Nuclear fix

docs/data.md

@@ -8,7 +8,7 @@ Marcel Buchhorn, Bruno Smets, Luc Bertels, Bert De Roo, Myroslava Lesiv, Nandin-
 
 - Source: Copernicus Global Land Service:
 - Link: https://land.copernicus.eu/en/products/global-dynamic-land-cover/copernicus-global-land-service-land-cover-100m-collection-3-epoch-2019-globe
-- License: Creative Commons Attribution 4.0 International 
+- License: Creative Commons Attribution 4.0 International
 - Description: 100m resolution land classification
 
 ### Administrative regions
@@ -50,3 +50,9 @@ Gridded population data
 - License: CC-BY 4.0 (reference)
 - Description: Gridded population data.
 
+### EV charging load
+Weipeng Zhan, Yuan Liao, Junjun Deng, Zhenpo Wang, & Sonia Yeh. (2025). Large-scale empirical study of electric vehicle usage patterns and charging infrastructure needs. *npj Sustainable Mobility and Transport*.
+- Source: Nature Portfolio
+- Link: https://www.nature.com/articles/s44333-024-00023-3
+- License: [Nature Portfolio license](https://www.nature.com/articles/s44333-024-00023-3)
+- Description: Empirical data on electric vehicle usage patterns and charging infrastructure needs, including charging ratio profiles for passenger and freight vehicles used to generate time-series charging demand.

workflow/scripts/solve_network.py

@@ -8,12 +8,12 @@
 """
 
 import logging
+import os
 
 import numpy as np
 import pandas as pd
 import pypsa
 import xarray as xr
-import os
 from _helpers import ConfigManager, configure_logging, mock_snakemake, setup_gurobi_tunnel_and_env
 from _pypsa_helpers import filter_carriers, mock_solve, store_duals_to_network
 from constants import YEAR_HRS
@@ -31,32 +31,25 @@ def calc_nuclear_expansion_limit(
 ) -> None:
     """
     Calculate and apply the nuclear expansion limit from configuration.
-    
+
     Args:
         n (pypsa.Network): the network object
         config (dict): full configuration dictionary (mutated in place)
         planning_year (int): target planning horizon year
         network_path (str): path to the current network file, used to locate base year
     """
     nuclear_cfg = config.setdefault("nuclear_reactors", {})
-    if not nuclear_cfg.get("enable_growth_limit"):
+
+    if not nuclear_cfg.get("enable_growth_limit", True):
         return
-    
+
     annual_addition = nuclear_cfg.get("max_annual_capacity_addition")
-    if not annual_addition:
-        logger.warning("Nuclear growth limit enabled but max_annual_capacity_addition missing")
-        return
-
     base_year = nuclear_cfg.get("base_year", 2020)
     n_years = planning_year - base_year
-    if n_years <= 0:
-        logger.info(
-            "Planning year %s is not after base year %s; skipping nuclear expansion limit",
-            planning_year,
-            base_year,
-        )
+
+    if not annual_addition or n_years <= 0:
         return
-    
+
     base_capacity = nuclear_cfg.get("base_capacity")
     if base_capacity is None:
         base_path = network_path.replace(f"ntwk_{planning_year}.nc", f"ntwk_{base_year}.nc")
@@ -65,26 +58,17 @@ def calc_nuclear_expansion_limit(
             base_capacity = n_base.generators[n_base.generators.carrier == "nuclear"]["p_nom"].sum()
         else:
             base_capacity = n.generators[n.generators.carrier == "nuclear"]["p_nom"].sum()
-
-    max_capacity = base_capacity + annual_addition * n_years
-    logger.info(
-        f"Adding nuclear expansion limit for {planning_year}: {max_capacity:.0f} MW "
-        f"[{base_capacity:.0f} + {annual_addition:.0f} × {n_years} years]"
-    )
 
+    max_capacity = base_capacity + annual_addition * n_years
     nuclear_gens_ext = n.generators[
         (n.generators.carrier == "nuclear") & (n.generators.p_nom_extendable == True)
     ].index
-
-    if len(nuclear_gens_ext) == 0:
-        logger.warning("No extendable nuclear generators found")
-        return
-
-    n.generators.loc[nuclear_gens_ext, "p_nom_max"] = max_capacity
-    nuclear_cfg["expansion_limit"] = max_capacity
-    logger.info(
-        f"Nuclear expansion limit set: {max_capacity:.0f} MW for {len(nuclear_gens_ext)} generators"
-    )
+
+    if len(nuclear_gens_ext) > 0:
+        logger.info(
+            f"Nuclear expansion limit for {planning_year}: {max_capacity:.0f} MW "
+            f"[{base_capacity:.0f} + {annual_addition:.0f} × {n_years} years]"
+        )
 
 
 def set_transmission_limit(n: pypsa.Network, kind: str, factor: float, n_years=1):
@@ -325,25 +309,33 @@ def prepare_network(
 def add_nuclear_expansion_constraints(n: pypsa.Network):
     """
     Add nuclear expansion limit constraint if configured.
-
+
+    This function adds a global constraint limiting the total capacity of all
+    extendable nuclear generators. The limit is based on max_annual_capacity_addition.
+
     Args:
         n (pypsa.Network): the network object
     """
-    limit = n.config.get("nuclear_reactors", {}).get("expansion_limit")
-    if limit is None:
+    nuclear_config = n.config.get("nuclear_reactors", {})
+
+    if not nuclear_config.get("enable_growth_limit", True):
         return
-    
+
     nuclear_gens_ext = n.generators[
         (n.generators.carrier == "nuclear") & (n.generators.p_nom_extendable == True)
     ].index
-    
+
     if len(nuclear_gens_ext) == 0:
         return
-
-    # Add global constraint: sum of all nuclear p_nom <= limit
-    lhs = n.model["Generator-p_nom"].loc[nuclear_gens_ext].sum()
-    n.model.add_constraints(lhs <= limit, name="nuclear_expansion_limit")
-    logger.info(f"Applied global nuclear constraint: sum(p_nom) <= {limit:.0f} MW")
+
+    limit = nuclear_config.get("max_annual_capacity_addition")
+    if limit is None:
+        return
+
+    n.model.add_constraints(
+        n.model["Generator-p_nom"].loc[nuclear_gens_ext].sum() <= limit,
+        name="nuclear_expansion_limit",
+    )
 
 
 def add_battery_constraints(n: pypsa.Network):
@@ -672,8 +664,10 @@ def add_remind_paid_off_constraints(n: pypsa.Network) -> None:
             continue
         else:
             paidoff_comp.dropna(subset=[paid_off_col], inplace=True)
-        _remind_only_techs = n.config["existing_capacities"].get("remind_only_tech_groups", [])
-        paidoff_comp = paidoff_comp.query("tech_group not in @_remind_only_techs")
+
+        # techs that only exist as paid-off don't have usual counterparts
+        remind_only = n.config["existing_capacities"].get("remind_only_tech_groups", [])  # noqa: F841
+        paidoff_comp = paidoff_comp.query("tech_group not in @remind_only")
 
         if paidoff_comp.empty:
             continue
@@ -726,14 +720,14 @@ def add_operational_reserve_margin(n: pypsa.network, config):
             contingency: 400000 # MW
     """
     reserve_config = config["operational_reserve"]
-    _VRE_TECHS = config["Techs"].get("non_dispatchable", ["onwind", "offwind", "solar"])
+    VRE_TECHS = config["Techs"].get("non_dispatchable", ["onwind", "offwind", "solar"])  # noqa F841
     EPSILON_LOAD, EPSILON_VRES = reserve_config["epsilon_load"], reserve_config["epsilon_vres"]
     CONTINGENCY = float(reserve_config["contingency"])
 
     # AC producers
     ac_mask = n.generators.bus.map(n.buses.carrier) == "AC"
-    _ac_buses = n.buses.query("carrier =='AC'").index
-    _attached_carriers = filter_carriers(n, "AC")
+    ac_buses = n.buses.query("carrier =='AC'").index  # noqa: F841
+    attached_carriers = filter_carriers(n, "AC")  # noqa: F841
     # conceivably a link could have a negative efficiency and flow towards bus0 - don't consider
     prod_links = n.links.query("carrier in @_attached_carriers & not bus0 in @_ac_buses")
     transport_links = prod_links.bus0.map(n.buses.carrier) == prod_links.bus1.map(n.buses.carrier)
@@ -825,7 +819,7 @@ def extra_functionality(n: pypsa.Network, _) -> None:
     add_battery_constraints(n)
     add_transmission_constraints(n)
     add_nuclear_expansion_constraints(n)
-    
+
     if config["heat_coupling"]:
         add_water_tank_charger_constraints(n, config)
         add_chp_constraints(n)