Public Interest Energy Research (PIER) provided funding to develop the Sensor Placement Optimization Tool, SPOT, software program to solve a lighting industry-wide gap between the design intent of these types of systems and the actual implementation. SPOT is a software package intended to assist designers in establishing the correct photosensor placement relative to the proposed daylighting and electric lighting design and to analyze and verify overall design performance. SPOT also provides useful annual daylight analysis as well as electric lighting analysis of the given space. SPOT consists of an Excel interface on top of a largely invisible Radiance calculation engine. The presentation will introduce users to SPOT and provide a demonstration of its implementation, focusing on the use of Radiance as a calculation engine.