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c_geo_more

What can I choose in the calculator?

The calculator lets you choose the share of total centralised heat demand covered by Deep Geothermal in Switzerland in the selected year (2035 or 2050).

Deep Geothermal

image

Contents

  • Impact
  • Global market
  • Definition
  • Constraints
  • Assumptions
  • References

IMPACT – What are the impacts of Deep Geothermal?

In Switzerland, increasing the share of Deep Geothermal will have the following impacts:

Energy system

image Reduces final energy demand.

image May decreases total electricity consumption.

image Likely to reduce total fossil fuel consumption.

image Likely to increase the share of renewable energy sources in the energy mix.

image Likely to increase energy independence and energy security by providing sustainable baseload electric power.

Environment & Climate

image Very likely to reduce global CO2 emissions.

image Avoid emissions of harmful pollutants by replacing combustion processes.

image Drilling and injection may cause seismic activity and have other unforeseen environmental impacts.

Society & Economy

image Likely to decrease the cost of the energy transition.

image May improve balance of payments by reducing fossil fuel imports.

image Likely to reduce Confederation income from the tax on mineral oil under the current taxation system.

GLOBAL MARKET – What is the global market for Deep Geothermal?

In 2013 there were 68 geothermal power plants in Europe, of which 8 were installed in 2013. The total electric capacity of these plants is about 2 GWe. Also in 2013 there were 237 geothermal district heating plants in Europe of which 15 were installed in 2013. The total thermal capacity of these plants is about 4 GWth. [3]

DEFINITION / CONSTRAINTS

DEFINITION - What is Deep Geothermal?

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.

CONSTRAINTS - What are the key barriers facing Deep Geothermal deployment?

• 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.

ASSUMPTIONS – WHAT ARE THE ASSUMPTIONS CONSIDERED IN THE CALCULATOR?

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 [2]. This EGS produces 19 MW of electricity and 34 MW of heat as shown on the next balance:

Inlets and outlets for an ORC with draw-off

Emissions
2035 2050
CO2-eq. emissions [kgCO2-eq./kWhe] 0.0105 0.0105
Deposited waste [UBP/kWhe] 19.8 19.8
Cost
2035 2050
Specific investment [CHF/kWe] 11'164 6'310

REFERENCES

[1] European Geothermal Energy Council, Geothermal Market Report 2013/2014

[2] L. Gerber (2012), Integration of Life Cycle Assessment in the conceptual design of renewable energy conversion systems.

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c_geo_more.txt · Last modified: 2019/10/22 09:17 (external edit)