Underground Thermal Energy Storage Application in Erbil City Kurdistan, Region-Iraq (Case Study)

Abstract

Energy storage technology is used to save energy. Different storage methods are used depending on the energy form. A borehole thermal energy storage system is an underground structure for large quantities of heat and cool energy in soil and rock. Earth energy design 2.0 PC-Program is used for borehole design. The test building consists of six class rooms. Total build area was about 1200m², height was 3m and the total volume was 3600m³.The annual mean temperature was 20.95 ͦ C. The degree hour method is used to calculate the energy demand above the base temperature 17 ͦ C for heating and 20 ͦ C for cooling. The required maximum power demand for heating is 158.4KW and the maximum power demand for cooling the building is 211.2KW. In the months of January, February, March, April and November and the total heating demand for the building is 254,52MWh. In the months of May, June, July, August and September, the total cooling demand for the building is 10MWh. Earth energy designer was applied for a proper hole system. Five attempts were applied by changing the seasonal performance factor and each attempt was divided in to two sections according to the assumed borehole spacing and details seasonal performance factor (SPF) is strongly correlated to the borehole depth and borehole spacing. To get a high SPF value, the borehole depth and spacing must be increased.

Keywords: Thermal energy, SPF, Kurdistan, Iraq.