Storage, and the value of an hour

Discussion of the Ukrainian power system usually concerns capacity — how many megawatts exist. By 2025 the more useful question had become when they are available.

Why timing became the constraint

A distributed system built around solar and small gas units produces power on a different schedule from demand. Solar peaks in the middle of the day; households need power in the evening. A generator can respond quickly but costs fuel.

Meanwhile, an attack that removes capacity for six hours does not require six hours of replacement generation if the system can carry the load through the gap.

What storage does

Batteries move energy across hours. They also do something the grid needs even more: they respond instantly, stabilising frequency when a large unit drops off unexpectedly — which in this system happens for reasons other than equipment failure.

Significant battery storage capacity was installed across 2024 and 2025, at grid scale and at the level of individual hospitals, water utilities and residential blocks.

The economics

Storage does not generate anything. It is pure infrastructure, it earns from arbitrage and balancing services, and it needs a market design that pays for those services — which Ukraine had to build alongside the hardware.

What I would note

Ukraine is being forced to construct, at speed and under attack, the kind of flexible decentralised grid that European systems are moving towards deliberately over decades. Whatever else that is, it is not backwardness.