Building integrated photovoltaics (BIPV) understood as an integral building component, is becoming more and more popular. In turn, the use of BIPV on curvilinear roofs is an interdisciplinary issue covering geometry, environmental engineering, architecture and construction. The article presents an approach to designing efficient steel bar structures of the modular solar canopies using genetic algorithms and their evaluation. Shaping effective forms of solar roofs was subordinated to the idea “form follows environment” in the original way as the roof form, and thus the shape of the structure depended on the amount of solar energy absorbed by the roof surface. The structures designed on a regular polygon plan were created from three, four, five, or six hyperbolic paraboloid (HP) modules arranged radially. Algorithmic definitions of their forms made it possible to obtain many variants of canopies with the adopted preliminary criteria, as well as to conduct genetic optimization, which helped to obtain the best results. For the best solutions in terms of geometrical forms, structural optimization was carried out due to the structures’ minimum masses. As a comparative criterion of structural effectiveness, a coefficient was used that specified the mass of the considered structure per square meter of the covered area. The proposed shaping method may constitute some guidelines for rational shaping of the steel bar structures with radially arranged modules, in which their effectiveness can be established already at the initial design stage. However, the best optimization results, that is, efficient and aesthetic canopies, can be ecological solutions to be used in practice.