  Europe as a whole as well as individual countries have many distinct pathways
to net carbon neutrality by 2050. We use novel near-optimal modelling
techniques to illuminate trade-offs and interactions between national and
continental energy transitions under uncertainty. Our results reveal extensive
and robust flexibility at a regional level in renewable and hydrogen
investments as well as in hydrogen and electricity exports. However, Europe's
energy interconnections lead to significant cross-border effects of national
energy strategies. Wind and hydrogen investments can easily be shifted
geographically within Europe, and Northern Europe's capacity as energy exporter
or importer can shape and be shaped by the remaining system. Solar in Southern
Europe and Germany comes out as an enabler, and can unlock design flexibility
for the rest of the system. Quantifying these regional trade-offs in energy
system planning is crucial in order to facilitate meaningful policy discussion
and enable a fair energy transition.
