovoltaic module.