Add option to specify fixed DC-AC ratio for solar PV

config/config.default.yaml

@@ -364,6 +364,8 @@ renewable:
     natura: true
     excluder_resolution: 100
     clip_p_max_pu: 0.01
+    dc_ac_ratio: 1.25
+    costs_given_for_ac: true
   "solar-hsat":
     cutout: default
     resource:
@@ -404,6 +406,8 @@ renewable:
     natura: true
     excluder_resolution: 100
     clip_p_max_pu: 0.01
+    dc_ac_ratio: 1.25
+    costs_given_for_ac: true
   hydro:
     cutout: default
     carriers:

config/schema.default.json

@@ -3771,6 +3771,17 @@
               "default": 0.01,
               "description": "To avoid too small values in the renewables` per-unit availability time series values below this threshold are set to zero.",
               "type": "number"
+            },
+            "dc_ac_ratio": {
+              "default": 1.25,
+              "description": "DC/AC ratio for solar PV. Capacity factors are clipped at 1/dc_ac_ratio and rescaled to express output as a fraction of AC capacity.",
+              "minimum": 1,
+              "type": "number"
+            },
+            "costs_given_for_ac": {
+              "default": true,
+              "description": "Switch to indicate that the capital_costs for solar are given for AC capacity. If `false`, costs are given for DC peak capacity.",
+              "type": "boolean"
             }
           }
         },
@@ -3895,6 +3906,17 @@
               "default": 0.01,
               "description": "To avoid too small values in the renewables` per-unit availability time series values below this threshold are set to zero.",
               "type": "number"
+            },
+            "dc_ac_ratio": {
+              "default": 1.25,
+              "description": "DC/AC ratio for solar PV. Capacity factors are clipped at 1/dc_ac_ratio and rescaled to express output as a fraction of AC capacity.",
+              "minimum": 1,
+              "type": "number"
+            },
+            "costs_given_for_ac": {
+              "default": true,
+              "description": "Switch to indicate that the capital_costs for solar are given for AC capacity. If `false`, costs are given for DC peak capacity.",
+              "type": "boolean"
             }
           }
         },
@@ -7609,6 +7631,17 @@
           "default": 0.01,
           "description": "To avoid too small values in the renewables` per-unit availability time series values below this threshold are set to zero.",
           "type": "number"
+        },
+        "dc_ac_ratio": {
+          "default": 1.25,
+          "description": "DC/AC ratio for solar PV. Capacity factors are clipped at 1/dc_ac_ratio and rescaled to express output as a fraction of AC capacity.",
+          "minimum": 1,
+          "type": "number"
+        },
+        "costs_given_for_ac": {
+          "default": true,
+          "description": "Switch to indicate that the capital_costs for solar are given for AC capacity. If `false`, costs are given for DC peak capacity.",
+          "type": "boolean"
         }
       }
     },
@@ -9650,6 +9683,17 @@
               "default": 0.01,
               "description": "To avoid too small values in the renewables` per-unit availability time series values below this threshold are set to zero.",
               "type": "number"
+            },
+            "dc_ac_ratio": {
+              "default": 1.25,
+              "description": "DC/AC ratio for solar PV. Capacity factors are clipped at 1/dc_ac_ratio and rescaled to express output as a fraction of AC capacity.",
+              "minimum": 1,
+              "type": "number"
+            },
+            "costs_given_for_ac": {
+              "default": true,
+              "description": "Switch to indicate that the capital_costs for solar are given for AC capacity. If `false`, costs are given for DC peak capacity.",
+              "type": "boolean"
             }
           }
         },
@@ -9774,6 +9818,17 @@
               "default": 0.01,
               "description": "To avoid too small values in the renewables` per-unit availability time series values below this threshold are set to zero.",
               "type": "number"
+            },
+            "dc_ac_ratio": {
+              "default": 1.25,
+              "description": "DC/AC ratio for solar PV. Capacity factors are clipped at 1/dc_ac_ratio and rescaled to express output as a fraction of AC capacity.",
+              "minimum": 1,
+              "type": "number"
+            },
+            "costs_given_for_ac": {
+              "default": true,
+              "description": "Switch to indicate that the capital_costs for solar are given for AC capacity. If `false`, costs are given for DC peak capacity.",
+              "type": "boolean"
             }
           }
         },

scripts/add_electricity.py

@@ -472,6 +472,7 @@ def attach_wind_and_solar(
     extendable_carriers: list | set,
     line_length_factor: float = 1.0,
     landfall_lengths: dict = None,
+    params_renewable: dict = None,
 ) -> None:
     """
     Attach wind and solar generators to the network.
@@ -543,6 +544,13 @@ def attach_wind_and_solar(
                 logger.info(
                     f"Added connection cost of {connection_cost.min():0.0f}-{connection_cost.max():0.0f} Eur/MW/a to {car}"
                 )
+            elif (
+                params_renewable[car].get("costs_given_for_ac")
+                and params_renewable[car].get("dc_ac_ratio", 1.0) != 1.0
+            ):
+                capital_cost = (
+                    costs.at[car, "capital_cost"] / params_renewable[car]["dc_ac_ratio"]
+                )
             else:
                 capital_cost = costs.at[car, "capital_cost"]
 
@@ -1269,6 +1277,7 @@ def attach_stores(
         extendable_carriers,
         params.line_length_factor,
         landfall_lengths,
+        params.renewable,
     )
 
     if "hydro" in renewable_carriers:

scripts/build_renewable_profiles.py

@@ -321,6 +321,13 @@
         )
     )
 
+    dc_ac_ratio = params.get("dc_ac_ratio", 1.0)
+    if dc_ac_ratio != 1.0:
+        logger.info(
+            f"Applying DC/AC ratio of {dc_ac_ratio} by clipping solar profiles at {1 / dc_ac_ratio:.2f}."
+        )
+        ds["profile"] = ds["profile"].clip(max=1 / dc_ac_ratio)
+
     if "clip_p_max_pu" in params:
         min_p_max_pu = params["clip_p_max_pu"]
         ds["profile"] = ds["profile"].where(ds["profile"] >= min_p_max_pu, 0)

scripts/lib/validation/config/renewable.py

@@ -256,6 +256,15 @@ class _SolarConfig(BaseModel):
         0.01,
         description="To avoid too small values in the renewables` per-unit availability time series values below this threshold are set to zero.",
     )
+    dc_ac_ratio: float = Field(
+        1.25,
+        description="DC/AC ratio for solar PV. Capacity factors are clipped at 1/dc_ac_ratio and rescaled to express output as a fraction of AC capacity.",
+        ge=1,
+    )
+    costs_given_for_ac: bool = Field(
+        True,
+        description="Switch to indicate that the capital_costs for solar are given for AC capacity. If `false`, costs are given for DC peak capacity.",
+    )
 
 
 class _HydroConfig(BaseModel):

scripts/prepare_sector_network.py

@@ -427,6 +427,7 @@ def update_wind_solar_costs(
     profiles: dict[str, str],
     landfall_lengths: dict = None,
     line_length_factor: int | float = 1,
+    params_renewable: dict = None,
 ) -> None:
     """
     Update costs for wind and solar generators added with pypsa-eur to those
@@ -445,6 +446,8 @@ def update_wind_solar_costs(
     profiles : dict[str, str]
         Dictionary mapping technology names to profile file paths
         e.g. {'offwind-dc': 'path/to/profile.nc'}
+    params_renewable : dict, optional
+        Dictionary of renewable parameters, by default None
     """
 
     if landfall_lengths is None:
@@ -464,6 +467,13 @@ def update_wind_solar_costs(
         n.generators.loc[n.generators.carrier == carrier, "capital_cost"] = costs.at[
             cost_key, "capital_cost"
         ]
+        if (
+            params_renewable[carrier].get("costs_given_for_ac")
+            and params_renewable[carrier].get("dc_ac_ratio", 1.0) != 1.0
+        ):
+            n.generators.loc[n.generators.carrier == carrier, "capital_cost"] /= (
+                params_renewable[carrier]["dc_ac_ratio"]
+            )
 
     # for offshore wind, need to calculated connection costs
     for key, fn in profiles.items():
@@ -689,11 +699,17 @@ def remove_non_electric_buses(n):
         n.buses = n.buses[n.buses.carrier.isin(["AC", "DC"])]
 
 
-def patch_electricity_network(n, costs, carriers_to_keep, profiles, landfall_lengths):
+def patch_electricity_network(
+    n, costs, carriers_to_keep, profiles, landfall_lengths, params_renewable=None
+):
     remove_elec_base_techs(n, carriers_to_keep)
     remove_non_electric_buses(n)
     update_wind_solar_costs(
-        n, costs, landfall_lengths=landfall_lengths, profiles=profiles
+        n,
+        costs,
+        landfall_lengths=landfall_lengths,
+        profiles=profiles,
+        params_renewable=params_renewable,
     )
     n.loads["carrier"] = "electricity"
     n.buses["location"] = n.buses.index
@@ -1505,6 +1521,7 @@ def insert_electricity_distribution_grid(
     options: dict,
     pop_layout: pd.DataFrame,
     solar_rooftop_potentials_fn: str,
+    params_renewable: dict,
 ) -> None:
     """
     Insert electricity distribution grid components into the network.
@@ -1529,6 +1546,8 @@ def insert_electricity_distribution_grid(
         Population data per node with at least:
         - 'total' column containing population in thousands
         Index should match network nodes
+    params_renewable : dict
+        Renewable energy parameters
 
     Returns
     -------
@@ -1611,11 +1630,18 @@ def insert_electricity_distribution_grid(
     solar = n.generators.index[n.generators.carrier == "solar"]
     n.generators.loc[solar, "capital_cost"] = costs.at["solar-utility", "capital_cost"]
 
+    dc_ac_ratio = params_renewable["solar"].get("dc_ac_ratio", 1.0)
+    if params_renewable["solar"].get("costs_given_for_ac") and dc_ac_ratio != 1.0:
+        n.generators.loc[solar, "capital_cost"] /= dc_ac_ratio
+
     fn = solar_rooftop_potentials_fn
     if len(fn) > 0:
         potential = pd.read_csv(fn, index_col=["bus", "bin"]).squeeze(axis=1)
         potential.index = potential.index.map(flatten) + " solar"
 
+        capital_cost = costs.at["solar rooftop", "capital_cost"]
+        if params_renewable["solar"].get("costs_given_for_ac") and dc_ac_ratio != 1.0:
+            capital_cost /= dc_ac_ratio
         n.add(
             "Generator",
             solar,
@@ -1625,7 +1651,7 @@ def insert_electricity_distribution_grid(
             p_nom_extendable=True,
             p_nom_max=potential.loc[solar],
             marginal_cost=n.generators.loc[solar, "marginal_cost"],
-            capital_cost=costs.at["solar-rooftop", "capital_cost"],
+            capital_cost=capital_cost,
             efficiency=n.generators.loc[solar, "efficiency"],
             p_max_pu=n.generators_t.p_max_pu[solar],
             lifetime=costs.at["solar-rooftop", "lifetime"],
@@ -1737,14 +1763,14 @@ def insert_gas_distribution_costs(
     n.links.loc[mchp, "capital_cost"] += capital_cost
 
 
-def add_electricity_grid_connection(n, costs):
+def add_electricity_grid_connection(n, costs, params_renewables):
     carriers = ["onwind", "solar", "solar-hsat"]
-
-    gens = n.generators.index[n.generators.carrier.isin(carriers)]
-
-    n.generators.loc[gens, "capital_cost"] += costs.at[
-        "electricity grid connection", "capital_cost"
-    ]
+    for car in carriers:
+        gens = n.generators.index[n.generators.carrier == car]
+        dc_ac_ratio = params_renewables[car].get("dc_ac_ratio", 1.0)
+        n.generators.loc[gens, "capital_cost"] += (
+            costs.at["electricity grid connection", "capital_cost"] / dc_ac_ratio
+        )
 
 
 def add_h2_gas_infrastructure(
@@ -6287,7 +6313,14 @@ def add_import_options(
         for tech, settings in snakemake.params.renewable.items()
         if "landfall_length" in settings.keys()
     }
-    patch_electricity_network(n, costs, carriers_to_keep, profiles, landfall_lengths)
+    patch_electricity_network(
+        n,
+        costs,
+        carriers_to_keep,
+        profiles,
+        landfall_lengths,
+        snakemake.params.renewable,
+    )
 
     fn = snakemake.input.heating_efficiencies
     year = int(snakemake.params["energy_totals_year"])
@@ -6548,7 +6581,12 @@ def add_import_options(
 
     if options["electricity_distribution_grid"]:
         insert_electricity_distribution_grid(
-            n, costs, options, pop_layout, snakemake.input.solar_rooftop_potentials
+            n,
+            costs,
+            options,
+            pop_layout,
+            snakemake.input.solar_rooftop_potentials,
+            snakemake.params.renewable,
         )
 
     if options["enhanced_geothermal"].get("enable", False):
@@ -6570,7 +6608,7 @@ def add_import_options(
         insert_gas_distribution_costs(n, costs, options=options)
 
     if options["electricity_grid_connection"]:
-        add_electricity_grid_connection(n, costs)
+        add_electricity_grid_connection(n, costs, snakemake.params["renewable"])
 
     for k, v in options["transmission_efficiency"].items():
         if k in options["transmission_efficiency"]["enable"]: