diff --git a/config/config.default.yaml b/config/config.default.yaml
index ad4144d5..b0b389b8 100644
--- a/config/config.default.yaml
+++ b/config/config.default.yaml
@@ -354,7 +354,7 @@ solar_thermal:
 
 # docs in https://pypsa-eur.readthedocs.io/en/latest/configuration.html#existing-capacities
 existing_capacities:
-  grouping_years_power: [1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2020, 2025, 2030]
+  grouping_years_power: [1960, 1965, 1970, 1975, 1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2020, 2025, 2030]
   grouping_years_heat: [1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2019] # these should not extend 2020
   threshold_capacity: 10
   default_heating_lifetime: 20
diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index 3471c0b0..b1234da1 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -9,7 +9,9 @@ Release Notes
 
 Upcoming Release
 ================
-* Corrected a bug leading to power plants operating after their DateOut (https://github.com/PyPSA/pypsa-eur/pull/958).
+* Corrected a bug leading to power plants operating after their DateOut 
+  (https://github.com/PyPSA/pypsa-eur/pull/958). Added additional grouping years
+  before 1980.
 
 * Upgrade default techno-economic assumptions to ``technology-data`` v0.8.1.