The latest weapon unleashed to battle California's growing energy demand comes in the form of free software. The State of California Energy Commission's Public Interest Energy Research (PIER) program is responsible for the development of a free software package dubbed the Sensor Placement and Orientation Tool (SPOT). The purpose of this software is to help designers establish correct photosensor placement relative to a given daylighting and electric lighting design.

Daylighting systems, which use natural lighting to supplement electric lighting, are sensitive to photosensor placement and performance. However, until now, there have been no easy-to-use tools to help designers predict performance and determine optimum sensor positioning. Using an Excel worksheet interface, SPOT accounts for variables such as room geometry, surface reflectances, solar orientation, electric lighting layout, and window design to help determine the best location for photosensors. It also helps designers comply with the daylighting requirements in California's Title 24 energy code, which calls for separate controls for daylit areas and offers substantial energy budget credits for automatic daylighting controls.

This software may be downloaded for free at www.archenergy.com/SPOT/index.html.