NOVELTY - The concentrator (100) has a replaceable film (102) refracting an incident sunlight. The film forms a tubular shape enclosing a cavity, where a portion of the film includes a refractive region directing the sunlight towards an elongated focus region (112) within the cavity. An inflation gas fills the cavity, where the inflation gas maintains the tubular shape of the film. A receiver captures the energy in the sunlight refracted from the film, where the receiver is located inside the cavity and at the focus regions. A circuitry converts the captured energy in the sunlight to electrical energy.    USE - Inflated tubular solar concentrator for concentrating solar radiation energy in photovoltaic cells.    ADVANTAGE - The concentrator facilitates chromatic aberration to increase the lateral spread of sunlight at the receiver, thus effectively reducing the amount of angular error due to misalignment or tracking offsets that can be tolerated without losing some power output. The concentrator applies a moth's-eye pattern to the outer surface of the primary optic/film, thus reducing Fresnel reflection losses to increase the system efficiency by a significant amount. The concentrator provides high levels of solar energy concentration/capture with improved conversion efficiency and lower cost. The concentrator reduces the amount and complexity of the structures of the mounting and tracking systems used with the solar concentrator, thus reducing the overall mass and cost of the solar collector system. The concentrator reduces sensitivity to tracking error, enhancing uniformity of illumination, steering light away from grout, and helping to define optical boundaries. The concentrator maximizes system efficiency, thus minimizing losses in and between components, and hence avoiding excessive non-uniformity of cell irradiance. The concentrator keeps the light away from the non-optical draft faces. The concentrator improves the chromatic aberration problem. The concentrator improves tolerance to displacement of the lens. The concentrator reduces levelized cost and maximized scale of a solar power plant, thus achieving through the use of elements employing minimal materials and low-cost. The concentrator facilitates three dimensional structures to allow for a smaller footprint of the receiver system, thus minimizing shading losses.    DETAILED DESCRIPTION - The film is a tubular shaped film.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of an inflatable concentrator.    Inflated tubular solar concentrator (100)    Replaceable film (102)    Reflective film (104)    Film seal (106)    Internal inflation space (110)    Incident ray (111)    Elongated focus region (112)