Category: Nonimaging Optics in Solar Energy


This is admittedly an oversimplified model and probably has some unrealistic features; however, some definite conclusions are clear. Since even optimistic cost estimates for most collector types (even flat plates) lie in the range of $200-$400/m2, it is clear that flat plate collectors cannot be eco­nomically viable under present-day conditions. Some kind of high-temperature collector […]

A Simple model

Our model assumes that the application is a solar-driven absorption cooling system displacing the electrical energy that would have been used to drive a conventional vapor-compression air conditioning system. It introduces a simple economic figure of merit that can be parameterized in terms of five di­mensionless quantities, all of order unity. These five parameters are […]


We have shown that the only rational optimization for a solar energy collection and conversion system is that for which the relative incremental efficiency gains are precisely balanced by the associated relative incremental cost increases—that is, when the logarithmic derivatives of the performance and cost functions are equal. Very generally, we conclude that the optimum […]

The Model

The approach assumes that one has a system model that provides a quantitative measure of perfor­mance, say, efficiency h, as a function of some design parameter u. Furthermore, we assume that we know (or can reasonably guess) the relationship between this design parameter and the system cost X. The model shows that the rational economic […]

The Importance of Economic Factors in. Effective Solar Concentrator Design

8.1 A RATIONAL Model FOR COST PERFORMANCE OPTIMIZATION One very important aspect of designing any kind of solar system has to do with rational evaluation of cost and performance trade-offs (O’Gallagher and Winston, 2003). Often, when evaluating such concepts, a major emphasis is placed on developing a quantitative understanding of the technical performance, perhaps optimizing […]


Solar air conditioning represents a potentially huge market for solar energy in which the resource avail­ability and load are well matched on both daily and seasonal bases. Analysis has shown that flat plate collectors cannot be economically viable for solar-driven absorption cooling under foreseeable condi­tions. Clearly, some kind of high-temperature collector is required even for […]


Operating data for several years were acquired from a small array of commercial XCPCs installed in Chicago in the late 1980s. These data provided the first direct measurement (O’Gallagher, Win­ston, and Dallas, 2004) of the optical acceptance characteristics of a representative stationary CPC with a design acceptance half-angle of ±35° and a geometric concentration ratio […]