Techno-economic analysis of ground and air source heat pumps in hot dry climates

The use of ground source heat pump (GSHP) systems in cold climates, such as those in parts of North America, Scandinavian countries and China has been discussed for decades. However, hot and dry climates are encountered in vast regions across the globe but, unfortunately, not much research has taken place in the use of GSHP systems in hot and dry regions. This paper aims to investigate the feasibility of using GSHP systems in hot and dry regions, and Saudi Arabia is an example. This paper introduces for the first time of a techno-economic analysis to evaluate the use of GSHPs compared to the conventional air source heat pump (ASHP) systems in this type of climate. In order to compare the economics of geothermal heat pump systems to other HVAC alternatives, a direct capital cost comparison is made between an example GSHP and ASHP. This is based on the initial investment, payback period, cost energy saving and length of the ground loop, which was calculated for a simple case using the ASHRAE method. Despite the increase in the initial capital costs of GSHP, because of the extra expensive drilling costs for the ground loop heat exchanger and piping the feasibility of GSHP system is worthy of investigates. It is concluded that the GSHP is feasible, albeit with a long payback period, typically 10-20 years, depending on the conditions, setup and predictions. Also it will be seen that there is a savings in CO2 emissions and there may be a substantially decrease in the total costs using GSHP compared to ASHP.