Foreground system:
The modelled geothermal power plant is an averaged flash steam state-of-the-art plant representative for the Icelandic geothermal power plants.
The model consists of geothermal production wells (with well head and silencer), steam separators incl. exhaust, mist eliminators, power plant buildings such as turbine hall and control house, a cooling tower and collection pipes to transport the hot water and steam from the production wells to the power plant and back to wells for re-injection.
The modelled power plant has a 30 MW installed capacity with a annual electricity generation of approx. 250 GWh.
The main parts of a 30 MW state-of-the-art geothermal power plant are:
- Five well heads with silencers for the five production wells to provide controlled hot water pressure for the collection system and noise reduction.
- Two steam separators to separate steam from geothermal brine/hot water
- One steam exhaust for pressure regulation
- Two mist eliminators to remove moisture from the steam
- Turbine hall with steam turbine, 30 MW generator and condenser
- Control building
- Cooling tower
- Collection pipes and other interconnecting pipelines
Background system:
Electricity: Electricity is modelled according to the individual country-specific situations. The country-specific modelling is achieved on multiple levels. Firstly, individual energy carrier specific power plants and plants for renewable energy sources are modelled according to the current national electricity grid mix. Modelling the electricity consumption mix includes transmission / distribution losses and the own use by energy producers (own consumption of power plants and "other" own consumption e.g. due to pumped storage hydro power etc.), as well as imported electricity. Secondly, the national emission and efficiency standards of the power plants are modelled as well as the share of electricity plants and combined heat and power plants (CHP). Thirdly, the country-specific energy carrier supply (share of imports and / or domestic supply) including the country-specific energy carrier properties (e.g. element and energy content) are accounted for. Fourthly, the exploration, mining/production, processing and transport processes of the energy carrier supply chains are modelled according to the specific situation of each electricity producing country. The different production and processing techniques (emissions and efficiencies) in the different energy producing countries are considered, e.g. different crude oil production technologies or different flaring rates at the oil platforms.
Thermal energy, process steam: The thermal energy and process steam supply is modelled according to the individual country-specific situation with regard to emission standards and considered energy carriers. The thermal energy and process steam are produced at heat plants. Efficiencies for thermal energy production are by definition 100% in relation to the corresponding energy carrier input. For process steam the efficiency ranges from 85%, 90% to 95%. The energy carriers used for the generation of thermal energy and process steam are modelled according to the specific import situation (see electricity above).
Transports: All relevant and known transport processes are included. Ocean-going and inland ship transport as well as rail, truck and pipeline transport of bulk commodities are considered.
Energy carriers: The energy carriers are modelled according to the specific supply situation (see electricity above).
Refinery products: Diesel fuel, gasoline, technical gases, fuel oils, lubricants and residues such as bitumen are modelled with a parameterised country-specific refinery model. The refinery model represents the current national standard in refining techniques (e.g. emission level, internal energy consumption, etc.) as well as the individual country-specific product output spectrum, which can be quite different from country to country. The supply of crude oil is modelled, again, according to the country-specific situation with the respective properties of the resources.