External-region representations: generator-based imports and boundary-metered CPUC contracted resources

docs/source/configtables/electricity.csv

@@ -52,6 +52,7 @@ demand_response:,,,Settings to activate and configure demand response
 ,,,
 imports:,,,Configure electric imports from regions outside of model scope
 -- enable,,``true`` or ``false``,Enable electric imports
+-- representation,,``store`` or ``generator``,"How out-of-footprint supply is represented. ``store`` (default) puts a bottomless ``Store`` behind each external zone and PRICES the interface ``Link``. ``generator`` puts a priced import ``Generator`` (carrier ``unspecified_imports``, carrying ``co2_emissions``) on the external bus, leaves the interface link unpriced, and moves the CPUC contracted out-of-state units behind the boundary so their deliveries are metered against ``volume_limit`` and the interface capacity."
 -- costs,$/MWh,``wholesale`` or ``<name of carrier>`` or ``float``,Cost of electric imports from regions outside of model scope. ``Wholesale`` will use in monthly wholesales electric prices. ``float`` will assign a user specified value. ``carrier`` will take average marginal cost of the carrier.
 -- co2_emissions,CO2/MWh,``float``,CO2 emissions of electric imports from regions outside of model scope.
 -- capacity_limit,,``true`` or ``false``,Enable capacity limit for electric imports from regions outside of model scope

workflow/repo_data/config/config.california.yaml

@@ -55,6 +55,8 @@ electricity:
     profile: servm
   imports:
     enable: true
+    representation: generator   # CPUC out-of-state contracts sit BEHIND the WECC boundary, so their deliveries are metered against the import cap
+    costs: 60                   # flat $/MWh for unspecified imports; the 'wholesale' EIA series is retail-priced (see issue #807)
     volume_limit: 25            # % of annual CA load
     balancing_period: year
   exports:
@@ -69,12 +71,6 @@ clustering:
   aggregation_strategies:
     generators:
       p_min_pu: 'capacity_weighted_average'   # keep the UC feasibility invariant through clustering
-      # CPUC out-of-state units (REMOTE_PREFIX "R ") are attached to CA buses with
-      # p_nom_extendable=False, while in-state units of the same carrier are extendable
-      # because their carrier is in extendable_carriers.Generator. Clustering groups
-      # one-ports by (bus, carrier), so those two land in one group and PyPSA's default
-      # `consense` raises. Same situation `committable: any` already handles in the base.
-      p_nom_extendable: any
       # Hydro units disagree on up_time_before ({0, 1}). `max` keeps the integer
       # dtype (capacity_weighted_average would yield a float) and is the
       # UC-feasibility-safe direction: the cluster inherits the longest online

workflow/repo_data/config/config.default.yaml

@@ -228,6 +228,7 @@ electricity:
   # neighbors using historical EIA interchange data.
   imports:
     enable: false
+    representation: store                  # store = priced links off a bottomless Store; generator = priced generator (+ CPUC contracted units) behind an unpriced interface link
     costs: wholesale                       # wholesale | carrier | float — how imported energy is priced
     co2_emissions: 0.428                   # tCO2/MWh assigned to imported energy
     capacity_limit: true                   # cap import power to historical maxima

workflow/rules/build_electricity.smk

@@ -804,6 +804,9 @@ rule add_electricity:
         planning_horizons=config["scenario"]["planning_horizons"],
         eia_api=config["api"]["eia"],
         remote_contracted=config["electricity"].get("remote_contracted_resources", {}),
+        imports_representation=config_provider(
+            "electricity", "imports", "representation", default="store"
+        ),
     input:
         unpack(dynamic_fuel_price_files),
         unpack(remote_contracted_resource_files),
@@ -870,7 +873,11 @@ rule add_electricity:
             else []
         ),
     output:
-        NETWORKS + "{interconnect}/elec_s{simpl}_l_pp.pkl",
+        network=NETWORKS + "{interconnect}/elec_s{simpl}_l_pp.pkl",
+        # CPUC contracted out-of-state units, serialized for attachment behind
+        # the model boundary when electricity.imports.representation == generator.
+        # Always declared; a sentinel is written otherwise.
+        remote_units=NETWORKS + "{interconnect}/remote_units_s{simpl}.pkl",
     log:
         LOGS + "{interconnect}/elec_s{simpl}_add_electricity.log",
     benchmark:
@@ -1064,6 +1071,7 @@ rule add_extra_components:
         + "{interconnect}/regions_onshore_s{simpl}_{clusters}.geojson",
         flowgates=flowgates_for_extra_components,
         reeds_memberships="repo_data/ReEDS_Constraints/membership.csv",
+        remote_units=NETWORKS + "{interconnect}/remote_units_s{simpl}.pkl",
         co2_storage=(
             CO2 + "{interconnect}/co2_storage_s{simpl}_{clusters}.csv"
             if config["scenario"]["sector"] == "" and config["co2"]["storage"] is True
@@ -1073,7 +1081,6 @@ rule add_extra_components:
     params:
         retirement=config["electricity"].get("retirement", "technical"),
         demand_response=config["electricity"].get("demand_response", {}),
-        trim_network=config_provider("model_topology", "trim", default=False),
         imports=config_provider("electricity", "imports", default={}),
         exports=config_provider("electricity", "exports", default={}),
         weather_year=config_provider("renewable_weather_years"),

workflow/schemas/config.schema.yaml

@@ -90,7 +90,6 @@ properties:
       transmission_network: {enum: [reeds, tamu]}
       topological_boundaries: {enum: [county, reeds_zone, state]}
       interface_transmission_limits: {type: boolean}
-      trim: {type: boolean}
       include:
         description: >
           Zone subset for footprint-scoped runs. null means "no filter"; see the
@@ -285,7 +284,12 @@ properties:
         additionalProperties: false
         properties:
           enable: {type: boolean}
-          costs: {enum: [wholesale, carrier, float]}
+          representation: {enum: [store, generator]}
+          costs:
+            description: >
+              'wholesale' (EIA price series), a carrier name (that fleet's
+              average marginal cost), or a flat number in $/MWh.
+            type: [string, number]
           co2_emissions: {type: number}
           capacity_limit: {type: boolean}
           volume_limit: {}
@@ -296,7 +300,11 @@ properties:
         additionalProperties: false
         properties:
           enable: {type: boolean}
-          costs: {enum: [wholesale, carrier, float]}
+          costs:
+            description: >
+              'wholesale' (EIA price series), a carrier name (that fleet's
+              average marginal cost), or a flat number in $/MWh.
+            type: [string, number]
           capacity_limit: {type: boolean}
           volume_limit: {}
           balancing_period: {enum: [day, week, month, year]}