use line length factor from single config source

config.default.yaml

@@ -599,8 +599,6 @@ costs:
     battery inverter: 0.
   emission_prices: # in currency per tonne emission, only used with the option Ep
     co2: 0.
-  lines:
-    length_factor: 1.25 #to estimate offwind connection costs
 
 clustering:
   simplify_network:

scripts/prepare_sector_network.py

@@ -386,7 +386,7 @@ def update_wind_solar_costs(n, costs):
         with xr.open_dataset(profile) as ds:
             underwater_fraction = ds["underwater_fraction"].to_pandas()
             connection_cost = (
-                snakemake.config["costs"]["lines"]["length_factor"]
+                snakemake.config["lines"]["length_factor"]
                 * ds["average_distance"].to_pandas()
                 * (
                     underwater_fraction