NOVELTY - Apparatus comprises: (a) a primary concentrator configured to receive incident light from a light source over a range of acceptance angles; (b) a secondary passive optical compensator configured to receive light from the primary concentrator, and to refract the light and submit the light to a total internal reflection; and (c) a receiver comprising an array of photovoltaic cells configured to receive from the secondary passive optical compensator, where the light has been subjected to the total internal reflection.    USE - The apparatus is useful as a solar collection apparatus.    ADVANTAGE - The apparatus employs certain techniques, alone or in combination, that enhances a range of acceptance angles to efficiently collect solar radiation. One technique positions a passive secondary optical compensator element between collected light and a receiver. Another technique employs a receiver having radially-oriented strings of cells connected in series, where strings in opposing sectors are connected in parallel and in series with each other to reduce a dependence of power and/or current output, on alignment of the collector apparatus relative to a light source.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) an apparatus comprising a host computer configured to design a secondary optical compensator configured to be interposed between a solar energy concentrator and a receiver comprising photovoltaic cells, where the host computer comprises: (a) a processor; and (b) a computer readable storage medium in electronic communication with the processor and having stored codes configured to instruct the processor to: (i) generate an input rayset based upon properties of solar light incident to the concentrator and a tracking error of the concentrator; (ii) generate an irradiance distribution profile at the receiver from the input rayset and an optical property of the concentrator; (iii) partition the receiver into cells, each cell configured to receive a substantially equal portion of the irradiance distribution profile; (iv) create refractive surfaces of the secondary optic structure, each of the refractive surfaces corresponding to one of the cells of the receiver; (v) create second surfaces of the secondary optic structure, each second surface corresponding to one of the refractive surfaces and having a profile configured to communicate light received from the corresponding refractive surface to the corresponding cell of the receiver; and (vi) generate a three-dimensional representation of a monolithic secondary optical compensator structure comprising the refractive surfaces and the second surfaces; and    (2) a method comprising: (a) receiving at a primary concentrator incident light from a light source over a range of acceptance angles; (b) receiving light at a secondary passive optical compensator from the primary concentrator, refracting the received light and subjecting the refracted light to the total internal reflection; and (c) receiving at a receiver the light which has been subjected to the total internal reflection, where the receiver comprises an array of photovoltaic cells.    DESCRIPTION OF DRAWING(S) - The drawing shows a simplified schematic view of the apparatus.    Inflated balloon (902)    Incident light (906)    Lower surface (908)    Receiver (910)    Secondary passive solar compensator element (912)