| abstract |
An apparatus comprising: a) a light concentrator (40) for concentrating and redirecting incident radiant energy, the light concentrator having an optical axis; b) a spectral separator (32) separated from the light concentrator and disposed along the optical axis and in the path of the redirected concentrated radiant energy, the spectral separator comprising: (i) a first flat surface (44) treated to reflect a first spectral band of light received from the light concentrator towards a first focal region and to transmit a second spectral band; (ii) a second flat surface (46) separated from the first flat surface, the second flat surface being treated to re-reflect the second spectral band across the first flat surface and towards a second focal region that is separated from the first focal region; and c) first and second light receivers (34, 36), in which the first light receiver (34) is arranged closer to the first focal region to receive the first spectral band and the second light receiver (36) is arranged closer to the second focal region to receive the second spectral band, and characterized in that the apparatus is for obtaining energy from the sun, the second flat surface (46) is oblique with respect to the first flat surface; and the first and second receivers (34, 36) of light are photovoltaic, thermo-PV or thermo-photovoltaic devices to obtain light energy of wavelengths in the respective spectral bands from the sun. |