The consortium has posted three documents (www.ssl.energy.gov/resources.html). The main document includes sections on items such as warranty, color temperature, environmental design elements, electrical requirements such as connectors, and mechanical mounting requirements. The main document also includes an Appendix B that is focused on evaluating LED lumen maintenance.
Appendix A covers the specification of luminaire electrical and optical parameters and has two different versions. The simple version of Appendix A, referred to as the material specification, covers a relatively small set of parameters such as beam pattern, power consumption, light output and color temperature. A more complex version of Appendix A – the system specification – includes a far more detailed set of requirements such as light uniformity, and a variety of illuminance parameters specified at ground level.
A buyer that wants to use the specification documents would combine their choice of Appendix A with the main document. The buyer would edit the Word files, inserting their own values for the specification parameters.
The posted documents include sample values for the parameters but those are strictly examples. For instance, the draft includes 105W and 210W luminaire examples for both versions of Appendix A. But the data in those example specifications should not be used by street-lighting buyers.
The intent of the specification documents is to allow buyers to “avoid starting from scratch and creating their own vocabulary,” stated Jason Tuenge, senior lighting designer at the DOE’s Pacific Northwest National Laboratory. Tuenge, who was instrumental in the creation of the documents, said buyers must identify their own parameter values to place into the specification documents and perhaps may still need consultants to help with that process.
Indeed, buyers that use the documents might even change the warranty requirements that are included in the templates. And Tuenge reminds that “If you are going to change the warranty period, you are also going to want to change the requirements for warranty enforcement.”
It’s possible that the DOE consortium will ultimately develop complete specifications for different types of roadways. But that would require significant time and effort given the breadth of the roadway lighting problem and the many different variables such as pole spacing that complicate the issue.
Still, the posted specification templates should help municipalities and utilities jumpstart their SSL street-lighting programs and to utilize a specification methodology that will be universally understood by luminaire manufacturers, distributors, and lighting designers.