A solar energy harvester comprises: a planar solar harvester panel serving to absorb sunlight and convert it to useful power such as electricity andor heat; a planar north wall which is specularly reflective on its south side, running east-west and positioned adjacent the north end of the harvester panel. For each WIP, a determination is made as to whether a cleared trajectory is available through all processing nodes subsequent to the bottleneck processing node and back to the re-entrant node or to exit of the production line. 9\xd7109 Joulesm3 or larger of volume of the heater stack, preferably not much larger so as to conserve energy. The BLOB may be stored within the relational database or may be stored separately.