Design and Development of Solar Thermal Energy using Phase Change Materials – Thermal Storage in Oman Sulaiman Al-Hashmi 1 , Peter Heggs 2 , Darron Dixon-Hardy 2 1 Center for Environmental Studies and Research, Sultan Qaboos University, Oman 2 Energy Research Institute, University of Leeds, Leeds, LS2 9JT, UK. Corresponding author Sulaiman Al-Hashmi emai : sulimans@squ.edu.om Abstract In Oman, the electricity demand is rapidly increasing. At the same time, Oman is very rich in solar energy resources and possesses large wasteland areas in the Sahara that represent 60% of the total area and the market of solar energy is very promising. All these indicators make Oman an ideal country for the implementation of the Concentrating Solar Thermal Power technologies (CSTP). In order to design and development of solar thermal energy using phase change materials –thermal storage in Oman. The suggested model based on Dish Stirling technology using hydrogen as working fluid for centralized electricity production and Dish phase change materials storage as well as their high capacity in the dynamic performance of heat exchange. Dish-Stirling concentrated solar power system is an important pathway for converting solar energy into electricity at high efficiency. The heat engine adopted the alpha-type Stirling engine. The absorber flux distribution simulation was conducted using ray tracing method and then the 2 m 2 parabolic dish concentrator system (diameter is 1.7m and focal length is 0.99 m) with single concentrator plus single pillar supporting has been designed and built. The testing result shows that this system achieved the net output power of 50W and solar-to-electricity efficiency (SEE) of 25.3% with the direct normal irradiation at 750 W/m 2 . The net output power can further increase to 40.5 kW with the SEE of 26.6% when the DNI reaches up to the maximum of 761 W/m 2 . The net output power of the 38 kW DS-CSP system has a linear function relationship with the DNI. The fitting function is Net power output = 0.1003×DNI－36.129, where DNI is at the range of 460~761 W/m 2 . This function could be used to predict the amount of the 50W DS-CSP system annual generation power. Keywords Solar energy, Stirling engine, Renewable energy, solar parabolic concentre system, thermal energy storage materials, Phase change materials –Storage. 1 Introduction The solar parabolic concentre system has ability to collect thermal energy in receiver point which using Stirling engine to convert solar energy to mechanical energy. These technologies reflect solar radiation onto a receiver centre, which is located inside the Stirling engine. Stirling engine is a heat engine operating by cyclic compression and expansion of working fluid at different temperature levels such as there was a net conversion of heat energy to mechanical function to generate energy. It is also possible to store solar thermal energy in PCMs [1]. There are some of the considerations in designing a parabolic model to be followed; the efficiency of Stirling engine, day period between winter and summer, efficient storage materials and heat transfer capacity on the carrier materials for heat. However, two forms of solar energy technologies used to produce high temperature based on direct radiation including parabolic dish technology and solar tower technology. The literature has shown that parabolic concentrators are used in order to generate power and used for power storage at high temperature. In this regard, researchers on parabolic dish systems focuses more on setting up test facilities only as power conversion units [1], while others focused only a simple solar tracking concentrator in their research applications [2]. Furthermore, some other research treated heat transfer in a conical cavity calorimeter for measuring thermal power of a point focus concentrator [3]. Parabolic concentrating technologies comprise a reflective surface in the shape of parabolic of revolution intended to concentrate solar energy on an absorbing receiver, which makes it possible to reach a high temperature of more than 1000℃ [4,5]. However, solar parabolic dish concentrator (SPDC) or solar dish with Stirling system recorded a world record in solar energy to electric energy conversion efficiency of 31.25 % in 2007 [1]. Since then, there