Integrated heat storage and e-conversion asset

CHANGELOG.md

@@ -1,7 +1,7 @@
 # [Unreleased-main] - 2026-02-05
 
 ## Added
-- xxx
+- Addition of heat buffer asset with electric charging (i.e. HeatBufferElec) is added
 
 ## Changed
 - xxx
@@ -28,7 +28,7 @@
 - Clean up of old code and removing duplicates.
 - Minimize TCO objective in the grow_workflow is now only based on capex and opex that can be influenced.
 - Removed the requirement of "_ret" for the return network pipes, for ESDLversion 21.10 and later. The relation between supply and return pipes is now based on the "related" attribute in the esdl.
-- Addtion of cooling assests (airco and low_temperature_ates) in the grow_workflow for heating and cooling networks
+- Addition of cooling assests (airco and low_temperature_ates) in the grow_workflow for heating and cooling networks
 - Inclusion of airco and low_temperature_ates in write_output
 - New data structute for specifying database connection inputs
 - Costs of available pipe classes are updated based on the asset measures and templates if they are provided.

src/mesido/esdl/asset_to_component_base.py

@@ -898,6 +898,7 @@ def _get_connected_i_nominal_and_max(self, asset: Asset) -> Tuple[float, float]:
             or asset.asset_type == "Electrolyzer"
             or asset.asset_type == "ElectricBoiler"
             or asset.asset_type == "HeatPump"
+            or asset.asset_type == "HeatStorage"
         ):
             for port in asset.in_ports:
                 if isinstance(port.carrier, esdl.ElectricityCommodity):

src/mesido/esdl/esdl_heat_model.py

@@ -41,6 +41,7 @@
     GasTankStorage,
     GeothermalSource,
     HeatBuffer,
+    HeatBufferElec,
     HeatDemand,
     HeatExchanger,
     HeatPipe,
@@ -323,7 +324,22 @@ def _generic_heat_modifiers(min_heat=None, max_heat=None, q_nominal=None) -> Dic
 
         return modifiers
 
-    def convert_heat_buffer(self, asset: Asset) -> Tuple[Type[HeatBuffer], MODIFIERS]:
+    def _get_min_voltage(self, asset: Asset) -> float:
+        """
+        Args:
+            asset: mesido common asset with all attributes
+
+        Returns:
+            value: minimum voltage of electric carrier in V
+        """
+        for port in asset.in_ports:
+            if isinstance(port.carrier, esdl.ElectricityCommodity):
+                min_voltage = port.carrier.voltage
+        return min_voltage
+
+    def convert_heat_buffer(
+        self, asset: Asset
+    ) -> Tuple[Union[Type[HeatBufferElec], Type[HeatBuffer]], MODIFIERS]:
         """
         This function converts the buffer object in esdl to a set of modifiers that can be used in
         a pycml object. Most important:
@@ -429,6 +445,8 @@ def convert_heat_buffer(self, asset: Asset) -> Tuple[Type[HeatBuffer], MODIFIERS
         )
 
         q_nominal = self._get_connected_q_nominal(asset)
+        if isinstance(q_nominal, dict):
+            q_nominal = q_nominal["Q_nominal"]
 
         modifiers = dict(
             height=r,
@@ -439,12 +457,43 @@ def convert_heat_buffer(self, asset: Asset) -> Tuple[Type[HeatBuffer], MODIFIERS
             Heat_buffer=dict(min=-hfr_discharge_max, max=hfr_charge_max),
             init_Heat=min_heat,
             **self._generic_modifiers(asset),
-            **self._generic_heat_modifiers(-hfr_discharge_max, hfr_charge_max, q_nominal),
             **self._supply_return_temperature_modifiers(asset),
             **self._rho_cp_modifiers,
             **self._get_cost_figure_modifiers(asset),
+            **self._generic_heat_modifiers(-hfr_discharge_max, hfr_charge_max, q_nominal),
         )
+        if len(asset.in_ports) == 2 and len(asset.out_ports) == 1:
 
+            # TODO: CO2 coefficient
+
+            min_voltage = self._get_min_voltage(asset)
+            i_max, i_nom = self._get_connected_i_nominal_and_max(asset)
+
+            # ToDo: Check if max_supply (and also elec_power_nominal)
+            #  can be defined via hfr_charge_max.
+            max_supply = hfr_charge_max
+            charging_efficiency = 1.0
+            if asset.attributes["chargeEfficiency"]:
+                charging_efficiency = asset.attributes["chargeEfficiency"]
+            else:
+                logger.error(
+                    f"'chargeEfficiency' attribute is not defined in esdl for {asset.name}."
+                    f" 1.0 is taken as default."
+                )
+                charging_efficiency = 1.0
+
+            modifiers.update(
+                dict(
+                    elec_power_nominal=max_supply,
+                    ElectricityIn=dict(
+                        Power=dict(min=0.0, max=max_supply, nominal=max_supply / 2.0),
+                        I=dict(min=0.0, max=i_max, nominal=i_nom),
+                        V=dict(min=min_voltage, nominal=min_voltage),
+                    ),
+                    charging_efficiency=charging_efficiency,
+                )
+            )
+            return HeatBufferElec, modifiers
         return HeatBuffer, modifiers
 
     def convert_heat_demand(self, asset: Asset) -> Tuple[Type[HeatDemand], MODIFIERS]:
@@ -2582,9 +2631,7 @@ def convert_heat_source_elec(
         # TODO: CO2 coefficient
 
         q_nominal = self._get_connected_q_nominal(asset)
-        for port in asset.in_ports:
-            if isinstance(port.carrier, esdl.ElectricityCommodity):
-                min_voltage = port.carrier.voltage
+        min_voltage = self._get_min_voltage(asset)
         i_max, i_nom = self._get_connected_i_nominal_and_max(asset)
 
         modifiers.update(
@@ -2661,9 +2708,7 @@ def convert_air_water_heat_pump_elec(
         # TODO: CO2 coefficient
 
         q_nominal = self._get_connected_q_nominal(asset)
-        for port in asset.in_ports:
-            if isinstance(port.carrier, esdl.ElectricityCommodity):
-                min_voltage = port.carrier.voltage
+        min_voltage = self._get_min_voltage(asset)
         i_max, i_nom = self._get_connected_i_nominal_and_max(asset)
         cop = asset.attributes["COP"] if asset.attributes["COP"] else 1.0
 

src/mesido/esdl/esdl_model_base.py

@@ -225,7 +225,7 @@ def __set_primary_secondary_heat_ports():
                             f"Heat out_ports "
                         )
             elif (
-                asset.asset_type == "ElectricBoiler"
+                (asset.asset_type == "ElectricBoiler" or asset.asset_type == "HeatStorage")
                 and len(asset.out_ports) == 1
                 and len(asset.in_ports) == 2
             ):
@@ -239,8 +239,8 @@ def __set_primary_secondary_heat_ports():
                         port_map[p.id] = getattr(component, out_suf)
                     else:
                         raise Exception(
-                            f"{asset.name} has does not have 1 electricity in_port 1 gas in port "
-                            f"and 1 Heat out_ports "
+                            f"{asset.name} has does not have 1 electricity in_port 1 electric "
+                            f"in port and 1 Heat out_ports "
                         )
             elif asset.asset_type == "Electrolyzer":
                 if len(asset.out_ports) == 1 and len(asset.in_ports) == 1:

src/mesido/pycml/component_library/milp/__init__.py

@@ -39,13 +39,15 @@
 from .multicommodity.elec_heat_source_elec import ElecHeatSourceElec
 from .multicommodity.electrolyzer import Electrolyzer
 from .multicommodity.gas_heat_source_gas import GasHeatSourceGas
+from .multicommodity.heat_buffer_elec import HeatBufferElec
 
 __all__ = [
     "Airco",
     "AirWaterHeatPump",
     "AirWaterHeatPumpElec",
     "ATES",
     "HeatBuffer",
+    "HeatBufferElec",
     "CheckValve",
     "ColdDemand",
     "Compressor",

src/mesido/pycml/component_library/milp/heat/heat_buffer.py

@@ -8,7 +8,7 @@
 
 
 @add_variables_documentation_automatically
-class HeatBuffer(_StorageComponent):
+class _HeatBufferComponent(_StorageComponent):
     """
     The buffer component is to model milp storage in a tank. This means that we model a tank of hot
     water being filled and radiating milp away (heat loss) over the hot surfaces. We assume that the
@@ -94,4 +94,23 @@ def __init__(self, name, **modifiers):
             (self.Heat_loss - self.Stored_heat * self.heat_loss_coeff) / self._nominal_heat_loss
         )
 
+
+@add_variables_documentation_automatically
+class HeatBuffer(_HeatBufferComponent):
+    """
+    HeatBuffer component represents the operational behavior of conventional heat buffer.
+    It sets heat_flow equal to heat_buffer.
+
+    Variables created:
+        {add_variable_names_for_documentation_here}
+
+    Parameters:
+        name : The name of the asset. \n
+        modifiers : Dictionary with asset information.
+
+    """
+
+    def __init__(self, name, **modifiers):
+        super().__init__(name, **modifiers)
+
         self.add_equation((self.Heat_flow - self.Heat_buffer) / self.Heat_nominal)

src/mesido/pycml/component_library/milp/multicommodity/__init__.py

@@ -2,10 +2,12 @@
 from .elec_heat_source_elec import ElecHeatSourceElec
 from .electrolyzer import Electrolyzer
 from .gas_heat_source_gas import GasHeatSourceGas
+from .heat_buffer_elec import HeatBufferElec
 
 __all__ = [
     "AirWaterHeatPumpElec",
     "ElecHeatSourceElec",
     "Electrolyzer",
     "GasHeatSourceGas",
+    "HeatBufferElec",
 ]

src/mesido/pycml/component_library/milp/multicommodity/heat_buffer_elec.py

@@ -0,0 +1,53 @@
+from mesido.pycml import Variable
+from mesido.pycml.component_library.milp.electricity.electricity_base import ElectricityPort
+from mesido.pycml.component_library.milp.heat.heat_buffer import _HeatBufferComponent
+from mesido.pycml.pycml_mixin import add_variables_documentation_automatically
+
+from numpy import nan
+
+
+@add_variables_documentation_automatically
+class HeatBufferElec(_HeatBufferComponent):
+    """
+    The HeatBufferElec component represents a heat buffer that can be charged exclusively
+    using electricity. This asset cannot be charged by water flow through the inlet/outlet pipes
+
+    Variables created:
+        {add_variable_names_for_documentation_here}
+
+    Parameters:
+        name : The name of the asset. \n
+        modifiers : Dictionary with asset information.
+    """
+
+    def __init__(self, name, **modifiers):
+        super().__init__(
+            name,
+            **modifiers,
+        )
+
+        self.component_subtype = "heat_buffer_elec"
+        self.elec_power_nominal = nan
+        self.charging_efficiency = nan
+
+        # # Assumption: heat in/out is nonnegative
+        self.add_variable(ElectricityPort, "ElectricityIn")
+        self.add_variable(Variable, "Power_elec", min=0.0, nominal=self.elec_power_nominal)
+        self.add_variable(Variable, "Heat_elec_charging", min=0.0, nominal=self.elec_power_nominal)
+        #
+        self.add_equation(((self.ElectricityIn.Power - self.Power_elec) / self.elec_power_nominal))
+        #
+        self.add_equation(
+            (
+                (self.Power_elec * self.charging_efficiency - self.Heat_elec_charging)
+                / self.elec_power_nominal
+            )
+        )
+
+        # Heat flow balance of the buffer
+        self.add_equation(
+            (self.Heat_flow + self.Heat_elec_charging - self.Heat_buffer) / self.Heat_nominal
+        )
+
+        # Buffer can only discharge into heat network. It cannot be charged by heat network
+        self.Heat_flow.max = 0.0

tests/models/simple_buffer/input/timeseries_import_ebuffer.csv

@@ -0,0 +1,46 @@
+DateTime,demand,elec
+19-5-2013 22:00,150000,5.00E-05
+19-5-2013 23:00,150000,5.00E-05
+20-5-2013 00:00,150000,5.00E-05
+20-5-2013 01:00,150000,5.00E-05
+20-5-2013 02:00,150000,5.00E-05
+20-5-2013 03:00,150000,5.00E-05
+20-5-2013 04:00,150000,5.00E-05
+20-5-2013 05:00,150000,5.00E-05
+20-5-2013 06:00,150000,5.00E-05
+20-5-2013 07:00,150000,5.00E-05
+20-5-2013 08:00,150000,5.00E-05
+20-5-2013 09:00,150000,5.00E-05
+20-5-2013 10:00,150000,5.00E-05
+20-5-2013 11:00,150000,5.00E-05
+20-5-2013 12:00,150000,5.00E-05
+20-5-2013 13:00,150000,5.00E-05
+20-5-2013 14:00,100000,5.00E-05
+20-5-2013 15:00,100000,5.00E-05
+20-5-2013 16:00,100000,5.00E-05
+20-5-2013 17:00,100000,5.00E-05
+20-5-2013 18:00,100000,0.00015
+20-5-2013 19:00,100000,0.00015
+20-5-2013 20:00,100000,0.00015
+20-5-2013 21:00,100000,0.00015
+20-5-2013 22:00,100000,0.00015
+20-5-2013 23:00,100000,0.00015
+21-5-2013 00:00,100000,0.00015
+21-5-2013 01:00,100000,0.00015
+21-5-2013 02:00,100000,0.00015
+21-5-2013 03:00,70000,0.00015
+21-5-2013 04:00,70000,0.00015
+21-5-2013 05:00,70000,0.00015
+21-5-2013 06:00,70000,0.00015
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+21-5-2013 08:00,70000,0.00015
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+21-5-2013 18:00,70000,0.00015