Add a constraint to limit DAC (#42)

* Add a constraint to limit DAC

* added doc and release note

* Set dac_limit as a pathway

* updated default DAC limit pathway based on EC Industral carbon management

* Update documentation

---------

Co-authored-by: daniel-rdt <daniel.ruedt@openenergytransition.org>
Co-authored-by: Daniel Rüdt <117752024+daniel-rdt@users.noreply.github.com>

config/config.default.yaml

@@ -615,6 +615,13 @@ sector:
   methanation: true
   coal_cc: false
   dac: true
+  dac_limit:  # limit in MtCO2, default pathway is based on EC Industrial Carbon Management (COM/2024/62) https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:52024DC0062
+    enable: false
+    2030: 0
+    2035: 20  # interpolated value for DAC share and total captured carbon
+    2040: 70
+    2045: 137  # interpolated value for DAC share and total captured carbon
+    2050: 180
   co2_vent: false
   central_heat_vent: false
   allam_cycle_gas: false

config/config.form.yaml

@@ -13,7 +13,7 @@ logging:
 # docs in https://pypsa-eur.readthedocs.io/en/latest/configuration.html#run
 run:
   prefix: "updated_initial_main_scenarios"
-  name: "main-mds-vanilla-no-methanation"
+  name: "main-mds-vanilla-dac-limit-ev40"
   scenarios:
     enable: true
     file: config/scenarios.form.yaml
@@ -183,6 +183,10 @@ sector:
   reduce_space_heat_exogenously_factor:
     2035: 0.21
   tes: false
+  dac: true
+  dac_limit:
+      enable: false
+      2035: 20  # limit in MtCO2
   marginal_cost_storage: 0. #1e-4
   stores: ["H2"]
   storage_units: ["li-ion battery", "vanadium", "lair", "pair", "iron-air battery"]

config/scenarios.form.yaml

@@ -77,6 +77,93 @@ main-mds-vanilla:
     stores: ["H2"]
     storage_units: ["li-ion battery", "iron-air battery"]
 
+main-mds-vanilla-dac-limit-ev35:
+  electricity:
+    max_hours:
+      li-ion battery: [1, 2, 4, 8]
+      vanadium: [10]
+      lair: [12]
+      pair: [24]
+      H2: [168]
+      iron-air battery: [100]
+  sector:
+    land_transport_electric_share:
+      2035: 0.35 # default assumptions
+    land_transport_ice_share:
+      2035: 0.65
+    stores: ["H2"]
+    storage_units: ["li-ion battery", "iron-air battery"]
+    dac: true
+    dac_limit:
+        enable: true
+        2035: 20  # limit in MtCO2
+
+main-mds-vanilla-dac-limit-ev40:
+  electricity:
+    max_hours:
+      li-ion battery: [1, 2, 4, 8]
+      vanadium: [10]
+      lair: [12]
+      pair: [24]
+      H2: [168]
+      iron-air battery: [100]
+  sector:
+    land_transport_electric_share:
+      2035: 0.40 # default assumptions
+    land_transport_ice_share:
+      2035: 0.60
+    stores: ["H2"]
+    storage_units: ["li-ion battery", "iron-air battery"]
+    dac: true
+    dac_limit:
+        enable: true
+        2035: 20  # limit in MtCO2
+
+main-mds-vanilla-dac-limit-ev45:
+  electricity:
+    max_hours:
+      li-ion battery: [1, 2, 4, 8]
+      vanadium: [10]
+      lair: [12]
+      pair: [24]
+      H2: [168]
+      iron-air battery: [100]
+  sector:
+    land_transport_electric_share:
+      2035: 0.45 # default assumptions
+    land_transport_ice_share:
+      2035: 0.55
+    stores: ["H2"]
+    storage_units: ["li-ion battery", "iron-air battery"]
+    dac: true
+    dac_limit:
+        enable: true
+        2035: 20  # limit in MtCO2
+
+main-mds-vanilla-dac-limit-ev45-nuc80:
+  electricity:
+    max_hours:
+      li-ion battery: [1, 2, 4, 8]
+      vanadium: [10]
+      lair: [12]
+      pair: [24]
+      H2: [168]
+      iron-air battery: [100]
+  sector:
+    land_transport_electric_share:
+      2035: 0.45 # default assumptions
+    land_transport_ice_share:
+      2035: 0.55
+    stores: ["H2"]
+    storage_units: ["li-ion battery", "iron-air battery"]
+    dac: true
+    dac_limit:
+        enable: true
+        2035: 20  # limit in MtCO2
+  conventional:
+    nuclear:
+      p_min_pu: 0.8
+
 main-no-mds-vanilla:
   electricity:
     max_hours:

doc/configtables/sector.csv

@@ -105,6 +105,8 @@ storage_units,--,List of storage technologies to include as StorageUnit componen
 methanation,--,"{true, false}",Add option for transforming hydrogen and CO2 into methane using methanation.
 coal_cc,--,"{true, false}",Add option for coal CHPs with carbon capture
 dac,--,"{true, false}",Add option for Direct Air Capture (DAC)
+dac_limit,MtCO2,Dictionary with planning horizons as keys.,Limit on Direct Air Capture (DAC) in MtCO2.
+-- enable,--,"{true, false}",Add limit on Direct Air Capture (DAC).
 co2_vent,--,"{true, false}",Add option for vent out CO2 from storages to the atmosphere.
 allam_cycle_gas,--,"{true, false}",Add option to include `Allam cycle gas power plants <https://en.wikipedia.org/wiki/Allam_power_cycle>`_
 hydrogen_fuel_cell,--,"{true, false}",Add option to include hydrogen fuel cell for re-electrification. Assuming OCGT technology costs

doc/release_notes.rst

@@ -11,6 +11,8 @@ Release Notes
 Upcoming Release
 ================
 
+* Added option to include an exogenous DAC yearly limit specified via the configuration file (in MtCO2)
+
 * Added Iron-Air battery storage technology and changed nomenclature for lithium-ion battery storages from ``battery`` to ``li-ion battery``.
 
 * Feature: Allow CHPs to use different fuel sources such as gas, oil, coal, and methanol. Note that the cost assumptions are based on a gas CHP.

scripts/solve_network.py

@@ -931,6 +931,17 @@ def add_co2_atmosphere_constraint(n, snapshots):
             n.model.add_constraints(lhs <= rhs, name=f"GlobalConstraint-{name}")
 
 
+def add_dac_limit(n):
+    """
+    Limit the amount of CO2 captured using DAC. The constraint is formulated in tCO2.
+    """
+    dac = n.links.query("Link.str.contains('DAC')")
+    lhs = (n.model["Link-p"].loc[:, dac.index] * n.snapshot_weightings.generators * dac.efficiency2 * -1).sum()
+    optimization_year = int(snakemake.wildcards.planning_horizons)
+    rhs = n.config["sector"]["dac_limit"][optimization_year] * 1e6  # DAC limit specified in config in MtCO2
+    n.model.add_constraints(lhs <= rhs, name="DAC limit")
+
+
 def extra_functionality(n, snapshots):
     """
     Collects supplementary constraints which will be passed to
@@ -966,6 +977,8 @@ def extra_functionality(n, snapshots):
     add_battery_constraints(n)
     add_lossy_bidirectional_link_constraints(n)
     add_pipe_retrofit_constraint(n)
+    if config["sector"]["dac"] and config["sector"]["dac_limit"]["enable"]:
+        add_dac_limit(n)
     if n._multi_invest:
         add_carbon_constraint(n, snapshots)
         add_carbon_budget_constraint(n, snapshots)