One of the major issues with the Ukraine power infrastructure is that it was set up back in the day by the, well, Soviets, which means most of the equipment dates from Soviet times, which also means most of the repairs/replacement work can only be done by factories located in the former USSR. Most of those factories are now located in present-day Russia, which is where the major problem comes from.

Speaking of this, I'm not sure how the three Baltic states handle this. Granted, they're way smaller compared to Ukraine and they had at least 20 years (since their NATO accession) to try and untangle themselves from all that, but until now I haven't seen any article written on this subject.