The grid that joined Europe in three weeks

This is the story I tell people who want to understand what Ukrainian engineering is capable of.

On 24 February 2022 the Ukrainian power system disconnected from the post-Soviet grid to run a planned isolation test — a routine step on a long road towards European synchronisation, scheduled for completion in 2023. The invasion began the same morning. Reconnection was never an option.

So the country ran its grid in island mode, alone, balancing frequency without any neighbour to lean on. Meanwhile ENTSO-E, the association of European transmission system operators, compressed a multi-year technical programme into three weeks. On 16 March the Ukrainian and Moldovan systems were connected to the continental European network in emergency synchronisation mode.

Why this was not a symbolic gesture

Synchronisation meant Ukraine could draw emergency power from Europe when generation was hit, and later export when it had a surplus. It gave a grid under physical attack the stability of a continent-sized system behind it. Every subsequent winter of strikes on the energy system was survivable partly because of a decision taken in three weeks in March.