Align battery cost with PyPSA modelling (#239)

* align battery cost with PyPSA modelling

* update unit test

* fix rounding issues and update release notes

* Update battery costs with grid connection and project financing costs

* add datail on grid connection and project financing costs included in battery investments

Author: danielelerede-oet

docs/release_notes.rst

@@ -16,6 +16,8 @@ Upcoming Release
 ..   The features listed below are not released yet, but will be part of the next release! 
 ..   To use the features already you have to use the ``master`` branch.
 
+* Align cost units for NREL battery data with PyPSA modeling, fetching investment cost and FOM for both `battery storage` and `battery inverter` instead of a single value for `battery storage`, which was instead representative of the full plant (battery storage + battery inverter).
+
 * Add excess heat output rates for Fischer-Tropsch and Haber-Bosch processes.
 
 * Updated indexing of DEA Excel data for PTES and revised capital cost and FOM assumptions for 2045 and 2050.

inputs/US/manual_input_usa.csv

@@ -69,7 +69,6 @@ def get_conversion_dictionary(flag: str) -> dict:
             "Offshore Wind - Class 3": "offwind",
             "Utility PV - Class 5": "solar-utility",
             "Commercial PV - Class 1": "solar-rooftop",
-            "Utility-Scale Battery Storage - 6Hr": "battery storage",
             "Biopower": "biomass",
             "Biopower - Dedicated": "biomass",
             "CSP - Class 2": "csp-tower",