# -*- coding: utf-8 -*-
"""Optional classes to be added to a network class.
SPDX-FileCopyrightText: Uwe Krien <krien@uni-bremen.de>
SPDX-FileCopyrightText: Simon Hilpert
SPDX-FileCopyrightText: Cord Kaldemeyer
SPDX-FileCopyrightText: Stephan Günther
SPDX-FileCopyrightText: Patrik Schönfeldt
SPDX-FileCopyrightText: jmloenneberga
SPDX-FileCopyrightText: Johannes Kochems
SPDX-License-Identifier: MIT
"""
from oemof.solph._plumbing import sequence
[docs]class Investment:
"""Defines an Investment object holding all the specifications needed
for investment modeling.
Parameters
----------
maximum : float, :math:`P_{invest,max}(p)` or :math:`E_{invest,max}(p)`
Maximum of the additional invested capacity;
defined per period p for a multi-period model.
minimum : float, :math:`P_{invest,min}(p)` or :math:`E_{invest,min}(p)`
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, :math:`c_{invest,var}`
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, :math:`P_{exist}` or :math:`E_{exist}`
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
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, :math:`c_{invest,fix}`
Additional fixed investment costs. Only applicable if `nonconvex` is
set to `True`.
overall_maximum : float, :math:`P_{overall,max}` or :math:`E_{overall,max}`
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 :math:`P_{overall,min}` or :math:`E_{overall,min}`
Overall minimum capacity investment that needs to be installed
in the last period of the optimization (taking into account
decommissionings); only applicable for multi-period models
lifetime : int, :math:`l`
Units lifetime, given in years; only applicable for multi-period
models
age : int, :math:`a`
Units start age, given in years at the beginning of the optimization;
only applicable for multi-period models
interest_rate : float, :math:`ir`
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 or list of float, :math:`c_{fixed}(p)`
Fixed costs in each period (given in nominal terms);
only applicable for multi-period models
For the variables, constraints and parts of the objective function, which
are created, see
:py:class:`~oemof.solph.blocks.investment_flow.InvestmentFlow`,
:py:class:`~oemof.solph.components.generic_storage.GenericInvestmentStorageBlock`
:py:class:`~oemof.solph.custom.sink_dsm.SinkDSMOemofInvestmentBlock`,
:py:class:`~oemof.solph.custom.sink_dsm.SinkDSMDLRInvestmentBlock` and
:py:class:`~oemof.solph.custom.sink_dsm.SinkDSMDIWInvestmentBlock`.
""" # noqa: E501
def __init__(
self,
maximum=float("+inf"),
minimum=0,
ep_costs=0,
existing=0,
nonconvex=False,
offset=0,
overall_maximum=None,
overall_minimum=None,
lifetime=None,
age=0,
interest_rate=0,
fixed_costs=None,
custom_attributes=None,
):
if custom_attributes is None:
custom_attributes = {}
self.maximum = sequence(maximum)
self.minimum = sequence(minimum)
self.ep_costs = sequence(ep_costs)
self.existing = existing
self.nonconvex = nonconvex
self.offset = sequence(offset)
self.overall_maximum = overall_maximum
self.overall_minimum = overall_minimum
self.lifetime = lifetime
self.age = age
self.interest_rate = interest_rate
self.fixed_costs = sequence(fixed_costs)
for attribute in custom_attributes.keys():
value = custom_attributes.get(attribute)
setattr(self, attribute, value)
self._check_invest_attributes()
self._check_invest_attributes_maximum()
self._check_invest_attributes_offset()
self._check_age_and_lifetime()
def _check_invest_attributes(self):
"""Throw an error if existing is other than 0 and nonconvex is True"""
if (self.existing != 0) and (self.nonconvex is True):
e1 = (
"Values for 'offset' and 'existing' are given in"
" investement attributes. \n These two options cannot be "
"considered at the same time."
)
raise AttributeError(e1)
def _check_invest_attributes_maximum(self):
"""Throw an error if maximum is infinite and nonconvex is True"""
if (self.maximum[0] == float("+inf")) and (self.nonconvex is True):
e2 = (
"Please provide a maximum investment value in case of"
" nonconvex investment (nonconvex=True), which is in the"
" expected magnitude."
" \nVery high maximum values (> 10e8) as maximum investment"
" limit might lead to numeric issues, so that no investment"
" is done, although it is the optimal solution!"
)
raise AttributeError(e2)
def _check_invest_attributes_offset(self):
"""Throw an error if offset is given without nonconvex=True"""
if (self.offset[0] != 0) and (self.nonconvex is False):
e3 = (
"If `nonconvex` is `False`, the `offset` parameter will be"
" ignored."
)
raise AttributeError(e3)
def _check_age_and_lifetime(self):
"""Throw an error if age is chosen greater or equal to lifetime;
only applicable for multi-period models
"""
if self.lifetime is not None:
if self.age >= self.lifetime:
e4 = (
"A unit's age must be smaller than its "
"expected lifetime."
)
raise AttributeError(e4)
[docs]class NonConvex:
"""Defines a NonConvex object holding all the specifications for NonConvex
Flows, i.e. Flows with binary variables associated to them.
Parameters
----------
startup_costs : numeric (iterable or scalar)
Costs associated with a start of the flow (representing a unit).
shutdown_costs : numeric (iterable or scalar)
Costs associated with the shutdown of the flow (representing a unit).
activity_costs : numeric (iterable or scalar)
Costs associated with the active operation of the flow, independently
from the actual output.
inactivity_costs : numeric (iterable or scalar)
Costs associated with not operating the flow.
minimum_uptime : numeric or list of numeric (1 or positive integer)
Minimum number of time steps that a flow must be greater then its
minimum flow after startup. Be aware that minimum up and downtimes
can contradict each other and may lead to infeasible problems.
minimum_downtime : numeric or list of numeric (1 or positive integer)
Minimum number of time steps a flow is forced to zero after
shutting down. Be aware that minimum up and downtimes can
contradict each other and may to infeasible problems.
maximum_startups : numeric (0 or positive integer)
Maximum number of start-ups in the optimization timeframe.
maximum_shutdowns : numeric (0 or positive integer)
Maximum number of shutdowns in the optimization timeframe.
initial_status : numeric (0 or 1)
Integer value indicating the status of the flow in the first time step
(0 = off, 1 = on). For minimum up and downtimes, the initial status
is set for the respective values in the beginning e.g. if a
minimum uptime of four timesteps is defined and the initial status is
set to one, the initial status is fixed for the four first timesteps
of the optimization period. Otherwise if the initial status is set to
zero and the first timesteps are fixed for the number of minimum
downtime steps.
negative_gradient_limit : numeric (iterable, scalar or None)
the normed *upper bound* on the positive difference
(`flow[t-1] < flow[t]`) of two consecutive flow values.
positive_gradient_limit : numeric (iterable, scalar or None)
the normed *upper bound* on the negative difference
(`flow[t-1] > flow[t]`) of two consecutive flow values.
"""
def __init__(
self,
initial_status=0,
minimum_uptime=0,
minimum_downtime=0,
maximum_startups=None,
maximum_shutdowns=None,
startup_costs=None,
shutdown_costs=None,
activity_costs=None,
inactivity_costs=None,
negative_gradient_limit=None,
positive_gradient_limit=None,
custom_attributes=None,
):
if custom_attributes is None:
custom_attributes = {}
self.initial_status = initial_status
self.minimum_uptime = sequence(minimum_uptime)
self.minimum_downtime = sequence(minimum_downtime)
self.maximum_startups = maximum_startups
self.maximum_shutdowns = maximum_shutdowns
self.startup_costs = sequence(startup_costs)
self.shutdown_costs = sequence(shutdown_costs)
self.activity_costs = sequence(activity_costs)
self.inactivity_costs = sequence(inactivity_costs)
self.negative_gradient_limit = sequence(negative_gradient_limit)
self.positive_gradient_limit = sequence(positive_gradient_limit)
for attribute, value in custom_attributes.items():
setattr(self, attribute, value)
if initial_status == 0:
self.first_flexible_timestep = self.minimum_downtime[0]
else:
self.first_flexible_timestep = self.minimum_uptime[0]