Remove internal interest rate

Unity-Energy-and-renewable-energy · Dec 17, 2024 · 3130ee5 · 3130ee5
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Showing 7 changed files with 7 additions and 30 deletions.
diff --git a/docs/usage.rst b/docs/usage.rst
@@ -1199,8 +1199,6 @@ but with a few minor additions and modifications in the investment object itself
   free to reinvest or choose another option to fill up the missing capacity.
 * You can define an initial `age` if you have `existing` capacity. If you do not specify anything, the default value 0 will be used,
   meaning your `existing` capacity has just been newly invested.
-* You can define an `interest_rate` that the investor you model has, i.e. the return he desires expressed as the weighted
-  average osts of capital (wacc) and used for calculating annuities in the model itself.
 * You also can define `fixed_costs`, i.e. costs that occur every period independent of the plants usage.
 
 Here is an example
@@ -1216,7 +1214,6 @@ Here is an example
                     maximum=1000,
                     ep_costs=1e6,
                     lifetime=30,
-                    interest_rate=0.06,
                     fixed_costs=100,
                 ),
                 variable_costs=3,
@@ -1250,7 +1247,6 @@ This would mean that for investments in the particular period, these values woul
                     maximum=1000,
                     ep_costs=[1e6, 1.1e6],
                     lifetime=30,
-                    interest_rate=0.06,
                     fixed_costs=[100, 110],
                 ),
                 variable_costs=3,

diff --git a/src/oemof/solph/_options.py b/src/oemof/solph/_options.py
@@ -63,11 +63,6 @@ class Investment:
     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
@@ -95,7 +90,6 @@ def __init__(
         overall_minimum=None,
         lifetime=None,
         age=0,
-        interest_rate=0,
         fixed_costs=None,
         custom_attributes=None,
     ):
@@ -111,7 +105,6 @@ def __init__(
         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():

diff --git a/src/oemof/solph/components/_generic_storage.py b/src/oemof/solph/components/_generic_storage.py
@@ -1087,8 +1087,6 @@ class GenericInvestmentStorageBlock(ScalarBlock):
         Lifetime for investments in storage capacity"
         ":math:`a`", "`flows[i, o].investment.age`", "
         Initial age of existing capacity / energy"
-        ":math:`ir`", "`flows[i, o].investment.interest_rate`", "
-        interest rate for investment"
         ":math:`\tau(t)`", "", "Duration of time step"
         ":math:`t_u`", "", "Time unit of losses :math:`\beta(t)`,
         :math:`\gamma(t)`, :math:`\delta(t)` and timeincrement :math:`\tau(t)`"
@@ -1776,7 +1774,7 @@ def _objective_expression(self):
             )
             for n in self.CONVEX_INVESTSTORAGES:
                 lifetime = n.investment.lifetime
-                interest = n.investment.interest_rate
+                interest = 0
                 if interest == 0:
                     warn(
                         msg.format(m.discount_rate),
@@ -1816,7 +1814,7 @@ def _objective_expression(self):
 
             for n in self.NON_CONVEX_INVESTSTORAGES:
                 lifetime = n.investment.lifetime
-                interest = n.investment.interest_rate
+                interest = 0
                 if interest == 0:
                     warn(
                         msg.format(m.discount_rate),

diff --git a/src/oemof/solph/components/experimental/_sink_dsm.py b/src/oemof/solph/components/experimental/_sink_dsm.py
@@ -1369,7 +1369,7 @@ def _objective_expression(self):
             for g in self.investdsm:
                 if g.investment.ep_costs is not None:
                     lifetime = g.investment.lifetime
-                    interest = g.investment.interest_rate
+                    interest = 0
                     if interest == 0:
                         warn(
                             msg.format(m.discount_rate),
@@ -3203,7 +3203,7 @@ def _objective_expression(self):
             for g in self.investdsm:
                 if g.investment.ep_costs is not None:
                     lifetime = g.investment.lifetime
-                    interest = g.investment.interest_rate
+                    interest = 0
                     if interest == 0:
                         warn(
                             msg.format(m.discount_rate),
@@ -5675,7 +5675,7 @@ def _objective_expression(self):
             for g in self.INVESTDR:
                 if g.investment.ep_costs is not None:
                     lifetime = g.investment.lifetime
-                    interest = g.investment.interest_rate
+                    interest = 0
                     if interest == 0:
                         warn(
                             msg.format(m.discount_rate),

diff --git a/src/oemof/solph/flows/_investment_flow_block.py b/src/oemof/solph/flows/_investment_flow_block.py
@@ -921,7 +921,7 @@ def _objective_expression(self):
             )
             for i, o in self.CONVEX_INVESTFLOWS:
                 lifetime = m.flows[i, o].investment.lifetime
-                interest = m.flows[i, o].investment.interest_rate
+                interest = 0
                 if interest == 0:
                     warn(
                         msg.format(m.discount_rate),
@@ -964,7 +964,7 @@ def _objective_expression(self):
 
             for i, o in self.NON_CONVEX_INVESTFLOWS:
                 lifetime = m.flows[i, o].investment.lifetime
-                interest = m.flows[i, o].investment.interest_rate
+                interest = 0
                 if interest == 0:
                     warn(
                         msg.format(m.discount_rate),

diff --git a/tests/test_processing.py b/tests/test_processing.py
@@ -166,7 +166,6 @@ def test_nodes_with_none_exclusion(self):
                     "initial_storage_level": 0,
                     "investment_age": 0,
                     "investment_existing": 0,
-                    "investment_interest_rate": 0,
                     "investment_nonconvex": False,
                     "investment_ep_costs": 0.4,
                     "investment_maximum": float("inf"),
@@ -206,7 +205,6 @@ def test_nodes_with_none_exclusion_old_name(self):
                     "initial_storage_level": 0,
                     "investment_age": 0,
                     "investment_existing": 0,
-                    "investment_interest_rate": 0,
                     "investment_nonconvex": False,
                     "investment_ep_costs": 0.4,
                     "investment_maximum": float("inf"),

diff --git a/tests/test_scripts/test_solph/test_multi_period_model/test_multi_period_investment_model.py b/tests/test_scripts/test_solph/test_multi_period_model/test_multi_period_investment_model.py
@@ -153,7 +153,6 @@ def test_multi_period_investment_model(solver="cbc"):
                         existing=0,
                         lifetime=20,
                         age=0,
-                        interest_rate=0.02,
                     ),
                     variable_costs=1,
                 )
@@ -172,7 +171,6 @@ def test_multi_period_investment_model(solver="cbc"):
                         existing=0,
                         lifetime=20,
                         age=0,
-                        interest_rate=0.02,
                     ),
                     variable_costs=2,
                 )
@@ -191,7 +189,6 @@ def test_multi_period_investment_model(solver="cbc"):
                         existing=0,
                         lifetime=20,
                         age=0,
-                        interest_rate=0.02,
                     ),
                     variable_costs=3,
                 )
@@ -210,7 +207,6 @@ def test_multi_period_investment_model(solver="cbc"):
                         existing=0,
                         lifetime=20,
                         age=0,
-                        interest_rate=0.02,
                         fixed_costs=1000,
                     ),
                     variable_costs=4,
@@ -231,7 +227,6 @@ def test_multi_period_investment_model(solver="cbc"):
                         existing=10,
                         lifetime=2,
                         age=1,
-                        interest_rate=0.02,
                     ),
                 )
             },
@@ -245,7 +240,6 @@ def test_multi_period_investment_model(solver="cbc"):
                         existing=10,
                         lifetime=2,
                         age=1,
-                        interest_rate=0.02,
                     ),
                 )
             },
@@ -265,7 +259,6 @@ def test_multi_period_investment_model(solver="cbc"):
                 existing=10,
                 lifetime=2,
                 age=1,
-                interest_rate=0.02,
                 fixed_costs=10,
             ),
         )
@@ -335,7 +328,6 @@ def test_multi_period_investment_model(solver="cbc"):
                 ep_costs=10,
                 lifetime=2,
                 age=1,
-                interest_rate=0.02,
             ),
         )