Reduction of prime energy consumption in the Middle East by GSHP systems

Abstract: The global energy consumption, which increased ~84% during last thirty years, exceeded 1.4.1011 MWh in 2008. It is projected to increase another ~39% until 2030. Current energy trends are unsustainable. Considering that 30-50 % of the global energy consumption is consumed for heating and cooling, more efficient heating and cooling systems are needed. The current power situation in Syria is serious and is likely to speed up the implementation of renewable energy systems. Comparison between the conventional fuel heater, electrical heater, air source heat pump and ground source heat pump in Syrian climate shows that GSHP systems have big potential and can make huge contributions to overcome the current energy shortage in Syria. Since the heating demand in Syria is almost twice the cooling demand, it is possible to use such systems for free cooling. Therefore, heat recharge of the borehole field is important. The amount of available solar energy in Syria, means that the combination of solar and GSHP has great potential. Climatic and geological conditions were analyzed for GSHP systems in Syria, which was chosen as a case study for the Middle East. A general study was made on the need for large-scale utilization of renewable energy, including an overview of different energy storage systems for heating and cooling. Chicken farms were chosen as a study case since the poultry industry is an important sector in Syria. There are 13,000 chicken farms with an annual production of 172,000 tons of meat. It employs almost 150,000 people and has a large heating and cooling demand (1.34 TWh/year). Next step was the design and simulate the operation of a GSHP system for a typical chicken farm in Syria. Based on this study the national potential for such systems was estimated. GSHP systems at all Syrian chicken farms would annually save 114,000 m3 of oil. Since GSHPs use the ground as a source or sink of thermal energy, the ground temperature is most important for its operation and efficiency. The ongoing global warming, whichmeans that air, ground, and water is getting warmer, has therefore some consequences on such systems. Firstly, the effect of global warming on the ground temperature was studied. An equation, which describes the change of ground temperature field as a function of depth, time, and ground thermal properties, and local (global) warming, was derived. Secondly, the effect of the warming on heating and cooling demand of a certain building was studied in combination with its affects on the efficiency of GSHP system. The proper design of BHE requires knowledge of ground thermal properties, i.e. effective ground thermal conductivity, thermal resistance, and undisturbed ground temperature. Such site specific data were determined by thermal response test for heating and cooling of the Kharseh chicken farm in Hama, Syria. Used thermal response test equipment was designed and constructed within the project. Borehole thermal resistance has considerable effect on the performance of borehole heat exchangers. Therefore,forced convection in a water filled borehole (i.e. non-grouted) was tested to improve the heat transfer. Injected air, at the bottom of a borehole, resulted in a 28% reduction of thermal resistance. Since injected air bubbles caused convection also in the groundwater, surrounding the borehole, the effective thermal conductivity was increased 28%. Future work aims at the construction, operation, and monitoring of suggested GSHP system at the Kharseh chicken farm in Syria. The idea is to demonstrate the GSHP system as a means of promoting and implementing such systems in the Middle East. The main problem now is to get required permissions to build the ground heat exchangers since there is no existing permit procedure for such systems.