The feasibility of employing stand-alone solar energy systems to meet demand-side loads depends strongly on providing appropriate solar energy storage. The present paper presents an efficient and economical, underground, thermal storage design to store hot water at a temperature of around 180?C required for running a double effect absorption chiller to cool a zero-energy-house in a desert environment. The performance of the design is evaluated employing a specially developed efficient mathematical model, for simulating the steady state radiation, convection and conduction processes occurring within the storage unit. The model is presented and analyzed, and employed to investigate the effects of various design parameters on storage efficiency. It is demonstrated that high storage efficiency may be reached, providing that appropriate insulation materials are used. It is also revealed that the soil conductivity has little effect on storage efficiency.
 M. A. Serag-Eldin, “Thermal Design of a Modern, AirConditioned, Single-Floor, Solar-Powered Desert Home,” International Journal of Sustainable Energy, Vol. 30, No. 2, 2011, pp. 121-141. doi:10.1080/1478646X.2011.562607
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 M. Medrano, A. Gil, I. Martorell, X. Potau and L. F. Cabeza, “State of the Art on High-Temperature Thermal Energy Storage for Power Generation. Part 2. Case Studies,” Renewable and Sustainable Energy Reviews, Vol. 14, No. 1, 2010, pp. 56-72. doi:10.1016/j.rser.2009.07.036
 M. A. Serag-Eldin, “Effect of Environmental Properties on Selection of Absorption Chiller and Thermal Storage for a Desert Home,” Proceedings of the 5th International Exergy, Energy and Environment Symposium, IEEES-5, Luxor, 12-15 December 2011.
 M. A. Serag-Eldin, “Lowering the Sink Temperature of a Desert Solar Air-Conditioning System,” In: C. A. Brebbia and E. Beriatos, Eds., Sustainable Development and Planning V, WIT Press, Southampton, 2011, pp. 227-238. doi:10.2495/SDP110201
 M. A. Serag-Eldin, “Analysis of a Roof-Top CLFR to Drive a Solar Air-conditioning System for a Desert Home,” Proceedings of the 5th International Exergy, Energy and Environment Symposium, IEEES-5, Luxor, 12-15 December, 2011.
 M. A. Serag-Eldin, “Modeling the Energy Systems in a PV Powered Two Floor Desert ZEH,” In: G. M. Carlomagno and C. A. Brebbia, Eds., Computational Methods and Experimental Measurements XV, WIT Press, Southampton, 2011, pp. 267-278.
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