Abstract: A panel for generating electrical and thermal power comprises an upper layer formed by a translucent sheet having an array of photovoltaic cells and a support structure including a pair of multi-walled translucent sheets, and an underlying reflective sheet. The multi-walled translucent sheets each include a number of elongated channels, with the two sheets being arranged so that their channels lie perpendicular to one another for rigidity. The channels within at least one of the sheets are filled with circulating water, which is heated by solar energy not absorbed within the photovoltaic cells.