Multifamily residence in Ramallah

This GSHP system with a heating capacity of 23 kW for a multifamily residence located in Ramallah, Palestine is the first geothermal heating and cooling system in the Middle East and North Africa. It is designed to achieve a SPF (Seasonal Performance Factor) of 4,4 compared to a conventional system that experiences a SPF of 2,3. The system utilizes a 70 meters deep vertical ground heat-exchanger. It is expected to reduce operating costs from $9.100 per year to merely $2.900 per year, which is 70 percent in savings, resulting in a simple payback period of 4,2 years. This geothermal system was funded by the European Union’s MED-ENEC project.

Project description

Building, overall energy concept

The Geothermal Pilot Project is part of the Etihad Subdivision, the largest residential subdivision undergoing construction in Palestine. Built in the city of Ramallah, located just north of Jerusalem and Bethlehem, the subdivision includes 62 semi-detached villas and a commercial center built on an area of 24.000 m² (Figure 1).

The purpose of Geothermal Pilot Project was to test the feasibility and functionality of geothermal heating and cooling in Palestine. The 300 m² model villa in the Etihad Subdivision was selected as the location for installing the pilot project. It includes three floors, a walk-out basement and a garage (Photo 1).

Before installing the geothermal system, it was necessary to focus on improving the model villa's efficiency. It was necessary to improve the villa's insulation thereby reducing the total heating and cooling energy requirement and the total required geothermal ground heat exchanger (ground loop). In order to meet the EU insulation standards the villa's walls and windows were insulated to reach U-values of 0,87 W/K•m² and 2,98 W/K•m² respectively. Even the floor was insulated to a U-value of 0,8 W/K•m² to reduce heat loss and heat gain from the walk-out basement and garage below. This improvement in insulation reduced the heating and cooling load requirements by 20 %.

Heat pump system

To meet the 23 kW cooling load and 21 kW heating load, two water-to-air geothermal heat pumps were selected to provide both heating and cooling to the model villa (Photo 2). The distribution system selected was a duct distribution system, as it can economically provide both heating and cooling. In addition, to creating a comfortable and healthy breathing environment in the villa, a fresh-air intake was incorporated in the duct design.

Due to the population density of Palestine, there is a lack of land area available for installing ground heat exchangers. To save space and provide an efficient heat exchange with the earth, the ground heat exchanger was designed as vertical closed loop, with borehole radial spacing of 3 m between each borehole. Ten holes were drilled at a depth of 70 m, giving a total ground heat exchanger length of 700 m (Figure 2).

This design is able to achieve an worst case scenario COP (coefficient of performance) of 4,4 year round. That is, for every 1 unit of electricity required to power the twin geothermal heat pumps and the small water circulating pumps, the system will provide 4,4 units of heating energy, giving the geothermal system a worst case efficiency rating of 440%.

- Number of heat pumps installed: 2

- Heating/cooling capacity: 14 kW each

- Refrigerant: 410A

- Annual hours of operation: 7.488 hrs (if operated 24 hrs/day), 5.489 hrs (if operated 18 hrs/day)

- Quality label for the appliance: ARI/ISO

- Certified drilling company: MENA Geothermal


For the schematic of the geothermal system click here.

Photo 3: Leading-in of ground source heat exchanger loops into the building

Operation experiences

• Measurement campaign: MENA Geothermal will be monitoring the geothermal system for a period of 1 year (one cooling season and one heating season).
• Customer's satisfaction: Very satisfied!

Costs, economic efficiency, incentives

The most common conventional HVAC systems in Palestine use diesel-powered boilers with radiators for heating and forced-air split units for air conditioning. With the current energy prices in Palestine, operating costs for conventional systems, especially diesel-powered boilers, have become simply unbearable for most Palestinians. If the geothermal system is operated to maintain a comfortable room temperature all year long it is expected to reduce operating costs from $9.100 per year to a merely $2.900 per year (Diagr. 1), which is 70 percent in savings, resulting in a simple payback period 0f 4,2 years. This amounts to a reduction in energy consumption of roughly 32.000 kWh per year (Diagr. 2).

- Geothermal investment cost: $53.000

- Annual heating/cooling cost: $2.900

- Maintenance cost: $100

- Electricity Price: $0,18/kWh

- Diesel Price: $1,98/litre

- Pay-back time: 4,2 years

- Cost savings compared to other technologies: 70%

- Financial support, incentive programmes: There are is no financial support or incentives currently in Palestine.

Regulations, guidelines, benchmarking

No information available.

References

• Press release: Geothermal goes MENA - MED-ENEC Pilot Project in Ramallah inaugurated. 17 August 2008
• An international Success story: Palestine's first geothermal project. Khaled Al Sabawi and Kelly Green, Geo Outlook, Vol. 5 No. 1 p. 18-22

¹ Undergoing monitoring 2008-2009
² ARI/ISO
³ ARI/ISO
⁴ Assuming system runs for 24 hrs/day
⁵ Assuming system runs for 24 hrs/day
⁶ Primary Energy Ratio: Useful heating (and cooling) energy delivered / primary energy input (kWh_UE / kWh_PE)