Direct Use of Geothermal Energy

 

 

                              District Heating Scheme                                                                       Geothermally heated greenhouse in Idaho

 

Geothermal reservoirs of low and moderate temperature water (20°C to 150°C) provide direct heat for commercial, industrial and residential uses. The primary uses are in district & space heating, greenhouses & fish farms. It is also used food processing facilities, gold mining operations, spas, for heating road and sidewalks.

 

Direct use systems typically include:

 

1. A production facility – usually a well – to bring the hot water to the surface;

 

2. A mechanical system – piping, heat exchanger, controls – to deliver the heat to the space or process;

 

3. A disposal system – injection well or storage pond – to receive the cooled geothermal fluid.

 

Advantages

• Economical to use & provides 80% saving over fossil fuels.
• Minimises land use and impact (there is no need to construct space for conventional space heating equipment, such as boilers and gas vents)
• Meets water and clean air standards

   

  Disadvantages

• The geothermal resource must be located near the demand, as transportation of hot fluids is not viable.

• •Uncertainty about the lifetime and productivity of the project due to individual geological characteristics affecting water flow.

• •Many locations for the utilisation of direct heat energy would need two boreholes to dispose of the fluids (which is less economically and environmentally attractive).