or solstice ray 22 enter the prism silver layer 18 sends it up diagonally to the top surface for a total internal reflection establishing the ray exit angle before it leaves the prism bottom facet 24 internally reflects all light that it collects toward the absorber adjacent optics are arrayed at an angle to accommodate the prism top surface optic 4 has a 23 5 u00b0 acceptance angle that collects sunlight three months before and three months after summer solstice the stationary wedge makes steam from march 21 st through september 21 st the brightest six months in the northern hemisphere if tilted once the collector can also work the other six months in fig3 a two sided wedge is shown for the first time sides 26 and 28 are identical where one side has been rotated in relation to the other with absorber 30 now being irradiated on both sides this arrangement is made possible by the collection optic 39 s 23 5 u00b0 acceptance angle which is centered overhead the stationary collector has a geometric concentration of 4 4 u00d7 fig4 is a perspective view of two sided wedge frame 32 constructed of welded square tubing if end mirrors 34 were removed it would be found that the interior is the same as in fig3 identical optics 4 are used on each side of the collector the south side equator.