From d976a8faf7af42e97ac3b35badccbd02fc269cd5 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Wed, 7 Jul 2021 17:58:47 +0200
Subject: [PATCH 01/14] add CO2 network [first draft]

---
 config.default.yaml               |  1 +
 scripts/prepare_sector_network.py | 58 +++++++++++++++++++++++++------
 2 files changed, 49 insertions(+), 10 deletions(-)

diff --git a/config.default.yaml b/config.default.yaml
index 5f1fa1b8..ecadc3c0 100644
--- a/config.default.yaml
+++ b/config.default.yaml
@@ -214,6 +214,7 @@ sector:
   SMR: true
   co2_sequestration_potential: 200  #MtCO2/a sequestration potential for Europe
   co2_sequestration_cost: 20   #EUR/tCO2 for transport and sequestration of CO2
+  co2_network: false
   cc_fraction: 0.9  # default fraction of CO2 captured with post-combustion capture
   hydrogen_underground_storage: true
   use_fischer_tropsch_waste_heat: true
diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index fa485e6a..aca8d76f 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -277,6 +277,18 @@ def patch_electricity_network(n):
 
 def add_co2_tracking(n, options):
 
+    if options["co2_network"]:
+        nodes = pop_layout.index
+        co2_nodes = nodes + " co2 stored"
+        co2_locations = nodes
+        co2_vents = nodes + " co2 vent"
+        co2_max_sequestration = np.inf
+    else:
+        co2_nodes = "co2 stored"
+        co2_locations = "EU"
+        co2_vents = "co2 vent"
+        co2_max_sequestration = np.inf # TODO should be nodal sequestration potentials
+
     # minus sign because opposite to how fossil fuels used:
     # CH4 burning puts CH4 down, atmosphere up
     n.add("Carrier", "co2",
@@ -299,26 +311,33 @@ def add_co2_tracking(n, options):
     )
 
     # this tracks CO2 stored, e.g. underground
-    n.add("Bus",
-        "co2 stored",
-        location="EU",
+    n.madd("Bus",
+        co2_nodes,
+        location=co2_locations,
         carrier="co2 stored"
     )
 
-    n.add("Store",
-        "co2 stored",
+    n.madd("Store",
+        co2_nodes,
         e_nom_extendable=True,
-        e_nom_max=options['co2_sequestration_potential'] * 1e6,
+        e_nom_max=co2_max_sequestration, 
         capital_cost=options['co2_sequestration_cost'],
         carrier="co2 stored",
-        bus="co2 stored"
+        bus=co2_nodes
     )
 
+    # TODO if nodally resolved total allowed sequestration needs to
+    # be an extra_functionality constraint
+    # (best to implement it this way for either case)
+    # let e_nom_max represent geological potential
+    # don't forget to log duals of extra functionality!
+    # options['co2_sequestration_potential'] * 1e6
+
     if options['co2_vent']:
 
-        n.add("Link",
-            "co2 vent",
-            bus0="co2 stored",
+        n.madd("Link",
+            co2_vents,
+            bus0=co2_nodes,
             bus1="co2 atmosphere",
             carrier="co2 vent",
             efficiency=1.,
@@ -326,6 +345,25 @@ def add_co2_tracking(n, options):
         )
 
 
+def add_co2_network(n, costs):
+
+    # TODO create co2 network topology from electricity 
+    co2_links = pd.DataFrame()
+    
+    # assumed to be bidirectional
+    n.madd("Link",
+        co2_links.index,
+        bus0=co2_links.bus0.values + " co2 stored",
+        bus1=co2_links.bus1.values + " co2 stored",
+        p_min_pu=-1,
+        p_nom_extendable=True,
+        length=co2_links.length.values,
+        capital_cost=costs.at['CO2 pipeline', 'fixed'] * co2_links.length.values,
+        carrier="CO2 pipeline",
+        lifetime=costs.at['CO2 pipeline', 'lifetime']
+    )
+
+
 def add_dac(n, costs):
 
     heat_carriers = ["urban central heat", "services urban decentral heat"]

From a98870e1597cc5cd25daa1d11cae14125960edec Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Wed, 7 Jul 2021 18:07:57 +0200
Subject: [PATCH 02/14] correction for .madd() and call co2_network

---
 scripts/prepare_sector_network.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index aca8d76f..c5a99fcc 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -284,9 +284,9 @@ def add_co2_tracking(n, options):
         co2_vents = nodes + " co2 vent"
         co2_max_sequestration = np.inf
     else:
-        co2_nodes = "co2 stored"
+        co2_nodes = ["co2 stored"]
         co2_locations = "EU"
-        co2_vents = "co2 vent"
+        co2_vents = ["co2 vent"]
         co2_max_sequestration = np.inf # TODO should be nodal sequestration potentials
 
     # minus sign because opposite to how fossil fuels used:
@@ -2074,6 +2074,9 @@ def limit_individual_line_extension(n, maxext):
     if "noH2network" in opts:
         remove_h2_network(n)
 
+    if options["co2_network"]:
+        add_co2_network(n, costs)
+
     for o in opts:
         m = re.match(r'^\d+h$', o, re.IGNORECASE)
         if m is not None:

From 56bdeafacbff5c731aa4859cec96917f3ed38ed1 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 9 Jul 2021 10:42:16 +0200
Subject: [PATCH 03/14] add co2 network topology

---
 scripts/prepare_sector_network.py | 37 ++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index c5a99fcc..bff2d840 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -54,6 +54,39 @@ def get(item, investment_year=None):
         return item
 
 
+def create_network_topology(n, prefix, connector=" -> "):
+    """
+    Create a network topology like the power transmission network.
+    
+    Parameters
+    ----------
+    n : pypsa.Network
+    prefix : str
+    connector : str
+        
+    Returns
+    -------
+    pd.DataFrame with columns bus0, bus1 and length
+    """
+
+    attrs = ["bus0", "bus1", "length"]
+
+    candidates = pd.concat([
+        n.lines[attrs],
+        n.links.loc[n.links.carrier == "DC", attrs]
+    ])
+
+    positive_order = candidates.bus0 < candidates.bus1
+    candidates_p = candidates[positive_order]
+    swap_buses = {"bus0": "bus1", "bus1": "bus0"}
+    candidates_n = candidates[~positive_order].rename(columns=swap_buses)
+    candidates = pd.concat([candidates_p, candidates_n])
+
+    topo = candidates.groupby(["bus0", "bus1"], as_index=False).mean()
+    topo.index = topo.apply(lambda c: prefix + c.bus0 + connector + c.bus1, axis=1)
+    return topo
+
+
 def co2_emissions_year(countries, opts, year):
     """
     Calculate CO2 emissions in one specific year (e.g. 1990 or 2018).
@@ -347,10 +380,8 @@ def add_co2_tracking(n, options):
 
 def add_co2_network(n, costs):
 
-    # TODO create co2 network topology from electricity 
-    co2_links = pd.DataFrame()
+    co2_links = create_network_topology(n, "CO2 pipeline ")
     
-    # assumed to be bidirectional
     n.madd("Link",
         co2_links.index,
         bus0=co2_links.bus0.values + " co2 stored",

From 62bba87cda517f253dce0ab6bb41d76b4831271a Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 9 Jul 2021 10:42:16 +0200
Subject: [PATCH 04/14] add co2 network topology

Co-authored-by: lisazeyen <lisa.zeyen@web.de>
---
 scripts/prepare_sector_network.py | 37 ++++++++++++++++++++++++++++---
 1 file changed, 34 insertions(+), 3 deletions(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index c5a99fcc..bff2d840 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -54,6 +54,39 @@ def get(item, investment_year=None):
         return item
 
 
+def create_network_topology(n, prefix, connector=" -> "):
+    """
+    Create a network topology like the power transmission network.
+    
+    Parameters
+    ----------
+    n : pypsa.Network
+    prefix : str
+    connector : str
+        
+    Returns
+    -------
+    pd.DataFrame with columns bus0, bus1 and length
+    """
+
+    attrs = ["bus0", "bus1", "length"]
+
+    candidates = pd.concat([
+        n.lines[attrs],
+        n.links.loc[n.links.carrier == "DC", attrs]
+    ])
+
+    positive_order = candidates.bus0 < candidates.bus1
+    candidates_p = candidates[positive_order]
+    swap_buses = {"bus0": "bus1", "bus1": "bus0"}
+    candidates_n = candidates[~positive_order].rename(columns=swap_buses)
+    candidates = pd.concat([candidates_p, candidates_n])
+
+    topo = candidates.groupby(["bus0", "bus1"], as_index=False).mean()
+    topo.index = topo.apply(lambda c: prefix + c.bus0 + connector + c.bus1, axis=1)
+    return topo
+
+
 def co2_emissions_year(countries, opts, year):
     """
     Calculate CO2 emissions in one specific year (e.g. 1990 or 2018).
@@ -347,10 +380,8 @@ def add_co2_tracking(n, options):
 
 def add_co2_network(n, costs):
 
-    # TODO create co2 network topology from electricity 
-    co2_links = pd.DataFrame()
+    co2_links = create_network_topology(n, "CO2 pipeline ")
     
-    # assumed to be bidirectional
     n.madd("Link",
         co2_links.index,
         bus0=co2_links.bus0.values + " co2 stored",

From 4f9d2f9d5f91286e334168a9ec8638d1d2141cd0 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 9 Jul 2021 12:50:40 +0200
Subject: [PATCH 05/14] add concept for management of spatial resolutions

---
 scripts/prepare_sector_network.py | 86 +++++++++++++++++++------------
 1 file changed, 54 insertions(+), 32 deletions(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index bff2d840..0ef06a00 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -19,6 +19,37 @@
 import logging
 logger = logging.getLogger(__name__)
 
+from types import SimpleNamespace
+spatial = SimpleNamespace()
+
+
+def define_spatial(nodes):
+    """
+    Namespace for spatial
+    
+    Parameters
+    ----------
+    nodes : list-like
+    """
+    
+    global spatial
+    global options
+    
+    spatial.nodes = nodes
+    
+    spatial.co2 = SimpleNamespace()
+    
+    if options["co2_network"]:
+        spatial.co2.nodes = nodes + " co2 stored"
+        spatial.co2.locations = nodes
+        spatial.co2.vents = nodes + " co2 vent"
+    else:
+        spatial.co2.nodes = ["co2 stored"]
+        spatial.co2.locations = "EU"
+        spatial.co2.vents = ["co2 vent"]
+
+    spatial.co2.df = pd.DataFrame(vars(spatial.co2), index=nodes)
+
 
 def emission_sectors_from_opts(opts):
 
@@ -310,18 +341,6 @@ def patch_electricity_network(n):
 
 def add_co2_tracking(n, options):
 
-    if options["co2_network"]:
-        nodes = pop_layout.index
-        co2_nodes = nodes + " co2 stored"
-        co2_locations = nodes
-        co2_vents = nodes + " co2 vent"
-        co2_max_sequestration = np.inf
-    else:
-        co2_nodes = ["co2 stored"]
-        co2_locations = "EU"
-        co2_vents = ["co2 vent"]
-        co2_max_sequestration = np.inf # TODO should be nodal sequestration potentials
-
     # minus sign because opposite to how fossil fuels used:
     # CH4 burning puts CH4 down, atmosphere up
     n.add("Carrier", "co2",
@@ -345,18 +364,18 @@ def add_co2_tracking(n, options):
 
     # this tracks CO2 stored, e.g. underground
     n.madd("Bus",
-        co2_nodes,
-        location=co2_locations,
+        spatial.co2.nodes,
+        location=spatial.co2.locations,
         carrier="co2 stored"
     )
 
     n.madd("Store",
-        co2_nodes,
+        spatial.co2.nodes,
         e_nom_extendable=True,
-        e_nom_max=co2_max_sequestration, 
+        e_nom_max=np.inf, 
         capital_cost=options['co2_sequestration_cost'],
         carrier="co2 stored",
-        bus=co2_nodes
+        bus=spatial.co2.nodes
     )
 
     # TODO if nodally resolved total allowed sequestration needs to
@@ -369,8 +388,8 @@ def add_co2_tracking(n, options):
     if options['co2_vent']:
 
         n.madd("Link",
-            co2_vents,
-            bus0=co2_nodes,
+            spatial.co2.vents,
+            bus0=spatial.co2.nodes,
             bus1="co2 atmosphere",
             carrier="co2 vent",
             efficiency=1.,
@@ -408,7 +427,7 @@ def add_dac(n, costs):
         locations,
         suffix=" DAC",
         bus0="co2 atmosphere",
-        bus1="co2 stored",
+        bus1=spatial.co2.df.loc[locations, "nodes"].values,
         bus2=locations.values,
         bus3=heat_buses,
         carrier="DAC",
@@ -1058,10 +1077,11 @@ def add_storage(n, costs):
     if options['methanation']:
 
         n.madd("Link",
-            nodes + " Sabatier",
+            spatial.nodes,
+            suffix=" Sabatier",
             bus0=nodes + " H2",
             bus1="EU gas",
-            bus2="co2 stored",
+            bus2=spatial.co2.nodes,
             p_nom_extendable=True,
             carrier="Sabatier",
             efficiency=costs.at["methanation", "efficiency"],
@@ -1073,10 +1093,11 @@ def add_storage(n, costs):
     if options['helmeth']:
 
         n.madd("Link",
-            nodes + " helmeth",
+            spatial.nodes,
+            suffix=" helmeth",
             bus0=nodes,
             bus1="EU gas",
-            bus2="co2 stored",
+            bus2=spatial.co2.nodes,
             carrier="helmeth",
             p_nom_extendable=True,
             efficiency=costs.at["helmeth", "efficiency"],
@@ -1089,11 +1110,12 @@ def add_storage(n, costs):
     if options['SMR']:
 
         n.madd("Link",
-            nodes + " SMR CC",
+            spatial.nodes,
+            suffix=" SMR CC",
             bus0="EU gas",
             bus1=nodes + " H2",
             bus2="co2 atmosphere",
-            bus3="co2 stored",
+            bus3=spatial.co2.nodes,
             p_nom_extendable=True,
             carrier="SMR CC",
             efficiency=costs.at["SMR CC", "efficiency"],
@@ -1442,7 +1464,7 @@ def add_heat(n, costs):
                 bus1=nodes[name],
                 bus2=nodes[name] + " urban central heat",
                 bus3="co2 atmosphere",
-                bus4="co2 stored",
+                bus4=spatial.co2.df.loc[nodes[name], "nodes"].values,
                 carrier="urban central gas CHP CC",
                 p_nom_extendable=True,
                 capital_cost=costs.at['central gas CHP', 'fixed']*costs.at['central gas CHP', 'efficiency'] + costs.at['biomass CHP capture', 'fixed']*costs.at['gas', 'CO2 intensity'],
@@ -1675,7 +1697,7 @@ def add_biomass(n, costs):
             bus1=urban_central,
             bus2=urban_central + " urban central heat",
             bus3="co2 atmosphere",
-            bus4="co2 stored",
+            bus4=spatial.co2.df.loc[urban_central, "nodes"].values,
             carrier="urban central solid biomass CHP CC",
             p_nom_extendable=True,
             capital_cost=costs.at[key, 'fixed'] * costs.at[key, 'efficiency'] + costs.at['biomass CHP capture', 'fixed'] * costs.at['solid biomass', 'CO2 intensity'],
@@ -1726,7 +1748,7 @@ def add_industry(n, costs):
         bus0="EU solid biomass",
         bus1="solid biomass for industry",
         bus2="co2 atmosphere",
-        bus3="co2 stored",
+        bus3="co2 stored", # TODO co2: where to allocate if co2 is spatially resolved?
         carrier="solid biomass for industry CC",
         p_nom_extendable=True,
         capital_cost=costs.at["cement capture", "fixed"] * costs.at['solid biomass', 'CO2 intensity'],
@@ -1764,7 +1786,7 @@ def add_industry(n, costs):
         bus0="EU gas",
         bus1="gas for industry",
         bus2="co2 atmosphere",
-        bus3="co2 stored",
+        bus3="co2 stored",  # TODO co2: where to allocate if co2 is spatially resolved?
         carrier="gas for industry CC",
         p_nom_extendable=True,
         capital_cost=costs.at["cement capture", "fixed"] * costs.at['gas', 'CO2 intensity'],
@@ -1847,7 +1869,7 @@ def add_industry(n, costs):
         nodes + " Fischer-Tropsch",
         bus0=nodes + " H2",
         bus1="EU oil",
-        bus2="co2 stored",
+        bus2=spatial.co2.nodes,
         carrier="Fischer-Tropsch",
         efficiency=costs.at["Fischer-Tropsch", 'efficiency'],
         capital_cost=costs.at["Fischer-Tropsch", 'fixed'],
@@ -1940,7 +1962,7 @@ def add_industry(n, costs):
         "process emissions CC",
         bus0="process emissions",
         bus1="co2 atmosphere",
-        bus2="co2 stored",
+        bus2="co2 stored",  # TODO co2: where to allocate if co2 is spatially resolved?
         carrier="process emissions CC",
         p_nom_extendable=True,
         capital_cost=costs.at["cement capture", "fixed"],

From 2b204c45e421b8459371a46f79e0bb4e24c50851 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 9 Jul 2021 12:51:48 +0200
Subject: [PATCH 06/14] run define_spatial in __main__

---
 scripts/prepare_sector_network.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index 0ef06a00..0552790a 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -2075,6 +2075,8 @@ def limit_individual_line_extension(n, maxext):
 
     patch_electricity_network(n)
 
+    define_spatial(pop_layout.index)
+
     if snakemake.config["foresight"] == 'myopic':
         
         add_lifetime_wind_solar(n, costs)

From cd99089628ea3c54925ddef7fa190a2d9e3bb729 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 9 Jul 2021 13:10:43 +0200
Subject: [PATCH 07/14] account for underwater fraction

---
 scripts/prepare_sector_network.py | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index 0552790a..aced4719 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -100,12 +100,13 @@ def create_network_topology(n, prefix, connector=" -> "):
     pd.DataFrame with columns bus0, bus1 and length
     """
 
-    attrs = ["bus0", "bus1", "length"]
+    ln_attrs = ["bus0", "bus1", "length"]
+    lk_attrs = ["bus0", "bus1", "length", "underwater_fraction"]
 
     candidates = pd.concat([
-        n.lines[attrs],
-        n.links.loc[n.links.carrier == "DC", attrs]
-    ])
+        n.lines[ln_attrs],
+        n.links.loc[n.links.carrier == "DC", lk_attrs]
+    ]).fillna(0)
 
     positive_order = candidates.bus0 < candidates.bus1
     candidates_p = candidates[positive_order]
@@ -400,6 +401,10 @@ def add_co2_tracking(n, options):
 def add_co2_network(n, costs):
 
     co2_links = create_network_topology(n, "CO2 pipeline ")
+
+    cost_onshore = (1 - co2_links.underwater_fraction) * costs.at['CO2 pipeline', 'fixed'] * co2_links.length
+    cost_submarine = co2_links.underwater_fraction * costs.at['CO2 pipeline submarine', 'fixed'] * co2_links.length
+    capital_cost = cost_onshore + cost_submarine
     
     n.madd("Link",
         co2_links.index,
@@ -408,7 +413,7 @@ def add_co2_network(n, costs):
         p_min_pu=-1,
         p_nom_extendable=True,
         length=co2_links.length.values,
-        capital_cost=costs.at['CO2 pipeline', 'fixed'] * co2_links.length.values,
+        capital_cost=capital_cost.values,
         carrier="CO2 pipeline",
         lifetime=costs.at['CO2 pipeline', 'lifetime']
     )

From d58a7f86a45c4825c843d1a35f64715f7cd7c376 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 9 Jul 2021 13:22:00 +0200
Subject: [PATCH 08/14] allow copperplated carbon capture to be distributed
 freely to co2 stores

---
 scripts/prepare_sector_network.py | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index aced4719..16eb12f6 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -1748,12 +1748,13 @@ def add_industry(n, costs):
         efficiency=1.
     )
 
-    n.add("Link",
-        "solid biomass for industry CC",
+    n.madd("Link",
+        spatial.co2.locations,
+        suffix=" solid biomass for industry CC",
         bus0="EU solid biomass",
         bus1="solid biomass for industry",
         bus2="co2 atmosphere",
-        bus3="co2 stored", # TODO co2: where to allocate if co2 is spatially resolved?
+        bus3=spatial.co2.nodes,
         carrier="solid biomass for industry CC",
         p_nom_extendable=True,
         capital_cost=costs.at["cement capture", "fixed"] * costs.at['solid biomass', 'CO2 intensity'],
@@ -1786,12 +1787,13 @@ def add_industry(n, costs):
         efficiency2=costs.at['gas', 'CO2 intensity']
     )
 
-    n.add("Link",
-        "gas for industry CC",
+    n.madd("Link",
+        spatial.co2.locations,
+        suffix=" gas for industry CC",
         bus0="EU gas",
         bus1="gas for industry",
         bus2="co2 atmosphere",
-        bus3="co2 stored",  # TODO co2: where to allocate if co2 is spatially resolved?
+        bus3=spatial.co2.nodes,
         carrier="gas for industry CC",
         p_nom_extendable=True,
         capital_cost=costs.at["cement capture", "fixed"] * costs.at['gas', 'CO2 intensity'],
@@ -1963,11 +1965,12 @@ def add_industry(n, costs):
     )
 
     #assume enough local waste heat for CC
-    n.add("Link",
-        "process emissions CC",
+    n.madd("Link",
+        spatial.co2.locations,
+        suffix=" process emissions CC",
         bus0="process emissions",
         bus1="co2 atmosphere",
-        bus2="co2 stored",  # TODO co2: where to allocate if co2 is spatially resolved?
+        bus2=spatial.co2.nodes,
         carrier="process emissions CC",
         p_nom_extendable=True,
         capital_cost=costs.at["cement capture", "fixed"],

From 36fdde788760e0f7fc943975ff57b64cfb10d83e Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 9 Jul 2021 14:36:13 +0200
Subject: [PATCH 09/14] correctly name co2 submarine pipeline!

---
 scripts/prepare_sector_network.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index 16eb12f6..ca956e44 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -403,7 +403,7 @@ def add_co2_network(n, costs):
     co2_links = create_network_topology(n, "CO2 pipeline ")
 
     cost_onshore = (1 - co2_links.underwater_fraction) * costs.at['CO2 pipeline', 'fixed'] * co2_links.length
-    cost_submarine = co2_links.underwater_fraction * costs.at['CO2 pipeline submarine', 'fixed'] * co2_links.length
+    cost_submarine = co2_links.underwater_fraction * costs.at['CO2 submarine pipeline', 'fixed'] * co2_links.length
     capital_cost = cost_onshore + cost_submarine
     
     n.madd("Link",

From 3754643e8192c57452c84d7a8a3639abd17a49a3 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 6 Aug 2021 12:46:03 +0200
Subject: [PATCH 10/14] add co2 sequestration potential global constraint

---
 scripts/prepare_sector_network.py |  9 +--------
 scripts/solve_network.py          | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index ca956e44..659fbf37 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -45,7 +45,7 @@ def define_spatial(nodes):
         spatial.co2.vents = nodes + " co2 vent"
     else:
         spatial.co2.nodes = ["co2 stored"]
-        spatial.co2.locations = "EU"
+        spatial.co2.locations = ["EU"]
         spatial.co2.vents = ["co2 vent"]
 
     spatial.co2.df = pd.DataFrame(vars(spatial.co2), index=nodes)
@@ -379,13 +379,6 @@ def add_co2_tracking(n, options):
         bus=spatial.co2.nodes
     )
 
-    # TODO if nodally resolved total allowed sequestration needs to
-    # be an extra_functionality constraint
-    # (best to implement it this way for either case)
-    # let e_nom_max represent geological potential
-    # don't forget to log duals of extra functionality!
-    # options['co2_sequestration_potential'] * 1e6
-
     if options['co2_vent']:
 
         n.madd("Link",
diff --git a/scripts/solve_network.py b/scripts/solve_network.py
index 8c0313f1..3796bc4d 100644
--- a/scripts/solve_network.py
+++ b/scripts/solve_network.py
@@ -3,6 +3,7 @@
 import pypsa
 
 import numpy as np
+import pandas as pd
 
 from pypsa.linopt import get_var, linexpr, define_constraints
 
@@ -150,9 +151,27 @@ def add_chp_constraints(n):
         define_constraints(n, lhs, "<=", 0, 'chplink', 'backpressure')
 
 
+def add_co2_sequestration_limit(n, sns):
+    
+    co2_stores = n.stores.loc[n.stores.carrier=='co2 stored'].index
+
+    if co2_stores.empty or ('Store', 'e') not in n.variables.index:
+        return
+    
+    vars_final_co2_stored = get_var(n, 'Store', 'e').loc[sns[-1], co2_stores]
+    
+    lhs = linexpr((1, vars_final_co2_stored)).sum()
+    rhs = n.config["sector"].get("co2_sequestration_potential", 200) * 1e6
+    
+    name = 'co2_sequestration_limit'
+    define_constraints(n, lhs, "<=", rhs, 'GlobalConstraint',
+                       'mu', axes=pd.Index([name]), spec=name)
+
+
 def extra_functionality(n, snapshots):
     add_chp_constraints(n)
     add_battery_constraints(n)
+    add_co2_sequestration_limit(n, snapshots)
 
 
 def solve_network(n, config, opts='', **kwargs):

From d7a290df31737f3127e05868c83ff7cb36ddd7f2 Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Fri, 6 Aug 2021 15:51:07 +0200
Subject: [PATCH 11/14] add release note

---
 doc/release_notes.rst      | 8 ++++++++
 doc/spatial_resolution.rst | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index bd99ce16..a24ccb7c 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -60,6 +60,14 @@ Future release
   These are included in the environment specifications of PyPSA-Eur.
 * Consistent use of ``__main__`` block and further unspecific code cleaning.
 * Distinguish costs for home battery storage and inverter from utility-scale battery costs.
+* Add option to regionally resolve CO2 storage and add CO2 pipeline transport because geological storage potential,
+  CO2 utilisation sites and CO2 capture sites may be separated.
+  The CO2 network is built from zero based on the topology of the electricity grid (greenfield).
+  Pipelines are assumed to be bidirectional and lossless.
+  Furthermore, neither retrofitting of natural gas pipelines (required pressures are too high, 80-160 bar vs <80 bar)
+  nor other modes of CO2 transport (by ship, road or rail) are considered.
+  The regional representation of CO2 is activated with the config setting ``sector: co2_network: true`` but is deactivated by default.
+  The global limit for CO2 sequestration now applies to the sum of all CO2 stores via an ``extra_functionality`` constraint.
 
 
 
diff --git a/doc/spatial_resolution.rst b/doc/spatial_resolution.rst
index 1be9f3ad..13e94543 100644
--- a/doc/spatial_resolution.rst
+++ b/doc/spatial_resolution.rst
@@ -48,7 +48,7 @@ Solid biomass:  single node for Europe, until transport costs can be
 incorporated.
 
 CO2:  single node for Europe, but a transport and storage cost is added for
-sequestered CO2.
+sequestered CO2. Optionally: nodal, with CO2 transport via pipelines.
 
 Liquid hydrocarbons: single node for Europe, since transport costs for
 liquids are low.

From e1a0a7d5fd45c83a2f4eeee371e47952f1c3972c Mon Sep 17 00:00:00 2001
From: Fabian Neumann <fabian.neumann@outlook.de>
Date: Tue, 10 Aug 2021 10:31:06 +0200
Subject: [PATCH 12/14] set co2 sequestration cost to 10 EUR/t excl. transport

---
 config.default.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.default.yaml b/config.default.yaml
index b2de9bf9..66a9f299 100644
--- a/config.default.yaml
+++ b/config.default.yaml
@@ -223,7 +223,7 @@ sector:
   co2_vent: true
   SMR: true
   co2_sequestration_potential: 200  #MtCO2/a sequestration potential for Europe
-  co2_sequestration_cost: 20   #EUR/tCO2 for transport and sequestration of CO2
+  co2_sequestration_cost: 10   #EUR/tCO2 for sequestration of CO2
   co2_network: false
   cc_fraction: 0.9  # default fraction of CO2 captured with post-combustion capture
   hydrogen_underground_storage: true

From 960d857d0bdf5d290878f7530e60902ed2909ca5 Mon Sep 17 00:00:00 2001
From: lisazeyen <35347358+lisazeyen@users.noreply.github.com>
Date: Fri, 24 Sep 2021 15:29:04 +0200
Subject: [PATCH 13/14] Update config.default.yaml

add color for CO2 pipelines
---
 config.default.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/config.default.yaml b/config.default.yaml
index 66a9f299..14a6cc0a 100644
--- a/config.default.yaml
+++ b/config.default.yaml
@@ -467,6 +467,7 @@ plotting:
     hot water storage: '#BBBBBB'
     hot water charging: '#BBBBBB'
     hot water discharging: '#999999'
+    CO2 pipeline: '#999999'
     CHP: r
     CHP heat: r
     CHP electric: r

From 7ed20aba7a06d02f5a3895b24857b6f3841f715d Mon Sep 17 00:00:00 2001
From: lisazeyen <35347358+lisazeyen@users.noreply.github.com>
Date: Fri, 24 Sep 2021 15:30:43 +0200
Subject: [PATCH 14/14] Update prepare_sector_network.py

add logger info if CO2 network is added
---
 scripts/prepare_sector_network.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index 33f9c4b6..b3fb0426 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -392,7 +392,8 @@ def add_co2_tracking(n, options):
 
 
 def add_co2_network(n, costs):
-
+    
+    logger.info("Adding CO2 network.")
     co2_links = create_network_topology(n, "CO2 pipeline ")
 
     cost_onshore = (1 - co2_links.underwater_fraction) * costs.at['CO2 pipeline', 'fixed'] * co2_links.length