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Investment

EnInvestment

Bases: EnBaseModel

Represents an investment model for energy system components.

This class defines the properties and configurations for managing investments in energy system components. The attributes include limits on capacity investment, cost-related parameters, and constraints for both standard and multi-period models. It supports nonconvex investments and custom limits through additional configurations.

Attributes:

Name Type Description
maximum float | None

Maximum additional invested capacity; defined per period in a multi-period model.
minimum float

Minimum additional invested capacity. Defines the threshold when nonconvex is True; defined per period in a multi-period model.
ep_costs float

Equivalent periodical costs or investment expenses per flow capacity in both standard and multi-period models.
existing float

Installed capacity without additional investment costs; not applicable if nonconvex is True.
nonconvex bool

Flag to enable binary variables for investment status, allowing offset costs independent of invested flow capacity.
offset float

Fixed costs for nonconvex investments.
overall_maximum float | None

Overall maximum capacity investment, applicable to multi-period models.
overalL_minimum float | None

Overall minimum capacity investment, applicable to multi-period models.
lifetime int | None

Lifetime of the unit in years, applicable to multi-period models.
age int | None

Start age of the unit in years at the beginning of optimization, applicable to multi-period models.
interest_rate float | None

Interest rate for annuities calculation in a multi-period model; defaults to the model's discount rate if unspecified.
fixed_costs float | None

Fixed costs per period in nominal terms, applicable to multi-period models.
custom_attributes dict

Dictionary of custom constraints or attributes for investment.
Source code in backend/app/ensys/components/investment.py 
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class EnInvestment(EnBaseModel):
    """
    Represents an investment model for energy system components.

    This class defines the properties and configurations for managing investments in energy
    system components. The attributes include limits on capacity investment, cost-related
    parameters, and constraints for both standard and multi-period models. It supports
    nonconvex investments and custom limits through additional configurations.

    :ivar maximum: Maximum additional invested capacity; defined per period in a
        multi-period model.
    :ivar minimum: Minimum additional invested capacity. Defines the threshold when
        nonconvex is True; defined per period in a multi-period model.
    :ivar ep_costs: Equivalent periodical costs or investment expenses per flow capacity
        in both standard and multi-period models.
    :ivar existing: Installed capacity without additional investment costs; not applicable
        if nonconvex is True.
    :ivar nonconvex: Flag to enable binary variables for investment status, allowing offset
        costs independent of invested flow capacity.
    :ivar offset: Fixed costs for nonconvex investments.
    :ivar overall_maximum: Overall maximum capacity investment, applicable to
        multi-period models.
    :ivar overalL_minimum: Overall minimum capacity investment, applicable to
        multi-period models.
    :ivar lifetime: Lifetime of the unit in years, applicable to multi-period models.
    :ivar age: Start age of the unit in years at the beginning of optimization,
        applicable to multi-period models.
    :ivar interest_rate: Interest rate for annuities calculation in a multi-period
        model; defaults to the model's discount rate if unspecified.
    :ivar fixed_costs: Fixed costs per period in nominal terms, applicable to
        multi-period models.
    :ivar custom_attributes: Dictionary of custom constraints or attributes for
        investment.
    :type maximum: float | None
    :type minimum: float
    :type ep_costs: float
    :type existing: float
    :type nonconvex: bool
    :type offset: float
    :type overall_maximum: float | None
    :type overalL_minimum: float | None
    :type lifetime: int | None
    :type age: int | None
    :type interest_rate: float | None
    :type fixed_costs: float | None
    :type custom_attributes: dict
    """
    maximum: float | None = Field(
        None,  # eigtl. float("+inf"),
        title='Maximum',
        description='Maximum of the additional invested capacity; defined per period p for a multi-period model.'
    )

    minimum: float = Field(
        0.0,
        title='Minimum',
        description='Minimum of the additional invested capacity. If nonconvex is True, minimum defines the threshold for the invested capacity; defined per period p for a multi-period model.'
    )

    ep_costs: float = Field(
        0.0,
        title='EP Costs',
        description='Equivalent periodical costs or investment expenses for the investment'
                    'For a standard model: equivalent periodical costs for the investment per flow capacity, i.e. annuities for investments already calculated.'
                    'For a multi-period model: Investment expenses for the respective period (in nominal terms). Annuities are calculated within the objective term, also considering age and lifetime.'
    )

    existing: float = Field(
        0.0,
        title='Existing',
        description='Existing / installed capacity. The invested capacity is added on top of this value. Hence, existing capacities come at no additional costs. Not applicable if nonconvex is set to True.'
    )

    nonconvex: bool = Field(
        False,
        title='Nonconvex',
        description='If True, a binary variable for the status of the investment is created. This enables additional fix investment costs (offset) independent of the invested flow capacity. Therefore, use the offset parameter.'
    )

    offset: float = Field(
        0.0,
        title='Offset',
        description='Additional fixed investment costs. Only applicable if nonconvex is set to True.'
    )

    overall_maximum: float | None = Field(
        None,
        title='Overall Maximum',
        description='Overall maximum capacity investment, i.e. the amount of capacity that can be totally installed at maximum in any period (taking into account decommissionings); only applicable for multi-period models'
    )

    overalL_minimum: float | None = Field(
        None,
        title='Overall Minimum',
        description='Overall minimum capacity investment, i.e. the amount of capacity that can be totally installed at minimum in any period (taking into account decommissionings); only applicable for multi-period models'
    )

    lifetime: int | None = Field(
        None,
        title='Lifetime',
        description='Units lifetime, given in years; only applicable for multi-period models'
    )

    age: int | None = Field(
        None,
        title='Age',
        description='Units start age, given in years at the beginning of the optimization; only applicable for multi-period models'
    )

    interest_rate: float | None = Field(
        None,
        title='Interest Rate',
        description='Interest rate for calculating annuities when investing in a particular unit; only applicable for multi-period models. If nothing else is specified, the interest rate is the same as the model discount rate of the multi-period model.'
    )

    fixed_costs: float | None = Field(
        None,
        title='Fixed Costs',
        description='Fixed costs in each period (given in nominal terms); only applicable for multi-period models'
    )

    custom_attributes: dict = Field(
        {},
        title="Custom Attributes",
        description="Custom Attributes as dictionary for custom investment limits."
    )

    # kwargs: Dict = Field(
    #    None,
    #    title='kwargs',
    #    description='Extra arguments for the object'
    # )

    def to_oemof(self, energysystem: solph.EnergySystem) -> solph.Investment:
        """
        Converts the object's internal configuration to an oemof.solph Investment object.

        This method takes an oemof EnergySystem object and uses the provided system
        configuration to construct and return an oemof.solph Investment object. The
        generated Investment object encapsulates investment-related parameters for
        use in energy system modeling, particularly for optimization.

        :param energysystem: The oemof.solph EnergySystem object containing the
            necessary system configuration and parameters.
        :type energysystem: solph.EnergySystem
        :return: An oemof.solph Investment object constructed based on the internal
            configuration and the provided EnergySystem object.
        :rtype: solph.Investment
        """
        kwargs = self.build_kwargs(energysystem)

        return solph.Investment(**kwargs)

to_oemof(energysystem)

Converts the object's internal configuration to an oemof.solph Investment object.

This method takes an oemof EnergySystem object and uses the provided system configuration to construct and return an oemof.solph Investment object. The generated Investment object encapsulates investment-related parameters for use in energy system modeling, particularly for optimization.

Parameters:

Name Type Description Default
energysystem EnergySystem

The oemof.solph EnergySystem object containing the necessary system configuration and parameters.

 required

Returns:

Type Description
solph.Investment

An oemof.solph Investment object constructed based on the internal configuration and the provided EnergySystem object.
Source code in backend/app/ensys/components/investment.py 
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def to_oemof(self, energysystem: solph.EnergySystem) -> solph.Investment:
    """
    Converts the object's internal configuration to an oemof.solph Investment object.

    This method takes an oemof EnergySystem object and uses the provided system
    configuration to construct and return an oemof.solph Investment object. The
    generated Investment object encapsulates investment-related parameters for
    use in energy system modeling, particularly for optimization.

    :param energysystem: The oemof.solph EnergySystem object containing the
        necessary system configuration and parameters.
    :type energysystem: solph.EnergySystem
    :return: An oemof.solph Investment object constructed based on the internal
        configuration and the provided EnergySystem object.
    :rtype: solph.Investment
    """
    kwargs = self.build_kwargs(energysystem)

    return solph.Investment(**kwargs)