Comparisons between ground and air source heat pumps in hot/dry climates : Saudi Arabia as a case study

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 data exists in terms of the GSHP systems. This paper aims to investigate the feasibility of using GSHP systems in hot and dry regions and Saudi Arabia is a case study by comparison between using a ground source heat pump and the conventional air source heat pump (ASHP) systems based on Saudi Arabia climates conditions. In order to compare the economics of geothermal heat pump systems to other HVAC alternatives, a direct capital costs comparison is made between GSHP and ASHP. Based on the length of the ground loop, which was calculated using the ASHRAE method, the initial installation cost for GSHP leads to an increase in the investment costs of GSHP because of the extra expensive drilling costs for the ground loop heat exchanger and piping. However, over the period of approximately 22 years there is a 19.6% total cost savings using GSHP compared to ASHP and the GSHP is more feasible with a long payback period. Also, the CO2 emission decrease by about 34%

Long-term desalinated water demand and investment requirements: a case study of Riyadh

The Kingdom of Saudi Arabia (KSA) is situated in an arid region and faces a chronic challenge to meet its increasing water demand. Riyadh is the capital of KSA and home to about six million people. The water demand is mostly met by groundwater resources (up to 48%), while the desalination plants cover the rest of the water supply requirements. There is a potential risk of a significant gap in water demand–supply due to the retirement of old desalination plants. This study, therefore, developed a probabilistic model to forecast desalinated water demand in Riyadh for domestic purposes up to the year 2040 based on three scenarios: low growth, the most likely (mean), and high growth scenario. The results showed that an investment of about US$6.24, 11.59, and 16.04 billion is required to meet the future domestic water demand of the city for the next 25 years based on low, mean, and high growth scenarios, respectively. Moreover, a strong commitment to public–private partnership is required to remove the fiscal budget burden related to the desalination along with public awareness campaigns to reduce per capita water consumption, upgrading the water tariff system and using renewable energy to run desalination plants