I assume it’s merely that they import energy from neighbours.

Here’s a map of who exported electricity in Europe in 2022, and who imported: https://www.powerengineeringint.com/wp-content/uploads/2023/03/EU-Interconnector-Map-H2-2022.jpg

Let me introduce you to open street maps. https://welcome.openstreetmap.org/what-is-openstreetmap/ or more simply https://www.openstreetmap.org/