Here is a _link_ to a page that contains a case study on the hybrid porch light and other PIER funded lighting technologies. I tried to post this earlier so if it comes through as a duplicate, oops.
http://cltc.ucdavis.edu/content/view/96/162/The case studies are part of the PIER funded Energy Efficient Campuses Program. See this _link_ for the overview
http://ciee.ucop.edu/