The "Vertical Heliostat Field" (VHF) concept proposes a solution to integrate solar heliostat fields in urban communities with the aim of deploying modular Concentrating Solar Power systems nearby populated areas. Its distinctive feature resides in the use of special mirror layouts where heliostats should be distributed on a vertical surface (i.e., a building facade). The VHF reflects radiation coming from the sun toward a common point where a solar receiver has been placed for power generation or other high temperature applications. This work presents the optical performance of the Vertical Heliostat Field as a shading system, studying the daylighting evolution inside the building as a function of VHF parameters (separation between heliostats, date, field zone, etc.), though always preserving the compatibility with the primary goal of achieving good performance and operational efficiencies as a solar thermal power plant comparable to a conventional central receiver system. Direct and diffuse components of solar radiation have been considered separately. Results indicate that a field with reduced spacing between heliostats provides a good performance as an element for shading building facades. (C) 2014 Elsevier B.V. All rights reserved.