fix storage cost (capacity) using CAP_F

ptxboa/api_calc.py

@@ -24,6 +24,14 @@ def calculate(data: CalculateDataType) -> pd.DataFrame:
         # start main chain calculation
         main_output_value = 1  # start with normalized value of 1
 
+        # pre-calculate main_output_value before transport
+        # for correct scaling of storeages.
+        # storage units use capacity factor CAP_F
+        # per produced unit (before transport losses)
+        main_output_value_before_transport = main_output_value
+        for step_data in data["main_process_chain"]:
+            main_output_value_before_transport *= step_data["EFF"]
+
         # accumulate needed electric input
         sum_el = main_output_value
         results = []
@@ -51,10 +59,19 @@ def calculate(data: CalculateDataType) -> pd.DataFrame:
             if not is_transport:
                 flh = step_data["FLH"]
                 liefetime = step_data["LIFETIME"]
-                capex = step_data["CAPEX"]
+                capex_rel = step_data["CAPEX"]
                 opex_f = step_data["OPEX-F"]
-                capacity = main_output_value / flh
-                capex = capacity * capex
+
+                if "CAP_F" in step_data:
+                    # Storage unit: capacity
+                    # TODO: double check units (division by 8760 h)?
+                    capacity = (
+                        main_output_value_before_transport * step_data["CAP_F"] / 8760
+                    )
+                else:
+                    capacity = main_output_value / flh
+
+                capex = capacity * capex_rel
                 capex_ann = annuity(wacc, liefetime, capex)
                 opex = opex_f * capacity + opex_o * main_output_value
 

ptxboa/api_optimize.py

@@ -377,6 +377,11 @@ def _merge_data(input_data: CalculateDataType, opt_output_data: OptOutputDataTyp
                     step["FLH"] = opt_output_data["ELY"]["FLH"] * 8760
                 elif step["step"] == "DERIV":
                     step["FLH"] = opt_output_data["DERIV"]["FLH"] * 8760
+                elif step["step"] == "EL_STR":
+                    step["CAP_F"] = opt_output_data["EL_STR"]["CAP_F"]
+                elif step["step"] == "H2_STR":
+                    step["CAP_F"] = opt_output_data["H2_STR"]["CAP_F"]
+
             # secondary processes
             for step, flow_code in [("H2O", "H2O-L"), ("CO2", "CO2-G")]:
                 sec_process_data = input_data["secondary_process"].get(flow_code)
@@ -389,8 +394,6 @@ def _merge_data(input_data: CalculateDataType, opt_output_data: OptOutputDataTyp
             logger.warning(f"Solver status:{opt_output_data['model_status'][0]}")
             logger.warning(f"Model status:{opt_output_data['model_status'][1]}")
 
-            # TODO: Storage: "CAP_F"
-
     def _get_hashsum(self, data, opt_input_data):
         src_reg = data["context"]["source_region_code"]
         # find res

tests/test_api.py

@@ -4,6 +4,7 @@
 import logging
 import unittest
 from pathlib import Path
+from tempfile import TemporaryDirectory
 
 import numpy as np
 import pytest
@@ -26,10 +27,19 @@ class TestApi(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
         """Set up code for class."""
-        cls.api = PtxboaAPI(data_dir=ptxdata_dir_static)
+        cls.temp_dir = TemporaryDirectory()
+        # create cahce dir (start context)
+        cache_dir = cls.temp_dir.__enter__()
+        cls.api = PtxboaAPI(data_dir=ptxdata_dir_static, cache_dir=cache_dir)
 
-    def _test_api_call(self, settings):
-        res, _metadata = self.api.calculate(**settings, optimize_flh=False)
+    @classmethod
+    def tearDownClass(cls):
+        """Tear down code for class."""
+        # cleanup cache dir
+        cls.temp_dir.__exit__(None, None, None)
+
+    def _test_api_call(self, settings, optimize_flh=False):
+        res, _metadata = self.api.calculate(**settings, optimize_flh=optimize_flh)
         # test that settings are in results
         for k, v in settings.items():
             if k in ["ship_own_fuel", "output_unit"]:  # skip some
@@ -344,6 +354,41 @@ def test_pmt(self):
         self.assertAlmostEqual(annuity(0.5, 10, 1), 0.5088237828522)
         self.assertAlmostEqual(annuity(1, 10, 1), 1.0009775171)
 
+    def test_issue_553_storage_cost(self):
+        """See https://github.com/agoenergy/ptx-boa/issues/553."""
+        settings = {
+            "region": "United Arab Emirates",
+            "country": "Germany",
+            "chain": "Ammonia (AEL) + reconv. to H2",
+            "res_gen": "PV tilted",
+            "scenario": "2040 (medium)",
+            "secproc_co2": "Direct Air Capture",
+            "secproc_water": "Sea Water desalination",
+            "transport": "Ship",
+            "ship_own_fuel": False,
+            "output_unit": "USD/t",
+        }
+        res = self._test_api_call(settings, optimize_flh=False)
+        res_opt = self._test_api_call(settings, optimize_flh=True)
+        self.assertAlmostEqual(
+            res.at[("Electricity and H2 storage", "CAPEX"), "values"],
+            896.432599,
+            places=4,
+        )
+        self.assertAlmostEqual(
+            res.at[("Electricity and H2 storage", "OPEX"), "values"], 4.396162, places=4
+        )
+        self.assertAlmostEqual(
+            res_opt.at[("Electricity and H2 storage", "CAPEX"), "values"],
+            221.907535,
+            places=4,
+        )
+        self.assertAlmostEqual(
+            res_opt.at[("Electricity and H2 storage", "OPEX"), "values"],
+            6.732894,
+            places=4,
+        )
+
 
 class TestRegression(unittest.TestCase):
     def test_issue_355_unique_index(self):

tests/test_api_data.py

@@ -392,6 +392,7 @@ def test_get_calculation_data_w_opt(ptxdata_dir, scenario, kwargs, request):
                 "CONV": {},
                 "step": "EL_STR",
                 "process_code": "EL-STR",
+                "CAP_F": 0.0,
             },
             {
                 "EFF": 0.715,
@@ -414,6 +415,7 @@ def test_get_calculation_data_w_opt(ptxdata_dir, scenario, kwargs, request):
                 "CONV": {},
                 "step": "H2_STR",
                 "process_code": "H2-STR",
+                "CAP_F": 0.6816605398116187,
             },
             {
                 "EFF": 0.819,