1 Article An Experimental Investigation of the Thermal and Economic Performance of PCM-Embedded Hybrid Water Heater under Saharan Climate Sidi Mohammed El Amine Bekkouche 1, *, Rachid Djeffal 1 , Mohamed Kamal Cherier 1 , Maamar Hamdani 1 , Zohir Younsi 2 , Saleh Al-Saadi 3 and Zaiani Mohamed 1 1. Unité de Recherche Appliquée en Energies Renouvelables, URAER, Centre de Développement des Energies Renouvelables, CDER, 47133, Ghardaïa, Algeria 2. FUPL, Hautes Etudes d’Ingénieur (HEI), LGCgE (EA 4515), Rue de Toul, F-59000 Lille, France. Univ. Artois, Laboratoire Génie Civil & Geo-Environnement LGCgE- EA 4515, Technoparc Futura, F-62400 Béthune, France 3. Department of Civil and Architectural Engineering, Sultan Qaboos University, PO Box 33, Postal Code 123, Oman * Correspondence: author: smabekkouche@gmail.com Abstract. The solar water heater must be integrated into future residential buildings as the main energy source, which will subsequently reduce the energy cost of water heating. An original configuration for efficient Domestic Hot Water "DHW" storage tank is developed and experimentally evaluated under Saharan climate. This novel DHW configuration includes a hybrid (solar and electric) energy system with a flat plate solar collector coupled with an electric heater. Additionally, phase change material "PCM" mixture that is composed of paraffin wax and animal fat with a melting temperature between 35.58°C and 62.58°C and latent heat between 180 and 210 kJ/kg is integrated into this novel tank configuration. The experimental results indicated that hot water production by using latent heat storage could be economically attractive. In this proposed configuration, one liter of hot water may cost around 0.1362 DZD/liter (i.e., 0.00096 US$/liter) compared to 0.4431 DZD/liter for the conventional water heater, an average energy cost savings of 69.26%. On a yearly basis, the average energy cost savings may reach up to 80.25% if optimal tilt for the solar collector is adopted on a monthly basis. The flat plate collector may be vulnerable to convective heat transfer, and therefore, other solar collectors such as vacuum tube collectors may provide enhanced energy performance. Keywords: hybrid DHW system; water heater; PCM; melting temperature; latent heat storage; produced water cost 1. Introduction According to the Ecological Transition Agency (ADEME), the domestic hot water (DHW) of a French household is a major energy consumption item since it represented, in 2012, 12.1% of the average energy consumption, against 61.3% for heating and 7% for cooking [1]. To determine the energy consumption of the electric water heater storage tank, several factors must be taken into account: the capacity of the hot water tank, the family composition, and hot water consumption patterns. Regardless of the tank volumes (i.e., 50 liters, 150 liters, or Disclaimer/Publisher’s Note: The statements, opinions, and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions, or products referred to in the content. Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 6 December 2022 doi:10.20944/preprints202212.0095.v1 © 2022 by the author(s). Distributed under a Creative Commons CC BY license.