(in lingua inglese)
We proposed a method that allows fast calculation of the blocking factor in heliostat fields. The method is not restricted to any particular arrangement or orientation of heliostats. Although the method is numerical in nature, it seems that accurate results are obtainable with little effort. Further comparisons of the proposed method with existing methods are planned. The proposed method relies on tracing the virtual shadows of points on the perimeter of the heliostat so that straight lines enclosing the area of the virtual shadow can connect them. The method can also be applied to circular heliostats or facets by replacing these by equivalent circumscribing polygons. Obviously, as one increases the number of the polygon sides more accurate results are obtained.