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Reduces final energy demand.
May decreases total electricity consumption.
Likely to reduce total fossil fuel consumption.
Likely to increase the share of renewable energy sources in the energy mix.
Likely to increase energy independence and energy security by providing sustainable baseload electric power.
Very likely to reduce global CO2 emissions.
Avoid emissions of harmful pollutants by replacing combustion processes.
Drilling and injection may cause seismic activity and have other unforeseen environmental impacts.
Likely to decrease the cost of the energy transition.
May improve balance of payments by reducing fossil fuel imports.
Likely to reduce Confederation income from the tax on mineral oil under the current taxation system.
Deep geothermal systems draw heat from the earth’s interior and use it to generate heat, electricity or both.
Systems that generate electricity either use the steam that is generated geothermally (steam plants) or use an intermediate working fluid (binary plants). In order to generate electricity, systems with relatively high operating temperatures are required (typically 200°C or above for steam plants and 120°C or above for binary plants). Systems that extract heat at lower temperatures are typically only used to generate heat.
Given the relatively high cost of drilling deep holes—often as deep as several kilometres—only large deep geothermal systems are likely to be economically viable.
• The drilling and liquid injection associated with deep geothermal systems can cause seismic activity.
• There is often significant uncertainty involved in the drilling process meaning that total plant costs are difficult to estimate until completion.
• Geothermal wells inherently have a limited lifetime of about 20-30 years after which the temperatures drop too low to continue operating the well economically. There is also uncertainty surrounding the lifetime of geothermal wells as the rock characteristics could change with time and use.
The selected technology for this model is an Enhanced Geothermal System at 9'500m that uses an ORC cycle with draw-off for the production of electricity and heat. This system is presented in L. Gerber . This EGS produces 19 MW of electricity and 34 MW of heat as shown on the next balance:
|CO2-eq. emissions [kgCO2-eq./kWhe]||0.0105||0.0105|
|Deposited waste [UBP/kWhe]||19.8||19.8|
|Specific investment [CHF/kWe]||11'164||6'310|
 L. Gerber (2012), Integration of Life Cycle Assessment in the conceptual design of renewable energy conversion systems.