A channel flow with a presence of phase change particles in the carrier fluid (water) is investigated for various Reynolds numbers in relation to a solar volumetric absorption system. The absorber plate is considered in the channel to resemble the selective surface in the solar volumetric absorbing system. The absorbing plate, which composes of a ZrN film deposited onto a thin silver plate, is placed at three different locations in the channel to enhance the absorption of the incident solar radiation. The performance parameter is defined to quantify the heat storage capacity of the working fluid. The pump power loss parameter is introduced to predict the pump power loss due to the different locations of the absorber plate in the channel. A radiation model is incorporated to account for the absorption of the solar radiation by the working fluid and the absorber plate in the channel. It is found that the performance parameter improves considerably for the absorbing plate located at the channel bottom. The pump power loss parameter becomes the highest for the absorber plate location at the mid-height of the channel.