diff --git a/workflow/scripts/export_ariadne_variables.py b/workflow/scripts/export_ariadne_variables.py
index 01b41246..c3bfc6e7 100644
--- a/workflow/scripts/export_ariadne_variables.py
+++ b/workflow/scripts/export_ariadne_variables.py
@@ -5210,6 +5210,19 @@ def process_postnetworks(n, n_start, model_year, snakemake, costs):
     n.links.loc[h2_links_kern, "capital_cost"] = capital_costs
     n.links.loc[h2_links_kern, "overnight_cost"] = overnight_costs
 
+    logger.info("Assing average Kernnetz cost to carrier H2 pipeline (Kernnetz)")
+    h2_links_kern = n.links.query("carrier == 'H2 pipeline (Kernnetz))'").index
+    capital_costs = (
+        0.7 * costs.at["H2 (g) pipeline", "fixed"]
+        + 0.3 * costs.at["H2 (g) pipeline repurposed", "fixed"]
+    ) * n.links.loc[h2_links_kern, "length"]
+    overnight_costs = (
+        0.7 * costs.at["H2 (g) pipeline", "investment"]
+        + 0.3 * costs.at["H2 (g) pipeline repurposed", "investment"]
+    ) * n.links.loc[h2_links_kern, "length"]
+    n.links.loc[h2_links_kern, "capital_cost"] = capital_costs
+    n.links.loc[h2_links_kern, "overnight_cost"] = overnight_costs
+
     logger.info("Post-Discretizing DC links")
     _dc_lambda = lambda x: get_discretized_value(
         x,
diff --git a/workflow/scripts/modify_prenetwork.py b/workflow/scripts/modify_prenetwork.py
index 387d01a6..690211d2 100644
--- a/workflow/scripts/modify_prenetwork.py
+++ b/workflow/scripts/modify_prenetwork.py
@@ -206,18 +206,31 @@ def add_wasserstoff_kernnetz(n, wkn, costs):
 
         names = wkn_new.index + f"-kernnetz-{investment_year}"
 
-        capital_costs = np.where(
-            wkn_new.retrofitted == False,
-            costs.at["H2 (g) pipeline", "fixed"] * wkn_new.length.values,
-            costs.at["H2 (g) pipeline repurposed", "fixed"] * wkn_new.length.values,
-        )
-
-        overnight_costs = np.where(
-            wkn_new.retrofitted == False,
-            costs.at["H2 (g) pipeline", "investment"] * wkn_new.length.values,
-            costs.at["H2 (g) pipeline repurposed", "investment"]
-            * wkn_new.length.values,
-        )
+        # capital_costs = np.where(
+        #     wkn_new.retrofitted == False,
+        #     costs.at["H2 (g) pipeline", "fixed"] * wkn_new.length.values,
+        #     costs.at["H2 (g) pipeline repurposed", "fixed"] * wkn_new.length.values,
+        # )
+
+        # overnight_costs = np.where(
+        #     wkn_new.retrofitted == False,
+        #     costs.at["H2 (g) pipeline", "investment"] * wkn_new.length.values,
+        #     costs.at["H2 (g) pipeline repurposed", "investment"]
+        #     * wkn_new.length.values,
+        # )
+
+        # fix: pipes from Kernnetz data in the model are over-proportinally many retrofitted projects as they are longer
+        # do not use own cost data for retrofitted and new build pipes as this would underestimate the investment cost
+        # reconstruct average Kernnetz invest (250€/MW*km) from our costs data
+
+        capital_costs = (
+            0.7 * costs.at["H2 (g) pipeline", "fixed"]
+            + 0.3 * costs.at["H2 (g) pipeline repurposed", "fixed"]
+        ) * wkn_new.length.values
+        overnight_costs = (
+            0.7 * costs.at["H2 (g) pipeline", "investment"]
+            + 0.3 * costs.at["H2 (g) pipeline repurposed", "investment"]
+        ) * wkn_new.length.values
 
         lifetime = np.where(
             wkn_new.retrofitted == False,