Mirror For Solar-Skypipe Collector

Abstract

A solar collector is disclosed in which a light pipe having an optical axis and extending from a proximal end configured to receive sunlight to a distal end, and a plurality of reflective elements optically coupled to the light pipe. Each of the reflective elements is configured to direct at least a portion of sunlight incident thereon into the light pipe via the proximal end substantially parallel to the optical axis for a plurality of positions of the sun in the sky. Baffles coupled to the reflective elements further enhance the collectors ability to increase the light collected.

1 . A solar collector, comprising:
 a light pipe having an optical axis and extending from a proximal end configured to receive sunlight to a distal end;   a plurality of reflective elements optically coupled to the light pipe;   wherein each of the reflective elements is configured to direct at least a portion of sunlight incident thereon into the light pipe via the proximal end substantially parallel to the optical axis for a different portion of a daily time interval.   
     
     
         2 . The solar collector of  claim 1 , wherein each of the reflective elements is configured to direct at least about 80 percent of the incident sunlight into the light pipe substantially parallel to the optical axis during said portion of the daily time interval associated with that reflective element. 
     
     
         3 . The solar collector of  claim 1 , wherein each of the reflective elements is configured to direct at least about 90 percent of the incident sunlight into the light pipe substantially parallel to the optical axis during said portion of the daily time interval associated with that reflective element. 
     
     
         4 . The solar collector of  claim 1 , wherein the reflective elements are fixedly disposed relative to one another and relative to the light pipe. 
     
     
         5 . (canceled) 
     
     
         6 . The solar collector of  claim 1 , wherein the reflective elements comprise at least a first reflector array configured for directing incident sunlight into the light pipe substantially parallel to the optical axis during a first time interval in spring or fall at a reference location and a second reflector array configured for directing incident sunlight into the light pipe substantially parallel to the optical axis during a second time interval in winter at the reference location. 
     
     
         7 . The solar collector of  claim 6 , wherein a surface area of the front reflector of at least one reflector in the second array is less than a respective surface area of at least one reflector in the first array. 
     
     
         8 . The solar collector of  claim 6 , wherein the first time interval is a time interval at winter solstice. 
     
     
         9 . The solar collector of  claim 6 , wherein the second time interval is a time interval at spring or fall equinox. 
     
     
         10 . The solar collector of  claim 5 , wherein the front reflective surface is flat. 
     
     
         11 .- 13 . (canceled) 
     
     
         14 . The solar collector of  claim 1 , wherein each of the positions of the sun in the sky is characterized by an altitude and an azimuth angle, and wherein each of the reflective elements is positioned around the optical axis so as to receive sunlight corresponding to a plurality of azimuth angles and is tilted relative to the optical axis so as to direct at least a portion of the received sunlight into the light pipe substantially parallel to the optical axis for a plurality of altitude angles. 
     
     
         15 . The solar collector of  claim 14 , wherein the reflective elements are positioned relative to the optical axis at tilt angles in a range of about 25 degrees about 50 degrees. 
     
     
         16 . The solar collector of  claim 1 , wherein the reflective elements are configured such that the irradiance of light exiting the distal end of the light pipe is characterized by a substantially flat lumens curve for at least one time interval within at least one day of the year. 
     
     
         17 . The solar collector of  claim 16 , wherein the at least one time interval comprises at least 8 hours. 
     
     
         18 . The solar collector of  claim 1 , wherein the light pipe comprises an internal reflective surface. 
     
     
         19 . The solar collector of  claim 18 , wherein the internal reflective surface is rotationally symmetric about the optical axis. 
     
     
         20 . The solar collector of  claim 1 , further comprising a diffuser optically coupled to the distal end of the light pipe. 
     
     
         21 . The solar collector of  claim 1 , wherein the reflectors are configured such that the back surface thereof block entry of at least about 20 percent of sunlight energy into the light pipe for an altitude angle of the sun greater than about 30 degrees. 
     
     
         22 . A solar collector, comprising:
 a light pipe extending from a proximal end to a distal end;   a plurality of reflective elements optically coupled to the proximal end so as to direct incident sunlight into the light pipe;   wherein the reflective elements are sized and configured such that the sunlight exiting the distal end of the light pipe exhibits a substantially flat lumens curve for at least one interval in at least one day of the year.   
     
     
         23 . The solar collector of  claim 22 , wherein the sunlight exiting the distal end of the light pipe exhibits the substantially flat lumens curve for at least  8  hours in the at least one day of the year. 
     
     
         24 . The solar collector of  claim 22 , wherein the sunlight exiting the distal end of the light pipe exhibits the substantially flat lumens curve for a plurality of time intervals in a plurality of days. 
     
     
         25 . The solar collector of  claim 22 , wherein the sunlight exiting the distal end of the light pipe exhibits the substantially flat lumens curve for a plurality of time intervals in a plurality of days in different seasons. 
     
     
         26 .- 41 . (canceled)