Move CO2 budgets from data/co2_budget.csv to dict in config.yaml

Strategy is too keep as much of configuration in config.yaml as
possible.

We also aim to allow exogenous investment-year-dependent
configurations to be done in a similar manner (e.g. share of district
heating or FCEV transport).

Snakefile

@@ -25,17 +25,12 @@ rule all:
 
 rule solve_all_networks:
     input:
-        expand(config['results_dir'] + config['run'] + "/postnetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc",
+        expand(config['results_dir'] + config['run'] + "/postnetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc",
-               **config['scenario'])
-
-rule test_script:
-    input:
-        expand("resources/heat_demand_urban_elec_s_{clusters}.nc",
                **config['scenario'])
 
 rule prepare_sector_networks:
     input:
-        expand(config['results_dir'] + config['run'] + "/prenetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc",
+        expand(config['results_dir'] + config['run'] + "/prenetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc",
                  **config['scenario'])
 
 
@@ -295,7 +290,6 @@ rule prepare_sector_network:
         heat_profile="data/heat_load_profile_BDEW.csv",
         costs=config['costs_dir'] + "costs_{planning_horizons}.csv",
 	h2_cavern = "data/hydrogen_salt_cavern_potentials.csv",
-        co2_budget="data/co2_budget.csv",
         profile_offwind_ac=pypsaeur("resources/profile_offwind-ac.nc"),
         profile_offwind_dc=pypsaeur("resources/profile_offwind-dc.nc"),
         busmap_s=pypsaeur("resources/busmap_{network}_s{simpl}.csv"),
@@ -321,20 +315,20 @@ rule prepare_sector_network:
         solar_thermal_total="resources/solar_thermal_total_{network}_s{simpl}_{clusters}.nc",
         solar_thermal_urban="resources/solar_thermal_urban_{network}_s{simpl}_{clusters}.nc",
         solar_thermal_rural="resources/solar_thermal_rural_{network}_s{simpl}_{clusters}.nc"
-    output: config['results_dir']  +  config['run'] + '/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc'
+    output: config['results_dir']  +  config['run'] + '/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc'
     threads: 1
     resources: mem_mb=2000
-    benchmark: config['results_dir'] + config['run'] + "/benchmarks/prepare_network/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}"
+    benchmark: config['results_dir'] + config['run'] + "/benchmarks/prepare_network/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}"
     script: "scripts/prepare_sector_network.py"
 
 
 
 rule plot_network:
     input:
-        network=config['results_dir'] + config['run'] + "/postnetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc"
+        network=config['results_dir'] + config['run'] + "/postnetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc"
     output:
-        map=config['results_dir'] + config['run'] + "/maps/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}-costs-all_{co2_budget_name}_{planning_horizons}.pdf",
+        map=config['results_dir'] + config['run'] + "/maps/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}-costs-all_{planning_horizons}.pdf",
-        today=config['results_dir'] + config['run'] + "/maps/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}-today.pdf"
+        today=config['results_dir'] + config['run'] + "/maps/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}-today.pdf"
     threads: 2
     resources: mem_mb=10000
     script: "scripts/plot_network.py"
@@ -351,10 +345,10 @@ rule copy_config:
 
 rule make_summary:
     input:
-        networks=expand(config['results_dir'] + config['run'] + "/postnetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc",
+        networks=expand(config['results_dir'] + config['run'] + "/postnetworks/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc",
                  **config['scenario']),
         costs=config['costs_dir'] + "costs_{}.csv".format(config['scenario']['planning_horizons'][0]),
-        plots=expand(config['results_dir'] + config['run'] + "/maps/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}-costs-all_{co2_budget_name}_{planning_horizons}.pdf",
+        plots=expand(config['results_dir'] + config['run'] + "/maps/elec_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}-costs-all_{planning_horizons}.pdf",
               **config['scenario'])
         #heat_demand_name='data/heating/daily_heat_demand.h5'
     output:
@@ -397,16 +391,16 @@ if config["foresight"] == "overnight":
 
     rule solve_network:
         input:
-            network=config['results_dir'] + config['run'] + "/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc",
+            network=config['results_dir'] + config['run'] + "/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc",
             costs=config['costs_dir'] + "costs_{planning_horizons}.csv",
             config=config['summary_dir'] + '/' + config['run'] + '/configs/config.yaml'
-        output: config['results_dir'] + config['run'] + "/postnetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc"
+        output: config['results_dir'] + config['run'] + "/postnetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc"
         shadow: "shallow"
         log:
-            solver=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}_solver.log",
+            solver=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}_solver.log",
-            python=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}_python.log",
+            python=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}_python.log",
-            memory=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}_memory.log"
+            memory=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}_memory.log"
-        benchmark: config['results_dir'] + config['run'] + "/benchmarks/solve_network/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}"
+        benchmark: config['results_dir'] + config['run'] + "/benchmarks/solve_network/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}"
         threads: 4
         resources: mem_mb=config['solving']['mem']
         # group: "solve" # with group, threads is ignored https://bitbucket.org/snakemake/snakemake/issues/971/group-job-description-does-not-contain
@@ -417,7 +411,7 @@ if config["foresight"] == "myopic":
 
     rule add_existing_baseyear:
         input:
-            network=config['results_dir']  +  config['run'] + '/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc',
+            network=config['results_dir']  +  config['run'] + '/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc',
             powerplants=pypsaeur('resources/powerplants.csv'),
             busmap_s=pypsaeur("resources/busmap_{network}_s{simpl}.csv"),
             busmap=pypsaeur("resources/busmap_{network}_s{simpl}_{clusters}.csv"),
@@ -425,7 +419,7 @@ if config["foresight"] == "myopic":
             costs=config['costs_dir'] + "costs_{}.csv".format(config['scenario']['planning_horizons'][0]),
             cop_soil_total="resources/cop_soil_total_{network}_s{simpl}_{clusters}.nc",
             cop_air_total="resources/cop_air_total_{network}_s{simpl}_{clusters}.nc"
-        output: config['results_dir']  +  config['run'] + '/prenetworks-brownfield/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc'
+        output: config['results_dir']  +  config['run'] + '/prenetworks-brownfield/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc'
         wildcard_constraints:
             planning_horizons=config['scenario']['planning_horizons'][0] #only applies to baseyear
         threads: 1
@@ -434,36 +428,36 @@ if config["foresight"] == "myopic":
 
     def process_input(wildcards):
         i = config["scenario"]["planning_horizons"].index(int(wildcards.planning_horizons))
-        return config['results_dir'] + config['run'] + "/postnetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_" + str(config["scenario"]["planning_horizons"][i-1]) + ".nc"
+        return config['results_dir'] + config['run'] + "/postnetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_" + str(config["scenario"]["planning_horizons"][i-1]) + ".nc"
 
 
     rule add_brownfield:
         input:
-            network=config['results_dir']  +  config['run'] + '/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc',
+            network=config['results_dir']  +  config['run'] + '/prenetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc',
             network_p=process_input, #solved network at previous time step
             costs=config['costs_dir'] + "costs_{planning_horizons}.csv",
             cop_soil_total="resources/cop_soil_total_{network}_s{simpl}_{clusters}.nc",
             cop_air_total="resources/cop_air_total_{network}_s{simpl}_{clusters}.nc"
 
-        output: config['results_dir'] + config['run'] + "/prenetworks-brownfield/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc"
+        output: config['results_dir'] + config['run'] + "/prenetworks-brownfield/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc"
         threads: 4
-        resources: mem_mb=2000
+        resources: mem_mb=10000
         script: "scripts/add_brownfield.py"
 
     ruleorder: add_existing_baseyear > add_brownfield
 
     rule solve_network_myopic:
         input:
-            network=config['results_dir'] + config['run'] + "/prenetworks-brownfield/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc",
+            network=config['results_dir'] + config['run'] + "/prenetworks-brownfield/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc",
             costs=config['costs_dir'] + "costs_{planning_horizons}.csv",
             config=config['summary_dir'] + '/' + config['run'] + '/configs/config.yaml'
-        output: config['results_dir'] + config['run'] + "/postnetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}.nc"
+        output: config['results_dir'] + config['run'] + "/postnetworks/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}.nc"
         shadow: "shallow"
         log:
-            solver=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}_solver.log",
+            solver=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}_solver.log",
-            python=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}_python.log",
+            python=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}_python.log",
-            memory=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}_memory.log"
+            memory=config['results_dir'] + config['run'] + "/logs/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}_memory.log"
-        benchmark: config['results_dir'] + config['run'] + "/benchmarks/solve_network/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{co2_budget_name}_{planning_horizons}"
+        benchmark: config['results_dir'] + config['run'] + "/benchmarks/solve_network/{network}_s{simpl}_{clusters}_lv{lv}_{opts}_{sector_opts}_{planning_horizons}"
         threads: 4
         resources: mem_mb=config['solving']['mem']
         script: "scripts/solve_network.py"

config.default.yaml

@@ -25,7 +25,11 @@ scenario:
   # solarx or onwindx changes the available installable potential by factor x
   # dist{n} includes distribution grids with investment cost of n times cost in data/costs.csv
   planning_horizons : [2030] #investment years for myopic and perfect; or costs year for overnight
-  co2_budget_name: ['go'] #gives shape of CO2 budgets over planning horizon
+
+#CO2 budget as a fraction of 1990 emission
+#this is over-ridden if CO2Lx is set in sector_opts
+co2_budget:
+  2030: 0
 
 # snapshots are originally set in PyPSA-Eur/config.yaml but used again by PyPSA-Eur-Sec
 snapshots:
@@ -166,7 +170,7 @@ solving:
 
 industry:
   'St_primary_fraction' : 0.3 # fraction of steel produced via primary route (DRI + EAF) versus secondary route (EAF); today fraction is 0.6
-  'H2_DRI' : 1.7   #H2 consumption in Direct Reduced Iron (DRI),  MWh_H2,LHV/ton_Steel from Vogl et al (2018) doi:10.1016/j.jclepro.2018.08.279
+  'H2_DRI' : 1.7   #H2 consumption in Direct Reduced Iron (DRI),  MWh_H2,LHV/ton_Steel from 51kgH2/tSt in Vogl et al (2018) doi:10.1016/j.jclepro.2018.08.279
   'elec_DRI' : 0.322   #electricity consumption in Direct Reduced Iron (DRI) shaft, MWh/tSt HYBRIT brochure https://ssabwebsitecdn.azureedge.net/-/media/hybrit/files/hybrit_brochure.pdf
   'Al_primary_fraction' : 0.2 # fraction of aluminium produced via the primary route versus scrap; today fraction is 0.4
   'MWh_CH4_per_tNH3_SMR' : 10.8 # 2012's demand from https://ec.europa.eu/docsroom/documents/4165/attachments/1/translations/en/renditions/pdf

config.myopic.yaml

@@ -25,7 +25,19 @@ scenario:
   # solarx or onwindx changes the available installable potential by factor x
   # dist{n} includes distribution grids with investment cost of n times cost in data/costs.csv
   planning_horizons : [2020, 2030, 2040, 2050] #investment years for myopic and perfect; or costs year for overnight
-  co2_budget_name: ['go'] #gives shape of CO2 budgets over planning horizon
+
+
+#CO2 budget as a fraction of 1990 emission
+#this is over-ridden if CO2Lx is set in sector_opts
+co2_budget:
+  2020: 0.7011648746
+  2025: 0.5241935484
+  2030: 0.2970430108
+  2035: 0.1500896057
+  2040: 0.0712365591
+  2045: 0.0322580645
+  2050: 0
+
 
 # snapshots are originally set in PyPSA-Eur/config.yaml but used again by PyPSA-Eur-Sec
 snapshots:
@@ -166,7 +178,7 @@ solving:
 
 industry:
   'St_primary_fraction' : 0.3 # fraction of steel produced via primary route (DRI + EAF) versus secondary route (EAF); today fraction is 0.6
-  'H2_DRI' : 1.7   #H2 consumption in Direct Reduced Iron (DRI),  MWh_H2,LHV/ton_Steel from Vogl et al (2018) doi:10.1016/j.jclepro.2018.08.279
+  'H2_DRI' : 1.7   #H2 consumption in Direct Reduced Iron (DRI),  MWh_H2,LHV/ton_Steel from 51kgH2/tSt in Vogl et al (2018) doi:10.1016/j.jclepro.2018.08.279
   'elec_DRI' : 0.322   #electricity consumption in Direct Reduced Iron (DRI) shaft, MWh/tSt HYBRIT brochure https://ssabwebsitecdn.azureedge.net/-/media/hybrit/files/hybrit_brochure.pdf
   'Al_primary_fraction' : 0.2 # fraction of aluminium produced via the primary route versus scrap; today fraction is 0.4
   'MWh_CH4_per_tNH3_SMR' : 10.8 # 2012's demand from https://ec.europa.eu/docsroom/documents/4165/attachments/1/translations/en/renditions/pdf

data/co2_budget.csv

@@ -1,8 +0,0 @@
-,go,wait
-2020,0.7011648746,0.7011648746
-2025,0.5241935484,0.6285842294
-2030,0.2970430108,0.3503584229
-2035,0.1500896057,0.0725806452
-2040,0.0712365591,0
-2045,0.0322580645,0
-2050,0,0

scripts/make_summary.py

@@ -522,7 +522,7 @@ outputs = ["nodal_costs",
 
 def make_summaries(networks_dict):
 
-    columns = pd.MultiIndex.from_tuples(networks_dict.keys(),names=["cluster","lv","opt", "co2_budget_name","planning_horizon"])
+    columns = pd.MultiIndex.from_tuples(networks_dict.keys(),names=["cluster","lv","opt","planning_horizon"])
 
     df = {}
 
@@ -571,21 +571,19 @@ if __name__ == "__main__":
         for item in outputs:
             snakemake.output[item] = snakemake.config['summary_dir'] + '/{name}/csvs/{item}.csv'.format(name=snakemake.config['run'],item=item)
 
-    networks_dict = {(cluster,lv,opt+sector_opt, co2_budget_name, planning_horizon) :
+    networks_dict = {(cluster, lv, opt+sector_opt, planning_horizon) :
-                     snakemake.config['results_dir'] + snakemake.config['run'] + '/postnetworks/elec_s{simpl}_{cluster}_lv{lv}_{opt}_{sector_opt}_{co2_budget_name}_{planning_horizon}.nc'\
+                     snakemake.config['results_dir'] + snakemake.config['run'] + '/postnetworks/elec_s{simpl}_{cluster}_lv{lv}_{opt}_{sector_opt}_{planning_horizon}.nc'\
                      .format(simpl=simpl,
                              cluster=cluster,
                              opt=opt,
                              lv=lv,
                              sector_opt=sector_opt,
-                             co2_budget_name=co2_budget_name,
                              planning_horizon=planning_horizon)\
                      for simpl in snakemake.config['scenario']['simpl'] \
                      for cluster in snakemake.config['scenario']['clusters'] \
                      for opt in snakemake.config['scenario']['opts'] \
                      for sector_opt in snakemake.config['scenario']['sector_opts'] \
                      for lv in snakemake.config['scenario']['lv'] \
-                     for co2_budget_name in snakemake.config['scenario']['co2_budget_name'] \
                      for planning_horizon in snakemake.config['scenario']['planning_horizons']}
 
     print(networks_dict)

scripts/plot_summary.py

@@ -256,7 +256,8 @@ if __name__ == "__main__":
         snakemake.input["balances"] = snakemake.config['summary_dir'] + '/test/csvs/supply_energy.csv'
         snakemake.output["balances"] = snakemake.config['summary_dir'] + '/test/graphs/balances-energy.csv'
 
-    n_header = 5
+    n_header = 4
+
     plot_costs()
 
     plot_energy()

scripts/prepare_sector_network.py

@@ -1747,11 +1747,9 @@ if __name__ == "__main__":
         snakemake = MockSnakemake(
             wildcards=dict(network='elec', simpl='', clusters='37', lv='1.0',
                            opts='', planning_horizons='2020',
-                           co2_budget_name='go',
                            sector_opts='Co2L0-168H-T-H-B-I-solar3-dist1'),
             input=dict(network='pypsa-eur/networks/{network}_s{simpl}_{clusters}_ec_lv{lv}_{opts}.nc',
                        timezone_mappings='pypsa-eur-sec/data/timezone_mappings.csv',
-                       co2_budget='pypsa-eur-sec/data/co2_budget.csv',
                        clustered_pop_layout='pypsa-eur-sec/resources/pop_layout_{network}_s{simpl}_{clusters}.csv',
                        costs='technology-data/outputs/costs_{planning_horizons}.csv',
                        profile_offwind_ac='pypsa-eur/resources/profile_offwind-ac.nc',
@@ -1868,21 +1866,21 @@ if __name__ == "__main__":
     else:
         logger.info("No resampling")
 
-
+    #process CO2 limit
-    if snakemake.config["foresight"] == 'myopic':
+    if type(snakemake.config["co2_budget"]) == dict:
-        co2_limits=pd.read_csv(snakemake.input.co2_budget, index_col=0)
+        year=int(snakemake.wildcards.planning_horizons[-4:])
-        year=snakemake.wildcards.planning_horizons[-4:]
+        limit=snakemake.config["co2_budget"][year]
-        limit=co2_limits.loc[int(year),snakemake.config["scenario"]["co2_budget_name"]]
-        add_co2limit(n, Nyears, limit)
     else:
+        limit=snakemake.config["co2_budget"]
+    print("CO2 limit set to",limit)
+
     for o in opts:
         if "Co2L" in o:
             limit = o[o.find("Co2L")+4:]
-                print(o,limit)
-                if limit == "":
-                    limit = snakemake.config['co2_reduction']
-                else:
             limit = float(limit.replace("p",".").replace("m","-"))
+            print("overriding CO2 limit with scenario limit",limit)
+
+    print("adding CO2 budget limit as per unit of 1990 levels of",limit)
     add_co2limit(n, Nyears, limit)
 
 

scripts/solve_network.py

@@ -351,7 +351,7 @@ def solve_network(n, config=None, solver_log=None, opts=None):
         #     fn = os.path.basename(snakemake.output[0])
         #     n.export_to_netcdf('/home/vres/data/jonas/playground/pypsa-eur/' + fn)
 
-    status, termination_condition = run_lopf(n, fix_ext_lines=True)
+    status, termination_condition = run_lopf(n, allow_warning_status=True, fix_ext_lines=True)
 
     # Drop zero lines from network
     # zero_lines_i = n.lines.index[(n.lines.s_nom_opt == 0.) & n.lines.s_nom_extendable]