Volumetric solar absorption system accommodating the absorber plate in a rectangular channel is investigated. The influence of the location of the absorbing plate on the heat transfer and hydrodynamic characteristics are examined in the channel. Phase change material (Lauric acid) of 5% concentration is used to increase the thermal storage capacity of the working fluid and water is incorporated as the carrier fluid in the channel. Thermal performance and pump power loss parameters are introduced to assess the thermal performance of the volumetric solar absorption system. The findings revealed that thermal performance parameter attains the highest value for the absorber plate location at the center and bottom of the channel. The pump power loss parameter becomes the highest for the absorber plate location at the mid-height of the channel.