District Heating

The district heating technology represents the district heating network (DHN).

The district heating network can be supplied with heat in two different ways: Firstly, it can import heat from an unknown source. This is what is represented when running the model for an arbitrary Swiss municipality with a district heating network without optimization. The imported district heat has a constant CO2 intensity and cost that do not depend on time. Alternatively, heat generators, which are connected in the heat_sources section, can be connected to the DHN. These heat_sources are only used when running the model with optimization.

Then running without optimization, the amount of heat demand attached to the DHN is determined from the heat generator entries in the RBD (Federal Registry of buildings and dwellings). When optimizing, also other buildings can be attached to the DHN. For this, there are two different capex calculation mode. Firstly, the if closeness_based_dh_expansio_cost is False, the cost is a constant capex cost per kW of power needed. Secondly, if closeness_based_dh_expansio_cost = True, the buildings are grouped into four groups: firstly those already connected to the DHN, and then three different categories grouped by their heat demand relative to their average distance to neighbouring buildings. Thereby, both an approximative distance to neighbouring buildings, giving a measure for the cost of grid expansion, and a heat demand per group is determiend. The cost of expansion and of maintaining the DHN is then calculated based on the parameters investment_dh_grid_per_m and maintenance_cost_dh_grid_per_m. In the distance based expansion mode, some buildings cannot be connected to the DHN as they are too far away from other nearby buildings.

Attribute	Description	Standard value	Unit	Data type
deployment	If set to ‘true’, the technology will be considered in the energy system model (this does not necessarily mean it will be used). Only relevant for optimisation.	True	—	bool
demand_share_type		free		str
demand_share_val		0.5		float
import_kW_th_max	Maximum thermal capacity of heat import (from outside the municipality).	‘inf’	kW	float
grid_kW_th_max	Maximum thermal capacity of the grid.	‘inf’	kW	float
investment_dh_grid_per_m		400	CHF/m	int
maintenance_cost_dh_grid_per_m		5	CHF/m/year	int
closeness_based_dh_expansio_cost		True		bool
capex		1000	CHF/kW	float
maintenance_cost		10	CHF/kW/year	float
tariff_CHFpkWh	Tariff for imported heat.	0.13	CHF/kWh	float
co2_intensity	Carbon-dioxide intensity of technology output (annual average value).	0.108	kg CO2/kWh	float
lifetime	Expected lifetime of technology before replacement is required.	25	years	int
interest_rate	Interest rate for computing levelised costs (if required).	0.025	—	float
heat_sources	Connected heat sources		—	dict
heat_sources: import	If set to ‘true’, heat import is allowed (based on ‘import_kW_th_max’)	True	—	bool
heat_sources: chp_gt	If set to ‘true’, CHP gas turbine plant is connected to district heating network (DHN). Technology must be deployed accordingly.	False	—	bool
heat_sources: steam_turbine	If set to ‘true’, steam turbine is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: waste_to_energy	If set to ‘true’, the waste-to-energy plant is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: heat_pump_cp	If set to ‘true’, a central heat pump is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: heat_pump_cp_lt	If set to ‘true’, a central heat pump converting low-temperature waste heat into useful heat is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: oil_boiler_cp	If set to ‘true’, a central oil boiler is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: electric_heat_cp	If set to ‘true’, a central electric resistance heater is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: wood_boiler_cp	If set to ‘true’, a central wood boiler is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: gas_boiler_cp	If set to ‘true’, a central gas boiler is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: waste_heat	If set to ‘true’, a hot waste heat source is connected to the DHN. Technology must be deployed accordingly.	False	—	bool
heat_sources: biomass	If set to ‘true’, biomass technologies are connected to the DHN. Technology must be deployed accordingly.	False	—	bool

The symbols and names of the flows are

m_h_dh

Import District Heat