diff --git a/Snakefile b/Snakefile
index cb50e3bf..b0dcc3b6 100644
--- a/Snakefile
+++ b/Snakefile
@@ -215,10 +215,22 @@ if 'hydro' in config['renewable'].keys():
         resources: mem=5000
         script: 'scripts/build_hydro_profile.py'
 
+if config['lines'].get('dynamic_line_rating', True):
+    rule build_line_rating:
+        input:
+            base_network="networks/base.nc",
+            cutout="cutouts/" + config["renewable"]['onwind']['cutout'] + ".nc"
+        output:
+            output="networks/base_line_rating.nc"
+    log: "logs/build_line_rating.log"
+    benchmark: "benchmarks/build_line_rating"
+    threads: 1
+    #resources: mem=3000
+    script: "scripts/build_line_rating.py"
 
 rule add_electricity:
     input:
-        base_network='networks/base.nc',
+        base_network = rules.build_line_rating.output[0] if config['lines'].get('dynamic_line_rating', True) else rules.base_network.output[0],
         tech_costs=COSTS,
         regions="resources/regions_onshore.geojson",
         powerplants='resources/powerplants.csv',
@@ -397,5 +409,4 @@ rule plot_p_nom_max:
     input: input_plot_p_nom_max
     output: "results/plots/elec_s{simpl}_cum_p_nom_max_{clusts}_{techs}_{country}.{ext}"
     log: "logs/plot_p_nom_max/elec_s{simpl}_{clusts}_{techs}_{country}_{ext}.log"
-    script: "scripts/plot_p_nom_max.py"
-
+    script: "scripts/plot_p_nom_max.py"
\ No newline at end of file
diff --git a/scripts/_helpers.py b/scripts/_helpers.py
index 30775ae5..f1e5e887 100644
--- a/scripts/_helpers.py
+++ b/scripts/_helpers.py
@@ -240,7 +240,7 @@ def mock_snakemake(rulename, **wildcards):
         if os.path.exists(p):
             snakefile = p
             break
-    workflow = sm.Workflow(snakefile)
+    workflow = sm.Workflow(snakefile, overwrite_configfiles=[])
     workflow.include(snakefile)
     workflow.global_resources = {}
     rule = workflow.get_rule(rulename)
diff --git a/scripts/build_line_rating.py b/scripts/build_line_rating.py
new file mode 100644
index 00000000..7e42419a
--- /dev/null
+++ b/scripts/build_line_rating.py
@@ -0,0 +1,85 @@
+# SPDX-FileCopyrightText: : 2017-2020 The PyPSA-Eur Authors
+#
+# SPDX-License-Identifier: MIT
+
+# coding: utf-8
+"""
+Adds dynamic line rating timeseries to the base network.
+
+Relevant Settings
+-----------------
+
+.. code:: yaml
+
+    lines_t:
+        s_max_pu
+
+
+.. seealso::
+    Documentation of the configuration file ``config.yaml`
+Inputs
+------
+
+- ``data/cutouts``: 
+- ``networks/base.nc``: confer :ref:`base`
+
+Outputs
+-------
+
+- ``networks/base_with_line_rating.nc``
+
+
+Description
+-----------
+
+The rule :mod:`build_line_rating` calculates the line rating for transmission lines. 
+The line rating provides the maximal capacity of a transmission line considering the heat exchange with the environment. 
+
+The folloing heat gains and losses are considered:
+
+- heat gain through resistive losses
+- heat gain trough solar radiation
+- heat loss through radiation of the trasnmission line
+- heat loss through forced convection with wind
+- heat loss through natural convection 
+
+
+With a heat balance considering the maximum temperature threshold of the tranmission line, 
+the maximal possible capacity factor "s_max_pu" for each transmission line at each time step is calculated.
+"""
+
+import logging
+from _helpers import configure_logging
+
+import pypsa
+import pandas as pd
+import numpy as np
+import geopandas as gpd
+from shapely.geometry import Point, LineString as Line
+import atlite
+
+
+def add_line_rating(n):
+    buses = n.lines[["bus0", "bus1"]].values
+    x = n.buses.x
+    y = n.buses.y
+    shapes = [Line([Point(x[b0], y[b0]), Point(x[b1], y[b1])]) for (b0, b1) in buses]
+    shapes = gpd.GeoSeries(shapes, index=n.lines.index)
+    cutout = atlite.Cutout(snakemake.input.cutout)
+    cutout.prepare(features=['temperature', "wnd100m", "height", "wnd_azimuth"])
+    s = np.sqrt(3) * cutout.line_rating(shapes, n.lines.r/n.lines.length) * 1e3 # in MW
+    n.lines_t.s_max_pu=s.to_pandas().transpose()/n.lines.s_nom
+    n.lines_t.s_max_pu.replace(np.inf, 1.0, inplace=True)
+
+
+if __name__ == "__main__":
+    if 'snakemake' not in globals():
+        from _helpers import mock_snakemake
+        snakemake = mock_snakemake('build_line_rating', network='elec', simpl='',
+                                  clusters='5', ll='copt', opts='Co2L-BAU-CCL-24H')
+    configure_logging(snakemake)
+
+    n = pypsa.Network(snakemake.input.base_network)    
+    add_line_rating(n)
+
+    n.export_to_netcdf(snakemake.output[0])
\ No newline at end of file
diff --git a/scripts/solve_network.py b/scripts/solve_network.py
index 6619f2d7..a5a29e1b 100755
--- a/scripts/solve_network.py
+++ b/scripts/solve_network.py
@@ -270,7 +270,7 @@ if __name__ == "__main__":
     if 'snakemake' not in globals():
         from _helpers import mock_snakemake
         snakemake = mock_snakemake('solve_network', network='elec', simpl='',
-                                  clusters='5', ll='copt', opts='Co2L-BAU-CCL-24H')
+                                  clusters='6', ll='copt', opts='Co2L-24H')
     configure_logging(snakemake)
 
     tmpdir = snakemake.config['solving'].get('tmpdir')
diff --git a/workflow.png b/workflow.png
new file mode 100644
index 00000000..9c149766
Binary files /dev/null and b/workflow.png differ