SPOT screen image

Quantifies existing or intended electric lighting performance, evaluate annual daylighting characteristics and help establish the optimal photosensor placement in a given space relative to annual performance and annual energy savings. The Sensor Placement and Optimization Tool, or SPOT, was developed with classroom daylighting in mind, but can be used for all types of spaces. Screen Shots


daylighting, electric lighting, photosensor, energy savings


Various individuals have tested the software. Testing and validation continues. Documentation of the test and validation results are available on the web site.

Expertise Required

Energy engineering or lighting design background is helpful for analysis of results. A working familiarity with Excel may be helpful, but it is not necessary. Radiance will be largely invisible to the majority of users, and only runs behind the Excel interface. Advanced Radiance users may use the �Advanced Options� page to interact with Radiance through the Excel interface or directly by manipulating the Radiance files, but this is NOT required in the execution of SPOT.


More than 250 and growing (includes United States and international users)


architects, lighting designers, design engineers, building scientists, contractors, facilities managers, and commissioning agents


SPOT consists of a series of screens that the user navigates sequentially. The program has two main sections: a design tool where geometry characteristics including spatial characteristics, wall and window apertures, shade control, and electric lighting information are requested. Site and schedule usage also is needed. The second part is the analysis tool that requires input on desired photosensor characteristics.


The program has two main sections: a Design Tool and an Analysis Tool. The Design Tool calculates electric lighting performance and preliminary annual daylighting results. The Design Tool also provides recommended photosensor placements for the analyzed space. These recommended placements provide good starting points for analysis but do not necessarily represent the optimal photosensor placement. Further iteration with the Analysis Tool is required to fine tune the photosensor system design. The Analysis Tool is the final phase of a SPOT analysis session and consists of two screens. The first screen allows the user to mix and match photosensor scenarios with luminaire zones and analyze resulting correlations and estimated annual performance. The second screen takes the set photosensor scenarios and analyzes their performance throughout the year using annual hour-by-hour weather data. Estimated energy savings are provided.

Computer Platform

PC-compatible with Windows 2000/NT/XP, Excel 97 or later, 400 MHz processor , and 128 MB available disk space.

Programming Language

Excel, Python


Easy to use interface; Excel is readily available for most users; complete install package; free to dowload and use. Also, SPOT Users forum is available to users which provides a forum for all issues related to the software.


Wait time for calculations may be lengthy. The sequence of input and result screens is designed to minimize user wait time. Wait time is reduced by running required calculations behind the scenes before they are needed. Though, much of the calculation time in the program occurs while the user is interacting with another input screen or reviewing a results screen, the wait time may be substantial depending on the speed of the users computer and the project complexity.



Architectural Energy Corporation


Suite 201
2540 Frontier
Boulder, Colorado 80301
United States


+1 (303) 444-4149


+1 (303) 444-4304




SPOT is available for use at no cost to the public. Users may download the install package after completing a registration form or request a CD-ROM by contacting SPOTsupport. The registration information will be used only to contact users when updated versions are released. A users manual is provided.