Phase Change Materials in a Domestic Solar Hot Water Storage Tank of the Lebanese Market

Abstract

The availability of some kinds of renewable energy resources is un-continuous, for example the solar collectors can only produce heat when the sun is shining. Thermal Energy Storage (TES) is crucial to match between the intermittent solar heat supply and the heat demand. In this paper, a Phase Change Material (PCM) is integrated in the Domestic Solar Hot Water Storage Tank (DSHWST) as a Latent Heat Storage (LHT). Based on the application requirements in Lebanon, a suitable PCM is selected. While this PCM solidifies, it releases its heat and keeps the water inside the DSHWST warmer than 55 °C along 10 hours. The needed mass of PCM was calculated and two types of containers were investigated: the tubes and the spheres. As well as, the comparison between DSHWST integrated with PCM (DSHWST-PCM) and the Conventional Domestic Solar Hot Water Storage Tank (CDSHWST) is introduced, in order to examine the performance of PCM heating against that with an Electrical Resistance (ER). Features are expressed in terms of system payback and CO2 emission. Due to the issue of electrical power availability in Lebanon, the PCM integrated in The DSHWST has the following two advantages: yearly, reducing the primary electricity power by about 6.5 MWh and get rid of about 5.5 tons of CO2.