Made changes to tools.costs related to base year and first year of modeling

doc/whatsnew.rst

@@ -7,6 +7,12 @@ What's new
 v2024.4.22
 ==========
 
+- Made changes to :doc:`/api/tools-costs` (:pull:`186`).
+
+  - Fixed jumps in cost projections for technologies with first technology year that's after than the first model year.
+  - Changed the use of base_year to mean the year to start modeling cost changes.
+  - Update cost assumptions for certain CCS technologies.
+  - Changed the default fixed O&M reduction rate to 0.
 - Incorporate the :doc:`/global/index` documentation (:pull:`107`, :pull:`110`).
   This documentation formerly lived at https://docs.messageix.org/global/ and in a separate repository at `iiasa/message_doc <https://github.com/iiasa/message_doc>`_.
 - Improve tool for :ref:`migrate-filter-repo` (:pull:`174`); expand documentation.

message_ix_models/data/costs/energy/cost_reduction_energy.csv

@@ -21,12 +21,12 @@ gas_cc_ccs,CCS,0.1,0.2,0.29,0.5,0.7
 bio_istig_ccs,CCS,0,0.1,0.3,0.4,0.6
 syn_liq,Coal,0,0.05,0.1,0.15,0.2
 meth_coal,Coal,0,0.05,0.1,0.15,0.2
-syn_liq_ccs,CCS,0,0.05,0.1,0.25,0.3
+syn_liq_ccs,CCS,0,0.05,0.1,0.15,0.2
 meth_coal_ccs,CCS,0,0.05,0.1,0.15,0.2
 h2_coal,Coal,0,0.25,0.4,0.4,0.5
 h2_smr,Gas/Oil,0,0.25,0.4,0.5,0.7
 h2_bio,Biomass,0,0.25,0.4,0.5,0.7
-h2_coal_ccs,CCS,0,0.25,0.4,0.5,0.7
+h2_coal_ccs,CCS,0,0.25,0.4,0.4,0.5
 h2_smr_ccs,CCS,0,0.25,0.4,0.5,0.7
 h2_bio_ccs,CCS,0,0.25,0.4,0.5,0.7
 eth_bio,Biomass,0,0.27,0.27,0.4,0.55

message_ix_models/data/costs/energy/scenarios_reduction_energy.csv

@@ -13,14 +13,14 @@ gas_cc_ccs,medium,medium,low,high,high,medium
 bio_istig_ccs,medium,medium,low,high,high,medium
 syn_liq,medium,medium,high,medium,medium,medium
 meth_coal,medium,medium,high,medium,medium,medium
-syn_liq_ccs,medium,medium,low,high,high,medium
-meth_coal_ccs,medium,medium,low,high,high,medium
+syn_liq_ccs,medium,medium,high,medium,medium,medium
+meth_coal_ccs,medium,medium,high,medium,medium,medium
 h2_coal,medium,medium,high,medium,medium,medium
 h2_smr,high,medium,low,medium,high,medium
 h2_bio,high,medium,low,high,medium,medium
-h2_coal_ccs,medium,medium,low,high,high,medium
+h2_coal_ccs,medium,medium,high,medium,medium,medium
 h2_smr_ccs,medium,medium,low,high,high,medium
-h2_bio_ccs,medium,medium,low,high,high,medium
+h2_bio_ccs,high,medium,low,high,medium,medium
 eth_bio,high,medium,low,high,medium,medium
 eth_bio_ccs,medium,medium,low,high,high,medium
 c_ppl_co2scr,medium,medium,low,high,high,medium
@@ -36,12 +36,12 @@ geo_ppl,high,medium,low,high,medium,medium
 hydro_lc,high,medium,low,high,medium,medium
 hydro_hc,high,medium,low,high,medium,medium
 meth_ng,high,medium,low,medium,high,medium
-meth_ng_ccs,medium,medium,low,high,high,medium
+meth_ng_ccs,high,medium,low,medium,high,medium
 coal_ppl_u,medium,medium,high,medium,medium,medium
 stor_ppl,high,medium,low,high,medium,medium
 h2_elec,high,medium,low,high,medium,medium
 liq_bio,high,medium,low,high,medium,medium
-liq_bio_ccs,medium,medium,low,high,high,medium
+liq_bio_ccs,high,medium,low,high,medium,medium
 coal_i,medium,medium,high,medium,medium,medium
 foil_i,high,medium,low,medium,high,medium
 loil_i,high,medium,low,medium,high,medium

message_ix_models/data/costs/energy/tech_map_energy.csv

@@ -1,6 +1,6 @@
 # The base year costs and WEO mappings are taken from the following file: ,,,,
 # https://github.com/iiasa/message_data/blob/dev/data/model/investment_cost/doc/NAM_technology_cost_input_20200507.xlsx,,,,
-# If base_year_reference_region_cost is blank then the 2021 WEO cost from the mapped technology is used in its place.
+# If base_year_reference_region_cost is blank then the 2021 WEO cost from the mapped technology is used in its place.,,,,
 message_technology,reg_diff_source,reg_diff_technology,base_year_reference_region_cost,fix_ratio
 bio_hpl,weo,igcc,275,
 bio_istig,weo,igcc,4064,
@@ -36,9 +36,9 @@ gas_ppl,weo,gas_turbine,1205,
 geo_hpl,weo,geothermal,1500,
 geo_ppl,weo,geothermal,2928,
 h2_bio,weo,igcc,3744,
-h2_bio_ccs,weo,igcc_ccs,3824,
+h2_bio_ccs,weo,igcc,3824,
 h2_coal,weo,igcc,2163,
-h2_coal_ccs,weo,igcc_ccs,2252,
+h2_coal_ccs,weo,igcc,2252,
 h2_elec,weo,csp,1139,
 h2_fc_I,weo,igcc,3500,
 h2_fc_RC,weo,igcc,3500,
@@ -55,15 +55,15 @@ hydro_lc,weo,hydropower_large,2187,
 igcc,weo,igcc,2106,
 igcc_ccs,weo,igcc_ccs,4819,
 liq_bio,weo,igcc,4264,
-liq_bio_ccs,weo,igcc_ccs,4344,
+liq_bio_ccs,weo,igcc,4344,
 loil_cc,weo,igcc,800,
 loil_i,weo,ccgt_chp,93,
 loil_ppl,weo,igcc,600,
 meth_coal,weo,igcc,2348,
-meth_coal_ccs,weo,igcc_ccs,2385,
+meth_coal_ccs,weo,igcc,2385,
 meth_i,weo,bioenergy_medium_chp,93,
 meth_ng,weo,igcc,1234,
-meth_ng_ccs,weo,igcc_ccs,1339,
+meth_ng_ccs,weo,igcc,1339,
 nuc_hc,weo,nuclear,5000,
 nuc_lc,weo,nuclear,3800,
 solar_i,weo,solarpv_buildings,737,
@@ -73,6 +73,6 @@ solar_pv_RC,weo,solarpv_buildings,,
 solar_th_ppl,weo,csp,969,
 stor_ppl,weo,csp,800,
 syn_liq,weo,igcc,3224,
-syn_liq_ccs,weo,igcc_ccs,3268,
+syn_liq_ccs,weo,igcc,3268,
 wind_ppf,weo,wind_offshore,1771,
 wind_ppl,weo,wind_onshore,1181,

message_ix_models/tests/tools/costs/test_decay.py

@@ -34,11 +34,13 @@ def test_get_cost_reduction_data(module: str, t_exp) -> None:
 
 @pytest.mark.parametrize("module", ("energy", "materials"))
 def test_get_technology_reduction_scenarios_data(module: str) -> None:
+    config = Config()
     # The function runs without error
-    result = get_technology_reduction_scenarios_data(Config.base_year, module=module)
+    result = get_technology_reduction_scenarios_data(config.y0, module=module)
 
-    # All first technology years are equal to or greater than the default base year
-    assert Config.base_year <= result.first_technology_year.min()
+    # All first technology years are equal to or greater than
+    # the default first model year
+    assert config.y0 <= result.first_technology_year.min()
 
     # Data for LED and SSP1-5 scenarios are present
     assert {"SSP1", "SSP2", "SSP3", "SSP4", "SSP5", "LED"} <= set(
@@ -70,5 +72,5 @@ def test_project_ref_region_inv_costs_using_reduction_rates(
     # Excluded technologies are *not* present
     assert set() == (t_excluded & t)
 
-    # The first technology year is equal to or greater than the default base year
-    assert Config.base_year <= result.first_technology_year.min()
+    # The first technology year is equal to or greater than the default first model year
+    assert config.y0 <= result.first_technology_year.min()

message_ix_models/tools/costs/config.py

@@ -15,7 +15,10 @@ class Config:
     """
 
     #: Base year for projected costs.
-    base_year: int = 2021
+    #: This is the first year for which cost reductions/decay are calculated.
+    #: If the base year is greater than y0 (first model year),
+    #: then the costs are assumed to be the same from y0 to base_year.
+    base_year: int = 2025
 
     #: Year of convergence; used when :attr:`.method` is "convergence". This is the year
     #: by which costs in all regions should converge to the reference region's costs.
@@ -27,9 +30,10 @@ class Config:
     final_year: int = 2100
 
     #: Rate of exponential growth (positive values) or decrease of fixed operating and
-    #: maintenance costs over time. The default of 0.025 implies exponential growth at a
+    #: maintenance costs over time. The default of 0 implies no change over time.
+    #: If the rate is 0.025, for example, that implies exponential growth at a
     #: rate of 2.5% per year; or :py:`(1 + 0.025) ** N` for a period of length N.
-    fom_rate: float = 0.025
+    fom_rate: float = 0
 
     #: Format of output from :func:`.create_cost_projections`. One of:
     #:

message_ix_models/tools/costs/decay.py

@@ -115,7 +115,7 @@ def get_cost_reduction_data(module) -> pd.DataFrame:
 
 
 def get_technology_reduction_scenarios_data(
-    base_year: int, module: str
+    first_year: int, module: str
 ) -> pd.DataFrame:
     """Read in technology first year and cost reduction scenarios.
 
@@ -184,13 +184,13 @@ def get_technology_reduction_scenarios_data(
         .assign(
             first_technology_year=lambda x: np.where(
                 x.first_year_original.isnull(),
-                base_year,
+                first_year,
                 x.first_year_original,
             )
         )
         .assign(
             first_technology_year=lambda x: np.where(
-                x.first_year_original > base_year, x.first_year_original, base_year
+                x.first_year_original > first_year, x.first_year_original, first_year
             )
         )
         .drop(columns=["first_year_original"])
@@ -309,9 +309,7 @@ def project_ref_region_inv_costs_using_reduction_rates(
     df_cost_reduction = get_cost_reduction_data(config.module)
 
     # Get scenarios data
-    df_scenarios = get_technology_reduction_scenarios_data(
-        config.base_year, config.module
-    )
+    df_scenarios = get_technology_reduction_scenarios_data(config.y0, config.module)
 
     # Merge cost reduction data with cost reduction rates data
     df_cost_reduction = df_cost_reduction.merge(
@@ -336,10 +334,9 @@ def project_ref_region_inv_costs_using_reduction_rates(
     for y in config.seq_years:
         df_ref = df_ref.assign(
             ycur=lambda x: np.where(
-                y <= config.y0,
+                y <= config.base_year,
                 x.reg_cost_base_year,
-                (x.reg_cost_base_year - x.b)
-                * np.exp(x.r * (y - x.first_technology_year))
+                (x.reg_cost_base_year - x.b) * np.exp(x.r * (y - config.base_year))
                 + x.b,
             )
         ).rename(columns={"ycur": y})

message_ix_models/tools/costs/demo.py

@@ -13,7 +13,7 @@
 # Defaults for all configuration settings:
 # - base_year=BASE_YEAR,
 # - convergence_year=2050,
-# - fom_rate=0.025,
+# - fom_rate=0,
 # - format="message",
 # - method="gdp",
 # - module="energy",