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|4 Sep 2011|
Masdar tests geothermal energy for green city.
One of the most exciting projects at Masdar City was the exploratory drilling deep underground to test the availability of sufficient, and sufficiently hot, geothermal water to be used in thermal cooling and domestic hot water.
Power production and desalination also constitute possible applications of geothermal energy, although in our case, purely thermal applications (cooling, domestic hot water, desalination) are the most advantageous.
The amount of cooling, desalination and heating the geothermal resource can provide is being evaluated. This will be a direct geothermal plant relying on heat exchange with deep underground aquifers.
Initial results are promising and confirm Masdar City’s ability to address a significant portion of the base cooling load of the city’s first phase using absorption chillers continuously supplied with geothermal heat. The main focus initially is expected to be thermal cooling and, possibly, central provision of hot water for showers and sinks.
The drilling of a pair of wells is complete – one for drawing hot water, one for re- injection of this water after heat extraction. Both wells have been drilled to about 2,500m, where sufficient temperature and flow have been achieved to drive an efficient configuration of absorption chillers.
For power generation and/or desalination, deeper wells would be needed to reach higher temperature aquifers. The stationary geothermal water temperatures in the aquifers below Masdar City can be estimated at between 85°C and 105°C.
The rig used for drilling was a relatively large oil and gas drilling rig that had undergone minor modifications for geothermal operations. Now that the rig has completed drilling, the wells will provide energy to Masdar City with a minimal visible footprint on the ground.